Patent GB-756071-A (GB)
Title: Improvements in or relating to the manufacture of bellows and the like devices
Inventor: JENKINS RHONALD FRANK
IPC: B21C37/20
Filed: 1953-12-10
Abstract: 756,071. Corrugating; cutting-off mechanism. SMITH & SONS (ENGLAND), Ltd., S. Dec. 3, 1954 [Dec. 10, 1953], No. 34374/53. Classes 83 (3) and 83 (4). A machine for manufacturing bellows or the like from a tubular blank comprises a chuck 4 which rotates the blank, a movable tool 19 rotatably mounted on an arm 20 for forming the corrugations in the blank while supported between a fixed steady 14 and a movable steady 15, and a counting-device 103 actuated on completion of each corrugation and including a trip 116 operated on completion of a predetermined number of corrugations to displace a parting-off tool 28 for severing the completed bellows from the blank. The chuck 4 is carried by a head 3 movable along the machine bed 1 by a rack-andpinion which is operated either manually by a hand-wheel 7 or is advanced step by step by a pawl- and-ratchet operated by a pneumatic cylinder K. The movable steady 15, Fig. 4, comprises a sector-plate 16 corresponding to the external diameter of the blank and is moved transversely by a pneumatic cylinder H and longitudinally by a push-rod 18 and a rack-and. pinion. Two other push-rods 24, 25 control, respectively, the transverse and longitudinal movement of the arm 20 carrying the internal tool or spinning roller 19 and a fourth push-rod 30 acting through cam-and-linkage 31 controls transverse movement of the parting-off tool 28. The push-rods 18, 24, 25, 30 are controlled by cams housed inside a cam-box 32 and are loaded outwards by spring or pneumatic pressure. Each push-rod is connected, as shown in Fig. 8, to a follower-lever 84 having a fulcrum 88 which is adjustable by a screw 92 to vary the amount of movement of the rod. The cams A, B, C for controlling the movable steady 15 and the tool 19 are mounted upon a shaft 34, Fig. 6, which is geared to a driving-shaft 44 provided with a key 148 enabling the shaft to be rotated manually. A sliding sleeve 47 is splined on the shaft 44 and is provided at one end with a conical surface 48 which can engage a corresponding surface 49 on the wall of the cam-box to brake the shaft, and at the other end is formed with teeth 51 for engaging corresponding teeth 52 on a sleeve 53 rotatable on the shaft 44; the sleeve 47 is slidable by a pneumatic cylinder Q and a fork 55. A motor 60, through worm gearing 57, 58, rotates the sleeve 53, and the sleeve, which is located against axial movement on the shaft 44, is formed, at the end away from the teeth 52, with teeth 61 capable of engaging with teeth 62 on the end of a sleeve 63, also rotatable on the shaft 44. A spring 64 tends to bring the teeth 62 into engagement with the teeth 61 but the teeth are normally held out of engagement by a pin 66 which engages a slot 67 in the sleeve 63. The pin 66 is mounted on a spring-loaded lever 68 and normally lies at the end 149 of the slot 67, but when air is supplied to a cylinder P, a plunger 78 pivots the lever 68 so that the pin 66 is withdrawn from the slot and, as the teeth 61, 62 engage, the sleeve 63 rotates. As the lever 68 is pivoted, a tapered surface 77 moves a spring-loaded plate 74 upwards and unmasks a hole 73 into which the plunger 78 enters and allows the lever 68 to return to its initial position. The pin 66 has dropped into the portion 150 of the slot and allows the sleeve 63 to be rotated until the pin contacts the sloping portion 151 thus withdrawing the teeth 62. Energization of cylinder P therefore results in a single revolution of sleeve 63 and before a further revolution can be made the cylinder must be deenergized and subsequently re-energized. The sleeve 63 carries the cam N operating the parting-off tool and also a cam O which engages an electric switch 82 for operating the holding- circuit of the main driving-motor towards the end of a revolution of sleeve 63. Cams D, E, F on shaft 34 operate, respectively, valves G, J, L immediately after the point in a complete revolution of shaft 34 corresponding to the completion of one corrugation of the bellows. The valve G controls the flow of air to cylinder H controlling the transverse motion of the movable steady 15 and the valve J controls the flow of air to the cylinder K controlling the movement of the chuck-head. Valve L controls the flow of air to a cylinder M whose piston engages an arm 102 pivoted about the axis of the counting-device 103. Arm 102 carries a spring- loaded pawl engaging the teeth of a ratchet, and at each operation of the cylinder M the pawl advances the ratchet-wheel and a shaft 107 by the space of one tooth of