Drop-Arm Barrier

Description

SUMMARY OF THE INVENTION

A kit is formed from an elongate arm, a shaft, a column from which the shaft is supportable, and at least one shear-resistant structure. The shaft is extendable through the arm, in orthogonal relationship thereto, and is rotatable with the arm as a unit. The column has an internal chamber through which a portion of the shaft is extendable. The at least one shear-resistant structure is positionable within the internal chamber in shear-receiving relationship to the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of a barrier situated on a terrain. The terrain is shown in cross-section.

FIG. 2 is a perspective view of the barrier shown in FIG. 1.

FIG. 3 is a perspective view of the actuator of the barrier shown in FIG. 2, including the shaft and the lift system.

FIG. 4 is a perspective view of an arm.

FIG. 5 is an enlarged rear perspective view of the body of the actuator shown in FIG. 3. The column caps, shaft, lift system and control enclosure have been removed.

FIG. 6 is a rear elevation view of the body shown in FIG. 5.

FIG. 7 is a top plan view of the body shown in FIG. 6, taken from plane 7-7.

FIG. 8 is a right side elevation view of the body shown in FIG. 7, taken from plane 8-8.

FIG. 9 is a section view of the body shown in FIG. 7, taken from plane 9-9.

FIG. 10 is a section view of the body shown in FIG. 7, taken from plane 10-10.

FIG. 11 is a perspective view of a shaft.

FIG. 12 is a front elevation view of the shaft shown in FIG. 11.

FIG. 13 is a perspective view of a first shear plate.

FIG. 14 is a top plan view of the first shear plate shown in FIG. 13.

FIG. 15 is a top plan view of a second shear plate.

FIG. 16 is a perspective view of a shear pin.

FIG. 17 is a front elevation view of the shear pin shown in FIG. 16.

FIG. 18 is a section view of the body, similar to FIG. 10, during one stage of assembly of the barrier. A first shear plate and a bearing have been installed in a column.

FIG. 19 is a perspective and partially exploded view of the upper portion of the column of the body shown in FIG. 18. The column has been partially cut away in order to display the bearing and the first shear plate.

FIG. 20 is a top plan view of the fully assembled actuator shown in FIG. 3. The arm lift system is not shown, and the column caps have been removed.

FIG. 21 is an enlarged top plan view of one column of the actuator shown in FIG. 20.

DETAILED DESCRIPTION

A barrier 10, shown in FIGS. 1 and 2, comprises an elongate arm 12 adapted to traverse a gap 14 to be selectively opened and closed by the barrier 10. The arm 12 is supportable at one end by an actuator 16, and at the opposite end by a receiver 18. The actuator 16 and receiver 18 are situated on opposite sides of the gap 14.

In the embodiment shown in FIG. 1, the actuator 16 is supported by a footing 20 embedded within a terrain 22. The receiver 18 is supported by a similar footing 24, spaced from the footing 20 and embedded within the terrain 22. Preferably, the footings 20 and 24 are of identical size, shape and construction.

Each of the footings 20 and 24 is preferably formed from a ballast material, such as steel-reinforced concrete. Preferably, each footing is buried such that its upper surface coincides with the surface of the terrain 22. In one embodiment, each footing has the external shape of a rectangular prism with surface dimensions of 5 feet by 5 feet and a depth of 4 feet. However, other shapes, sizes and arrangements for the footings are possible.

In another embodiment, not shown in the Figures, the actuator and and receiver may be supported by the same single footing, which is a shallow structure, embedded within the terrain, that extends continuously between the actuator and the receiver.

The actuator 16, shown in detail in FIG. 3, comprises a rigid body 26 supported by the footing 20. An axially rotatable rigid shaft 28 is supported by the body 26 at an elevated position above the terrain 22. As shown in FIG. 2, the arm 12 is joined to the shaft 28, and extends in orthogonal relationship thereto. The shaft 28 and the arm 12 are rotatable as a unit around the longitudinal axis of the shaft 28.

