Patent GB-1016922-A (GB)
Title: Apparatus for forming annular workpieces
IPC: B21D53/30
Filed: 1963-01-16
Abstract: 1,016,922. Making wheels; bending; curling; corrugating. WALLACE EXPANDING MACHINES Inc. Jan. 16, 1963 [Jan. 19, 1962], No. 2002/63. Headings B3A, B3E and B3Q. In apparatus for forming an annular double flaring workpiece such as a wheel rim comprising a pair of coaxial generally conical dies adapted to move together to seat within and engage the inner surfaces of the opposite ends of an annular workpiece and a plurality of outer dies arranged in a pattern coaxial with the conical dies and adapted to move radially inwardly to engage the outer surface of the workpiece and co-operate with the conical dies to form the workpiece. The generally conical dies 200 are provided with stuffing ledges 206 which co-operate with inwardly facing recesses 208 in the outer dies 201 to effect curling of the edge of the blank. A press 30 comprises upper and lower dies 35, 42 movable towards one another and divided into coaxial alignment by an interengaging recess 50 and spigot 47 and a plurality of downwardly projecting posts 36, e.g. six, fixed to the platen 32 which during the lowering of the upper die pass through a plate 40 to depress an annular cam 61 which co-operates with die-carrying elements 57, to effect radial movement of forming dies 55 and disengaging and supporting means 139. The dies 55 which comprise joined portions 91, 92 have forming surfaces 56 which define an annular shape complementary to the surfaces 51, 52 of the upper and lower dies and have radially extending slots 110 on their top and bottom faces which engage with keys 106 on upper and lower hexagonal rings 65 to guide the dies radially. The rings also maintain the dies in their correct vertical relationship. The upward vertical movement of the die assembly is limited by stops 108, 109 and each die is vertically slidably coupled to the elements 57 by a pair of " T "-shaped elements 131 which engage complementary slots on its back face 137. The elements 57 are slidably connected to the ring 61 by a plurality of inclined " T " elements 116 which engage corresponding slots 120 therein and by inclined bearing insets 112 fixed thereto which cam against surface 115 of the elements. The elements are mounted on bearings on the base and guided radially along keys 130. A pair of disengaging and supporting means 139 comprise reciprocal members 145, mounted between guides on the plate 40, doublelipped members 140 attached to the inner ends thereof, the outer ends having a tongue 147, a spring-loaded mounting block 56, a pivoted arm 166 and a cam member 165 fixed to the platen 32. Operation.-With a pair of hydraulic jacks 71 backed by a constant air pressure holding the outer die assembly in an upward position against the stops 108, 109 a roughly formed double tapered blank 70 of, e.g., sheet or strip material, formed, welded and partially flared is inserted between the lips 141, 142 of the means 139, the members 145 being locked inwardly to support the blank by cam member 165. The upper die 35 is lowered to engage the blank and the posts 36 engage the cam 61 to effect closure of the outer dies 55; this occurs when the inclined cam surfaces 57A, 61A of the cam and elements are disengaged and the vertical surfaces 57B, 61B are engaged. Continued lowering of the die forces the blank into engagement with lower die and the two dies to become interengaged during which time the outer die assembly will ride downwardly against the means 71. Also during the downward stroke the flared portion 70A of the blank cams against the tapered lip 141 to effect retraction of the arms 145. Opening of the dies causes a projection 181 on the cam 165 to release the arm 145 and the lips 142 to engage the blank whereby further upward movement withdraws the die from the blank. The cam 61 is returned to its upward position to open the outer dies by hydraulic jacks 62.