AUTOMOTIVE DOOR SKIN EDGE FOLDER AND BOLSTER

Abstract: A sheet metal folding tool comprising a guide tongue (2) in space parallel relationship to a folding tongue (1) at lest partially in register therewith. The internal faces of such tongues defining a channel therebetween, such tongues being adapted to be urged by percussion down either side of an intended fold line upon a piece of sheet metal thereby folding a peripheral portion of such sheet metal around the corresponding frame and thereby affixing such sheet metal thereto.

Description: AUTOMOTIVE DOOR SKIN EDGE FOLDER AND BOLSTER " * This invention relates to a device for folding the ' edges of a piece of sheet metal around an object or a fra to which it is desired to affix such sheet metal. The invention has particularly useful application as a tool used in relation to the panel beating trade although it should be understood that the invention is not restricted to use in such, trade. One known method of folding the edges of sheet metal in the form of doorskins over doorshells is by utilization of large pieces of capital equipment involving moveable arms and rollers attached thereto. Such method as last mentioned is not suitable for adaptation to the needs of small metal working firms, panel beaters or other individuals due to the cost of the capital equipment involved. Another known method involving little capital investment is the use of a hammer in conjunction with a solid metal dolly; such tools being used so that narrow peripheral strips of the sheet metal metal being worked which are usually pre-folded to an angle of approximately 90° to the plane of the sheet concerned) are folded around the periphery of a frame or shell , the worked peripheral strip of the sheet metal finally lying at an angle of approximately 180° to the main body of the sheet metal; said worked peripheral strip and main body sandwiching between them the frame or doorshell involved thereby securing the sheet metal to the periphery of said shell or frame. The dolly is placed behind the portion of sheet metal being worked and acts as a solid base taking the force of the hammering thereby avoiding local distortion of the sheet, panel, frame or shell. This last mentioned method is necessarily quite slow, it involves a high* degree of skill on the part of the operator in order to avoid undue damage to the sheet metal being worked. When utilizing the last mentioned known method of attaching door skins to frames, it has been found difficult to sandwich sealant in.between the surface of the frame and the surface of the peripheral strip which eventually comes to rest facing such first mentioned surface. Sealant is often desirable particularly in respect of automotive door skins in order to guard against rust. The violent nature of hammer blows- tends to force out any sealant placed on the surface of the frame immediately prior to hammering the peripheral strip down on to such surface. The present invention overcomes the last mentioned defect in the conventional method. The present invention requires little capital expenditure and provides a tool for working sheet metal as abovementioned whereby a peripheral sheet of a piece of metal may be easily and simply folded around the periphery of a frame without damage to said sheet metal or frame. The present invention additionally facilitates folding peripheral strips of door skins around many automotive door frames without the necessity of removing such frames from the relevant vehicle and in particular it has been found that this is useful in respect of the peripheral strips folded around the front of the rear door frames of many automobiles. According to the present invention there is provided a tool having a percussion head and a working head, the working head including two or more substantially parallel spaced planar tongues defining at least one channel therebetween, in the preferred embodiment of the invention one of the tongues is shorter than the other. The tool according to the present invention is utilized to ' fold sheet metal about a frame by bringing the leading edge of the shorter planar tongue (if the tongues differ in size) into contact with the peripheral area of the panel intended to be folded with respect to the main body' of the panel in such a manner that the leading edge and/or inside face of the remaining tongue comes into contact with the main body of such panel at a locality on the opposite side of the line about which it is intended t fold the panel. The tool is then driven by hammer blows o otherwise on to the panel in such a manner that the inner- faces of both tongues advance on to the panel on either side of the fold line until such time as the fold line at which the panel, is folded around its frame arrives at the base of the channel defined by said tongues at which time, if the spacing of the tongues is correct with respect to the panel and frame involved, the panel will be affixed to the frame and at least a portion of the peripheral strip o the panel will be bent around the frame at an angle of approximately 180° to the plane of the main body of the panel. .The length of the portion of strip so folded in each operation of the tool will of course be determined by the width of the tongues of the tool and in order that the entire periphery of a panel may be so folded the last mentioned action must be repeated along the entire length of the strip desired to be folded about a frame. As will be appartent from the foregoing description, one of the tongues, preferably the shorter, does the folding whilst the opposite tongue in use merely guides an locates the first mentioned tongue. It should be appreciated that the tool is only intended to be utilized in respect of panels which have a peripheral strip pre-folded about the intended fold line to an angle of approximately 90° to the plane of the panel adjacent the intended fold line. Preferably the leading edge of the tongue which carries out the folding operation exhibits a tapered appearance with respect to the main body of such tongue so as to provide sheet metal advancing up the inner face of said tongue with a ramp, thereby facilitating its easy entry into the channel. In the case of rectangular tongues, the inside faces of such tongues along either of the edges not being the leading edges and the edge opposite the leading edge are preferably bevelled in order that the metal being worked will not be stretched at the interface of the portion of the metal being worked in any one application of the tool with the metal not being so worked. Stretching may further be avoided by utilizing the tool in a two-stage manner whereby the initial application of the tool does not accomplish a complete fold from the initial 90° to the final 180° but initially accomplishes a fold of say approximately 120-135°. Once the entire length of peripheral strip being worked is folded to such angle then the final series of applications of the tool along the entirety of the peripheral strip is utilized to accomplish the final folding operation. From the foregoing it will be appreciated that the two tongues of the tool need not be congruent and indeed it is desirable that the leading edge of the guide tongue intended to pass down the sheet metal on the side of the folding line not being folded should ideally precede the leading, edge of the tongue intended to pass down the side of the folding line intended to be folded thus dictating that the latter tongue preferably is shorter than the former tongue. This last mentioned configuration ensures that the leading edge of the larger tongue does no damage to the sheet metal not intended to be bent (usually the decorative and exposed part of the panel) and further ensures a guide function at the moment the folding tongue comes into contact with the peripheral strip to be folded. In the preferred embodiment of the tool, a further refinement relates to the shape of the base of the channel which is of course determined by the manner in which the sides of the rectangular tongues opposite the leading edges meet thereby forming the channel base. It is possible for the tongues last mentioned to meet in such a manner that a sectional view of the base of the channel will conform to that? of the letter π U n or M V n and be substantially symmetrical. It is preferable however that the base when viewed as last mentioned presents the appearance of a "V" rotated about its base in such a ' manner that the side of the V representing the face of the folding tongue becomes vertical. It will be appreciated that as the folded line of the sheet metal approaches the base of the channel of the last mentioned embodiment of the tool the internal fac of the guide tongue will tend to move away from the decorative face of the sheet metal whilst the opposite fac (that of the folding tongue) will remain in positive contact with the folded metal on its side of the fold line, in this manner damage to the decorative face of the panel not being folded is avoided. It should be appreciated that the last mentioned analysis of the cross-section of the base of the channel by analogy with the lette.rs U & V is only intended to relate to the areas of the tongues' internal faces adjacent to the base as the channel as defined by the tongues for the majority of its depth has substantially parallel sides. A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which:' Figure 1 is a perspective view of the tools; Figure 2 is an end elevation of the tool depicted in Figure 1. Referring now to Figure 1, the tool comprises spaced parallel tongues, 1 and 2, and shank 3. The tongue 1 being the folding tongue and the tongue 2 being the guide tongue. The shank of the tool (3) is additionally depicted and in this embodiment is adapted to be struck by hammer blows at point 4 and hand held. Referring now to Figure 2, a bevel 5 is depicted along the visible side of internal face 7 and a tapered ramp (6) is additionally depicted by way of a bevel adjacent the leading edge of face 7. Figure 2 additionally contains an enlargement of the area adjacent the base of the channel 8. .The area immediately adjacent the base being non-symmetrical insofar as the internal face 9 contains a segment 10 non-parallel to a posing planar internal face 7 but converging upon internal face 7 to meet same at the base of the channel 8. It should be appreciated that a tool in accordance with the present invention may be adapted to be fitted as the working head on a percussion tool or hydraulic ram. The preferred embodiment of the present invention above described with reference to drawings may advantageously be drop forged off stainless steel.