the ratchet. Shaft 107 carries a disc 113 provided with holes adjacent its periphery corresponding to the teeth of the ratchet and the disc is surrounded by an annular scale 114 carrying numbers corresponding to the ratchet-teeth. A trip 115 carried on an arm rotatable round the shaft 107 is positioned in one of the holes in the disc 113 and is retained in selected position by a spring-loaded plunger. When member 115 reaches the zero position of scale 114 it engages a tappet 116 and operates a valve S. Valve S then supplies air to a cylinder R which moves an arm 108 so that the driving pawl and a non-return pawl are released from the ratchet and the shaft 107 can return to its datum position. Compressed air is supplied from a source 122 through two pushbutton control-valves 123, 124, and two automatically-operated change-over valves X, Y. In the initial position of the machine, the shaft 34 is stationary since the braking surfaces 48, 49 are in contact, the teeth 51, 52 and 61, 62 are disengaged, all the cams are stationary in the zero position, the trip 115 has been set to indicate the desired number of corrugations on the scale 114, the internal tool 19 is in maximum rearward position, i.e. towards the cam-box 32, with its periphery just clear of the inside wall of the blank, and the movable steady 15 is at minimum distance from the cam-box 32 and is positioned away from the wall of the tube. When the button of valve 123 is pressed the valves X, Y are brought to the position shown in Fig. 15, thus admitting air to one port of cylinder Q, which disengages the surfaces 48, 49 and engages the teeth 51, 52 so causing shaft 34 and cams A, B, C, D, E, F to rotate. Valve G, closed by cam D, causes the cylinder H to position the tool 15 adjacent the wall of the tube; cam A moves the tool 19 forwards away from the box 32 and cam B moves it outwards for a fraction of the eventual depth of a corrugation and simultaneously the movable steady 15 is moved by cam C towards the fixed steady 14 to take account of the decreasing length owing to increasing diameter. The tool 19 then moves back at a constant distance from the tube axis, increasing the diameter of the tube between the steadies. These steps are repeated with the tool 19 moving outward laterally in steps, the final steps being preferably comparatively small for finishing purposes and there being no longitudinal movement of the tool after its last outward lateral movement. When the corrugation has been completed, the tool 19 moves laterally to clear the tube and the cams A, B, C are approaching the end of a complete revolution from zero position as cams D, E, F operate their associated valves G, J, L. Valve G is opened to operate cylinder H and retract the tool 15 through a sufficient distance to clear the formed corrugation and valve J is opened to energize cylinder K to feed the chuck towards the cam-box through a distance equal to the length of tube required for a further corrugation. Immediately afterwards, the valve J closes and valve L is opened to energize cylinder M thus moving the trip 115 one division along the scale 114. When the required number of corrugations have been formed, the trip strikes the tappet 116 and operates valve S, so energizing cylinder R to allow the shaft 107 of the counting device to return to its zero position and moving valve Y to its second position. Operation of valve Y reverses cylinder Q, engages the surfaces 48, 49 and disengages the teeth 51, 52, thus braking the shaft 34 in such a position that tools 14, 19 are disengaged from the tube. Cylinder P is also energized and lifts arm 68, thus disengaging pin 66 from groove 67 and allowing the teeth 61, 62 to engage and cause sleeve 63 to make one revolution. The sleeve 63 feeds the parting-off tool 28 forwards to sever the finished bellows under the control of the cam N and, towards the end of the revolution of the sleeve 63, cam 0 operates switch 82 thus stopping the chuck motor. By pressing the emergency stop button 124, valve X causes the teeth 51, 52 to be disengaged and engages surfaces 48, 49 so that rotation of the shaft 34 ceases. Cutting-off mechanism. The parting-tool 28, Fig. 4, is fed by linkage 31 and a cam on pushrod 30, which is reciprocated by a slide 24, Fig. 8, actuated by a lever 84 engaging a smailcam N, Fig. 6, at its upper end and pivoted at 88 to a block which is vertically adjustable by a screw 92 to vary the stroke of the tool. Cam N is carried by a sleeve 63, Fig. 6, which is driven by a separate motor when a clutch 53 is automatically engaged at the end of a corrugation operation. The work is supported during cutting-off by a fixed steady 14, Figs. 1 and 4, which is a running fit thereon.