GB191423785A - Improvements relating to Gear-cutting or Generating Machines. - Google Patents

Abstract

23,785. Ogden, J., and Turbine Gears, Ltd. Dec. 9. Gear-cutting machines employing end mills have a special arrangement of reversing-gearing and are particularly designed for double helical wheels, though single helical wheels and worms and plain spur and bevel gearing can also be cut. The clutches of the reversing-gears 6, 42, Fig. 1, have spring throw-over devices to ensure rapid reversal and are operated from a dog rod 11 reciprocated by gearing to correspond with the traverses of the cutter slide 22, Fig. 2. The gear 6 reverses both the slide 22 and the mechanism turning the wheel blank 20 and acts at the end of each traverse; and the gear 42 reverses the wheel blank only and acts at the mid-point of each traverse to produce the change in the helix angle. The cutter-slide screw 25 is driven by change-gearing 26 and shafts 17, 16, 5. The wheel blank on its support, angularly adjustable at 31, is driven through worm gearing 30, change-gearing 32, indexing-mechanism 35, and shaft 40 connected to the shaft 5 through the reversing-gear 42. The shaft 5 is driven from belt pulleys 3, 4 through the reversing- gear 6. The gearing for traversing the rod 11 comprises a pinion 48, Fig. 5, engaging circular rack teeth on the rod and driven by worm gearing 49, shaft 50, and change-gearing 51 from the shaft 17. Since the shaft 11 proceeds still in the' same direction after the action of the stops 46 or 47, means to prevent further engagement or fouling are provided. Cam-plates 60, Fig. 5<a>, are secured to the rod and engage a fixed pin 61. After a stop has acted, an inclined portion 62 on one of the plates rotates the rod to clear the stop. On reversal of the cutter slide and consequent reversal of the shaft 50, a pinion on which engages the long pinion 55 yieldingly mounted on the rod 11, the rod is turned until the other plate contacts with the pin, thus bringing the other stop into operative position. The drive 55 may be dispensed with by replacing the plates 60 by a cam grooved as shown in development in Fig. 8. If the stops 46, 47 are set to reverse the wheel blank exactly half a pitch before the cutter reaches its midplane, the dividing is effected without the mechanism 35 and staggered teeth are cut, successive cuts being along the lines 1 to 9, Fig. 7.