The actuator 16 may further comprise a lift system 30, which causes the arm 12 to rotate from a lowered position, shown in FIGS. 1 and 2, to a raised position that clears the gap 14. The lift system 30 is offset from the shaft 28, and is characterized by an output shaft that pivotally engages the underside of the arm 12. The lift system may be powered hydaulically or electrically. Alternately, the lift system could be gravity-powered, with the use of one or more counterweights.

The arm 12, shown in detail in FIG. 4, is an elongate and hollow structure having a restrained first end 32 and a free second end 34. The arm 12 is preferably formed from a material that is relatively lightweight, but strong and durable as well. One suitable material for the arm 12 is aluminum.

A first pair of opposed openings 36 are formed in the arm 12 adjacent the first end 32, and a second pair of opposed openings 38 are formed in the arm 12 adjacent the second end 34. The first pair of openings 36 are sized and positioned to receive the shaft 28 therethrough, while the second pair of openings 38 are sized and positioned to receive a rigid pin 40 therethrough.

Preferably, the arm 12 is filled to near-capacity with an energy-absorbing material, such as a strong and flexible cable. Within the arm 12, the cable is arranged in multiple windings, each of which loops around both the shaft 28 and the pin 40. The cable may be formed from metal, such as wire rope, or more preferably from non-metallic fibers.

In one embodiment, the arm 12 is formed from A6061 aluminum alloy. The arm 12 is configured to traverse a gap of 12 feet, and is 173.25 inches in length. The hollow interior of the arm 12 is filled with 12-strand HMPE rope having a 0.5 inch diameter. Within the arm 12, each winding of the rope has a length of about 165 inches.

The body 26 of the actuator 16 is shown in detail in FIGS. 5-10. It comprises a pair of spaced and vertical columns 42, specifically first column 44 and second column 46. The columns 42, which are preferably parallel, extend from the same single side of a flat base plate 48, in orthogonal relationship thereto. The base plate 48, which is preferably rectangular in shape, is perforated by a plurality of openings 50. The openings 50 permit the base plate 48 to be joined by bolts to the footing 20 underlying the actuator 16.

The columns 42 are preferably of identical size, shape and construction, except that first column 44 is a mirror image of second column 46. Each column 42 comprises an elongate tubular structure having opposed upper and lower ends 52 and 54. Preferably, each column 42 has a square cross-sectional shape and is laterally bounded by four flat walls, including a first side wall 56 and an opposed second side wall 58, a forward wall 60 and an opposed rearward wall 62. The opposed walls 56 and 58 extend in parallel relationship, as do the opposed walls 60 and 62.

At its lower end 54, each column 42 is permanently attached to the same single side of the base plate 48, preferably by welding. For strengthening of the body 26, one or more external gussets 64 may join the exterior of a column 42 to its base plate 48. To further enhance column strength, a flat brace plate 66 internally bisects each column 42 adjacent its lower end 54, and is held in place by welds.

Adjacent its upper end 52, each column 42 is provided with a flat and internal chamber panel 68, which spans the column interior and blocks loose tools and hardware from falling into difficult-to-access areas near the lower end 54 of the column 42. The chamber panel 68 forms the lower boundary of an internal chamber 70 that extends within the column 42 to its upper end 52.

A pair of aligned openings 72 are formed in each column 42 and communicate with the internal chamber 70 of that column. More specifically, a first access opening 74 is formed in the first side wall 56, and a second access opening 76 is formed in the second side wall 58. The first and second access openings 74 and 76 are preferably circular in shape. Also preferably, the size of the first access opening 74 exceeds the size of the second access opening 76.

A plurality of fastener openings 78 are formed in the first side wall 56 of each column 42, and are arranged peripherally about the first access opening 74. In one embodiment, the number of fastener openings 78 is four, and they are arranged about the first access opening 74 in a square pattern.