Claims: CLAIMS 1. A metal working tool including a- working head a percussion head, the working head comprising at least two spaced parallel tongues at least partially in register defining an unobstructed channel therebetween, the spacing means obstructing no more than one side of such channel. 2. A tool as in claim 1 wherein the spaced parallel planar tongues are substantially rectangular. 3. A tool as in claim 2 wherein the spacing means comprise a fillet between the opposing internal faces alon one set of corresponding opposite sides of two parallel tongues thus rendering the unobstructed channel substantially U-shaped in cross-section. 4. A tool as in claim 3 wherein the fillet comprising th base of the unobstructed channel is parallel to the side o at least one rectangular planar tongue at the opposite end of the head comprising the leading edge of such tongue. 5. A tool in accordance with any of claims 3 or 4 wherei the base of the unobstructed channel comprising the spacin means is formed by the internal face of one tongue converging out of parallel relationship with its opposite face to meet such opposite face without the opposite face similarly converging out of a substantially planar configuration; the resulting cross-section of the area of the unobstructed channel immediately adjacent the base substantially conforming to that of a V rotated about its base so as to display one vertical side. 6. A tool in accordance with any of claims 1-4 in which one tongue is of different dimensions to its opposing tongue in order that the leading edge of the larger tongue may precede that of the smaller tongue. 7. A tool in accordance with claim 5 wherein the tongue whose internal face converges upon the substantially planar inte'rnal face of the opposing is of greater dimension than such opposing tongue in order that its leading edge may precede that of such opposing tongue. - j ϊlή 8. A tool in accordance with any of claims 1-7 wherein the internal faces of opposing parallel tongues are bevelled along at least one side not being the leading edge or the side incorporating the spacing means. 9. A tool in accordance with any of claims 1-8 wherein the internal face of the leading edge of at least one parallel tongue is bevelled so as to provide a ramp for sheet metal entering the unobstructed channel. 10. A tool in accordance with any of claims 1-9 wherein the percussion head comprises the free end of a shaft whose opposite end is attached to the side of the working head incorporating the spacing means so that the longitudinal axis of such shaft remains perpendicular to the leading edge of the parallel planar tongue defining the entrance to the channel and parallel to a direct line joining such leading edge and the side of such tongue incorporating the spacing means. 11. A tool as substantially hereinbefore described with reference to the accompanying drawings.

Inventors: BROWNE DOUGLAS MACARTHUR
Applicants: BROWNE DOUGLAS MACARTHUR
Application year: 1982
Main classification: B21D5
IPC codes: B21D5