Patent GB-1377347-A (GB)
Title: Gear cutter head grinder
IPC: B24B3/34
Filed: 1973-04-07
Abstract: 1377347 Grinding cutters VITEBSKOE SPETSIALNOE KONSTRUKTORSKOE BJURO ZUBOOBRABATYVAJUSCHIKH SHLIFOVALNYKH I ZATOCHNIKH STANKOV 7 April 1973 16803/73 Heading B3D A gear cutter head grinder comprises a tool head 46 mounted on a carriage 3 movable by drive means 62 along longitudinal guideways on a bed 1, a work head 4 mounted on a support 2 movable along cross guideways on the bed, tool dressing means 36 mounted on the bed between the support 2 and carriage 3, means 66 for shifting the carriage into the grinding zone operatively connected to said driving means 62, the shifting means 66 also being connected to means 59 for moving the carriage in the course of tool dressing by a double-arm lever 54. The tool head 46 is reversibly rotatable and vertically movable by means 82 connected to the shifting means 66 for moving the carriage, and means 103 are provided for effecting a compensating movement of the carriage and are connected to the means 59 for effecting the dressing movement of the carriage. Vertical compensation of the tool head is effected by means 80 connected to the means 82 for effecting vertical movement of the tool during the grinding. The means 52 for compensating movement of the carriage is in direction communication with the doublearm lever 54 by a movable bearing member 56. Cam means 59 connect the bearing member to the carriage driving means 62, and the means 52 for compensating movement of the carriage is operatively connected to the means 80 for vertical compensating movement of the tool head in order to provide timed relationship between the compensating movements. The work head 4 is movable and rotatable in both horizontal and vertical planes and is carried by a column 5 on the support 2 which is movable along the cross guideway on the bed 1 by rotation of a handle 13 on a shaft 7 connected by gearing 6, 8 to a pinion 10 meshing with a rack 12 on the bed 1. A second handle 18 is connected by worm gearing 16, 17 to a pinion 15 meshing with a rack 14 formed on the side of the column 5. The upper end of the column is formed with a horizontal table 19 having a groove 20 along which a nut 21 can be adjusted by a screw 23 having a handle 24. The nut supports the work head which is secured thereto by a screw 25 extending through a supporting member 26 into the nut; slackening of the screw permits angular adjustment of the work head about a vertical axis. A worm 27 mounted in the supporting member 26 can be rotated by a handle 29 and engage a wheel 28 for rotatably adjusting the work head about a horizontal axis. A spindle 30 in the work head, at one end, carries the gear cutter head 31, and at the other end, has a dividing disc 32 of a dividing mechanism 33, a worm and wheel 34, 35 adjusting the spindle relative to the disc 32. The dressing mechanism 36 is mounted on the bed 1 and has a motor 37 which, through a worm and wheel 38, 39, rotates a lead screw 40 engaging a nut 41 in a bush 42 carrying a dressing diamond 43 which is thereby raised and lowered to positions determined by a limit switch 44 controlling the motor 37. The carriage 3 is movable along the longitudinal guideways on the bed 1 and carries a vertical sleeve 45 to which the tool head 46 is secured, the tool head having a spindle 47 driven by a belt 50 from a motor 51 and mounting a grinding wheel 48 of truncated conical form. The carriage is movable for dressing of the grinding wheel, moving the wheel to the grinding zone, and for compensating for wear of the wheel. A lead screw 52 on the carriage engages a nut 53 connected to one end of the double-arm lever 54 mounted on a bearing 55 of a carrier 56 movable along guides 57 in the bed. The carrier has a roller 58 engaging a cam 59 on a shaft 60 driven through worm gearing 61, 64, and an electromagnetic clutch 63 from a motor 62. The other end of the lever 54 has a roller 65 engaging a cam 66 on a shaft 67 mounted in the bed 1. A gear 68 on shaft 67 meshes with a gear 69 on a shaft 70 connected by gearing 