WORK STAGE APPARATUS

Description

FIELD OF THE INVENTION

The present invention generally relates to temporary or movable platforms or staging for supporting workers at elevated locations in the construction, maintenance, and repair of human-made structures.

DESCRIPTION OF RELATED ART

Scaffolding, staging or work stages are temporary structures used to support workers at elevated locations to enable the workers to construct, maintain, and repair human-made structures. Adaptive forms of staging are routinely used for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes, art projects, and elevator hoistways.

In the field of elevator hoistways, shafts built to allow an elevator to move between the floors of a building, skilled artisans have developed highly specialized formats of work stages adapted to support workers in elevator hoistways through access points, such as the hoistway door openings that separate the elevator hoistway from a floor landing on the other side. However, known staging formats configured for elevator shaft implementations are expensive, cumbersome, complicated, time-consuming to erect and take down, and inherently unsafe. Given these and other deficiencies, there is a need in the art for a work stage apparatus configured to support at least one worker in an elevator hoistway through an access point between the elevator hoistway and a floor landing that is inexpensive, easy to construct, portable, easily movable, easy to use without specialized skill, and safe, and that overcomes the deficiencies of prior art staging formats.

SUMMARY OF THE INVENTION

According to the invention, a work stage apparatus includes a backspan and a frame. The backspan has a rear extremity and an opposed front extremity. The frame has a stage extending outward from a base mounted to the front extremity of the backspan for selective movement of the frame between a lowered position in which the base extends downward from the front extremity to the stage extending forward from the base a raised position in which the base extends upright from the front extremity to the stage extending rearward above the backspan from the base, the stage for supporting a worker at an elevated location when the frame is in the lowered position. A tensile stay coupled between the base and the stage reinforces the stage. A lift mechanism coupled between the backspan and the frame is configured to lift and lower the frame out of and into the lowered position. The lift mechanism is a winch. The backspan has wheeled trucks each including a wheel mounted to a frame swiveled to a fixture mounted to the backspan for movement into and out of a lowered surface engaging position of the wheel extending below the backspan and a lock assembly, in which the fixture is enabled for moving into and out of the lowered surface engaging position of the wheel when the lock assembly is in an unlocked position and disabled from moving out of the lowered surface engaging position of the wheel when the lock assembly is in a locked position. An extensible and retractable brace extends upright from the rear extremity of the backspan. The brace includes a lower member and an upper member. The lower member extends upright from the rear extremity of the back span to the upper member. The upper member extends upright from the lower member to a head. The lower member and the upper member are joined reciprocally. An adjustment member is rotated to the lower member and operatively coupled between the lower member and the upper member in which rotation of the adjustment member in opposite directions reciprocates the upper member relative to the lower member.

According to the invention, a work stage apparatus includes a backspan and a stage assembly. The backspan has a rear extremity and an opposed front extremity. The stage assembly has a frame, including a base and an inner stage, and an outer stage. The inner stage extends outward from the base to the outer stage mounted to the inner stage for selective movement between a folded position in juxtaposition with the inner stage and an unfolded position extending outward from inner stage, the stage assembly closed when the outer stage is in the folded position and open when the outer stage is in the unfolded position. The base is mounted to the front extremity for selective movement of the stage assembly when closed between a lowered position in which the base extends downward from the front extremity to the inner stage extending forward from the base to the outer stage in the folded position and a raised position in which the base extends upright from the front extremity to the inner stage extending rearward above the backspan from the base and the outer stage in the folded position. The inner stage and the outer stage are for supporting a worker at an elevated location when the frame is in the lowered position and the outer stage is in the unfolded position. A tensile stay coupled between the base and the inner stage reinforces the inner stage. A lift mechanism coupled between the backspan and frame is configured to lift and lower the stage assembly when closed out of and into the lowered position. The lift mechanism is a winch. The backspan has wheeled trucks each including a wheel mounted to a frame swiveled to a fixture mounted to the backspan for movement into and out of a lowered surface engaging position of the wheel extending below the backspan and a lock assembly, in which the fixture is enabled for moving into and out of the lowered surface engaging position of the wheel when the lock assembly is in an unlocked position and disabled from moving out of the lowered surface engaging position of the wheel when the lock assembly is in a locked position. An extensible and retractable brace extends upright from the rear extremity of the backspan. The brace includes a lower member and an upper member. The lower member extends upright from the rear extremity of the back span to the upper member. The upper member extends upright from the lower member to a head. The lower member and the upper member are joined reciprocally. An adjustment member is rotated to the lower member and operatively coupled between the lower member and the upper member in which rotation of the adjustment member in opposite directions reciprocates the upper member relative to the lower member.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific objects and advantages of the invention will become readily apparent to the person having ordinary skill in the art from the following detailed description of illustrative embodiments thereof, taken in conjunction with the drawings in which:

FIG. 1 is a right front perspective view of a work stage apparatus constructed and arranged according to the principle of the invention, the work stage apparatus including a backspan and a stage assembly mounted to the backspan, the backspan including a rear extremity, an opposed front extremity, a length adjustable brace, and wheeled trucks, the backspan extending forward over a floor landing from its rear extremity to its front extremity at an access point to a hoistway, the brace including a lower member extending upright from the rear extremity of the backspan to an upper member telescoped to and extending upright from the lower member and an adjustment member operatively coupled between the lower member and the upper member, whereby rotation of the adjustment member in opposite directions reciprocates the upper member relative to the lower member for length adjusting the brace, and the stage assembly shown in a deployed position relative to the backspan and including a frame and an outer stage, the frame including a base extending downward into the hoistway below the floor landing from the front extremity of the backspan and along an inner wall depending downward from the floor landing to the inner stage extending forward into the hoistway to the outer stage extending forward into the hoistway from the inner stage;

FIG. 2 is a left front perspective view of the embodiment of FIG. 1;

FIG. 3 is a right rear perspective view of the work stage apparatus first illustrated in FIG. 1;

FIG. 4 is a view of circled area A of FIG. 1;

FIG. 5 is a view of circled area B of FIG. 1;

FIG. 6 is a section view taken along line 6-6 of FIG. 5; and

FIG. 7 is a view corresponding to FIG. 6, showing the adjustment member adjusted, length adjusting the brace by extending the upper member upward from the lower member;

FIG. 8 is a view of circled area C of FIG. 1;

FIG. 9 is a view of circled area D of FIG. 2;

FIG. 10 is a view of circled area E of FIG. 1;

FIG. 11 is a view of circled area F of FIG. 2;

FIG. 12 is a view of circled area G of FIG. 1;

FIG. 13 is a view of circled area H of FIG. 2;

FIG. 14 is a view of circled area I of FIG. 1;

FIG. 15 is a view of circled area J of FIG. 2;

