The invention relates to clamps and more particularly to a hold-down clamping apparatus for securing and holding down a sheet material for processing.
Various mechanisms for supporting and clamping sheet materials to be processed by a tool or otherwise are known in the art. Vises and supports such as X-Y tables and work benches as well machine tools and robotic tools and parts thereof are often employed to hold sheet materials of different shapes and sizes to be processed by a tool or otherwise. There have been difficulties with sufficiently securing sheet materials to a tool or portion of a tool or to a support resulting in movement of the work sheet and imprecise processing.
Additionally, sheet materials can be deformed where vises and the like are used to constrain the work material. Kurt Manufacturing provides a vise with interchangeable jaws that can be replaced when damaged. The jaws of the vise apply significant force to the material being held as the axis being constrained by the vise is a function of the friction between the vise jaws and the sheet material. When the sheet material is thin in cross-section or flexible it can be deformed significantly resulting in imprecise processing. Even thicker and/or more rigid sheet materials may buckle or deform somewhat when constrained by vise jaws resulting in vibration and poor tolerance control at the center of the sheet material.
It is therefore an object of the present invention to secure and/or to provide an apparatus to secure sheet material for use in machining or processing.
It is a further object of the invention to prevent and/or to provide an apparatus capable of preventing deformation to secured sheet material for machining or processing.
It is an additional object to provide a clamping apparatus for securing and holding down sheet material for machining or processing.
These objects, as well as others, have been achieved with a hold-down clamping apparatus comprising a sheet material support plate and a hold-down clamp for securing and holding-down sheet material for processing or machining. The hold-down clamp has a body with a top lip, a pair of downwardly depending guide legs, and a central clamping screw disposed in the central screw hole between the pair of guide legs. The sheet material support plate has holes in vertical alignment with the pair of guide legs and the central screw. The pair of guide legs is inserted within the support plate holes and the central screw is threaded into its support plate hole as the top lip of the hold-down clamp is positioned into contact with the material support and presses against a sheet material disposed on the support plate, typically an edge portion, so as to hold down the material to prevent deformation, to secure the material and to prevent twisting of the hold-down clamp. The sheet material may be thin or thick and of any dimension. In one example, the sheet material is rectangular in shape. In another example, the sheet material is a block. In one example, the hold-down clamping apparatus may be fastened to a vise where a clamping force along a different axis may additionally be applied. In other examples, the clamp-down apparatus may be fastened to supports such X-Y tables and work benches as well as to machines or robotic tools.
In one embodiment, the clamp-down apparatus includes a first clamping assembly comprising a hold-down clamp and a first sheet material support and a second clamping assembly comprising an opposing second hold-down clamp and an opposing second sheet material support for securing and holding down a sheet material extending from the first sheet material support to the second sheet material support. A material sheet is placed on the material supports and extends from one material support to the other. First guide legs are inserted and a first central screw is threaded in holes in the first material support and second guide legs are inserted and a second central screw is threaded in holes of the second material support. Guide legs of each of the hold-down clamps are inserted in holes corresponding to a cross-sectional shape of the guide legs and the central screws are threaded in central screw holes as the top lips of the clamps are positioned into contact with and press against portions of the sheet material to hold it down and in place and so that twisting of the hold-down clamps is prevented. Additional holes and hold-down clamps disposed linearly along the material supports may be used to further secure and hold down the material sheet. In one example, the hold-down clamping apparatus is used with a vise. The first sheet material support abuts a first jaw of a vise and the second sheet material support abuts a second jaw of a vise so that a clamping force along a different axis may also be applied.
In another embodiment, the hold-down clamping apparatus includes a different clamping assembly comprising a hold-down clamp having a body with a top lip and a downwardly depending rectangular guide beam having a central screw hole, a central screw disposable within the central screw hole, a sheet material support having a guide beam slot in vertical alignment with the guide beam and corresponding to a rectangular cross-sectional shape of the guide beam, and a central screw hole in a block beneath the slot in vertical alignment with the central screw guide beam hole. The sheet material is disposed on the sheet material support and the guide beam is inserted within the guide beam slot until the top lip of the hold-down clamp contacts the support at which point the screw is threaded into the central screw hole beneath the slot so that the lip presses upon the sheet material to prevent twisting of the clamp and deformation of the sheet material. A pair of these clamping assemblies may replace the clamping assembly described above and may be integrated with a vise or other tool.
In another embodiment, the clamping apparatus comprises a sheet material support sized to support multiple sheet materials on the upper surface and having a grid pattern of holes in the support within which select holes the guide legs and central screws of hold-down clamps may be inserted to hold-down multiple sheet materials at different, selected positions. Processing of multiple sheet materials provides greater productivity. Also, the ability to select positions for the hold-down clamp allows for different sized sheet materials to be accommodated. In one example, all of the holes are threaded at the bottom and the central screw is longer than the guide legs so that the central screw may be threaded into the bottom portion of any selected hole to hold down the sheet material upon which the top lip presses against and to prevent twisting of the clamp. In other examples, only select holes may be threaded in which case the hold-down clamp would be used at particular positions where the central screw would be threadable in that hole.
