GB555120A - Generative gear and like cutting machine - Google Patents

Abstract

555,120. Gear-cutting. FELLOWS GEAR SHAPER CO. Dec. 1, 1941, No. 15458. Convention date, Dec. 20, 1940. Addition to 536,997. [Class 83 (iii)] The machine for generating the profiles of gear teeth of the like set forth in the parent Specification is modified in that the work spindle and generating cam-shaft mounted on parallel axes on a reciprocable carriage are coupled by a connecting rod of the same length as the distance between the spindles. The frame supports an annular bed 25 which is adjustable about a vertical axis for generating helical gears. A table 26 on the bed carries a reciprocable work carriage 27 moving beneath an adjustable grinding-wheel 28 supported from the part 24 of the frame. The carriage is reciprocated to roll the work past the cutter by a cam 29 coacting with an abutment 30, return movement being effected by a weight, 291. The cam is mounted on a shaft 31 oscillated from a motor 33 in the manner described in the parent Specification. The work-spindle 43 carrying a blank 46 is carried between centres 44, 45. An arm 47 on the cam shaft is connected by a coupling rod 48 to an arm 49 loosely mounted on the work spindle, the length of the rod being the same as the distance between the centres of the work and cam shafts. The arm 49 carries a pawl engaging an index wheel 55 fixed to the work spindle, the pawl being normally held in engaged position by a spring 57 thus coupling the cam and work shafts so that they rotate in unison. For indexing, a motor 61 applies a torque to a pulley 56 on the index wheel through a slipping belt 59. When the work has rolled clear of the tool a pin 62 on the pawl engages a trip 63 on the carriage, the pawl being thus lifted and the work immediately indexed by the applied torque. The trip member is adjustable and is spring mounted so that it can be moved away from the pin 62 on the return movement. The work spindle may be advanced relatively to the cam 29 to increase the depth of cut. For this purpose the cam is keyed to a sleeve 71 loose on the shaft 31, the sleeve having arms 72 embracing a yoke 75, Fig. 10, and connected thereto by keys 73 engaging inclined grooves 74 in the yoke which is itself connected by keys 77 to a collar 78 on shaft 31. The yoke is mounted on a shaft 80 which is spring urged towards an abutment 83. Axial movement of the yoke 75 through the abutment 83 causes the yoke to be rotated through the inclined key-ways 74, this movement being transmitted through keys 77 to shaft 31 and thence to the work spindle. The keys are tapered and are adjusted to take up wear by screws 87. The inclinations of the grooves engaged by the keys 73, 77 respectively may be modified according to the fineness of angular adjustment desired. Traverse of the work carriage forward and' back with indexing at the end of each return traverse is repeated until all the teeth are ground. In some cases the abutment 83 may be actuated automatically to apply a feed after each revolution of the work. The grinding- wheel may be replaced by a milling-cutter. Specification 555,145 is referred to.