FIG. 16 is a right side elevation view of the work stage apparatus of FIGS. 1 and 2, additionally illustrating the hoistway extending upright between the inner wall and an opposed outer wall forward of the outer stage, and the brace length adjusted between the rear extremity of the backspan and an overhead structure above the floor landing, bracing the backspan against the floor landing;

FIGS. 17-19 illustrate a sequence of adjusting the stage assembly between its deployed position in FIGS. 1-3 and 16 and its stowage position in FIG. 19;

FIG. 20 is an enlarged perspective view corresponding to FIG. 1, illustrated one of the wheeled trucks including a wheel mounted to a frame swiveled to a fixture mounted rotatably to the backspan for movement between a raised position of the wheel and a surface engaging position of the wheel extending below the backspan, the fixture in the raised position of the wheel;

FIG. 21 is a section view taken along line 21-21 of FIG. 20;

FIG. 22 is a section view taken along line 22-22 of FIG. 20;

FIGS. 23-26 show a sequence of steps of adjusting the wheeled truck of FIG. 20 between the raised position of the wheel in FIG. 20 to the lowered surface engaging position of the wheel extending below the against the floor landing in FIG. 26, elevating the backspan above the floor landing;

FIG. 27 is a section view taken along line 27-27 of FIG. 25, illustrating the wheeled truck in an intermediate position of the wheel between its raised position in FIGS. 20 and 23 and its lowered surface engaging position extending below the backspan in FIG. 26;

FIG. 28 is a section view taken along line 28-28 of FIG. 26; and

FIG. 29 is a view corresponding to FIGS. 19 and 26, the wheel of each wheeled truck shown in the lowered surface engaging position extending below the backspan, elevating the backspan above the floor landing, and the brace shown length adjusted, releasing it from the overhead structure.

DETAILED DESCRIPTION

Disclosed is a work stage apparatus configured to support at least one worker in an elevator hoistway through an access point to the elevator hoistway from a floor landing. The work stage apparatus, a staging or staging format, is inexpensive, easy to construct, portable, easily movable, inherently safe, easy to deploy, easy to use, and easy to take down without specialized tools or skill.

Referring to FIGS. 1-3, a work stage apparatus 50 includes a base or backspan 52 and a stage assembly 54 mounted to the backspan 52. The stage assembly 54 is collapsable and expandable and mounted to the backspan for selective movement relative to the backspan 52 between a deployed position in FIGS. 1-3 and 16 for supporting a worker in an elevator hoistway 40 when the backspan 52 is set upon and braced to a floor landing 41 open to the elevator hoistway 40 by an opening 42, and a stowage position in FIG. 19 for compact storage. The stage assembly 54 is expanded when in the deployed position and collapsed when in the stowage position. The opening 42 is an access point to the hoistway 40. In FIG. 16, the hoistway 40 extends upright between an inner wall 43 extending downward from the floor landing 41 and an opposed parallel outer wall 44. The inner wall 43 and the outer wall 44 are parts of the building that form the standard hoistway 40. An overhead structure 45, such as a ceiling or a beam of the building, is above the floor landing 41 and the work stage apparatus 50 and used to brace the backspan 52 on the floor landing 41.

The backspan 52 is a stout, rugged framework of metal. It is configured to be mounted directly atop the floor landing 41 in FIGS. 1, 2, and 16. The backspan 52 supports the stage assembly 154. In FIGS. 1-3, the backspan 52 includes mirror image rails 60 and 70 and a transom 80. The rails 60 and 70 are on either side of the backspan 52. The rail 60 has a rear end 62 and a front end 64 including a clevis 66, also shown in FIGS. 8 and 9. The clevis 66 projects upward from the front end 64. The rail 60 is elongate and straight longitudinally from the rear end 62 to the front end 64. The rail 70 has a rear end 72 and a front end 74 including a clevis 76, also shown in FIGS. 10 and 11. The clevis 67 projects upward from the front end 74. The rail 70 is elongate and straight longitudinally from the rear end 72 to the front end 74. The rails 60 and 70 are parallel relative to one another and spaced apart axially. They extend horizontally outward in the same forward direction from the rear ends 62 and 72 at the rear extremity of the backspan 52 to the front ends 64 and 74 configured with the respective clevises 66 and 76 at the front extremity of the backspan 52. The transom 80 at the rear extremity of the backspan 52 extends between and is connected rigidly, mechanically or by welding, to the rear ends 62 and 72 of the respective rails 60 and 70, holding the rails 60 and 70 together. The rear ends 62 and 72 and the transom 80 define the rear extremity of the backspan 52, the rear extremity of the backspan 52 denoted generally at 90. The front ends 64 and 74 of the respective rails 60 and 70 define the front extremity of the backspan 52, the rear extremity of the backspan 52 denoted generally at 92.

At the rear extremity 92 of the backspan 52 is brace 100 configured to brace the backspan 52 against the floor landing 41 under the overhead structure 45. The brace 100 extends upright from the rear extremity 90 of the backspan 52. The brace 100 is strong, rugged, and length adjustable, i.e., extensible and retractable, for selectively bracing the backspan 52 against the floor landing 41 from an overhead structure above the floor landing 41, such as the overhead structure 45 above the floor landing 41 in FIGS. 16-19.

In FIGS. 1-3, the brace 100 includes a lower member 102 and an upper member 104. The lower member 102 and the upper member 104 are coaxial and joined reciprocally, allowing the upper member 104 to slide reciprocally relative to the lower member 102. The lower member 102, a hollow pole, has a lower end 110 and an opposed upper end 112. The lower member 102 is straight longitudinally from the lower end 110 to the upper end 112. The upper member 104, a hollow pole, has a lower end 140 and an opposed upper end 142 including a wide, flat head 144. The upper member 104 is straight longitudinally from the lower end 140 to the head 144 at the upper end 142.

The lower member 102 extends vertically upright to its upper end 112 from its lower end mounted to the transom 80 of the backspan's 52 rear extremity 90. The upper member 104 extends vertically upright to the head 144 from the lower end 140 received telescopingly within the lower member 102 through its upper end 112 in FIGS. 4 and 5 so the upper member 104 slides reciprocally within the lower member 102 in the directions of double arrow 130, allowing for extension and retraction of the upper member 104 relative to the lower member 102 like the sections of a telescope for length adjusting the brace 100 between the lower end 110 of the lower member 102 mounted to the transom 80 and the head 144 at the upper end 142 of the upper member 104.

