Abstract
A hold-down clamping apparatus comprising a hold-down clamp with body having a top lip and pair of guide legs disposed between a central screw in the body and a support having holes in vertical alignment with the legs and the screw for securing and holding down a sheet material for processing. The screw is threaded through the support screw hole as the legs are inserted within support holes until the top lips contacts the sheet material to hold down the material and to prevent twisting of the hold-down clamp. Supports with clamps may be fastened to tools or supports. In one embodiment, the support has a grid of holes for securing a plurality of materials with hold-down clamps. In another embodiment, the hold-down clamp comprises a top lip and a guide beam slotted in a support and secured.
Claims
1. A hold-down clamping apparatus for securing sheet material for processing the sheet material having opposed edges to be held in place, comprising: a plurality of hold-down clamps arranged as first parts of opposed clamping assemblies at opposed edges of a sheet material, each hold-down clamp having a body with a top lip and a downwardly depending rectangular guide beam, and a central screw disposed within the body, the top lip having a size retaining the sheet material; and a sheet material support plate arranged as second parts of the opposed clamping assemblies and having a guide beam slots in vertical alignment with the guide beam and corresponding to a rectangular cross-sectional shape of the guide beam and a central screw hole extending adjacent to the guide beam slots and in vertical alignment with the guide beam slots, the central screw threadable within the central screw hole, whereby for each clamping assembly the guide beam is insertable within the guide beam slots until the top lip of the hold-down clamp rests upon the sheet material disposed on the sheet material support plate, the central screw of each hold-down clamp being threaded into the central screw hole when the guide beam is disposed in the guide beam slots and the top lip rests upon the sheet material thereby holding down opposed edges of the sheet material upon which the top lip rests and preventing twisting of the hold-down clamp of each clamping assembly; and wherein each sheet material support plate further comprises a pair of plate members with spaced apart rectangular blocks forming the guide beam slots between the pair of plate members.
2. The apparatus of claim 1, wherein the sheet material support further comprises support retention bolt holes configured to fasten the sheet material support plate to a tool.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is perspective view of a hold-down clamping apparatus of the present invention in use with a tool and a thin sheet material.
(2) FIG. 2 is a top view of the hold-down clamping apparatus and tool of FIG. 1.
(3) FIG. 3 is a perspective view of the hold-down clamping apparatus of FIG. 2 including two hold-down clamping assemblies.
(4) FIG. 4 is a perspective view of a clamping assembly of the hold-down clamping apparatus of FIG. 3 with hold-down clamps in a different position.
(5) FIG. 5 is a perspective view of a hold-down clamping apparatus and tool in use with a thicker sheet material.
(6) FIG. 6 is an alternate embodiment of a hold-down clamping assembly of the present invention.
(7) FIG. 7A is another alternate embodiment of a hold-down clamping apparatus of the present invention.
(8) FIG. 7B is a plan view of a hold-down clamp of FIG. 7A.
DETAILED DESCRIPTION
(9) With reference to FIGS. 1-4, there is seen a hold-down clamping apparatus 100 of the present invention integrated with a tool, in this example, vise 102. The hold-down clamping apparatus, comprises, in one embodiment, a pair of opposed clamping assemblies 103 and 105, each assembly having at least one hold-down clamp and a material support. With reference to clamping assembly 103, hold-down clamps 104a-e are shown each respectively with a body 107A-e, a top lip 108a-e, a pair of downwardly depending guide legs 400a-e, and a clamping central screw 112a-e disposed in and secured to a body 107A-e between the pair of guide legs 400a-e and a sheet material support 119 having a pair of holes 404a-e in vertical alignment with the pair of guide legs 400a-e and a threaded hole 406a-e in vertical alignment with the central screw 112a-e and the central screw hole 402a-e.
(10) 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.
(11) 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.
