Patent GB-850548-A (GB)
Title: Improvements in and relating to apparatus for the convex grinding of gear wheels
IPC: B23Q35/18
Filed: 1958-04-11
Abstract: 850,548. Gear-grinding. ZAHNRADFABRIK FRIEDRICHSHAVEN A.G. April 11, 1958 [April 11, 1957], No. 11656/58. Class 83 (3). [Also in Group XXIII] Apparatus for use in conjunction with grinding-machines for the lengthwise convex grinding of a straight-toothed and helical spurgears is characterized by a feeler-device having a guide curve and a double lever controlled according to the guide curve, the guide curve and the double lever being mounted on different parts of a grinding-machine which can move longitudinally in relation to one another, the feeler device having also a change-over mechanism actuated by auxiliary power, with controlmembers which can be brought alternately into contact with one or the other arm of the doublelever so that with one and the same guide curve, right and left flanks of a work-gear can be crowned in one cycle. A machine for grinding straight-toothed spur-gears, Figs. 1, 2 and 4, has a grinding-wheel 3 profiled on both sides and carried by a bracket 2 fixed to the machine-bed 1; several grinding-wheels may be provided for simultaneously machining a number of flanks. The work 11 is held between centres 5, 6, on a work-table 4 reciprocated on the bed 1. The work is connected to an indexing spindle 10 to which is fixed a notched disc 12 engaged by a pawl 15 on an indexing-plate 14 rotatable about the spindle 10. Indexing is effected at the end of a double-stroke of the worktable 4, and on completion of an indexing-operation a plate 16 is locked to the indexing-spindle 10 by a pawl 17; an arm 19 is secured to the plate 16 and is loaded by a spring 49. Members 21, 21<1> are adjustably-secured to the arm 19. The member 21 comprises a cylinder 29 secured in adjusted position in a slot 20 in the arm 19 by a nut 31, and containing a piston 30 having a finger 32 normally held in inoperative position by a spring 60 but movable to operative position by admitting pressure through pipeline 34 to the cylinder 29 above the piston 30, the movement of the finger 32 being set by adjustment of a nut 43 on a rod 44 extending upwardly from the piston. The member 21<1> is similarly constructed. Pressure is supplied alternately to the cylinders 29, 29<1>, by a valve 40, operated at each end of a stroke of the work-table by adjustable dogs 37, 38, on the table. A cam 58, on a support 59, adjustable longitudinally of the bed 1, is engaged by a roller 56 mounted on a lever 51, 51<1>, pivoted at 53 to a housing 47 and loaded by a spring 57. In operation, one flank is ground during one stroke of the work-table, the finger 32 being in contact with the arm 51, and the cam 58 causing to-and-fro rotation of the work during the stroke to give a convex shape to the flank. On reversal of the table, valve 40 causes finger 32 to become inoperative and finger 32<1> to become operative; finger 321 is set so that its movement into contact with arm 51<1> of the lever causes the work to rotate to bring the other flank into contact with the grinding-wheel, this flank being given a convex shape by the cam 58. In a modification, Fig. 3, for grinding helical teeth, a roller 70 is connected by bands 72 to a slide 73 mounted on the work-table 4 for movement transversely thereof, and carrying a follower 74 engaging a groove 77 in a plate angularly-adjustable on a carriage 79; by adjustment of the plate the workpiece is given a rotary motion during the stroke of the work-table in accordance with the helix. The carriage 79 is movable transversely of the machine on a table 80, and is connected by members 81, 82, with the arm 19 carrying members 21, 21<1>, alternately transmitting motion from the lever 51, 51<1>, actuated by the cam 58 on the work-table 4. In a further modification, Figs. 5, 6 and 7, bands 102, 103, operating a roller 101 are connected to a topslide 105 on a bottom-slide 106, movable transversely of the work-table 111 by a follower 107 engaging a template 110 fixed to the machineframe 109. A pin 114 secured to the top-slide 105 is located between wedge-members 116, 117, connected by bolts 121, 122, to a cylinder 127 containing a piston 126 attached to housing 125 secured to the bottom slide 106. A doublearmed lever 131,132 is pivoted on a support 134 fixed to the housing 125, the arms of the lever registering with adjustable set-screws 136, 137. A recess 140 on the arm 132 is engaged by an intermediate lever 142 with a support 141 fixed on the housing 125. The other end of the lever 142 carries a follower-roller 146 co-operating with cam 156 carried by support 157 adjustable on the work-table 111. The cam may be in two parts, relatively adjustable to vary the effective length.