Patent GB-1106149-A (GB)
Title: Gear generating machine and method
IPC: B23F9/10
Filed: 1966-07-08
Abstract: 1,106,149. Gear - cutting. GLEASON WORKS. 8 July, 1966 [5 Aug., 1965], No. 30807/66. Headings B3B and B3K. A method of generating a spiral bevel or hypoid gear P, Figs. 2 and 7, with a rotary cutter C representing a tooth of which the opposite sides are coaxial surfaces of revolution comprises effecting a plunge feed with the gear and cutter at the terminal position 6 of the generation of the concave side of a tooth slot, rolling the gear and cutter to generate the concave side, reversing the rolling to generate the convex side, relatively withdrawing the gear and the cutter, indexing the work and rolling the gear and cutter to the initial position, and finally arresting the generating movement again to effect a further plunge cut. The cutter cradle axis 35 is set at an angle of 20 degrees to enable the plunge cut to be made without interference, The cradle 34 is mounted in a slide 33 movable to-and-from cutting position. The cutter can be offset and adjusted axially or angularly. The work P can be adjusted laterally, axially and angularly by a column (39) and slides 45, 44. The reversing rotations of the cradle and work are controlled by a barrel cam 66, Fig. 8, rotated by a worm drive 75 from a motor 51 which also rotates the cutter. The barrel cam rotates the work P via a follower 111, a screw 113 and a differential 132. The work and cradle movements are modified if a tapered slot is to be produced by adding a rotational movement to the differential 132 during a generating roll by a cam 116, a lever 118, a rack 120 and taperadjusting gears 128, and by subtracting a movement on the return roll. If it is not desired to alter the ratio-of-roll in this way, one of the gears 128 is removed and the differential carrier 132 is looked. The work is set-over angularly at the conclusion of each direction of roll by a piston 124. It is set-over rectilinearly by a cylinder 144, Fig. 9, attached to the work-column (39). The amounts and directions of set-over can be adjusted or reduced to zero to adjust the shape of the tapered tooth-slots. The set-over movements are controlled by a cam 138 and a switch 135. To unload a gear, the slide 44 is swung angularly by an hydraulic piston associated with an adjustable stop to bring the work axis to a vertical position. In operation, the cradle housing 33 is fed by cam 158, Figs. 8 and 11, by an amount adjustable by an inclined surface 172. The initial position of the housing is previously set by adjusting a bracket 164 in which a piston-rack (162) is movable, the rack engaging a pinion 166 secured to a crank 167 having a pin 168 engaging a slot 169 in a slide 171 carrying the surface 172. Movement of the rack moves the slide 171 to advance the housing to cutting position at a slow rate determined by a valve (184). Towards the end of the movement, the gear is swung up into cutting position. At the end of the movement of the rack, ports are uncovered to operate hydraulic clamps 193. Fig. 7, to secure the slide 44 in position. The motor 51 is then started to commence the cutting operations. The periods when the work is stationary or substantially so are determined by dwells in the cams 66 and 116. (In a modification, there may be a slight rotation during the plunge feed to equalize chip load.) At the end of an in-feed, the cam 158 presses the housing against a stop 194 to clamp the housing in position. At the end of a return roll, a fall on the cam 158 allows a piston 177 to withdraw the housing and a cam 196 operates a valve 195 to index the work. During generation, the column (39) is clamped to the frame by means (202) actuated by a cam 199 and a valve 201. The clamps are released only to allow set-over by the cylinder 144.