Patent GB-782343-A (GB)
Title: Improvements relating to machine tools, particularly gear-cutting machines
IPC: B23Q7/04
Filed: 1955-10-10
Abstract: 782,343. Gear-cutting; chucks. GLEASON WORKS. Oct. 10, 1955 [Oct. 18, 1954], No. 28792/55. Class 83 (3). [Also in Group XXIV] A machine comprises a work-supporting spindle 34, Fig. 1, in a housing on a frame 30, a transfer member 52 mounted on the frame for unidirectional rotation and axial reciprocation, a magazine comprising a plurality of workpiece carriers 45, Fig. 11, and an indexible supporting member 46 therefor, the axis of the transfer member being parallel to and equally spaced from one workpiece on the spindle and another on a carrier, and the transfer member having a plurality of equally-spaced sets of jaws of which one set engages a workpiece on the carrier and another set engages a workpiece on the spindle as the transfer member is advanced along its axis. A workpiece P is clamped by hydraulic means 44 in a workhead 36 adjustable vertically on a column 37 which is adjustable in the direction 38 on a base 39 angularly adjustable on a base 42 about an axis 41 which is the intersection of the work and tool axes 35, 31. The base 42 is adjustable on the frame 30 in the direction 43 and is movable by hydraulic means to carry the workpiece to and from a working position P<SP>1</SP>. The base 42 and its hydraulic means are also movable as a unit by a cam to permit indexing of the work. A main drive motor rotates the cutter and oscillates a cutter cradle 32 and the work P to cut a tooth between each indexing operation of the work. The machine is stopped automatically when all teeth are cut. The chain magazing 45, Fig. 2, and the work transfer member 52 are mounted in a housing 55 adjustable by a screw 57 on a table 56 adjustable vertically by a screw 62 on a plate 61 which can be adjusted by a screw 63. The housing 55 supports a motor 64 which, through a magnetic clutch-brake and a worm shaft 67, Fig. 5, rotates a shaft 69, carrying cams 71, 72, 73 and, through bevel gears 74, an hydraulic sequence control valve 76 and further cams 78, 79, 81, 82. The barrel cam 71 oscillates an arm 84 to control axial movement of the transfer member 52; the face cam 72 oscillates an arm 89 bearing a gear-segment 92 to rock a shaft 88, which shaft bears cams 112 each of which can co-operate with a conically headed rod 109 to open a pivoted work-jaw 106, Fig. 12, and a twin pivoted jaw 105 to grip or release a workpiece positioned by a spring-pressed centre 116 surrounded by flexible seals 117; and the disc 73 carries a. drive pin 97, Fig. 4, to rotate a Geneva wheel 94 and gears 95, 102 to advance the transfer member by 120 degree increments, the wheel 94 being held still between movements by a ridge 99 on the disc 73 engaging gaps in a ridge 101 on the wheel. A further Geneva mechanism 128, 129, 131, Fig. 7, is rotated by the motor 64, the pin 128 of the mechanism being engaged periodically by movement of a lever 137 controlled by a cam-groove 142. The wheels 127 and 129 have co-operating ridges 135, 136 to hold the wheel 129 still between indexing movements. The latter mechanism controls the advance of the chain magazine 45 by rotating the shaft 132 of the sprocket 46. Each workpiece is held in a link of the chain by a leaf spring 148, Fig. 3. When placing a workpiece in a link, the operator raises a flag 152 which is moved to its lower position (shown in full lines) when the workpiece is removed from its carrier. It remains down until the operator again raises it. If he fails to do so, the flag engages an arm 155 of a switch which stops the machine. Chamfering.-A motor 162, Figs. 1 and 16, rotates a cam 165 having a groove 166 controlling an arm 49 carrying two tools 50, 51 which are positioned to chamfer the acute edges of spaced teeth, one acting at the small ends of the teeth and the other at the large ends. A further cam groove 175, Fig. 17, controls an arm 171 to raise and lower the tools for relief purposes, the tools taking four cuts from each tooth. Chucks.-At the chamfering station the gear is correctly located by a ball-ended rod 209, Fig. 5, adjustably mounted on a lever 206 which is operated by a lever 119 linked to the rod 109. Thus, as the rod 109 is moved to release the gear from the transfer member 52 it is located by the ball 209 before it is gripped against a locating shoulder 204, Fig. 16, by a collet 202 operated by a fluid piston 200. It is indexed by a slotted disc 189 engaged peiiodically by a pin 187, Fig. 17, on a shaft controlled by a groove on the end face of the cam 165. Between movements, the disc 189 is locked by a dog on a lever pivoted at 193 and controlled by a cam 186 which carries the pin 187. When all teeth are chamfered, a button 196 operates a switch 190 to stop the motor 162. At the cutting station, the work P, Fig. 13, is gripped against a shoulder 221 by a collet 228 operated by a tapered sleeve 218 drawn rearwardly by an hydraulic piston 222 through rods 224, 227. Further rearward. movement of the piston moves a second collet 219 to grip the rear shank of the blank P. If, due to an incorrectly-sized blank, the piston 222 moves back unduly far, a switch 235 is operated by a lever 236 to stop the main motor. When the piston 222 is in its forward unclamping position, a switch 234 is operated to control the motor 64. Removing cuttings.-A line 231 leads pressure air to the collet 219 to blast chips from the workpiece and chuck and is controlled by the cam 79, Fig. 5. Operation. In operation, blanks are positioned in all of the carriers and in the chuck at the cutting station. The base 42 is in its advanced position and the operator presses a machine start switch, a cycle reset switch and a cycle start switch. All the teeth are cut on one workpiece, and the main motor is then stopped and the loading motor 64 is started. The motor rotates the valve 76 to withdraw the base 42 and the cam 81 opens a switch to stop the motor until the base is fully withdrawn. The base then actuates a further switch to restart the motor. The cam 71 moves the transfer member 52 axially to cause the jaws 105, 106 to engage workpieces on the axes 35 and 54, Fig. 11, there being no gear at the chamfering station at this stage. The pistons 200, 222 are moved to de-chucking positions and the cam 82 opens a switch to stop the motor 64 until it is restarted by the switch 234 which is actuated when the work-chuck is fully open. Just prior to this, the cam 79 has operated the air blast and the cam 72 has turned the shaft 88 to allow the springs 107 to close the work-gripping jaws 105, 106 which are next withdrawn with the transfer member by the cam 71. The cam 79 shuts off the blast and the indexing mechanism 94 acts to rotate the transfer member 120 degrees. The cam 71 then advances the member 52 to insert the cut gear into the chamfering chuck. (If there were a chamfered gear it would deposit it in the empty carrier 45.) With the air blast again operating, the workpieces are released from the member 52 and clamped in the chucks. The transfer member is retracted, the carrier 45 is indexed, the motor 64 is stopped, and the base is advanced to cutting position. As the base advances, it closes a switch to start the chamfering motor 162 and the chamfering and cutting cycles then proceed. The machine continues to operate until the operator opens a switch or a flag 152 operates the switch 156 to indicate that there are no more blanks. A loading reset switch enables the machine to be actuated to perform two loading cycles consecutively, and a further similar switch permits two consecutive cutting cycles. The finished gears may then be transferred to a finishing machine which has no chamfering means but which has the gearlocating means 206, 209 mounted on the workhead 36. Modified carriers 45 then have an adjustable pin 281, Fig. 21, which enters a tooth-space of the gear, incorrect engagement causing the flag 152 to stop the machine. Specification 782,344 is referred to.