An elongate channel-shaped bracket 80 is oriented vertically and attached externally to the rearward wall 62 of each column 42. The brackets 80, which should be parallel, in turn support a control enclosure 82, shown in FIGS. 1-3. The control enclosure 82 houses components of the lift system 30.

A plurality of L-shaped mounting elements 84 are internally installed on at least two opposed walls of each column 42 at its upper end 52. The mounting elements 84 provide attachment surfaces for a cap 86, shown in FIGS. 2 and 3, that closes the upper end 52. In one embodiment, two mounting elements 84 are installed on the forward and rearward walls 60 and 62 of each column 42.

A pin storage element 88 is internally installed within each column 42, preferably by welding. The pin storage element 88 is preferably situated at a corner of the column 42, at a level reachably below the upper end 52. The pin storage element 88 features a perforation within which a service pin 90 may be received, as shown in FIGS. 20 and 21. The service pin 90 is configured to hold the arm 12 in a raised position during maintenance operations. When in use, the service pin 90 is held by a reinforced opening 92 in the first side wall 56 of a column 42.

The columns 42 forming the actuator 16 should be arranged on the base plate 48 such that their respective first side walls 56 are adjacent and parallel. The pairs of aligned openings 72 in the columns 42 should be aligned.

In one embodiment of the barrier 10, the base plate 48 is shaped as a rectangle with sides of 16 inches and 36 inches. Each of the columns 42 is a square tube having sides of 8 inches and a length of 42.63 inches. The centers of the aligned pair of openings 72 are 8 inches from the upper end 52 of their associated column 42. The first access opening 74 has a circular shape with a diameter of 4.75 inches, and the second access opening 76 has a circular shape with a diameter of 2.88 inches. The center-to-center separation between adjacent columns 42 on the base plate 48 is about 19 inches.

Components of the body 26, including the columns 42 and the base plate 48, are preferably formed from a strong and durable material, such as steel. To enhance resistance to corrosion, such components are preferably galvanized before assembly.

The shaft 28, shown in detail in FIGS. 11 and 12, is preferably formed from a strong and durable material, such as steel. It is a rectilinear member comprising a central body 94. In one embodiment, the body 94 is flanked at opposed ends by a pair of stub sections 96.

The body 94 and stub sections 96 each have a cylindrical shape, and are disposed in axially concentric relationship. The body 94 is bisected into equal parts by an imaginary plane 98. Adjacent each of its opposed ends, the body 94 is diametrically perforated by a rectilinear passage 100. Preferably, the passages 100 are coplanar. If present, the stub sections 96 are identical, and of lesser length and diameter than the body 94.

In one embodiment, the shaft 28 is formed from 17-4 PH stainless steel. The body 94 is 23.514 inches long, while each stub section 96 is 5.118 inches long. The diameter of the body 94 is about 2 inches, while the diameter of each stub section 96 is 0.787 inches. Each passage 100 has a circular cross-sectional shape, with a diameter of 0.906 inches.

When installed, the shaft 28 extends through the pairs of aligned openings 72 of the columns 44 and 46. Between the columns 44 and 46, the shaft 28 passes through the arm 12 at its first pair of openings 36. The shaft 28 is fixed to the arm 12 so that they rotate together as a unit around the longitudinal axis of the shaft 28. The arm 12 extends in orthogonal relationship to the shaft 28.

The shaft 28 is rotatably supported by a pair of flat bearing plates 102, one of which is installed within the internal chamber 70 of each column 42, as shown in FIGS. 18-21. Each bearing plate 102 features a central opening 104, within which an annular bearing 106 is installed. The shaft body 94 is sized to be closely but clearingly received through central opening of the annular bearing 106.

Each bearing plate 102 permits the shaft 28 to rotate axially, and is supported by the first side wall 56 of the column 42 within which it is installed. A plurality of fastener openings 108 penetrate the bearing plate 102, and are arranged peripherally about around the central opening 104. The fastener openings 108 should be are provided in the same number as the fastener openings 78 in the first side wall 56. The pattern of the fastener openings 108 should register with that of the fastener openings 78.