In FIGS. 1-3, a receiver 150 connects the lower end 110 of the brace 100 to the backspan 52. The transom 80 supports the receiver 150 at the rear extremity 90 of the backspan 52. The receiver 150 is between the rear ends 62 and 72 of the respective rails 60 and 70. The receiver 150) is connected rigidly, mechanically or by welding, to the top of the transom. The receiver 150, a stout, hollow metal sleeve, extends upright vertically from the transom 80. The receiver 150 is open to receive the lower 110 of the lower member 102. When the receiver 150 receives the lower end 110 of the lower member 102, it connects the lower end 110 of the lower member 102 to the rear extremity 90 of the backspan 52, connecting the brace 100 to the backspan 52. Inserting the lower end 110 of the brace 100 into the receiver 150 connects the lower end 110 to the transom 80. The receiver 150 is sufficiently long to receive the lower end 110 of the lower member 102 and hold the brace 100 upright and stable. The receiver 150 receives the lower end 110 removably, allowing a worker to selectively withdraw the lower end 110 from the receiver 150, separating the brace 100 from the backspan 52.

In FIGS. 4-7, the lower member 102 has an externally threaded section 114 adjacent to the upper end 112. The externally threaded section 114 includes an external thread 116 extending downward along a preselected length of the lower member 102 from proximate to the upper end 112, and two mirror image slots 118. The slots 118 are opposed and axially aligned. The slots 118 extend through the externally threaded section 114 on either side of the lower member 102 at an intermediate location of the externally threaded section and extend vertically upright along a preselected length of the externally threaded section 114 below the upper end 112 of the lower member 102. The slots 118 are closed, i.e., enclosed circumferentially, which limits movement within their defined areas.

An adjustment member 120, an annular body of metal, circumscribes the externally threaded section 114 of the lower member 102. In FIG. 4, the adjustment member 120 has an attached handle 124. In FIGS. 6 and 7, the adjustment member 120 is rotated to the lower member 102 by its internal thread 122 threaded on the external thread 116. The internal thread 122 interacts threadably with the external thread 116, wherein rotation of the adjustment member 120 in opposite directions imparts corresponding reciprocal movement of the adjustment member 120 up and down along the externally threaded section 114 in the directions of double arrow 130 in opposition to the upper end 112. A worker can take up the handle 124 by hand and use it to rotate the adjustment member 120. Rotation of the adjustment member 120 in a raising or counterclockwise direction indicated by arrow 132 in FIGS. 4 and 5 moves the adjustment member 120 upward along the externally threaded section 114 in the raising direction of arrow 134 in FIGS. 4-6 toward the upper end 112. Rotation of the adjustment member 120 in a lowering or clockwise direction indicated by arrow 136 in FIGS. 4 and 5 moves the adjustment member 120 downward along the externally threaded section 114 in the lowering direction of arrow 138 in FIGS. 4-6 away from the upper end 112. The adjustment member 120 is configured to be operatively coupled between the lower member 102 and the upper member 104, in which rotation of the adjustment member 120 in opposite directions extends and retracts the upper member 102 relative to the lower member 104.

The brace 100 has a lock mechanism to secure the lower member 102 to the upper member 104 and extend and retract the upper member 104 relative to the lower member 102 to length adjust the brace 100 to a selected length from the lower end 110 of the lower member 102 to the head 144 when the adjustment member 120 is operatively coupled between the lower member 102 and the upper member 104. This lock mechanism includes the externally threaded section 114, the adjustment member 120, each pair of aligned holes 160 vertically spaced along the length of the upper member 104 between the lower end 140 and the upper end 142, and a suitable pin 162. The slots 118 and each pair of holes 160 aligned with the slots 118 accept the pin 162 to secure the upper member 104 to the lower member 102,. The various pairs of holes 160 correspond to different lengths of the brace 100 between the lower end 110 and the head 144.

The worker secures the upper member 104 to the lower member 102 by rotating the adjustment member 120 in the lowering direction of arrow 136 in FIGS. 4 and 5 to lower the adjustment member 120 below the slots 118, such as to its dotted line position in FIG. 6 below and out of the way of the slots 118 in FIGS. 4-6. He slides the upper member 104 into or out of the upper end 112 end of the lower member 102 to a desired approximate length of the brace 100 from the lower end 110 of the lower member 102 and the head 144 at the upper end 142 of the upper member 104, selective rotating the upper member 104 relative to the lower member 104 to axially align a chosen pair of holes 160 with the slots 118. Axially aligning a selected pair of the holes 160 with the slots 118 corresponds to an approximate desired length of the brace 100 from the lower end 110 of the lower member 102 to the head 144 at the upper end 142 of the upper member 104. He inserts the pin 162 through the selected pair of holes 160 accessed through one of the slots 118 so the pin 162 extends through the pair of holes 160 and the slots 118 and the pin's 162 free ends 164 and 166 extend outward from the respective holes 160 and through and beyond the respective slots 118 to interference positions over the underlying adjustment member 120, pinning the lower member 102 to the upper member 104, securing the lower member 102 to the upper member 104. The lateral interference between the pin's 162 free ends 164 and 166 and the slots 118 constrain the upper member 104 from rotating relative to the lower member 102. At the same time, the pin's 162 free ends 164 and 166 can reciprocate up and down along the externally threaded section 114 through the defined vertical areas of the slots 118, allowing the worker to extend and retract the upper member 104 slidably relative to the lower member 102 along the vertical lengths of the slots 118 while the pin 162 secures the upper member 104 to the lower member 102. The closed upper and lower ends of the respective slots 118 constrain the pin 162 from moving downward beyond and upward beyond the slots 118 along the lower member's 102 externally threaded section 114, restricting the reciprocal movement of the upper member 104 relative to the lower member 102 to along the slots 118.