With reference to
With reference to clamping assembly 105, hold down clamps 106a-e have the same structure as hold-down clamps 104a-e. Labeled on clamp 106a is a body 117, top lip 118, a pair of downwardly depending guide legs 200, and a central screw 120 disposed in and secured to the body between the pair of guide legs 200 and a material sheet support. 122 having a pair of holes in 308 in vertical alignment with the pair of guide legs 200, and a central threaded screw hole 301 in vertical alignment with the central screw 120. Guide legs and central screws for clamps 106b-e also have corresponding holes in the support, as for clamp 106a, though are not shown here.
The sheet material 128 may be positioned against the guide legs of each hold-down clamp and where the guide legs are aligned with the lateral plane of the tool or vise jaws 124 and 126, the sheet material is also aligned with the vise 102. Hold-down clamps 104a and 106a hold down and secure sheet material 128 to first and second sheet material supports 119 and 122 in between which sheet material 128 extends.
With reference to
Referring to
Referring to
Referring to
With reference to
Though not shown here, a second opposing clamping assembly 600 comprising a material sheet support with a hold-down clamp with a rectangular beam, block and slot configuration is used to secure a sheet material on the opposite end of the clamping assembly, the sheet material extending in between the two material sheet supports for processing, as seen in
Each hold-down clamp 602a-d is insertable within the corresponding guide beam slot 620 until the top lip 606a-606d of the respective hold-down clamp 602a-602d rests upon a sheet material disposed on the support 614 at which point the corresponding central screw 612a-d is threadable within the respective central screw hole of the corresponding block 622a-d. Hold-down clamp 602a is shown inserted in its slot and screw 612a is shown threaded in its corresponding screw hole. For each-hold down clamp, the central screw is threaded into the central screw hole when the guide beam leg is in place in the slot and the top lip rests upon the sheet material thereby holding down the sheet material which the top lip contacts and preventing twisting of the hold-down clamp. The size of each top lip should be sufficient to retain the sheet material but not so big that it covers a large portion of the sheet material which is to be worked on or processed. In one example the lip should not extend more than 5 mm over the edge portion of the sheet material to be worked on.
This clamping assembly may be integrated with a tool such as vise 102 as seen in
With reference to
In one example, the sheet material 702a is secured by one pair of opposing clamps 712a and 712b. However, additional clamps, for example clamps 712c and 712d, in a linear arrangement along sheet material support 702a may be used to hold down the material sheet 702a. Material sheets 702b and 702c are held down by hold-down clamp pairs 712b,712e and 712d, 712f, and 712e, 712g and 712f, 712h, respectively. The lip 722 of one-hold down-clamp may be used to secure adjacent sheet materials, for example, the lip 714e of clamp 712e holds-down sheet materials 702b and 702c. The support 704 may be fastened to a machine or tool or other support such as an X-Y table or work bench and may include bolt holes and bolts for fastening (not shown).
The pattern of holes allows sheet materials of different shapes and sizes, including blocks, to be supported on the material sheet support by placing the hold-down clamps in openings near the periphery of the sheet material. Referring to
The present application claims the benefit of priority from prior U.S. provisional application 62/231,535 filed on Jul. 8, 2015, which is hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
1578898 | Littleford | Mar 1926 | A |
2365436 | Saucier | Dec 1944 | A |
2654932 | Goudie | Oct 1953 | A |
2770156 | Brettrager | Nov 1956 | A |
2832395 | Fisher | Apr 1958 | A |
3423885 | Crandall | Jan 1969 | A |
3982740 | Gutman | Sep 1976 | A |
4519592 | Russell | May 1985 | A |
4830350 | Kuei | May 1989 | A |
4948108 | Sullivan | Aug 1990 | A |
5244194 | Nishimura | Sep 1993 | A |
5562277 | Swann | Oct 1996 | A |
6000688 | Giangrasso | Dec 1999 | A |
6196536 | Hintze | Mar 2001 | B1 |
6554265 | Andronica | Apr 2003 | B2 |
6672578 | Martens | Jan 2004 | B1 |
6773003 | Dermody, Jr. | Aug 2004 | B2 |
6896249 | Ferrara | May 2005 | B1 |
7152855 | Martens | Dec 2006 | B1 |
7568683 | Lovas | Aug 2009 | B1 |
8540225 | Ehnstrom | Sep 2013 | B2 |
9448537 | Lindsay | Sep 2016 | B2 |
20110089621 | Seidel | Apr 2011 | A1 |
Number | Date | Country | |
---|---|---|---|
20170008154 A1 | Jan 2017 | US |
Number | Date | Country | |
---|---|---|---|
62231535 | Jul 2015 | US |