At least one, and preferably a plurality of shear-resistant structures are situated within the internal chamber 70 of each column 42, in shear-receiving relationship to the shaft 28. Such shear-resistant structures preferably comprise thick and substantially solid blocks of a strong and durable material, such as steel. The at least one shear-resistant structure preferably comprises a first shear plate 110, a second shear plate 112 and a shear pin 114.

The first shear plate 110 is shown in detail in FIGS. 13 and 14. It is a flat and solid member having a central opening 116 through which the shaft 28 is clearingly receivable. The external cross-sectional shape of the first shear plate 110 is preferably rectangular, and more preferably square. The external dimensions of the first shear plate 110 should exceed the diameter of the first access opening 74.

A plurality of peripheral fastener openings 118 perforate the first shear plate 110, and are arranged around the central opening 116. The fastener openings 118 are provided in the same number as the fastener openings 78 in the first side wall 56, and in the same number as the fastener openings 108 in the bearing plate 102. The pattern of the fastener openings 118 should register with that of the fastener openings 78, and that of the fastener openings 108.

The first shear plate 110 is interposed between the bearing plate 102 and the first side wall 56 of each column 42, and engages both such structures in face-to-face relationship. Within the internal chamber 70 of a column 42, the first shear plate 110 and bearing plate 102 are installed by aligning their respective fastener openings 108 and 118, and further aligning these aligned openings with the fastener openings 78 of the first side wall 56. Fasteners 120, shown in FIG. 19, are inserted through the aligned openings and actuated to join the first shear plate 110 and the bearing plate 102 to each other, as well as to the first side wall 56.

In one embodiment, the first shear plate 110 is a square member formed from plain carbon steel. It has sides of 5.63 inches and a thickness of 0.75 inches. The central opening 116 has a diameter of 3 inches.

The second shear plate 112 is shown in detail in FIG. 15. It is a flat and solid member having a central opening 122 through which the shaft 28 is clearingly receivable. The external cross-sectional shape of the second shear plate 112 is preferably circular. The external diameter of the second shear plate 112 should exceed the diameter of the first access opening 74.

As shown in FIG. 21, the second shear plate 112 resides on the body 94 of the shaft 28, which passes through the central opening 122. The second shear plate 112 is situated on the opposite side of the bearing plate 102 from the first shear plate 110.

In one embodiment, the second shear plate 112 is an annular member formed from plain carbon steel. It has an external diameter of 5.63 inches and a thickness of 0.75 inches. The central opening 122 has a diameter of 2 inches.

The shear pin 114 is shown in detail in FIGS. 16 and 17. It is an elongate solid member, preferably cylindrical in shape. The shear pin 114 has a length less than the side length of the columns 42, but greater than the diameter of the first access opening 74.

The cross-sectional shape and size of the shear pin 114 should closely match that of the passages 100, so that the shear pin 114 is closely, but clearingly, receivable in the each of the passages 100. On opposite sides of its midpoint, the shear pin 114 is perforated by a pair of diametrical passages 124, which are preferably parallel.

Within the internal chamber 70 of each column 42, the shear pin 114 is installed by pressing it through the passage 100 that perforates the shaft 28, as shown in FIGS. 20 and 21. The shear pin 114 extends in orthogonal relationship to the shaft 28, and is held in place by cotter pins 126 installed in the passages 124.

In one embodiment, the shear pin 114 is a cylindrical member formed from 17-4 PH stainless steel. It has a length 5.74 inches and a diameter of 0.88 inches. The passages 124 are symmetrically disposed about the midpoint of the shear pin 114, with a separation distance of 2.375 inches.

