EDGE FOLDING TOOL

Abstract: A hand held tool for use by a panelbeater when folding over an edge of a metal sheet comprises a tool body (6) with a flat upper face (11) and a die block (13) which is reciprocally mounted for movement parallel to the upper face (11). The die block (13) has a front face (17) perpendicular to the upper face (11) and an under-face (19) parallel to and spaced from the upper face (11) whereby the space so formed is dimensioned to accommodate the folded edge of the metal sheet as produced by the reciprocation of the die block (13) against an edge flange of a metal sheet.

Description: Title: "EDGE FOLDING TOOL" TECHNICAL * FIELD OF * THE " INVENTION This invention relates to hand tools usable for folding over an edge margin of a sheet. Such tools may be used, for example, by a panel beater when applying an exterior metal ski to a vehicle door frame and although the tool is usable in other situations it is described hereinafter primarily with reference to that use. BACKGROUND ART Conventionally vehicle doors have an internal structural frame which provides an outwardly projecting, peripheral, supporting flange for the support of an external metal skin. The supporting flange lies flatly against the inner surface of the skin and an edge margin of the skin is wrapped about the flange to hold the skin in place. If the door skin is damaged and requires to be replaced it is customary for a replacement skin to be obtained from a parts supplier which has an edge margin which is partly folded over to constitute a peripheral flange extending substantially perpendicularly from the main body of the sheet of metal constituting the skin. That replacement skin is then applied to the door frame and its edge flange is then folded down about the frames supporting flange to secure the skin in place. Hitherto the folding over of the skin edge flange has either been accomplished by the use of a hammer and dolly or, more recently, by means of a V-shaped tool which is hammered along the periphery of the skin panel to progressively fold its edge margin about the supporting flange. Both of those prior known expedients cause damage to the external surface finish of the replacement skin necessitating a subsequent re-finishing operation to produce a satisfactory end result. An object of the present invention is to provide a tool which is usable to fold over the edge flange of a door skin and which minimises external damage to the skin surface while so doing. DISCLOSURE OF THE * INVENTION The invention consists in a tool for folding over an edge flange on a sheet comprising a tool body with a platform surface adapted to support the sheet and a reciprocable die block mounted on said body for reciprocation along an axis parallel to the platform surface; said die block having a front surface adapted to contact the sheet edge flange for partial folding thereof during the first part of a forward stroke of the block and an under surface substantially parallel to the surface of the platform and spaced therefrom adapted to OMPI VIPO contact the sheet edge flange for furtherance of the folding during the final part of the forward stroke of the block. For preference, the movement of the die block is induced by means of a pneumatic jack hammer and to that end a stem adapted to engage in the bore of such a hammer is furnished on the tool. That stem preferably extends from the body although in some embodiments of the invention it may extend directly from the die block. For preference the transition from the front surface of the die block to its under surface is smoothly curved. By way of example two embodiments of the invention are described hereinafter with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a tool according to the invention. Fig. 2 is a side elevation of the tool of Fig. 1. Fig. 3 is a rear elevation of the tool of Fig. 1. Fig. 4 is a front elevation of the tool of Fig. 1. Fig. 5 is a view similar to Fig. 2 of another tool according to the invention. DESCRIPTION * OF " PREFERRED EMBODIMENTS The tool illustrated by Figs. 1 to 4 comprises a body 6 having a central portion 7, a forwardly projecting 8 portion and a rearwardly directing, tubular, plunger guide 9. A handle 10 (shown only in part) is secured to the central portion 7 of the body to provide a grip extending downwardly therefrom. The forwardly projecting platform 8 has a substantially planar upper surface 11 which is substantially perpendicular to the axis of the handle 10. The rearwardly directed tubular guide 9 has its axis substantially perpendicular to that of the handle 10 and thus substantially parallel to the upper surface 11 of the platform 8. A plunger 12 is slidable to and fro within the bore of the tubular guide 9 and at its front end carries a die block 13 for reciprocating motion to and fro above the upper surface 11 of the platform 8. The plunger 12 projects rearwardly beyond the end of the guide 9 and a helical compression spring 14 is sleeved upon the projecting part of the plunger 12 between an abutment washer 15 or the like on the plunger and the rear face of the guide 9. The spring 14 is normally compressed and biases the plunger 12 rearwardly to a position wherein the die block 13 is retracted rearwardly of the platform surface 11. A stem 16 projects rearwardly from the body 6. The free, rear-end of the strem 16 is adapted for insertion as a tool bit into the bore of a conventional pneumatic jack hammer. In use the hammer delivers a succession of hammer blows OMPI to the stem and each impact shock is transmitted to the block 13 causing it and the plunger 12 to move through a forward stroke against the effect of the loading spring 14 and then allowing the plunger and die block to return through a rearward stroke under the influence of that spring. The front face 17 of the die block may be a substantially planar face whereas the underface 19 may be stepped to provide a rear land 18 adapted to slide upon the platform surface (to prevent unwanted rotation of the block about the plunger axis) and a front part which is parallel to the platform surface but is spaced above it. There is a smoothly curved intermediate transition surface 20 extending smoothly from the front face 17 to the underface 19 of the underface. It will be seen that the land 18 is narrower than the block as a whole so that the side portions of the block extend as "wings" therefrom. In use when folding a vehicle door skin edge flange about a frame supporting flange the door is presented to the tool with the skin margin lying on the table surface 11 and the edge flange lying against the die block front surface 17. The jackhamer is then energized and the tool moved forwardly to fold the skin edge flange over the supporting flange as the latter enters the space between the front part of the underface 19 of the die block and the table surface 11. That operation is repeated until the entire periphery of the door skin has been worked on. Thereafter the tool may be turned so as to face along a peripheral edge of the door with the folded over flanged sandwiched between the table surface 11 and one or other side wing of the die block to one side if the land 18. The tool may then be traversed along the periphery of the door to finish the folding operation. Because the thickness of the metal in vehicle doors may vary from one make of vehicle to another, in preferred embodiments of the invention (such as the one now being described) the upper face of the die block has a land 18A which stands proud of the surrounding die block surface by a different amount than does the land 18. Thus upon removal of anchor pin 21, the block 13 and plunger 12 may be removed, turned over and replaced so that the land 18A then slides against the table surface 11. Furthermore, the under faces of the die block wings adjacent to the respective lands 18 and 18A are disposed at differing distances from the surface 11 to provide four different clearances between the block and the table surface any one of which may be selected for the finishing operation depending upon the thicknesses of the metals being folded. For preference, a sharp pointed screw 22 is provided which may be screwed upwardly to penetrate the damaged skin of a door to be repaired, following which the tool may be progressed around the periphery of that door to cut away the damaged skin to enable its ready removal. The Fig. 5 embodiment of the invention is the same in all respects as the Fig. 1 to 4 embodiment except that the rear end of the die block plunger is itself adapted for co-operation with a jackhammer so that the die block is moved directly by the jack hammer and not by percussive shock transmitted to it from the body. Components of the Fig. 5 embodiments corresponding to those of the first described embodiment are correspondingly numbered and it is thought that further description of them is not required. ^ _OM

