Machine for bending edges of sheet metal plates
United States Patent 2434028

This invention relates to the forming of sheet metal plates, particularly for use as fire coverings for wooden surfaces, and the principal object of the invention is to provide a method of bending the margins of the sheets quickly to the required form and a machine for carrying out the method....

Roy, Wieland
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Roy, Wieland
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US Patent References:
1708394Sheet-metal structure1929-04-09
1676222Process of making sheet-metal frames1928-07-03


This invention relates to the forming of sheet metal plates, particularly for use as fire coverings for wooden surfaces, and the principal object of the invention is to provide a method of bending the margins of the sheets quickly to the required form and a machine for carrying out the method.

Other objects and advantages of the invention will appear in the following description and accompanying drawings.

In the drawings, Fig. 1 is a perspective view of a foot and hand operated machine for carrying out the special margin bending or folding operations required.

Fig. 2 is a longitudinal vertical section of the machine of Fig. 1 as taken through the line 2-2 of Fig. 1.

Fig. 3 is a plan section of the machine taken along the line 3-3 of Fig. 2.

Fig. 4 is a vertical section of the upper part of the machine taken along the line 4-4 of Fig. 2.

Fig. 5 is an enlarged view of the die portions of the machine as of Fig. 4 shown clamped together upon the plate and with the plate side margins in the finally bent form required.

Fig. 6 is a view similar to that of Fig. 5 taken along the line 6-6 of Fig. 3 showing a longitudinal section through the die members and plate.

Fig. 7 is a perspective view showing the completed plate as taken from the machine.

Fig. 8 is an end view of the plate of Fig. 7.

Fig. 9 is a plan view of the plate blank showing its notched out corners.

Before describing the machine, attention is called to Fig. 7 which shows in perspective a flat sheet metal plate A with its margins variously bent up and down as required to interlock with similarly formed plates used in the sheet metal covering of wood, particularly fire doors, though it may be used for covering any desired flat surface.

The flat blank sheet metal plate before forming is as shown in Fig. 9, notched out at its four corners as at 1, 2, 3, 4 to the depth of the folded margin required, and the steps in forming the plate are as follows: First, the right-hand margin of the plate is folded downwards and under along the line 5 to bring the edge 6 flat under the plate to the line 7.

This is done on any folding machine.

Second, the sheet metal plate with its wide under-folded right-hand margin is placed upon the lower horizontal die plate 8 of the machine with its margins overlapping the plate, the upper die plates 9 and 10 are brought down upon the sheet metal plate, by pushing down the treadle II of the machine with one foot of the operator to bend the rear margin down as at 36 in Fig. 7 and clamp the plate, and while down lifting the 6 handle 12 to thereby swing up the several folding blades 13, 14 and 15 to fold the other three margins upwardly and finish the plate to the condition of Fig. 7.

With the above brief outline of the nature of the work to be done and the mechanical steps taken with the aid of the machine to accomplish it, the detailed construction and operation of the machine will be easily understood and is as follows: The machine comprises a general frame preferably made of pieces of angle iron suitably secured together forming four legs 16 joined by longitudinal side members or rails 17, transversely extending rear members 18 and front end transverse members 19. The legs are preferably provided with floor flanges 20.

Extending across the front of the machine adjacent the floor is a treadle strip II secured at the forward ends of two arms 21 pivoted at their rear ends at 22 to a transversely extending bar 23 supported across and suitably secured to lower side rails 17. The treadle is normally raised by a coiled tension spring 24.

The upper ends of the rear legs 16 project above upper transverse members 18, while extending longitudinally between the upper ends of the legs are long angle bars 25 which are spaced to come within the legs and are pivoted to them on a transversely extending rod 26 so as to form a tiltable frame. Secured to the forward end of these bars 25 are the upper die plates 9 and 10, and secured to the rearwardly extending ends of the bars is a counterweight 27 to overbalance the die plates and normally keep them lifted as shown in Fig. 1.

