Patent GB-465197-A (GB)
Title: Improvements relating to the cold working of materials
IPC: B21D28/00
Filed: 1935-07-27
Abstract: 465,197. Working metals. SHEARMAN, C. H. HOWLAND-. July 27, 1935; No. 21432. Convention date, July 27, 1934. [Class 83 (iv)] Punching.-Apparatus for cold-working particularly by the method described and claimed in Specification 465,196 includes a tool in contact with the work and means for applying intense pressure at a low initial velocity increasing smoothly by small increments. The apparatus may comprise a ram operating through toggle levers commencing in a straight line position and pulled out to transmit pressure at an increasing speed. The pressure decreases correspondingly during the stroke. Before the application of the intense pressure mentioned a preoperative clamping pressure is exerted on the work around for example a hole which is to be "cold flowed" from the work-piece. A reciprocating table mechanism brings this clamping pressure to bear and one embodiment is shown in Fig. 5. The work is placed on a plate 21 having an inserted die plate 30 with hole 23 corresponding to the part of the workpiece to be " flowed " out. A bolster 29 supporting the plate 21 rests on a table 31 guided vertically on rails 35. The lower part of the table is wedge-shaped to engage a corresponding wedge 33 slidable horizontally with the aid of linkage 54,52,51, toggle links 48, 47, and sliding wedge 43. Manual adjustment of the wedge is obtained by bevel gearing 55 and the nut-andscrew mechanism shown. A knock-out rod 330 is employed to remove the die from the supports. The link 54 is as shown in Fig. 6 linked to a plunger 57 on which bear three springs, two of which may be adjusted by gearing 64. A rod 59 is secured to the plunger and by linkage to a beam 61 pivoted at 62 and connected at 79 to a yoke 80. Pivoted to the yoke are segments 83 moving in slits 82 and attached to a nut 85 mounted on a micrometer screw 86 carrying an exterior hand wheel. The slots 82 are provided in a beam 81 swinging on a cross pin 90 and connected to a plunger 92. An eccentric 98 on revolving from the position shown in Fig. 6 a plunger 94 is drawn upwardly and with it the plunger 92, a latch 102 being in a notch therein. Thereby the beam 81 is swung and with it the yoke 80, beam 61, rod 59 to draw the plunger 57 downwardly to compress the spring and operate the link 54 to communicate movement to the wedge 33 for lowering the table. At the upper position of the plunger 94 the latch is withdrawn and the springs expand to straighten the toggle 46 and raise the table. Movement of the segments 83 adjust the amplitude of movement of the table. In Fig. 13 is shown the mounting and operation of the tool 194 on the work-piece 20 in a position at the end of the working stroke, the stroke commencing with the straight line position of toggle links 181, 182, and 167, 169. The alinement of the links is assured by the upward preliminary pressure placed on the work and any lost motion is also taken up. A crank pin 141 moves to rock segment gears 165, 166 and link 167 thereby transmitting motion to the link 169 and in turn to the toggle links 18, 182 and tool beam 185. The work is clamped around the hole to be " cold flowed " before the application of the intense pressure by the tool beam. Specification 465,198 also is referred to.