The adjustment member 120 is used to length adjust the brace 100 vertically along the slots 118, namely, to extend and retract the upper member 104 relative to the lower member 102 vertically along the confined areas of the respective slots 118, when the pin 162 secures the upper member 104 to the lower member 102 and the adjustment member 120 is operatively coupled between the lower member 102 and the upper member 104 for setting the upper member to a desired length of the brace 100 from the lower end 110 of the lower member 102 to the head 144 at the upper end 142 of the upper member 104. After pinning the lower member 102 to the upper member 104 with the pin 162 as described, the worker operatively couples the adjustment member 120 between the lower member 102 and the upper member 104 by rotating the adjustment member 120 in the raising direction of arrow 132 in FIGS. 4 and 5, raising the adjustment member 120 upward in the direction of arrow 134 from its dotted line position under the pin 162 in FIG. 6 to into direct contact against the overlying ends 164 and 166 of the pin 162 sitting at the bottoms of the respective slots 118 when the upper member 104 is at rest. The ends 164 and 166 of the pin 162 in direct contact against the underlying adjustment member 120 in FIG. 6 operatively couples the adjustment member 120 between the lower member 102 and the upper member 104, wherein continued rotation of the adjustment member 120 in the raising direction of arrow 132 in FIGS. 4, 5 and 7 moves the adjustment member 120 upward in the raising direction of arrow 134, urging the pin 162 upward in the same raising direction along the slots 118 and with it the upper member 104 the pin 160 is pinned to in FIG. 7, extending the upper member 104 relative to the lower member 102, lengthening the brace 100 between the lower end 110 of the brace 100 and the head 144 to raise the head 144 into contact against an overhead structure. Upon the head 144 contacting the overhead structure 45 over the backspan 52 atop the floor landing 41 in FIG. 16, the worker can continue to forcibly rotate the adjustment member 120 in the raising direction of arrow 132 in FIGS. 4, 5 and 7. This further urges the pin 160 upward to further lengthen the brace 100 between the overhead structure and the rear extremity 90 of the backspan 52, tightening the head 144 against the overhead structure 45 and urging the backspan 52 downward 52 against the floor landing 41, bracing the backspan 52 against the floor landing 41 from the overhead structure 45. The free ends 164 and 166 slide over the adjustment member 120 as it rotates. Rotation of the adjustment member 120 in the lowering direction of arrow 136 in FIG. 7 moves the adjustment member 120 downward in the lowering direction of arrow 138, lowering the pin 162 supported atop the adjustment member 120 downward in the same lowering direction along the slots 118 and with it the upper member 104 under the influence of gravity, retracting the upper member 104 into the lower member 102, shortening the brace 100 between the lower end 110 and the head 144 to withdraw the head 144 downward away from the overhead structure 45. The worker can set the pin 162 to any location along the lengths of the slots 118 with the adjustment member 120 by length adjusting the brace 100 along the slots 118 to a desired length from the lower end 110 of the lower member 102 to the head 144 at the upper end 142 of the upper member 104 based on the height of the overhead structure 45 over the floor landing 41.

Accordingly, direct contact of the adjustment member 120 against the free ends 164 and 166 of the pin 162 operatively couples the adjustment member 120 between the lower member 102 and the upper member 104, whereby rotation of the adjustment member 120 in opposite directions reciprocates, i.e. extends and retracts, the upper member 104 relative to the lower member 102. The confined areas of the slots 118 inherently disable the pin 162 from moving upward beyond the slots 118 and downward beyond the slots 118. Since the upper member 104 follows the pin 162, i.e. reciprocates up and down with the pin 162, the slots 118 concurrently limit the path of reciprocal movement of the pin 162 and, with it, the upper member 104. Rotating the adjustment member 120 in the lowering direction of arrow 136 in FIGS. 4 and 5 to below the slots 118 and out of engagement with the ends 164 and 166 of the pin 162 withdraws the operative coupling between the lower member 102 and the upper member 104. Withdrawing the pin 162 from the respective holes 160 and the slots 118 releases the upper member 104 from the lower member 102, allowing the upper member 104 to slide telescopingly into and out of the upper end 112 of the lower member 102 in the directions indicated by the double arrow 130 for extending and retracting the upper member 104 relative to the lower member 102 to facilitate length adjustment of the brace from the lower end 110 of the lower member 102 installed in and held by the receiver 150 to the head 144 at the upper end 142 of the upper member 104.

The described process of length adjusting the brace 100 by telescoping the upper member 104 relative to the lower member 102 to a desired approximate length of the brace 100 from the lower end 110 of the lower member 102 and the head 144 at the upper end 142 of the upper member 104, securing the upper member 104 to the lower member 102 with the pin 162, operatively coupling the adjustment member 120 between the lower member 102 and the upper member 104, and extending and retracting the upper member 104 relative to the lower member 102 along the lengths of the slots 118 with the adjustment member 120 is repeatable as required.

Referring to FIGS. 1-3, the stage assembly 54 includes a frame 170 and a stage 172. The frame 170 and the stage 172 are each stout, rugged frameworks of metal.

The frame 170 has a base 180 and a stage 210. The stage 210 is the inner stage of the stage assembly 54. The stage 172 is the outer stage of the stage assembly 54. The stages 210 and 172 are for supporting at least one worker as described herein. The base 180 is mounted to the front extremity 92 of the backspan 52 pivotally for selective movement of the frame 170 between its lowered position relative to the backspan 52 in FIGS. 1-3, 16 and 17 and its raised position relative to the backspan 52 in FIG. 19. In the lowered position of the frame 170 in FIGS. 1-3, 16 and 17, the base 180 extends downward from the front extremity 92 to the inner stage 210 extending outward and horizontally forward from the base 180 to the outer stage 172 mounted to the inner stage 210 pivotally for selective movement relative to the frame 170 between an unfolded position in FIGS. 1-3 and 16, extending outward and horizontally forward from the inner stage 210, and a folded position in juxtaposition with the inner stage 210 in FIG. 19. The stage 210 is in a worker supporting position for supporting a worker at an elevated location when the frame 170 is in the lowered position. The stage assembly 54 is open and expanded when the outer stage 172 is unfolded to its unfolded position in FIGS. 1-3 and 16. When the frame 170 is in its lowered position and the stage 172 is unfolded, the stage 172 is in a worker supporting position for supporting a worker at an elevated location. The stage assembly 54 is closed and collapsed when the outer stage 172 is folded to its folded position folded over the inner stage 210 in FIGS. 17-19. The outer stage 172 can be repeatedly folded and unfolded relative to the frame 170 as desired.

The stage assembly 54 is deployed from the backspan 52 in FIGS. 1-3 and 16 when the frame 170 is in its lowered position and the outer stage 172 is in its unfolded position. When the frame 170 is in its lowered position and the stage assembly 54 is closed in FIG. 17, the base 180 extends downward from the front extremity 92 to the inner stage 210 extending outward and horizontally forward from the base 180 to the outer stage 172 in its folded position. When the stage assembly 54 is closed and the frame 170 is in its lowered position, the closed stage assembly 54 is in its lowered position. When the stage assembly 54 is closed and the frame 170 is in its raised position, the closed stage assembly 54 is in its raised position. Pivoting the frame 170 upward relative to the backspan 52 from the lowered position of the closed stage assembly 54 in FIG. 17 to the raised position of the closed stage assembly 54 in FIG. 19 sets the closed stage assembly 54 to its stowage position relative to the backspan 52. When the closed stage assembly 54 is in its stowage position, the base 180 extends upright from the front extremity 92 to the inner stage 210 inverted and extending rearward over the backspan 52 to the outer stage 172 in its folded position inverted over the backspan 52 and disposed between the inner stage 210 and the backspan 52. FIG. 18 shows the closed stage assembly 54 as it would appear between its FIG. 17 lowered position and its FIG. 19 raised position. The closed stage assembly 54 can be repeatedly moved between its lowered and raised positions as desired.