71, 72 to a shaft 73, in turn, connected by gearing 74, 75 and an electromagnetic clutch 76 to the worm gearing 64 and motor 62. Limit switches 77, 78 on the shafts 60, 67 de-energize the electromagnets after the completion of the dressing operation and the moving of the grinding wheel into the grinding zone. The tool head is lowered during the grinding of each tool of the cutter head 31, the sleeve 45 having a nut 79 at its lower end engaged by a lead screw 80 having a roller 81 resting on one or other of master cams 82, 83, used, respectively, for course and fine grinding. The cams are mounted on a shaft 84 which is splined to the shaft 67 and is axially movable to align one or other cam 82, 83 with the roller 81 by a handle 42 connected by gearing 91, 90, 88, 87 to a rack 86. Vertical compensation for wear of the grinding wheel after each grinding operation is effected by rotation of the lead screw 80 by gearing 93, 94 from a shaft 95 pivotally connected to a shaft 96 having a ratchet wheel 97 engaged by a pawl 98. The pawl is mounted on a member 99 connected by a rod to one end of a lever 101, the other end of which has a roller 102 engaging a cam 103 on the shaft 60. Simultaneous horizontal compensation for wear of the grinding wheel by movement of the carriage 3 is effected by gearing 105, 106 connecting the lead screw 52 to the shaft 96. The tool head 46 and sleeve 45 are oscillated when the grinding wheel is in the grinding zone by a crank 112 which is connected by a rod to the head and is mounted in a gear 111 connected by gearing 109, 107 to a shaft 108 having a splined connection to the shaft 73 for moving the carriage and grinding wheel into the grinding zone. During dressing, oscillation of the tool head is prevented by a stop 114 which is advanced into a recess 119 in the gear 111  by a screw 117 driven by worm gearing 116 from a motor 115. In operation, the carriage 3 is initially to the right, the dressing mechanism 36 is raised, and the stop 114 is engaged with the recess 119 to prevent oscillation of the tool head. The cutter 31 is mounted on the spindle 30 and the angular horizontal and vertical positions of the head 4 is adjusted by the handles 13, 18, 24 and 29. The motor 51 driving the tool is started, and the motor 62 and clutch 63 are switched on to rotate shaft 60 and cams 59 and 103. Initially the cam 59 retains the carrier 56 stationary but the cam 103 acts through the pawl and ratchet 97, 98 to rotate shaft 96 which, through gears 105, 106, rotates the lead screw 52 to advance the carriage 3 and, through gearing 93, 94, to rotate lead screw 80 to raise the sleeve, whereby horizontal and vertical compensation of the amount of wear of the grinding wheel is accomplished. The cam 59 then acts on the carrier 56 to move the lever 54 and thus the carriage so that the grinding wheel moves across the diamond 43 after which the limit switch 77 switches out clutch 63 and motor 62 and switches on motor 37 to lower the dressing apparatus 36 and motor 115 to retract the stop 114. When the bush 42 of the dressing apparatus is lowered, a switch 44 actuates motor 62 and clutch 76 to rotate shaft 73 which through gears 72, 71 rotates shaft 70 and hence gears 69, 68 and shaft 67 carrying cam 66 to rock the lever 54 and advance the carriage 3 to the grinding zone. Shaft 73 also acts through gears 107, 109 to rotate the crank 112 and oscillate the tool head 46. The roller 65 then engages a part of cam 66 which acts to stop movement of the carriage through the lever 54. However, shaft 67 rotates shaft 84 and the master cam 82 which controls rough grinding and acts upon roller 81 so that sleeve 45 and the tool head 46 are lowered and the grinding wheel engages a tooth of the cutter head 31. The cam 82 then raises the tool head and the cam 66 acts to move the carriage 3 and retract the wheel from the grinding zone. The cutter head is indexed and the process repeated for each tooth of the cutter head. When all the teeth have been coarse ground, the master cams are changed over and cam 83 controls fine grinding of the teeth.