Patent GB-688587-A (GB)
Title: Improvements in or relating to forging machines
IPC: F16K11/078
Filed: 1951-02-06
Abstract: 688,587. Forging-machines. SAXER, A. Feb. 6, 1951 [Feb. 9, 1950], No. 2910/51. Classes 83 (iii) and 83 (iv). [Also in Group XXIX] In a machine for forging axially symmetrical workpieces by radially disposed hammers driven by eccentrics adjustable through eccentric bearing bushes for forging different sizes of work, hydraulic pistons for adjusting the hammers and for feeding the work are controlled through valves by rollers which move in dependence on each other at the ends of the piston movements. A machine for forging shoulders or collars on shafts has three radiallymoving eccentrics 10, Figs. 2 and 3, actuated by eccentric shafts 3 mounted in the forging table 1 and driven by an electric motor 4 through gears 6, 7, the gears 7 carrying pins 16 engaging slots in flywheels 8 on the shafts 3. The eccentrics 10 carry detachable hammers 11 and slide radially in a disc 12, which is free to oscillate about the work axis. The shafts 3 are mounted in eccentric bushings 13 on the table 1 which are rotatably adjusted for changing the stroke position of the hammers when forging shoulders or collars &c. by a hydraulic piston 17, Fig. 9, through a rack 18 and pinion 19 engaging a gear 15 common to gears 14 on the bushings 13. The pin and slot engagement 16 between the driving gears 7 and the flywheels 8 permits radial adjustment relative to the work between the gears and flywheels. A hydraulic piston 20 carrying a chuck 21, Fig. 2, feeds the work axially between the hammers. Automatic hydraulic control system. The hydraulic cylinders 17, 20 are controlled through cam-actuated slide valves, the cams being carried on a pair of shafts 22, 23, Figs. 4 and 7, disposed at right angles in directions parallel to the piston movements and geared together through helical gears 24. The rollers carry adjustable pairs of stops 25, 26 having sloping faces 27 engageable by followers 28, 29 carried on the rack 18 of the piston 17 and on the chuck 21 of the piston 20 respectively, and give the rollers 22, 23 an initial small rotary motion on engagement. Each initial motion given to the rollers by one of the stops is automatically continued to exactly <SP>1</SP>/ 16 th of a turn by a hydraulic piston 39, Fig. 4, having a rack 36 engaging a ratchet pinion 37 on the end of the roller 22. The roller 22 carries a cam wheel 33 with sixteen notches engageable in turn by one end of a slide valve 34 controlling the flow of oil to the piston 39. The cam wheel 33 may have detachable lands on the raised portions which move the valve 34 to an alternative second setting. At one setting the oil is directed to a lock valve 40 controlling the flow of oil to the piston 39, and passes through a throttle valve 41 reducing the speed of operation of the piston 39. In the other position of the valve 34 the oil is supplied unrestricted to the piston 39, bypassing the valve 40 and throttle 41. When the cam wheel 33 has been turned sufficiently for the valve 34 to engage the next notch the oil flow is directed to actuate the valve 40 in the opposite direction and thereby to the opposite end of the piston 39 which returns without rotating the roller 22, due to the free wheel action of the ratchet pinion 37. A stop 57 on the rack 36 and a resilient lever 56 are further arranged to lock the valve 40 until the piston 39 has returned to its initial position. The arrangement prevents the cylinder 39 from being actuated should the valve 34 receive a second impulse from the cam wheel 33 directed to move the valve 40, before the cylinder 39 has completed its return stroke. The control rollers 22, 23 carry respectively adjustable or interchangeable cam discs 58, 59 controlling the settings of valves 60, 61 in the supply system for the hammer setting piston 17 and the work feed piston 20 respectively. The valve 60 is constantly pressurized against.the cam disc 58 and has four settings by which the piston 20 is raised and lowered at different speeds controlled by adjustable throttle valves 68, 76. The valve 61 is similarly pressurized against the cam 59 through a crank arm 81 and has three settings. In one position the hammers are opened and in the intermediate position the hammers are closed at a speed controlled by an adjustable throttle valve 90. In the third position the valve 90 is by-passed for high speed adjustment. The sequence of operations is initiated by a manually controlled valve 62 which normally remains in a neutral position under spring loading. Depression of the valve opens the line 66 pressurizing the valve 60 against its cam 58 to operate the piston 20. After starting, the valve 62 returns to its neutral position and the valve 60 is pressurized through a line 93 from a further valve 98 which is constantly pressurized against a further cam 97 on the control roller 22. The valve 98 finally cuts off the pressure supply after the final operation in the sequence so that after the piston 20 has returned to its initial position the manual control valve 62 is again ready for initiating the next cycle of operations. The valve 62 has a second position providing an emergency over-ride which operates the pistons 17, 20 to open the hammers and withdraw the work. A cock 103 is further provided for cutting off the pressure supply to the underside of the piston 20 and opening it to exhaust so that the piston 20 may be held in any desired position during setting up. In a modification for forging conical or other work where the change in shape is gradual, a template cylinder 107, Fig. 8, parallel to the control roller 23 may control the hammer setting through pinions 19, 19a and the central gear 15. The cylinder is rotated according to a template 108 which is engaged by a follower 109 on the work feed piston 20. Chucks.-The work is resiliently supported in the chuck 21 which prevents the setting up of reaction forces during the hammer blows. A sleeve 111, Fig. 10, carrying the gripping jaws 110 is rotatably mounted in the chuck casing 21 and bears axially through a roller bearing 138 against a resilient rubber ring 112 at one end of the casing. An annular piston 114 in the casing opens and closes the gripping jaws 110 through the movement of an annular body 115 connected to the piston and having oblique grooves 119 engaged by pins 120 on lever 116 pivoted at the base of the casing and engaging the jaws 110. Impact on the work in the vertically upward direction is cushioned by the rubber ring 112. Air behind the piston 114 cushions impact in the vertically downward direction but in order to reduce the impact load at which the piston 114 yields, the sleeve 111 is urged downward against the piston 114 by air pressure in an annular groove 128 in the upper part of the casing. The sleeve 111 is rotated by an electric motor 137, Fig. 2, through a worm 136 and worm wheel 135 which transmits the rotation to the sleeve 111 through a rotatably yieldable coupling which cushions torsional loads during hammer impacts. The coupling comprises discs 131, 132, Fig. 11, keyed to the worm wheel 135 and sleeve 111 respectively and having claws which interengage through springs 133, 134. Specification 650,550 is referred to.