In FIGS. 1-3, the base 180 includes mirror image studs 190 and 200 on either side of the base 180. The stud 190 has an upper end 192 and a lower end 194. The stud 190 is elongate and straight longitudinally from the upper end 192 to the lower end 194. The stud 200 has an upper end 202 and a lower end 204. The stud 200 is elongate and straight longitudinally from the upper end 202 to the lower end 204. The studs 190 and 200 are parallel relative to one another and spaced apart axially. They extend downward at either side of the base 180 to their respective lower ends 194 and 204 from their respective upper ends 192 and 202 mounted pivotally to the front ends 64 and 74 of the respective rails 60 and 70.

The inner stage 210 includes mirror image rails 220 and 230 and a platform 230 coupled between the rails 220 and 230. The rails 220 and 230 are on either side of the inner stage 210. The rail 220 has an inner end 222 and an outer end 224 including a clevis 226 projecting upward from the outer end 224. The rail 220 is elongate and straight longitudinally from the inner end 222 to the outer end 224. The rail 230 has an inner end 232 and an outer end 234 including a clevis 236 projecting upward from the outer end 234. The rail 230 is elongate and straight longitudinally from the inner end 232 to the outer end 234. The rails 220 and 230 are parallel relative to one another and spaced apart axially. They extend outward in the same forward direction from their respective inner ends 222 and 232 connected rigidly, mechanically or by welding, to the lower ends 194 and 204 of the respective studs 190 and 200 to their outer ends 224 and 234. A platform 240, a reinforced grate of metal, extends longitudinally along the lengths of the rails 220 and 230 from their respective inner ends 222 and 232 at the inner extremity of the inner platform 210 to their respective outer ends 232 and 234 at the outer extremity of the inner platform 210 and transversely between the rails 220 and 230, the platform 240 connected rigidly, mechanically or by welding, to the rails 220 and 230, holding the rails 220 and 230 and, by extension, the studs 190 and 200 together, forming a consolidated frame 170.

The upper ends 192 and 202 of the studs 190 and 200 define the upper extremity of both the frame 170 and its base 180, the upper extremity of the frame 170 and its base 180 denoted generally at 250. The lower ends 194 and 204 of the studs 190 and 200 define the lower extremity of the base 180, the lower extremity of the base 180 denoted generally at 252. The inner ends 222 and 232 of the rails 220 and 230 define the inner extremity of the inner stage 210, the inner extremity of the inner stage 210 denoted generally at 260. The outer ends 224 and 234 of the rails 220 and 230 define the outer extremity of the both the frame 170 and its inner stage 210, the outer extremity of the frame 170 and its inner stage 210 denoted generally at 262.

In FIGS. 8 and 9, the rail's 60 clevis 66 receives and is hinged to the stud's 190 upper end 192 by a suitable pin 196 received by appropriate holes in the clevis 66 and the end 192, hinging or otherwise pivotally connecting the stud's 190 upper end 192 at the upper extremity 250 of the base 180 to the rail's 60 outer end 64 at the outer extremity 92 of the backspan 52. In FIGS. 10 and 11, the rail's 70 clevis 76 receives and is hinged to the stud's 200 upper end 202 by a suitable pin 206 received by appropriate holes in the clevis 76 and the end 202, hinging or otherwise pivotally connecting the stud's 200 upper end 202 at the upper extremity 250 of the base 180 to the rail's 70 outer end 74 at the outer extremity 92 of the backspan 52. The hinged or pivotal connections connecting the upper ends 192 and 202 of the respective studs 190 and 200 to the front ends 64 and 74 of the respective rails 60 and 70 mount the upper extremity 250 to the front extremity 92 of the backspan 52 for hinged or pivotal movement of the frame 170 between its lowered position in FIGS. 1-3, 16 and 17 and its raised position in FIG. 19. In the frame's 170 lowered position in FIGS. 1-3, 16 and 17, the base 180 extends downward from its upper extremity 250 pivoted to the backspan's 52 front extremity 92 to the lower extremity 252 and the inner stage 210 extending forward horizontally to its outer extremity 262 from its inner extremity 260 connected to the base's 170 lower extremity 252 and the forwardly projecting front ends 64 and 74 are in direct contact against the opposed back sides of the respective studs 190 and 200 proximate to their respective upper ends 192 and 202. The back sides of the studs 190 and 200 buttressed directly against the respective front ends 64 and 74 hold the frame 170 in its lowered position. In the frame's 170 raised position in FIG. 19, the base 180 extends upright from its upper extremity 250 pivoted to the backspan's 52 front extremity 92 to the lower extremity 252 and the inner stage 210 above the backspan 52, extending rearward over the backspan 52 and toward the rear extremity 90 to the outer extremity 262 from the inner extremity 260 connected to the base's 170 lower extremity 252.

The outer stage 172 includes mirror image rails 270 and 280 and a platform 290 coupled between the rails 270 and 280. The rails 270 and 280 are on either side of the inner stage 210. The rail 270 has an inner end 272 and an outer end 274. The inner end 272 has a clevis 276 projecting upward from the inner end 272. The rail 270 is elongate and straight longitudinally from the inner end 272 to the outer end 274. The rail 280 has an inner end 282 and an outer end 284. The inner end 282 has a clevis 286 projecting upward from the inner end 282. The rail 280 is elongate and straight longitudinally from the inner end 282 to the outer end 284. The rails 270 and 280 are parallel relative to one another and spaced apart axially. They extend horizontally outward to their respective outer ends 274 and 284 from their respective inner ends 272 and 282 hinged or otherwise connected pivotally to the outer ends 224 and 234 of the respective rails 220 and 230. The platform 290, a reinforced grate of metal, extends along the lengths of the rails 270 and 280 from their respective inner ends 272 and 282 at the inner extremity of the outer stage 172 to their outer ends 282 and 284 at the outer extremity of the outer stage 172 and transversely between the rails 270 and 280, the platform 290 connected rigidly, mechanically or by welding, to the rails 270 and 280, holding the rails 270 and 280 together, forming a consolidated outer stage 172. A transom 292 at the outer extremity of the outer stage 172 extends between and is connected rigidly, mechanically or by welding, to the outer ends 274 and 284 of the respective rails 270 and 28, securing the outer ends 274 and 284, reinforcing the outer stage 172. The platform 290 is preferably secured rigidly, mechanically or by welding, to the transom 292.

The inner ends 272 and 282 of the rails 270 and 280 define the inner extremity of the outer stage 172, the inner extremity of the outer stage 172 denoted generally at 300. The outer ends 274 and 284 of the rails 270 and 280 define the outer extremity of the outer stage 172, the outer extremity of the outer stage 172 denoted generally at 302.