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. A tool for folding over an edge flange on a sheet comprising a tool body with a platform surface adapted to support the sheet and a reciprocable die block mounted on said body for reciprocation along an axis parallel to the platform surface; said die block having a front surface adapted to contact the sheet edge flange for partial folding thereof during the first part of a forward stroke of the block and an undersurface substantially parallel to the surface of the platform and spaced therefrom adapted to contact the sheet edge flange for furtherance of the folding during the final part of the forward stoke of the block. 2. A tool according to claim 1 wheren said die block includes laterally extending wing portions. 3. A tool according to claim 2 wherein a sharp pointed cutting screw projects upwardly through said platform surface towards the underside of one of said wing portions. 4. A tool according to any one of the preceding claims wherein said body has a rearwardly projecting stem adapted to be engaged by a jackhammer. 5. A tool according to claim 4 wherein said die block is on a spring-loaded plunger. 6. A tool according to any one of the preceding claims wherein said die block is invertable thereby providing for more than one working clearance between the block and the platform surface. 7. A tool for folding over an edge flange on a sheet substantially as described herein with reference to Figs. 1 to 4 or Fig. 5 of the accompanying drawings. OMPI Yλ

Inventors: GALE AMI AMNON, GALE, AMI, AMNON
Applicants: GALE AMI AMNON, GALE, AMI, AMNON
Application year: 1982
Main classification: B21D5
IPC codes: B21D5, B21D19