MULTI-PUNCH TOOL AND METHOD OF PUNCHING HOLE IN A PART

Description

FIELD OF THE INVENTION

The instant relates to the field of metal stamping. More particularly, the invention relates to cutting or punching holes in a part, such as a metal plate, in the formation of various housings, such as electrical boxes.

BACKGROUND OF INVENTION

Prior Art

Electrical enclosures and panels need to include knock-outs, which have a center point and may include one opening which must be removed from a wall of the enclosure, to create a passage for a device or fixture, such as wiring and conduit or provide a location to insert a meter, display, disconnect, plug or communication ports to be place in location. The usual practice is to produce such knock-out (a singular hole) in the enclosure, for example, in order to install one of the devices/fixtures.

Many of these components require circular or non-circular shape hole with several mounting holes surrounding the large hole, which typically needs installation person (installer) to layout the required cutout, and subsequently drill pilot holes. The holes seen in each corner enable the installer to insert a saw blade into one of the drilled holes and cut away the material between the holes until the target opening is produced.

The installer drills holes at the perimeter of mounting holes and hold accuracy and location of these holes. Many times, the installer will have to take a grinder or metal file to the edges of the cutout to make sure it is straight and free from burrs. As a result of this process, a large number of shavings will end up in a cavity of the panel which can causes problems particularly in the case of sensitive electronics being installed inside box.

The prior method has many drawbacks, some of which are listed below include:

Requires extensive amount of time in layout of the part to be cut;

Requires an extensive amount of time to cut-out the desired areas of the metal part;

Often results in inaccurate holes sizing and location;

Opens for opportunity for installer to make erros in layout and cut-out;

Requires additional tools to produce separate cut-outs;

Very loud when sawing or grinding is used in creating a part;

Generates large number of shavings;

Results in possible damage to control items inside finished cabinet/housing;

Requires cleaning of inside of a formed part, e.g., box, and possibly preparation time to cover electronics in panel; and

Requires finish work to create clean edges of cut-out after sawing is used in creating cut-outs.

SUMMARY OF THE INVENTION

It is an objective to improve metal box formation.

It is a further objective to reduce the cost in forming metal box housing.

Another objective is reducing the time required in forming openings in metal plates.

Still another objective is to provide a hand tool capable of forming multiple openings in a plate, such as a metal plate.

It is another objective of the present invention to provide a tool adapted to knock out identified geometries in a single action.

Another objective is to provide a hand operated tool which forms multiple openings in a work piece in single pass operation.

Accordingly, the invention is directed to a tool, which can be hand operated or power assisted, for forming at least one open surface in a work piece, such as a metal plate. This invention is a method of punching one or more hole in an electrical, communication, construction frame or panel that requires one or multiple holes. The tool includes a primary punch surface equipped to punch a hole in a work piece. These holes are generally termed “knock-outs” and typically only produce one hole at a time with some standardize round hole tooling. The primary punch surface is connected to a punch holder which has a draw bar opening surface, which can be centrally oriented. In an embodiment, the primary punch surface can be part of separate primary punch member removably connected to a primary punch member receiving surface of the punch holder and include a plurality of peripheral ridges and valleys and a central open surface through coaxially aligned with the draw bar open surface. The punch holder can include a plurality of secondary orifices about the punch member receiving surface. The secondary orifices can receive secondary punch members having punch surfaces, and in the case of multiple holes required to be punched in a grouping, the secondary punch members surfaces are equipped to punch multiple holes in a predetermined orientation providing accuracy from hole to hole.

There is a die holder which has a front formed with an open surface to receive the primary and secondary surfaces and work piece material as the work piece is punched as will be described. The die holder has a draw bar open surface which coaxially aligns with the draw bar open surfaces of the punch holder and primary punch member. The draw bar open surfaces are preferably formed with a unique geometric shape having at least a plurality of flat connected surfaces and in a preferred embodiment an arcuate surface as well.

A draw bar is provided which has a threaded end, a mid-section configured with a complementary configuration to be longitudinally slid through the draw bar open surfaces, and an enlarged end which will not pass through the draw bar open surfaces. Upon the die holder front, primary punch surface of primary punch member, and punch holder being aligned with the pull bar open surfaces co-aligned, the draw bar can be inserted through a back of the punch holder, through the primary punch member, and die holder with the threaded end extending outside a back of the die holder. It is noted that the work piece to be punched will be placed between the primary punch surface and the front of the die holder, with the work piece having at least been predrilled with an open surface to receive the draw bar therethrough.