The shaft 28 is installed after the bearing plate 102 and first shear plate 110 have been installed in their respective columns 42. A free end of the shaft 28 is passed into the internal chamber 70 of the first column 44 through the second access opening 76. Within the internal chamber 70, the free end of the shaft 28 is passed through the central opening 122 of a second shear plate 112, through the central openings 104 and 116 of the bearing plate 102 and the first shear plate 110, and through the first access opening 74 of the first side wall 56.

Outside the first column 44, the free end of the shaft 28 is next passed through the arm 12, by way of the first pair of openings 36. Within the arm 12, the free end of the shaft 28 passes through the windings of the contained energy-absorbing cable. These steps are preferably carried out while the arm 12 is suspended by a crane or other lifting apparatus. The arm 12 should thereafter remain in suspension until the shaft 28 has been fully installed.

Once through the arm 12, the free end of the shaft 28 is next passed into the second column 46 through its first access opening 74. Within the second column 46, the free end of the shaft 28 passes through the central openings 116 and 104 of the first shear plate 110 and the bearing plate 102. Within the internal chamber 70, the free end of the shaft is then passed through the central opening 122 of a second shear plate 112, and then through the second access opening 76 in the second side wall 58.

When the foregoing installation steps are complete, the shaft 28 passes through both columns 44 and 46 and is situated such that the opposed stub sections 96 project outside these columns at opposite ends of the shaft 28. The arm 12 is moved into alignment with the plane 98, if necessary, and fixed into position on the shaft 28. After any necessary positioning adjustments are made, the fasteners 120 are fully tightened, thereby completing installation of the shaft 28.

Optionally, the actuator 16 may be equipped with a torsion spring (not shown), which engages the shaft 28 at a stub section 96 and controls the force and heat associated with descent of the arm 12.

Like the actuator 16, the receiver 18 is characterized by a body comprising a pair of spaced and vertical columns. The columns, which are preferably parallel, extend from the same single side of a flat base plate. The base plate is joined to the footing 24 underlying the receiver 18, preferably by bolts. When the arm 12 is lowered, it rests adjacent its free end on an elevated support structure, such as a bumper pad, that extends between the paired columns of the receiver 18.

When a moving vehicle strikes the arm 12, the energy from the collision is transmitted to the shaft 28 and thence into the columns 42. That energy can be so great as to threaten destruction of any bearing within either column 42. If bearings are the only structures that engages the shaft within the internal chambers of the columns, destruction of those bearings could allow the shear forces associated with the collision to bend the shaft to its breaking point, pull the shaft out of the columns, and ultimately snap the shaft in two. Such a process would leave the arm without support, thereby causing it to fall, and the barrier to fail.

Loading the internal chamber 70 with shear-resistant materials reduces the susceptibility of the barrier 10 to the foregoing scenario. The first shear plate 110 absorbs and dissipates a portion of the shear collision force that would otherwise be internalized within the shaft 28. The second shear plate 112 and the shear pin 114 absorb and dissipate collision energy as well. In addition, the size of the first and second shear plates 110 and 112, and the shear pin 114, serves to block the shaft 28 from being withdrawn through the first access opening 74. The shaft 28 is thereby able to better maintain its structural integrity after the arm 12 undergoes a vehicular collision.

Kits of components can be useful for building a barrier 10. A kit may comprise an arm 12, a shaft 28, at least one, and preferably at least two columns, and at least one, and preferably a plurality of shear-resistant structures. The columns may comprise the first and second columns 44 and 46 of a body 26. The shear-resistant structures may comprise one of more of a first shear plate 110, a second shear plate 112 and a shear pin 114. At least one, and preferably at least two, bearing plates 102 may also be included in the kit. Other components of the barrier 10, and the hardware needed to assemble it, may be included in the kit.

Unless otherwise stated herein, any of the various parts, elements, steps and procedures that have been described should be regarded as optional, rather than as essential. Changes may be made in the construction, operation and arrangement of the various parts, elements, steps and procedures described herein without departing from the spirit and scope of the invention as described in the following claims.