(12) With reference to FIGS. 2-4, for each hold-down clamp 104a and 106a, the pair of guide legs is inserted within the pairs of sheet material support holes 404a and 308 respectively, which constrain the motion of the hold-down clamps to only vertical motion, and the central screws 112a and 120 are threaded in sheet material support screw holes 406a and 301, respectively, so that the hold-down clamp moves down and so that the top lip of each hold-down clamp contacts a sheet material 128 disposed on the supports 119 and 122. Central screws are threaded in the support screw holes to tighten the hold-down clamps against the sheet material and sheet material supports 119 and 122, respectively, securing the sheet material 128 in place and holding it down. Top lips 108a and 118 each apply force to the sheet material 128, typically an edge portion of the sheet material. The size of each top lip should be sufficient to retain the sheet material 128 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. In one example, the sheet material is secured by one pair of opposing clamps 104a and 106a. However, additional clamps 104b-104e in linear arrays along sheet material support 119 and opposing clamps 106b-106e along sheet material support 122 may be used to hold-down the sheet material 128. In another example, only one hold-down clamp is used with one sheet material support.
(13) Referring to FIGS. 3 and 4, pairs of guide leg holes, for example 404a and 308, correspond to a cross-sectional shape of respective pairs of guide legs 400a and 200. Each central screw 112a and 120 is threaded in a corresponding central screw hole 406a and 301, respectively, as the guide legs are inserted in the support holes. In one example, guide legs comprise pins or shafts which have a friction fit in holes in the clamp body. In this example, the guide legs and the central screw are the same length. In each set of three holes, the central screw hole is threaded all the way through and the central screw is either completely threaded or threaded at a lower portion so as to secure the sheet material to the sheet material support and hold it down and to prevent twisting of the hold-down clamp. The holes for the pair of guide legs may or may not be threaded. In another example, the central screw may be longer than the guide legs and is received within a hole that is threaded at a lower portion beneath leg length and at a length of the screw so as to secure the hold-down clamp and sheet material to the sheet material support and to prevent twisting of the hold-down clamp.
(14) Referring to FIG. 3, sheet material supports have bolt assemblies for bolting the sheet material supports 119 and 122 to tools or supports allowing for connection with tools other supports. Support retention bolt holes 300 and 302 of support 122 are seen but not bolts and bolts 304 and 306 of support 119 are seen but not the openings. Referring to FIG. 1, the first sheet material support 119 abuts jaw 124 of the vise 102 and the second sheet material support 122 abuts jaw 126 of the vise 102 so that a clamping force along an x-axis may also be applied. The additional clamping force makes for easier cutting and allows for increased cutting rates.
(15) Referring to FIG. 5, clamping apparatus 500 fastened to vise 102 is seen, the apparatus having an opposed pair of clamping assemblies 502 and 504 with each hold-down clamp of the clamping assemblies having a pair of guide legs and a central screw longer than pairs of guide legs 400a-e and 200 and central screws 112a-e and 120 seen in FIG. 1 in order to hold-down thicker sheet material 510. As seen with regard to hold-down clamp 512a, more of the screw and pair of legs are visible outside the support because the length of the pair of guide legs 506 and central screw 518 is longer than pairs of guide legs 400a-e and 200 and than central screws 112a-e and 120 seen in FIG. 1 to hold down thicker sheet material 510. The length of the pairs of legs and screws are the same for each of the hold-down clamps 512a-e and 514a-e. For each hold-down clamp the length of each pair of guide legs and screw is selectable and may be dependent on the thickness of the sheet material used. The cross-sectional shape of the pairs of guide legs for each hold-down clamp of clamping assemblies 103 and 105 may be the same as the cross-sectional shape of the guide legs 400 and 308 of clamping apparatus 100. The screws of the hold-down clamp clamping apparatus 500 may be of a cross-sectional shape that fits within the screw holes of the hold-down clamp body and sheet material supports 119 and 122 of clamping assemblies 103 and 105, respectively. The legs in clamping apparatus 500 are longer so as to be insertable deep within holes of the sheet material supports 515 and 516 and the screws are longer to so as to be threadable deep within the central screw holes of the material supports 514 and 516 to hold down and secure the thicker sheet material and prevent the hold-down clamp from twisting.
