862,154. Mechanical presses. GOLDING, W. F. Feb. 6, 1958 [Feb. 15, 1957], No. 5272/57. Class 87(2). [Also in Group XXII] The reciprocating platen 3 of a press is actuated by toggles 4 in each of which the lower link 6 is pivoted to a member 8 connected to the base 1 by screw means for varying the distance between the member 8 and the base 1 and thereby the daylight between the platens 2, 3. The screw means comprise a screw threaded member (or members) 9 secured to the member 8 and a cylindrical nut 10 housed in a bore 12 and having on its periphery worm-wheel teeth 25 engaged by a worm 26. In the arrangement shown, in which the platen 3 is supported at each corner by a toggle, simultaneous adjustment is achieved by the worms on one side being on a common shaft 27 and those on the other side on a common shaft 28 which is chain-driven from the shaft 27 when this is turned by a hand wheel 30. The turning of the nuts 10 is facilitated by each resting on a ball or roller thrust bearing 24 when the press is not applying the working pressure. The bearing 24 is interposed between the lower face 13 of the nut 10 and the head of a sleeve member 16 abutted by a spring 21 which rests on an adjustable support 22. The springs 21 are adjusted so that their combined strength can lift the platen 3 when the press is idle, but when the press is operated the working pressure between the platens compresses the springs 21 and the face 13 seats on the bottom face 14 of the bore 12, which takes the thrust. Alternatively a ball or roller bearing between the faces 13, 14 may take the load at all times.
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