The lower die plate 8 is secured to the top of upper rails 17 in position to cooperate with the upper die plates when the forward end of thd tiltable frame 25 is pulled down, and to accomplish which a pair of upwardly extending links 28 are pivoted at their lower ends at 29 to the treadle arms 21 and at their upper ends at 30 to a bar 31 straddling across the tiltable frame members 25, so that upon pushing down on the treadle II the upper die members will be forcibly pulled down upon the lower die members.

To align the upper and lower die members laterally I provide a pair of vertical guides or angle bars with flat front faces 32 and longitudinally extending confronting walls 33 which form guiding walls against opposite ends of a bar 34 welded across and projecting beyond the tiltable upper die frame members 25. These vertical guides are rigidly secured in place as by welding to transverse members 19' of the frame.

Die plates 8 and 10 are substantially the same width as shown in Fig. 5 but die plate 9 which is secured to upper plate 10 is relatively thin and wider and overhangs both sides of plate '10 as at 9', and also is longer to overhang the forward end of plate 10 as shown at 9", but upper plate 10 extends rearwardly beyond plate 9 and carries a cross bar portion 10' which projects downward beyond the upper surface of lower die plate 5.so as to form a rear downwardly bent margin 36 on the sheet metal plate A when the -dies are closed, and as shown in Fig. 6 and where the cross bar portion 10' of the upper die is shown with its rear edge in contact with a fixed cross bar 37 which extends across and is rigidly secured to -upper rails 17 of the frame, and which construction insures member 10' coming down in the correct position, and member 37 also forms a stop or rear guide for positioning the rear edge of the sheet metal plate A when placing it in the machine. Preferably the-standing edge portion of angle bar 37 is provided with two inverted Ushaped spaced strips of smooth metal 37'to function as stops in placing the sheet metal plate A and cross -bar 10' is notched at its rear side to pass these stops.

To form the two side folds 13', 14', and the front end fold 15' of the sheet metal plate, three pivoted folding blades 13, 14, 15 are provided which are operated by lifting the handle -12. Blades 13 and 14 are respectively hingedly pivoted to their adjacent frame members 17 as at 38 and 39 to swing as indicated in Fig. 4, and -similarly blade 15 is hingedlypivoted as at 40 to the upper transversely extending angle bar 19 of the frame.

These folding blades are all operated in the proper- sequence :as well as to the proper degree of .swinging, by the operator pushing the handle 12 upward. Handle 12 is preferably a pipe roller free on a stay rod 12' which is secured at its ends to rearwardly extending side levers 42. and 42' which are pivoted at their.rear ends at 43 to a transversely extending angle bar 44 'welded to upper rails .17, and each. pivoted folding blade is .provided with a projecting arm engageable with the. handle. asseribly for operation thereby, thus blade 13.has secured .to it an arm 45 which curves outward land downwardly. (when the blades are open) over the left side lever 42 and under a rod -46 spaced along the edge of lever 42 and welded at opposite ends thereto to form an open slot 47 in which the curved arm 45.slides as the .handle is -raised or lowered.

Blade 14 similarly is provided with a laterally extending operating arm 48 which, when the blade-is open,:lies upon-a:plate 49 secured to right side-lever 42' as shown in. Fig. 3 -and is in turn overlapped by .an .arm ,50 secured at :one end as :atI 51 :to plate 499, -and which :members change their relation as the handle is lifted as shown from that of Fig. 4 to that of -Fig. 5.

Blade -:5 is provided with -a lateral extension 35 *which :has a backwardly bent heel 52 forming .a stop'against the front surface of left-hand guide 32 to hold the blade in open position, and projecting from-which-is a long arm 53 which curves forwardly-and upwardly over handle bar 12 adja'cent 'he left side of the machine so as to be contacted by-the bar as the handle is raised to thereby swing the blade 15 upward to form the marginal bend 15' of the sheet metal plate.