A threaded nut preferably along with a thrust bearing can be disposed on the draw bar. Upon threading the nut, the thrust bearing causes the pull bar to axially move and draw the punch holder and primary punch member and primary punch surface into engagement with the work piece. Continued threading results in the punch surface to pierce the work surface.

In the case of the introduction of secondary punch members, these can be inserted through the secondary orifices and are configured with one end having the punch surface which extends through the secondary orifice and its other end larger than the secondary orifice and prevented from passing therethrough. In this case, a back cap is provided which is removably connected to the back of the punch holder and maintains the secondary punch members in place.

The invention as outline below is to provide a single tool, with associate grouping of holes, that relates to a component or group of components that position, orientation, control size and tolerances from one geometry to another. The tool of the instant invention is held with more accuracy than the conventional methods which produce one hole at a time. This method does not require any automated equipment to achieve its objective, though it is able to assisted with power if desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view illustrating the instant invention.

FIG. 2 is a perspective view illustrating the instant invention.

FIG. 3 is a side view illustrating the instant invention.

FIG. 4 is a sectional view illustrating the instant invention through line E-E of FIG. 3.

FIG. 5 is an end view illustrating the instant invention.

FIG. 6 is a sectional view through line A-A of FIG. 5.

FIG. 7 is a sectional view through line B-B of FIG. 5.

FIG. 8 is a sectional view through line C-C of FIG. 3.

FIG. 9 is another end view of the instant invention.

FIG. 10 depicts a work piece predrilled with an opening.

FIG. 11 is a perspective view of the work piece formed by the instant invention.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings instant invention, there is provided a convenient tool which will enable cut-outs (knock-outs) from metal plates, for example, more readily and thus enable installation in a timely fashion with high degree of accuracy. Accordingly, the invention provides a multi-punch tool which is generally designated by the numeral 10. The tool 10 can be hand operated or power assisted, for forming at least one opening 11 in a work piece 12, such as a metal plate.

The invention also provides for a method employing the tool 10 for punching one or more hole 11,13 in the work piece 12. The work piece 10 can be a cover or wall part for an electrical, communication, construction frame or panel that requires one or multiple holes.

The tool 10 includes a primary punch surface 14 equipped to punch a hole 11 in a work piece 12. Secondary punch surfaces 32 can punch holes 13. These holes have been referred to in the industry as “knock-outs” which were heretofore made one hole at a time with some standardize round hole tooling, such as a drill bit. The primary punch surface 14 is part of a primary punch member 16 which is removably connected to a punch holder 18 and seated in recessed receiving surface 17. It is contemplated that the primary punch surface 14 could be integrally part of the punch holder 18, though here it is shown as part of the primary punch member 16 to enable interchangeability.

In each of the primary punch member 16 and punch holder 18 there is a respective draw bar open surface 20 and 22, which can be centrally oriented. Again, the primary punch surface 14 can be part of separate primary punch member 16 removably connected to the punch holder 18 and include a plurality of peripheral ridges 24 and valleys 26. In the exemplary embodiment, the ridges 24 are disposed in corners 25 with valleys 26 disposed in medial areas 27 between the corners 25. When the primary punch member 16 and punch holder 18 are connected, the draw bar open surfaces 20 and 22 are coaxially aligned.

The punch holder 18 can include a plurality of secondary orifices 28 which are positioned about a recessed receiving surface 17 for the primary punch member 16. The primary punch member 16 has threaded open surfaces 19 to receive head cap screws 21 which secure the primary punch member 16 to the punch holder 18. A urethane stripper member 23 can be employed between the primary punch member 16 and the work piece 12 to assist in removing work piece material from secondary punch members 30.

The secondary orifices 28 can receive secondary punch members 30 having punch surfaces 32, and in the case of multiple holes 11, 13 being required to be punched in a grouping, the secondary punch members surfaces 32 are equipped to punch multiple holes 13 in a predetermined orientation providing accuracy from hole 11 and with respect to each other hole 13.

