Patent GB-931875-A (GB)
Title: Improvements in or relating to methods of and apparatus for inserting inserts through solid bodies
Inventor: PRESTIGE HARRY THOMAS
IPC: B21D39/03
Filed: 1961-03-23
Abstract: 931,875. Perforating. J. & S. ENGINEERS Ltd. March 15, 1962 [March 23, 1961], No. 10752/61. Class 83 (4). [Also in Group XXXII] A method of inserting a rubber or like elastomeric insert 8 into a sheet of material 10, e.g. aluminium, which has no previously prepared opening to receive the insert, comprises locating the insert within the bore 5 in a shrouding member 4 between the sheet 10, a die 1, and a ram 3, which is a sliding fit within the bore 5, the ram 3 having a recess in its lower end corresponding to the adjacent surface of the insert, applying pressure first between the shrouding member 4 and the die 1 to produce a sealing contact between the shrouding member 4 and the sheet 10 and then between the ram 3 and the die 1 to expand the insert within tne bore 5 so that the rubber of the insert acts temporarily as an hydraulic fluid to press out a piece of the sheet 10 into the die 1. The lower part of the insert 8 is then squeezed through the aperture in the sheet 10 and then reverts to its original shape. As shown in Fig. 3, the insert includes a mild steel electrical conductor 7 which projects from the bush 8 so that the lower end of the conductor 7 first pierces the plate 10 before the piece of metal is finally stamped out in the die 1. The bore-hole 5 is greater than the diameter of the die hole 2 which is slightly reduced adjacent its aperture at 9, Fig. 2, to form a lip around the pressed-out opening and key the insert therein. The shrouding member 4 is removably attached, by means of a ring of circumferentially-spaced, and radially-spring loaded, pins 31 within a recess in the bottom of a carrier 28 which is urged downward by a pair of compression springs 11, 12, axial movement of the carrier being limited by a screw 33 which is threadedly engaged in the carrier 28 and has its inner end projecting into a slot 34 in the ram 3. The die 1, comprising two parts 1a, 1b which are biased away from one another by rubber pads, Fig. 4, not shown, are held together in a recess 13 in a die-holder 14 during an operative stroke by means of a cam surface 25 which is controlled by a rotatable lever 26 and acts on the die part 1a through a rod 23, the relative position of the die part 1b being adjustable by means of a screw 20. The lever 26 can be rotated so that the die parts 1a, 1b spring apart and the bush 8 is released. In a modification, Figs. 6-8, not shown, the upper end of the conductor 7 is formed as a terminal, the recess in the ram 3 being correspondingly shaped. The die hole 2 may be of non-circular section, e.g. square, so that the lower part of the hole in the plate 10 is of corresponding shape and rotation of the bush in the hole in the plate is prevented. A number of conductors 7 may be embedded in a single bush 8. In a further modification, Figs. 11, 13, the insert is in the form of a rubber pad 37 which acts as a supporting foot in the bottom 36 of a telephone receiver. The apparatus operates in substantially the same manner as that shown in Fig. 3. More than one apparatus may be used simultaneously for inserting two or more inserts, e.g. the two holders of a standard cartridge fuse.