In FIGS. 12 and 13, the rail's 270 clevis 276 receives and is hinged to the rail's 220 clevis 226 by a suitable pin 278 received by appropriate holes in the clevises 226 and 276, hinging or otherwise pivotally connecting the rail's 270 inner end 272 at the inner extremity 300 of the outer stage 172 to the rail's 220 outer end 224 at the outer extremity 262 of the inner stage 210. In FIGS. 14 and 15, the rail's 280 clevis 286 receives and is hinged to the rail's 230 clevis 236 by a suitable pin 288 received by appropriate holes in the clevis 286 and the clevis 236, hinging or otherwise pivotally connecting the rail's 280 inner end 282 at the inner extremity 300 of the outer stage 172 to the rail's 230 outer end 234 at the outer extremity 262 of the inner stage 210. The pivotal connections connecting the inner ends 272 and 282 of the respective rails 270 and 280 to the outer ends 224 and 234 of the respective rails 220 and 230 hinged or otherwise pivotally mount the inner extremity 300 of the outer stage 172 to the outer extremity 262 of the inner stage 210 for hinged or pivotal movement of the outer stage 172 between its unfolded position in FIGS. 1-3 and 16 and its folded position in FIG. 17. When the frame 170 is in its lowered position and the stage assembly 54 is open when the outer stage 172 is in its unfolded position in FIGS. 1-3 and 16, the stage assembly 54 is in a worker supporting position in which the outer stage 171 extends forward horizontally to its outer extremity 302 from its inner extremity 300 pivoted to the outer extremity 262 of the inner frame 210 and the inner ends 272 and 282 in direct contact against the outer ends 224 and 234 of the respective rails 220 and 23. The inner ends 272 and 282 buttressed directly against the respective outer ends 224 and 234 hold the outer stage 172 in its unfolded position. The horizontally extending platforms 240 and 290 of the respective inner and outer stages 210 and 172 each in their worker supporting position can support a worker standing, kneeling or sitting thereon when the stage assembly 54 is deployed relative to the backspan 52, i.e., when the frame 170 is in its lowered position and the stage assembly 54 is open when the outer stage 172 is unfolded to its unfolded position. The worker can selectively reside on the platform 240, the platform 290, or both platforms 240 and 290 at the same time, and can bring with him tools and equipment that he may carry or set onto either or both of the platforms 240 and 290 as needed. Also, one worker can reside on platform 240 and another worker can reside on platform 290, including their tools and equipment. When the frame 170 is in its lowered position and the stage assembly 54 is closed when the outer stage 172 is in its folded position in FIG. 17, the outer stage 172 is folded over the inner stage 210, extending rearward over the inner stage 210 from its inner extremity 302 connected to the outer stage's 172 outer extremity 262 to its outer extremity 302 proximate to the base 180 between the base's 180 upper and lower extremities 250 and 252.

FIGS. 1, 2 and 16 show the work stage apparatus 50 in use with the stage assembly 54 deployed in the hoistway 40 and supported by the backspan 52 braced against the floor landing 41 by the brace 100 extending and tightened between the rear extremity 90 of the backspan 52 and the overlying overhead structure 45 in FIG. 16. Referring in relevant part to FIGS. 1, 2 and 16, the backspan 52 is set onto the floor landing 41 in its operative position, extending horizontally over the floor landing 41 forwardly from its rear extremity 90 to its front extremity 92 at the opening 42 and the stage assembly 54 in its deployed or operative position in the hoistway 40. The brace 100 extends upright from the rear extremity 90 of the backspan 52 and is length adjusted so it extends between its head 144 tightened against the overhead structure 45 and the rear extremity 90 of the backspan 52 urged by the brace 100 downward against the floor landing 41, anchoring the backspan 52 to the floor landing 41. The base 180 extends downward into the hoistway 40 from its upper extremity 250 connected to the backspan's 52 front extremity 92 at the opening 42 and along and against the inner wall 43 below the floor landing 41 to the base's 180 lower extremity 252. The inner stage 210 is below the floor landing 41 and, like a cantilever, extends or otherwise projects outward and horizontally forward into the hoistway 40 toward the outer wall 44 in FIG. 16 from the inner extremity 260 connected to the base's 180 lower extremity 252 to the inner stage's 210 outer extremity 262. The outer stage 172 is unfolded into its unfolded position and, like a cantilever, extends or otherwise projects outward horizontally forward into the hoistway 40 to its outer extremity 302 toward the outer wall 44 in FIG. 16 from in its inner extremity 300 connected to the inner stage's 210 outer extremity 262. The inner stage 210 and the outer stage 172 deployed in the hoistway 40 when the stage assembly 54 is open and deployed in the hoistway 40 in its operative position extend or otherwise project like a cantilever outward horizontally forward into the hoistway 40 from the inner stage's 210 inner extremity 260 connected to the base's 180 lower extremity 252 against the inner wall 43 to the outer stage's 172 outer extremity 302 toward the outer wall 44, the horizontally extending platforms 240 and 290 of the respective inner and outer stages 210 and 172 serving as stable horizontal landing areas for supporting a worker in the hoistway 40 while the backspan 52 anchored to the floor landing 41 by the brace 100 extending between the overhead structure 45 and the rear extremity 90 of the backspan 52 secures the stage assembly 54 deployed in the hoistway 40. The back sides of the studs 190 and 200 buttressed directly against the respective front ends 64 and 74 of the backspan 52 and the inner wall 43 hold the stage assembly 54 in its operative position deployed in the hoistway 40.

In FIGS. 1-3, the frame 170 has mirror image stays 310 and 320 coupled between the base 180 and the inner stage 210. The stays 310 and 320 on either side of the frame 170 are tensile stays that structurally brace or other reinforce the inner stage 210 for load capacity purposes. The stays 310 and 322 are each coupled to the base 180 proximate to the inner extremity 250 and to the inner stage 210 proximate to the outer extremity 262. In FIGS. 8 and 9, the stay 310 has an inner end 312 coupled to the stud 190 proximate to its upper end 192 by the pin 196 and an opposed outer end 314 in FIGS. 12 and 13 coupled to the rail 220 proximate to its outer end 224 by the pin 278. In FIGS. 10 and 11, the stay 320 has an inner end 322 coupled to the stud 200 proximate to its upper end 202 by the pin 288 and in FIGS. 14 and 15 an opposing end 324 coupled to the rail 230 proximate to its outer end 234 by the pin 288.

