Patent GB-187673-A (GB)
Title: Improvements in or relating to means for controlling movement, by power, of a heavy mass
IPC: G05D13/00
Filed: 1921-07-15
Abstract: 187,673. British United Shoe Machinery Co., Ltd., and Keall, F. B., (United Shoe Machinery Corporation). July 15, 1921. Gearing for stopping and starting machinery.- In machines used in manufacturing operations wherein the operator is required to control the movement of a massive part by power, the control provided is carried by the part which is moved and is capable of but little movement relative to that part, this relative movement setting the part in motion under power and thereafter the control moves in unison with it to maintain the power movement, the cessation of impulse on the control causing the motion of the part to cease. Two forms of mechanism capable of carrying out these requirements are shown, one using hydraulic power, the other being driven from the pulley of the machine. The invention is illustrated as applied to a machine for cutting leather or, like materials as described in Specification 22023/05 wherein a heavy beam swings horizontally and imparts pressure to a shaped knife on a sheet of material resting on a block or bed. The control handle 1 Fig. 2 is pivoted to the moving beam 4 so as to be capable of both vertical and horizontal motion, which motion is imparted either through a finger 5 or a pin 7 to one end of a bar 6. Concentric with the vertical column 17, Fig. 1 is a toothed ring 13 which rotates on a flange formed on an arm 14 of a lever 15 pivoted to the frame of the machine on a shaft 16, and provided with a stop 19 to limit its upward movement, which is spring-controlled. The bar 6 is connected to the front arm 14 of the lever 15, and the rear arm 24 is connected to the usual clutch mechanism through a vertical rod 25. A bevel-pinion 21, carried by the pivoted lever meshes with the toothed ring and through a universal coupling 26 actuates a bevel-pinion 30 which meshes with a bevelpinion 31 rotatably mounted on a horizontal shaft 32. This shaft is rotatably mounted in bearings in bracket 28 and has fixed on it a bevel-pinion 33 and a spur wheel 78, which meshes with a rack 77 on a piston 69, thus the shaft 32 is stationary until the piston moves, and since both the bevel pinions 31, 33, mesh with a bevel gear 34 mounted in a swinging frame 36, this frame is swung on actuation of the handle 1 and operates a valve through its pivotal connection 37 to the valve-controlling rod 38. The end of this rod is tapered Fig. 6, and raises or lowers a conical valve 59 which closes the outlet 57 in a hollow sleeve 53 attached to the plunger 52 of the control valve, which is stated in the Provisional Specification to be of the type described in Specification 153,938, [Class 17 (i), Boots and shoes, Apparatus for making, &c.]. Oil under pressure is supplied by a pipe 60 to the annular space 58 below the plunger and escapes through the hollow sleeve, the pressure tending to raise the plunger against the action of a spring 50 at its upper end, the parts being so proportioned as to normally maintain the plunger in the neutral position shown in the drawings. The plunger slides in a valve-casing 43 held by a boss 44 formed on a bracket 45, Fig. 4 bolted to the machine, and it is formed with enlargements 160 which control the flow of liquid under pressure, supplied by the inlet pipe 61. When the plunger 52 is raised, fluid enters the central bore of the valve casing Figs. 6, 7, 8 through the inlet port 61 and travelling through passages 70 in the plunger, passes out by a port 64 and enters a cylinder 66, Fig. 4, moving the piston 69; a pipe 71 conveys the fluid from the other cylinder 65, which fluid enters a port 63 and passes to the exhaust pipe 62 through passages 72 in the plunger. A similar but converse action would take place if the plunger were lowered, the direction of flow being then reversed. The plunger is reduced in diameter in two places 79 in order to permit a slight leakage for " cushioning " effects and to prevent a vacuum forming in the exhausted cylinder. The piston 69, through rack gearing 74, 75 rotates the beam, and a second rack 77 on the piston rotates the spur wheel 78, Fig. 1, which causes the bevel pinion 33 to rotate at the same speed as the pinion 31 and hence the swinging frame remains stationary in its displaced position and maintains the valve open until the handle 1 is released and the pinion 30 stops rotating, when the relative motion of the beam swings the frame back to its normal position and closes the valve. Depression of the handle 1 actuates a clutch of the usual construction and causes the beam to descend, the toothed sector 75 being of sufficient depth to allow of this without its becoming unmeshed from the rack 74. In an alternative form the column has rotatably mounted on it two pulleys 80. 81. Figs. 9 and 10. which are driven in opposite directions by a belt 82, passing round a pullev 83 formed on the driving pulley 84 of the machine, guide pulleys 85 being provided mounted on the machine frame. The pulleys 80, 81 are formed with drums 86, 87 around each of which passes a band 88. Each band is connected at one end to the beam 4 and at the other end to the rear arm, 89 of the lever 90 pivoted on a vertical stud 91 on the beam, the connections being such that movement of the arm in one direction tightens one band and slackens the other and the beam will be driven round in the direction in which the handle is displayed, and on ceasing to move the handle, the beam will stop. For this purpose the handle has a slight lateral movement on the clutch-actuating lever 92, relatively to the beam. A mechanism bv which the beam can be automatically swung to one side or the other of the block or bed on completion of the cutting stroke is arranged as in Fig. 11 wherein a lever 95, on which is the handle effecting the movement of the beam as previously described, is pivoted to the beam. A link 102, centrally pivoted to the lever, carries arms 98, 99, pivoted to the beam at their ends 96, 97, these arms carrying cam-rolls 100, 101. The lever is urged to the right or left by a spring 104, the direction depending on the position of the arm 105 which is pivoted to the beam and may rest against either of two pins 108, 109. Thus on releasing the handle, the beam swings over until the appropriate cam-roll engages the cam-face 106 or 107 on the machine frame, and the lever 95 is thereby returned to its central position causing the power movement to cease. Specification 122.639, [Class 31(i), Cutting and severing machines &c.], also is referred to.