The two side bars 42, 42' of the handle are guided in swinging along the outer edges of ver, tical guides 32 and are limited in their travel by lower and upper stop lugs 54, 55 projecting laterally therefrom.

The curves and shapes of the various folding blade operating arms are such as to insure the margins of the plate A folding to the positions shown in Fig. 7, margin 15' being first folded inward at a low angle but free from the body of plate A, margin 13' folded at a steeper angle for the major portion of its length and swerving out5 ward near its forward end as indicated at 56 in the drawing-this is to provide for hooking the downwardly bent margin 36 of another plate hooking under margin 15' and after which the portion 56 is manually bent over it to the same slant as the remainder of the margin 13' to then have the margin 6' of another plate hooked over 13' in the process of laying the -plates. Margin 6' is for this purpose left slightly open as indicated in Fig. 7. The particular manner and approximate degree of these bends comprises an important feature of the invention as it greatly reduces the time of hooking a large number of similar plates together in staggered overlapping relation in forming the fire-proof covering for wooden doors and other structures.

I should mention that when placing the blank sheets one at a time upon the lower die plate its rear edge is abutted against stops 37', 37' and its right-hand edge against a side-stop 57 shown in Fig. 3.

Also, that in order to have the bent under edge 6' of the right hand margin 5 slightly .opened from the under side.-of plate A, I permit the originally flat underfolded margin to .open slightly upon the doubled margin being'bent upward along the lines 59 .to form the standing margin 14', and to this end the originally folded under edge 6' is not supported tightly below die plate 9 during the bending operation but is permitted to back off or "unwind" as it were a short distance -until it contacts a fixed stop bar shown at 58 in Fig. 5.

Regarding the bent over margin 13', in order to form the bend at 56, it suffices to terminate the folding blade 13.at the point-where this outward bend begins by rounding off the end.

Removal of the finished plate is made by allowing the machine to return to normal open position, as shown in Figure 1-and the operator pulling the finished plate forward and off of upper die plate 9.

Having thus described my invention and manner of its operation and novel product and purpose thereof, what I claim is: A machine for bending the margins of a sheet metal plate comprising a machine frame supporting a horizontal lower flat rectangular die plate, a tiltable frame pivotally supported on the machine frame with one end overhanging the die plate, an upper rectangular die plate carried by said end of the tiltable frame in position to come down upon the lower die plate, means normally raising the upper die plate with its frame, foot operated means for forcing the upper die-plate downwardly to clamp -a rectangular sheet-metal plate between the die plates, clearance being provided around the die plates to permit the sheet metal to project beyond all four edges of the lower die plate, means carried by the upper die plate arranged to force one overhanging margin of the metal sheet downward over one-edge of the lower die plate, folding blades movably mounted respectively along the other three edges of the lower die plate arranged to fold the other three overhanging margins of the sheet metal upwardly, and manually operated means arranged to oper- 6 ate said blades to various degrees respectively to variously fold the remaining three margins of the sheet metal upwardly, said upper die plate provided with a relatively thin plate extension overhanging said other three edges of the lower die plate, and over the edges of which extension the margins of the sheet metal are folded when the folding blades are operated.


Number 79,438 85,531 145,660 152,523 195,035 329,149 329,613 410,066 655,903 1,092,486 1,676,222 1,708,394 Name Date Best ---------- June 30, 1868 McLea ------------- Jan. 5, 1869 Kuessner ------__ Dec. 16, 1873 Secor ------------- June 30, 1874 Morgan ------- - Sept. 11, 1877 Eager et al. ---- - Oct. 27, 1885 Andrews --------Nov. 3, 1885 Bohn --------__ Aug. 27, 1889 Martin ------------Aug. 14, 1900 Hoffman ----------- Apr. 7, 1914 Sheldon ------- - July 3, 1928 Mugler ---------_ Apr. 9, 1929