Patent GB-649563-A (GB)
Title: Multiple spindle planetary gear generating machine
IPC: B23F5/16
Filed: 1948-11-02
Abstract: 649,563. Gear-cutting. FELLOWS GEAR SHAPER CO. Nov. 2, 1948, No. 28448. Convention date, Nov. 20, 1947. [Class 83 (iii)] A gear-shaping machine comprises a turret T, Fig. 1, rotatatable on a support 22, a cutter spindle 28 reciprocable axially of the turret, a circular gear cutter C mounted on the spindle 28 and having peripheral cutting teeth t<SP>1</SP> .. t<SP>5</SP>, Fig. 17, separated by a toothless gap G, a number of work spindles S which are angularly spaced around the axis of the turret in positions for holding workpieces W in operative relation to the cutter C and rotatably mounted in aprons 51 movable on and radially of the turret under the control of back-off cams 75, mechanism for rotating the turret and work spindles so that the workpieces roll around the cutter gear, a ring gear 135 disposed coaxially of the turret for rotation independently thereof for operating the back-off cams, and mechanism driven conjointly by the means for reciprocating the cutter spindle and rotating the turret for rotating the ring gear. The teeth t<SP>1</SP> ... t<SP>5</SP> are arranged in groups on the cutter gear, all the teeth of each group being alike but those of successive groups being of progressively increasing width and heights ; the gap G provides for substituting a new workpiece W for a finished one. The cutter spindle 28 is movable axially in a vertical guideway carried by an overhanging member 27 upstanding from the base 22, and is reciprocated by an electric motor 33, Figs. 1 and 19, which drives a crankshaft 34 through belt and pulley mechanism 35, 36 and pick-off gears 38, 39 ; a crank-pin 43, radially adjustable on the shaft 34, is coupled by an adjustable connecting rod 44 with a lever 45 carrying a gear segment 47 meshing with teeth 48 on the spindle. At the upper end of the spindle, the guideway includes two co-operating bushes 30, 31 which are connected by parallel or helical splines, according to the type of gear being shaped. The turret T, Fig. 1, is rotatable on a platen 21 in the base 22 and carries a peripheral worm gear 25 meshing with a gear 115, Fig. 19, by which it is driven from a motor 96 ; the drive from the motor includes belt and pulley mechanism 97, a train of gears, including pick-off gears 102, 103, a shaft 109, and bevel gears 110, 113. Each work spindle S is rotatable in a sleeve 50 secured in an apron 51, Fig. 8, which is movable radially of the turret on a carriage 52, for the purpose of backing off the workpiece and returning it to operative position. The carriage 52 is, itself, adjustable radially of the turret on ribs 53, 54 of the latter by a screw 61 engaging a nut 63 on the carriage ; a graduated dial 64 on the outer end of the screw indicates the movements of the carriage, which is clamped in adjusted position by bolts passing through slots in the carriage. The backing- off and return movement of each apron is effected by a cam 75 which is mounted on a shaft 76 on the turret and acts upon a lever 78 carrying a gear segment 79 in mesh with a tubular screw 80 in the apron ; 'a spring 89, Fig. 1, acts between the apron 51 and its carriage so as to take up back-lash. Pinions 139, Figs. 1 and 19, on the cam-shafts 76 mesh with external teeth on the ring gear 135 which is rotatably mounted beneath the turret and is driven from the motor 33 through differential gearing in a rotatable housing 134, bevel gear 136, and a pinion 138 meshing with internal teeth on the gear 135. A compensatory incremental rotation of the ring gear to eliminate error in the timing of the cams due to the planetary motion of the latter is effected by imparting rotation to the housing 134 from the motor 96 through a sprocket and chain drive 141 and gearing. The adjusting screw 61 for the carriage 52 has an extension 61a in splined connection with the screw 80, and the two screws are oppositely threaded to permit adjustment of the carriage without disturbing the lever 78. In its backing-off and return movements, the apron is guided by contact surfaces and a spring (Fig. 12, not shown). The work spindles S are rotated from the shaft 109, Fig. 19, through pick-off gears 116-119 and a pinion 124 meshing with the internal teeth of a ring gear 121 rotatably mounted beneath the ring gear 135. Pinions 125 mesh with external teeth on the ring gear 121 and are so spaced around the axis of the latter that each drives one of the spindles S through bevel gear 127, axially-movable shaft 128, and worm gearing 129, 130. Workpieces W are secured to a spindle S by a headstock 86, Fig. 1, which is secured to the apron 51 so as to overhang the spindle and has a sliding clamp movable to and from the spindle by an arm 87 ; a holding clamp for the slide is operated by an arm 88. A pan 89, Fig. 1, arranged adjacent the spindle collects lubricating fluid and chips, and conducts them to a central passage 90 in the turret for deflection by a guide 91 to a screw conveyer 93. The gap G in the cutter teeth is long enough to permit the substitution of a new workpiece for a finished one on the spindle then in position, but means are provided to interrupt the operation of ,the machine if the substitution has not been made in the allotted time. For this purpose, limit switches 146, 147, Fig. 14, are provided for actuation by cams 148, 149 driven from the shaft 109, Fig. 19. The switch 146 is closed as soon as a spindle S arrives at the gap, thereby energizing a signal lamp, and later the cam 147 operates the switch 149 to stop the motor 96 unless the operator has previously closed a starting switch. The cutter C, which is of ring form, has a bevelled surface 159 engaging an adapter 32 on the spindle 28. A jack for mounting and removing the cutter comprises a spider 161, Fig. 1, supported in the turret and having a central depending tube 162 which extends into the passage 90 and is centred therein by a tube 163. A nut 164, Fig. 15, on the tube 162 is in screw-threaded engagement with a sleeve 165, which is, in turn, in screw-threaded engagement with a rod 166 carrying a disc 167 at its upper end. A circular plate 175 for supporting and centring the cutter is laid on the disc 167 which is raised and lowered by means of a socket wrench 171 applied to a head 170 on a pinion 169 meshing with a face gear 168 keyed to the sleeve 165. The Specification as open to inspection under Sect. 91 also describes a modification of the drive of the ring gear 135 in which the differential gear in the housing 134 is driven from the motor 96 and the housing 134 is rotated from the motor 33. This subject-matter does not appear in the Specification as accepted.