The worker withdraws the stage assembly 54 deployed in the hoistway 40 by pivoting the outer stage 172 upward from its unfolded position in FIG. 16 to its folded position in FIG. 17, closing the stage assembly 54, and pivoting the closed stage assembly 54 upward and out of the hoistway 40 through the opening 41 from its lowered position in FIG. 17 to its raised stowage position in FIG. 19. Again, FIG. 18 shows the closed stage assembly 54 as it would appear between its FIG. 17 lowered position and its FIG. 19 raised position. Reversing this operation deploys the stage assembly 54 into the hoistway 40. Upon setting the closed stage assembly 54 to its raised stowage position, the worker can length adjust the brace 100 to retract it for withdrawing the head 144 from the overhead structure 45 in FIG. 29, releasing the backspan 52 from it being braced against the floor landing 41. Length adjusting the brace to tighten the head 45 against the overhead structure 45, tightening the brace 100 between the overhead structure 45 and the backspan 52 on the floor landing 41 re-anchors the backspan 52 to the floor landing 41.

In FIGS. 1-3 and 16-19, the work stage apparatus 50 has a lift mechanism 330 coupled between the backspan 52 and frame 170 for assisting a user in lifting and lowering the stage assembly 54 when closed between its lowered and raised positions. The lift mechanism 330 is a standard cable winch including drum 332 on which a cable 334 is wound. The cable 334 is coupled between the drum 332 and the inner stage 210 by the pin 278 in FIG. 12. The cable 334 extends outward from the drum 332 to its cable end, a fixed loop 336 looped around the pin 278 on the outer side of the clevis 276, connecting the cable 334 to the pin 278. A stanchion 340 extends upright from the rail 60 adjacent to its front end 64 at the backspan's 52 front extremity 92 to a pulley 342.

When the frame 170 is in its lowered position, the cable 334 is let out or otherwise unwound from the drum 332, extends upward and forward to and over the pulley 342 and downward and forward from the pulley 342 to the pin 278 connecting the cable 334 to the frame 170 proximate to the outer end 224 of the rail 220. Rotation of the drum 332 in a winding direction takes up the cable 334 by winding it about the drum 332, in which the cable 334 pulls upward against the closed stage assembly 54 from the pulley 342, forcibly pivoting the stage assembly 54 upward toward the pulley 342 from its lowered position in FIG. 17 and beyond the pulley 342 to its raised position in FIG. 19. When the cable 334 straightens between the drum 332 and its attachment point to the stage assembly 54 while the closed stage assembly 54 pivots upward out of its lowered position, it withdraws upward from over the pulley 342 as shown in FIG. 18, showing the closed stage assembly 54 as it would appear between its FIG. 17 lowered position and its FIG. 19 raised position. Rotation of the drum 332 in an unwinding direction lets out the cable 334 by unwinding it from the drum 332, allowing a worker to pivot the closed stage assembly 54 from its raised stowage position in FIG. 19 to its lowered position and set the unwound cable 334 over the pulley 342 in FIG. 17. The drum 334 is rotated by manual cranking, although it can be powered by a motor in an alternate embodiment. This process is repeated for repeatedly raising and lowering the closed stage assembly 54.

In FIGS. 1-3, the work stage apparatus 50 has mirror image wheeled trucks 350. There are three wheeled trucks 350 in this example, one carried by and extending outward from the rail 60 adjacent to its front end 64 at the backspan's 50 front extremity 92, one carried by and extending outward from the rail 70 adjacent to its front end 74 at the backspan's 50 front extremity 92, and one carried by and extending outward from the transom 80 at the backspan's 50 rear extremity 92. The wheeled trucks 350 act as wheeled levers movable into and out of lowered ground or surface engaging positions of their respective wheels in FIG. 29 extending below the backspan 52 for lifting or otherwise raising the backspan 52 to and supporting it at an elevated position over the floor landing 41 and allowing the work stage apparatus 50 to be wheeled over the floor landing 41 and other floor or ground surfaces. Since the wheeled trucks 350 are identical, the discussion of the rail's 60 wheeled truck 350 applies equally to the other ones.

In FIG. 20, the wheeled truck 350 includes a wheel 352 mounted to a frame 354 swiveled to a fixture 356 of metal mounted to the rail 60 for repeated movement into and out of a lowered surface engaging position of the wheel 352 in FIGS. 26 and 28 extending below the rail 60 of the backspan 52 relative to a raised position of the wheel 352. The wheel 352 and frame 354 are a standard plate caster. The fixture 356 is a hollow body received over and that turns about a support 360 of metal connected rigidly, mechanically or by welding, to and extending outwardly laterally from the outer side of the rail 60 in FIG. 22. The fixture 356, a moving part, turns or otherwise rotates about the support 360, a fixed stationary part, into and out of the wheel's 352 lowered surface engaging position relative to the wheel's 352 raised position. The support 360 serves as a fulcrum about which the fixture 356 turns. A lock assembly 370 operating between the fixture 356 and the support 360 adjusts between a first or upper locked position to lock the fixture 356 in the raised position of the wheel 356 and disable the fixture 356 from rotating out of the raised position of the wheel 352 to into the lowered surface engaging position of the wheel 352, a second or lower locked position to lock the fixture 356 in the lowered surface engaging position of the wheel 352 and disable the fixture 356 from rotating out of the lowered surface engaging position of the wheel 352 to into the raised position of the wheel 352, and an unlocked position to enable the fixture 352 to rotate back and forth between the raised position of the wheel 352 and the lowered surface engaging position of the wheel 352.

In FIGS. 21 and 22, the support 360 is a hollow sleeve configured with circumferentially spaced apart holes 362 and 364. The lock assembly 370 includes a spring-loaded plunger 380 that works with the holes 362 and 364 formed in the support 360. The plunger 380 includes a shank 382 that extends from a handle 384 to the shank's 382 flange 386 and its outer end 388 extending outward from the flange 386. A housing 390, connected rigidly, mechanically or by welding, to the fixture 356, extends outward from the fixture 356 to an outer end 392 configured with an opening 394. The housing 390 houses a compression spring 394. The shank 382 extends into the housing 390 through the opening 394 from the handle 384 on the outer side of the outer end 392. The shank 382 extends through the housing 390 to the flange 386. The outer end 388 extends outward from the flange 386 through an opening 398 through the fixture 356 and into and through the support's 360 opening 362. The spring 396 constantly acts between the outer end 392 of the housing 390 and the shank's 382 flange 386, constantly urging the plunger 380 into its extended position, the upper locked position in which the spring 386 urges the flange 386 against the fixture 356 inserting the outer end 388 into and through the aligned holes 398 and 362, locking the fixture 356 to the support 360, securing the fixture 356 to the support 360 in a raised position of the wheel 352 out of engagement from the floor landing 41, and disabling the fixture 356 from rotating out of the raised position of the wheel 352 in FIGS. 20, 21 and 23 to its lowered surface engaging position of the wheel 352 extending below the backspan 52 in FIGS. 26 and 28.

