Patent GB-566598-A (GB)
Title: Improvements in forming corrugated sheet metal annuli
IPC: B21D13/02
Filed: 1943-02-13
Abstract: 566,598. Corrugating. WELLMAN CO., S. K. Feb. 13, 1943, No. 2400. Convention date, Feb. 2, 1942. [Classes 83 (ii) and 83 (iv)] Making clutch discs.-Strip stock is corrugated in such manner as to produce elements of arcuate or annular shape, such as the ventilated friction clutch discs described in Specification 566,572, [Group XXIV]. Strip is fed through a guide 50, Fig. 6, laterally adjustable at 52 on a support 43, Fig. 7, to pass tangentially to a lower corrugating die, in the form of a disc 29 rotatable about a central boss and held in place by a cap disc 31, Fig. 8. An annulus 39 is bolted to the die and has upstanding teeth 40 that serve to widen the die that has slots receiving sets of blades 34 that form oppositelydisposed major corrugations, a, d, Fig. 3, each separated by two minor corrugations b, c. The crests of the corrugations a, d are parallel to the plane of the die, but those of the corrugations b, care oppostely inclined thereto, and the blades are shaped accordingly. The blades are retained in the slots by toes 35 engaged by an undercut bevel on a clamp ring 36. The movable die carrier 26 is attached to or operated by the press-head, and is formed with bosses guided on pins, 24 carried by the lower die plate 20, forming a sub-press mechanism. A plate 56'attached at 59 to a block mounted on the plate 20 carries an adjustable resilient hold-down 54 that maintains the corrugated stock in engagement with the lower die during the indexing, which is employed also to draw the stock through the guide 50 from the reel or source of supply. The corrugations are formed one at a time by a blade 91, Figs. 7 and 8 riveted at 101 to a carrier 100 pivoted at 98 to a block 94 laterally adjustable at 96 on an angle iron 92, secured to the carrier 26, and supporting also a guide 103 for the outer end of the blade 91. A spring 105 maintains the blade in contact with a cam 106, Fig. 15, that is indexed <1>/6 of a turn on each up-stroke of the press-head by a ratchet wheel 112 engaged by a pawl 123 spring-biassed at 124 and pivoted at 121 to a bell-crank carrying a pin 120 that contacts below a block 130 vertically adjustable on supports 129 secured at 128 to the cap disc 31. The return is effected by a spring 125. The cam changes the position of the blade according to the corrugation to be made, and the cam bracket is vertically adjustable at 111. Blades 144, 145 engage the two corrugations previously made to hold the strip in contact with the blades of the lower die and prevent slip. The blade holders 140, 141 are backed up by resilient means, such as spring rubber 143, to permit the blades to adapt themselves to the particular corrugations engaged. At the same time that the cam 106 is indexed, a pawl 79, Figs. 6 and 10, is operated to index the lower die one tooth, being pivoted to a lever 77 mounted at 78 in a bracket 75 secured to the plate 20. A lug 132 vertically adjustable at 134 on a bracket on the die carrier 26 engages a projection 83 on the lever. Linkage 80, 81 operates an index bolt 87 to secure exact location, a spring-controlled brake 68 preventing overrun. The blade 91 is further guided towards the end of the corrugating stroke by lugs 146 carried by the cap disc, by the slots between the indexing teeth, and by lugs 65 carried by the plate 20. In a modification, a series of blades, as illustrated (five), are mounted side-by-side in a holder and each blade is controlled by a cam on a transverse cam-shaft. Two of the blades function as 'hold-downs and the other three effect a set of corrugations, the lower die being indexed three spaces after each stroke of the press-head. In a further modification, the lower die blades are mounted in slots in the periphery of a disc. The corrugated strip is cut into lengths sufficient to form a complete annulus with sufficient overlap for connecting the ends by spot welding, the crests of the major corrugations being spot welded to the discs carrying the friction material.