(16) With reference to FIG. 6, an alternate embodiment of a clamping assembly 600 is seen featuring one or more hold-down clamps. Each clamp 602a-d respectively has a body 604a-d with a top lip 606a-d and a downwardly depending rectangular guide beam 608a-d and a central screw 612a disposed within and constrained to limited vertical movement in the respective body 604a-d and a sheet material support 614 having guide beam slots 620b-c, each slot in vertical alignment with a corresponding guide beam 608a-d and corresponding to a rectangular cross-sectional shape of the guide beam. Each respective guide beam 608a-d has a U-shaped cross-section cutout within which a respective screw is disposed. In one example, the sheet material support 614 comprises a pair of plates 616 with spaced apart rectangular blocks 618a-c forming guide beam slots 620a-d between the pair of plates 616 within which respective slot 620 slots the guide beam 608. The guide beam slots constrain the guide beam motion to vertical only motion. A block 622a-d beneath a respective slot 620 has a threaded central screw hole, screw holes 624b-d seen, in vertical alignment with the corresponding central screw 612.
(17) 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 FIG. 1. The clamp assembly 600 may replace the clamp assemblies of FIG. 1. As with the clamping assemblies of FIG. 1, one or more opposed pair of hold-down clamps may be used to hold-down the sheet material. However, additional hold-down clamps in linear arrays along sheet material supports may be used to hold-down the material sheet. For example, hold-down clamps 602a-d in linear arrays along the sheet material support 614 and opposing hold-down clamps in linear arrays in an opposing clamp assembly (not shown) may hold down and secure the sheet material to the sheet material support.
(18) 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.
(19) This clamping assembly may be integrated with a tool such as vise 102 as seen in FIG. 1. Sheet material support 614 has support retention bolt holes 626 and 628 which allow for bolting of the sheet material support with bolts to tools allowing for integration or connection with tools or other supports. The sheet material support 614 may be positioned to abut jaw 124 of the vise 102 and a second sheet material support (not shown) of a second clamping assembly with a guide beam may be positioned to abut jaw 126 of the vise 102 so that a clamping force along an x-axis may also be applied. The additional clamping force makes for easier cutting and allows for increased cutting rates.
(20) With reference to FIGS. 7A and 7B, there is seen another embodiment of a hold-down clamping apparatus 700 capable of supporting one or a plurality of sheet materials 702a-l. The apparatus comprises sheet material support 704 having a pattern of holes 706 disposed in a pattern through the sheet material support 704 and at least one hold-down clamp 712, preferably, at least one pair of opposed hold-down clamps per sheet material to secure and hold down the sheet material 702. A plurality of sheet materials, for example sheet materials 702a-l labeled here, may be positioned on and secured to the support 704 with one or more hold-down clamps. Each hold-down clamp, for example hold-down clamp 712 shown in detail in FIG. 7B, has a respective body 714, with a top lip 722, a pair of downwardly depending guide legs 716 on either side of a central screw 718 which is disposed in and secured to the body. Each pair of guide legs, for example 716, slide into a pair of selected holes for example 720 (FIG. 7A) in the sheet material support 704 and the central screw 718 is threaded in a sheet material screw hole 724 (FIG. 7A) to position top lip 722 of the hold-down clamp 702 into contact with a sheet material 702 disposed on the support 704 and to tighten the lip against the sheet material 702 and the sheet material support 704 with the screw, securing the sheet material 702 in place and holding it down. The holes in the sheet material support constrain the motion of the clamps 712 to only vertical motion. Top lip 722 applies force to the sheet material 702 contacting the sheet material support 704. 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 702 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.
(21) 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).
(22) 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 FIG. 7A, three holes are arranged adjacent to each other. The screw hole 724 is central to the pair of guide leg holes 720. Alternatively, the screw hole could be used as a guide leg hole and vice-versa because all the holes are the same. In one example, all of the holes are threaded at the bottom as seen with guide leg holes 720 and 729 and central screw hole 724, and the central screw 718 is longer than the pair guide legs 716 so that the central screw may be threaded into the bottom portion of the any selected hole to secure the hold-down clamp to the sheet material and to prevent twisting of the clamp. As seen with hold-down clamp 712k, legs 727 are inserted in threaded openings 729 and screw 725 is threaded all the way through a threaded central screw hole, not seen. In other examples, only select holes may be threaded in which case the hold-down clamp would be inserted at particular hole positions where the central screw would be threadable in that hole.