Pulling the plunger 380 outward from the outer end 390 of the housing 390 by the handle 384 with a force sufficient to defeat the influence of the spring 396 retracts the plunger 380 to its dotted line retracted and unlocked position in FIG. 21, compressing the spring 396 between the flange 386 and the housing's 390 outer end 392 and withdrawing the shank's 382 outer end 388 from the support's 360 opening 362, unlocking the fixture from 356 from the support 360, enabling the fixture 356 to rotate the wheel downward out of its raised position in FIGS. 20, 21 and 23 to its lowered surface engaging position in FIGS. 26 and 28 extending below the rail 60 of the backspan 52. FIG. 23 illustrates the plunger 380 as it would appear in its retracted and unlocked position. The fixture 356 now unlocked from the support 360 enables the fixture 356 to rotate about the support 360 to lower the wheel 352 from the raised position of the wheel 352 in FIGS. 20, 21 and 23 to an initial lowered surface engaging position of the wheel 352 initially contacting the floor landing 41 in FIGS. 24, 25 and 27 and therebeyond to the lowered surface engaging position of the wheel 352 extending below the rail 60 of the backspan 52 in FIGS. 26 and 28, exerting the wheel 352 against the floor landing 41 to lift or otherwise raise the backspan's 52 rail 60 upward to an elevated position over the floor landing 41. When the fixture 356 reaches the lowered surface engaging position of the wheel 352 extending below the rail 60 of the backspan 52 in FIGS. 26 and 28, raising the backspan's 52 rail 60 above the floor landing 41, the openings 398 and 364 and the outer end 388 of the plunger 380 align in FIG. 28, allowing the influence of the spring 396 acting constantly between the outer end 392 of the housing 390 and the shank's 382 flange 386 to snap the plunger 380 inwardly to its extended position, the second or lower locked position applying the flange 386 against the fixture 356, inserting the outer end 388 into and through the aligned holes 398 and 364, locking the fixture 356 to the support 360, disabling the fixture 356 from rotating out of the lowered surface engaging position of the wheel 352 in FIG. 28. The wheeled truck 350 supports the rail 60 above the floor landing 41 when it is locked in the lowered surface engaging position of the wheel 352 against the floor landing 41. A worker can reverse this process to release the fixture 356 from its second or lower locked position securing the fixture 356 in the lowered surface engaging position of the wheel 352, rotate the fixture 356 to raise the wheel 352 out of the lowered surface engaging position of the wheel 352 to the wheel's 352 raised position, lowering the rail 60 onto the floor landing 41, and resecure the fixture 356 to the raised position of the wheel 352. The wheeled truck 350 can be repeatedly adjusted into and out of the lowered surface engaging position of its wheel 352. As shown in FIG. 27, the outer end 388 of the plunger 38 slides across the support 360 between the openings 362 and 364 when the fixture 356 rotates between its two locking positions corresponding to the respective openings 362 and 364.

In FIGS. 20, 21, 23, 24, 27 and 28, an elongate member 400 affixed to the fixture 356 rigidly, mechanically or by welding, extends outward from the fixture 356. In FIGS. 25, 26, 27 and 28, a worker can fit a handle 402 over the elongate member 400 to provide a lever for a worker to use as leverage for rotating the fixture 356 about the support 360 into and out of the lowered surface engaging position of the wheel 352 extending below the rail 60 of the backspan 52, exerting the wheel 352 against the floor landing 41 to pry, lift or otherwise raise the backspan's 52 rail 60 upward and out of engagement from the floor landing 41. The worker can withdraw the handle 402 from over the elongate member 400 after the fixture 356 is locked in the lowered surface engaging position of the wheel 352 by the lock assembly 370.

In FIGS. 1-3 and 16-19, each fixture 370 is locked by its lock assembly 370 in the raised position of its wheel 352, securing its wheel 352 in its raised position with the backspan 52 extending upward from the floor landing 41. Upon setting the closed stage assembly 54 to its raised stowage position and length adjusting the brace 100 to retract it, withdrawing the head 144 from the overhead structure 45 in FIG. 29, a worker can unlock the lock assemblies 370 from the upper locked positions, rotate the fixture 356 from the raised positions of the respective wheels 352 to the lowered surface engaging positions of the respective wheels 352 extending below the backspan 52, lifting or otherwise raising the backspan 52 to an elevated position over and out of engagement from the floor landing 41 in FIG. 29, and lock the lock assemblies 370 in the second or lower locked positions, locking the fixtures 356 in the lowered surface engaging position of the wheel 352, securing the wheels 352 in their lowered surface engaging positions against the floor landing 41 with the backspan 52 supported at an elevated position over the floor landing 350 by the wheeled trucks 350. In the lowered surface engaging position of the wheel 352 of the rail's 60 wheeled truck 350, the wheel 352 extends downward below rail 60 to the floor landing 41. In the lowered surface engaging position of the wheel 352 of the rail's 70 wheeled truck 350, the wheel 352 extends downward below rail 70 to the floor landing 41. In the lowered surface engaging position of the wheel 352 of the transom's 80 wheeled truck 350, the wheel 352 extends downward below rail transom 80 to the floor landing 41. The backspan 52 now supported at an elevated location above the floor landing by the wheeled trucks 350 extending upright from their wheels 352 against the floor landing 41 in FIG. 29 allows the worker to easily wheel the work stage apparatus 50 over the floor landing 41 and other floor or ground surface. The swiveled wheels 352 enable convenient multi-directional wheeled movement of the work stage apparatus 50. Although the backspan 52 has three peripherally offset wheeled trucks 350, it can include more, if desired. Adjusting the wheeled trucks 350 out of the lowered surface engaging positions of the wheels 350 to their raised positions lowers the backspan down onto the floor landing 41.

The work stage apparatus 50 can be repeatedly raised over and lowered onto the floor landing 41 by repeatedly adjusting the wheeled trucks 350 into and out of the lowered surface engaging positions of their wheels 352. A worker can selectively set the wheeled trucks 350 to the lowered ground engaging positions of the wheels 352 when the stage assembly 54 is set to its raised stowage position, wheel the work stage apparatus 50 to the opening 42 to the hoistway 40 as in FIG. 28, lower the backspan 52 onto the floor landing 41 into its operative position as in FIG. 19 by adjusting the wheeled trucks 350 out of the lowered surface engaging positions of the wheels 352, anchor the backspan 52 against the floor landing 41 with the brace 100, and deploy the stage apparatus 54 into its operative position into the hoistway 40 through the opening 42 for supporting a worker in the hoistway, as in FIG. 16, and reverse this operation to move the stage assembly 50 to and deploy it at another location as needed.

The present invention is described above with reference to illustrative embodiments. Those skilled in the art will recognize that changes and modifications may be made in the described embodiments without departing from the nature and scope of the present invention. Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the invention, they are intended to be included within the scope thereof.

Having fully described the invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is: