Patent GB-1014007-A (GB)
Title: Machine for forming deformations in a hollow blank
Inventor: LEER OSCAR JACQUES VAN
IPC: B21D22/12
Filed: 1963-07-24
Abstract: 1,014,007. Corrugating; flanging. METAL CONTAINERS Ltd. July 24, 1963, No. 29307/63. Heading B3Q.  Apparatus for forming de-  formations, for example, corrugations in a cylindrical, conical or other blank of sheet material without a reduction in wall thickness, comprises a plurality of angular die members and a resiliently deformable bag disposed within the dies, the bag and dies defining an annular work space for the blank and the bag being inflated by fluid pressure to expand the blank against the dies, and means to contract the bag axially during said expansion. The apparatus comprises an extendable supporting post 34 about which is located a flange ended rubber bag 33 connected to the top and bottom ends thereof by a corrugated ring 81 retained by a screwed collar 82 and a corrugated collar 78 respectively, and a plurality of annular semicircular die-sets 51-61 mounted on carrier members 51c-61c, 51d-61d hinged about a post 270 and axially movable towards one another. Within the post 34 is located a piston 90 having upper and lower extending portions 91, 92 slidable in a guide 100 and sleeve 93 respectively. To the upper end of the portion 92 is screwably attached the extendable portion of the post comprising a piston 84 slidable in the guide 100, a member 80, an adjustable nut 120 located in an anti-friction lining 122 and the upper bag holding members 81, 82. Fluid pressure is admitted from a conduit 105 to the underside of the piston 90 to effect the raising of the post until the piston abuts the guide 100 whilst fluid pressure admitted from a conduit 110 to a space 111 and thence through a central bore 115 to the top side of the piston through openings 112, 113 effects the lowering thereof until the piston 84 bottoms at 104 on the guide 100. A head assembly 40 comprises an annular frame 141 having a plurality of lugs 142, in which are slidable locking bolts 143 spring- biased in the open condition and a conical skirt 155 having a flange 156. The assembly is located and clamped over the collar 82, after insertion of a blank 36, the bolts 143 being moved radially inwards by a pair of segmented pivoted clamping members 150, welded to the die supporting plates 51e, 51f and lockable with the die support members in the closed condition into the head recess 148. The skirt 155 supports the upper end of the bag during expansion thereof and the flange 156 abuts the top stepped face of the die element 51a against which the flanged end of the blank is formed. The blank is supported on radially depressable spring- loaded pins 210 on a platform 200, which also acts as a support for the bottom die unit 61 during the forming operation, suspended from the head, expansion of the bag serving to depress the pins. and disengage the blank therefrom. Upon deflation the pins re-engage the formed blank which is lifted clear of the dies by raising the head. The die units are initially held in their axial position by two pairs of stepped spacing plates 221, one such pair being hooked to the supporting member 51e, Fig. 6, each die unit 51-61 gravity resting on a step thereof. To facilitate replacement of the plates 221 six auxiliary posts, supported on rollers, and each comprising a support lug 252a engageable with a leadscrew are coupled together by a chain- and-sprocket arrangement, rotation of the screw causing the lug to engage the lower die member and successively lift all the dies off the steps of the plate. To facilitate replacement of the bag without stretching it is mounted on upper and lower supporting sleeves 325 having fluid pressure access holes 326. In operation the dies 51-61 are closed, the head 40 lowered, with a blank 36 resting on the carrier pins 210 thereof, into engagement with the upper end of the post 34, the clamps 150 closed, fluid pressure applied via post 85 to inflate the bag and cause the blank to frictionally engage the die units at which point the top of the post is lowered to cause the flange 156 to axially depress the die supporting members 51e and 51f which lower the spacing plates 221 into an inactive position and free the die units 51- 61. Lowering of the post and increasing the pressure in the bag simultaneously forms the end flanges on the blank which is also axially compressed to form the corrugations, Fig. 7a, and simultaneously cause all the die units to axially close together. Pressure is subsequently released and the formed blank lifted from the unit by the pins 210 re-engaging the underside thereof.