There is a die holder 34 which has a front 36 formed with an open surface 38 large enough to receive the primary punch surface 14 and secondary punch surfaces 32 as well as cut out material of work piece 12 as it is punched as will be described. The die holder 34 has a draw bar open surface 40 and coaxially aligns with the draw bar open surfaces 20 and 22 of the primary punch member 16 and punch holder 18, respectively. The draw bar open surfaces 20 and 40 are preferably formed with a unique geometric cross-sectional shape. In this regard, the cross-sectional shape have at least a plurality of flat connected surfaces 42 and in a preferred embodiment an arcuate surface 44 as well. In a preferred embodiment there are three flat surfaces 42 with one arcuate surface 44 interconnecting two of the flat surfaces 42.

A draw bar 46 is provided which has a threaded end 48, a mid-ection 50 configured with a complementary cross section configuration to be longitudinally slid through the draw bar open surfaces 20 and 40, and an enlarged end 52 which will not pass through the draw bar open surfaces 20 and 40 but will pass through draw bar open surface 22. Enlarged end 52 has a collar 53 which seats against punch holder 18.

Upon the die holder front 36, primary punch surface 14 of primary punch member 16, and punch holder 18 being held in position as seen in the drawings, with the pull bar open surfaces 20, 22 and 40 coaxially aligned, the draw bar 46 can be inserted through a back 60 of the punch holder 18, through the primary punch member 18, and die holder 34 with the threaded end 48 extending outside a back 62 of the die holder 34.

As seen in FIG. 8, the draw bar 46 cross section has a plurality of sides to form a partial polygon with three sides 42 and an interconnected arcuate portion 44. Providing this configuration lends strength to the draw bar 46 while accomplishing its task in maintaining relative position of the punch holder 18 and die holder 34. It is noted that the work piece 12 to be punched will be placed between the primary punch surface 14 and the front 36 of the die holder 34, with the work piece 12 having at least been predrilled with an open surface 15 to receive the draw bar 46 therethrough.

A threaded nut 70 preferably along with a thrust bearing 72 can be disposed on the draw bar 46. Upon threading the nut 70, the thrust bearing 72 causes the draw bar 46 to axially move therethrough and draw the punch holder 18, primary punch member 16 with primary punch surface 14 and optional secondary punch surface 32 into engagement with the work piece 12. Continued threading results in piercing or punching the work piece 12 to produce the desired knockout geometry.

In the case of the introduction of secondary punch members 30, these can be inserted through the secondary orifices 28 and are configured with one end 31 having the punch surface which extends through the secondary orifice 28 and its other end 33 larger than the secondary orifice 28 and prevented from passing therethrough. In this case, a back cap 80 is provided which is removably connected to the 60 back of the punch holder 18 and maintains the secondary punch members 30 in place when secured. In this regard, there are through holes 82 in back cap 80 and threaded open surfaces extending into back 60 of punch holder 18 which receive threaded socket head cap screw 90. Additionally, there are recessed surfaces 84 for receiving head cap screws 30 and recessed surface 86 for receiving draw bar collar 53.

Accordingly, the invention the provides single tool, with associated grouping of holes, that relates to a component or group of components that enables the position, orientation, control size and tolerances from one geometry to another. The tool of the instant invention is held with more accuracy than the conventional methods which produce one hole at a time. This method does not require any automated equipment to achieve its objective, though it is able to be assisted with power if desired.

While prior to the current invention, it is common practice in the industry to furnish an installer just a simple layout sketch to produce the desire geometry to install the target components in an opening of a machine, panel, wall, etc. This would result in many of the cons described above and at a cost of time, damage electrical components, repairing or scrapping out panels due to installer's inaccuracy and mistakes.

Thus, this invention has been conceived to remove many of the potentials for mistakes, damage and loss of time by incorporating a grouping of geometries required for such devices to be mounted. Many of the manufactures of these components use the same grouping of geometries, such as that shown in FIG. 10 for similar mounting of various components. Such geometry as a duplex outlet for household home uses the same geometry from one manufacturer to another (thus having a standard geometry across the industry). Therefore, this invention uses these standardized geometries to develop a tool to produce the mounting geometry in a panel or machine for various components.

While the instant invention has been described with the above exemplary disclosure, it is not intended to be limiting in the claims appended hereto. According the claims are to be afforded a scope encompassing modifications, derivations and improvements thereof.

What is claimed is: