Patent GB-368259-A (GB)
Title: Improvements in or relating to mechanical presses
IPC: B41F1/26
Filed: 1930-11-22
Abstract: 368,259. Mechanical presses. SCHETTLER, G. A., 46, Westover Road, Bramley, near Leeds. Nov. 22, 1930, No. 35219. [Class 87 (ii).] In a mechanically-operated press which may be designed for the purposes of embossing, ironing, smooth-plating, or pressing leather, skin, or other pliable or fibrous material, or for making lincrusta or for use in metal work, comprises in combination relatively movable platens 8, 9, Figs. 1 and 2, a very slightly flexible frame structure on which one or each of the platens is mounted, platen-operating mechanism constituted by peripherally opposed coacting rotary members one or each of which is a cam or ceccentric, and driving gear for the rotary members which is thrown out automatically with the platens in the open position and, if desired, in the closed position also. The press frame comprises a set of horizontal T-beams 1 carried on feet 2 and having supported above them a similar set of beams 4. Fixed to the upper beams 4 and insulated therefrom by an asbestos sheet 11 is the heated stationary platen. Beneath the movable platen 9 is secured a casing 15, Fig. 2, which slides within guides 23 fixed to a similar casing 14 mounted on the beams 1. Half-bearings 16, 17 are formed integrally with the casings 14, 15 to carry shafts 18, 19 on which are mounted coacting eccentrics 20, 21. The shaft 19 is driven from the shaft 18 by eccentric toothed gears 25, 26. Instead of the eccentrics 20, 21 having direct engagement with one another, floating blocks may be interposed between them. The lower part of the casing 14 forms an oil reservoir. Either or both platens may be operated as described. Further, suitably shaped cams can be employed instead of eccentrics, e.g. one cam having two high points and rotating at half the speed of the contacting cam. Also, the yieldability of the girder construction may be obtained by springs, weighted levers, or hydraulic buffers. In order to deal with work of varying thicknesses the platen 9 is adjustably mounted, having inclines 29, Fig. 1, beneath its surface resting in wedges 31 which are operated from a hand-wheel 36 through a worm gear 34, 35 and a right- and left-handed screwed spindle 33. A bolster of felt, rubber, or similar resilient material is provided on the platen 9 to allow for small inequalities in the thickness of the material. In a form of machine particularly adapted for use by a single operator, the movable platen 9a, Fig. 6, and the shaft 19a carrying the upper eccentrics 21 are mounted on a frame 15a having arms 38 pivoted to the fixed framing at 39 so that in the inoperative position gravity will cause the material placed on the platen from the right, Fig. 6, to lie flat thus obviating the necessity of a second operator on the opposite side of the press. The platen 9a is pivoted to the frame 15a at 43 and is supported by springs 44, screws 46 being provided to limit the compression of the springs when pressure is applied. Apparatus for indicating the applied load by utilizing the deflection of the beams 1, 4, Fig. 1, comprises horizontal T-bars 88, 89 connected by vertical bars 90 and supported on the beams 4 by springs 91. The lower bar 89 bears against a stop 92 on the beams and the upper bar 88 carries a lever system 98 bearing against adjustable screws 94 on the beams 4, one of the levers 105 being extended to form a pointer moving over a graduated scale 104. The shaft 18 is driven from a clutch shaft 47, Fig. 1, through gearing 48 .. 51 and a flexible coupling 52. A half-cycle or whole-cycle stop motion is provided and consists of a disc 54 on the shaft 18 with suitably disposed notches into which a follower roller on a lever 56 drops thus allowing a link 63 to drop. A catch 65 on the link 63 engages a catch 61 on a spring- controlled clutch lever 58 during driving so as to hold the lever 58 in driving position against the action of its spring 60. When the link 63 drops, the catch 61 is released and the lever 58 is moved to throw out the clutch 53, at the same time making operative a brake mechanism 58b, 53a. In order to stop the press at any point of its cycle, the catch 61 is slidably mounted in the lever 58 and can be moved out of engagement with the catch 65 by a treadle 67, levers 69 and links 68, 72, so that the lever 58 is free to throw out the clutch under the action of the spring 60. The link 63 carrying the catch 65 is extended upwardly and has pivoted thereto a starting handle 59 which is connected by a link 83 to a counterbalancing lever 82. Where two operators are necessary, one at each side of the press, a safety handle 73 is provided at the opposite side of the handle 59 and has to be held continuously in operative position by both hands of the assistant operator before the main operator can start the press by means of the handle 59. The handle 73, which is counterbalanced by a lever 86 similarly to the handle 59, is connected to the shaft 70a of the lever 69 by links 74, 85 so that normally the catch 61 is caused to be retracted to inoperative position. Operation of the lever 73 causes the catch 61 to be pulled outwardly so that movement of the handle 59 will cause the press to start. When a safety lever 73 is provided, the treadle link 72 is connected to the lever 71 by a lost-motion connection consisting of an adjustable nut 76 on the link 72 and a collar 75 on the lever 71 which is slidable on the link 72, so that the machine can be stopped at any time by the main operator depressing the treadle so as to overcome the pull of the other operator on the lever 73. Specification 160,016, [Class 80 (iii), Linkwork &c.], is referred to.