GB634297A - Improvements in driving mechanisms for reciprocating work carrying tables of surface grinders and similar machines - Google Patents

Abstract

634,297. Traverse mechanism for grinding- machines. ROBACZYNSKI, L. Dec. 10, 1945, No. 33353. [Class 60] [Also in Group XXIV] A driving mechanism for a reciprocating work-carrying table of a surface grinder or similar machine, adapted to be selectively manually operated and power operated, comprises a rotatable shaft, a driving gear fast on said shaft, a manually operable element, means to engage said element with the shaft to rotate the shaft upon the manual operation of said element, said means being disengaged when said element is in an idle position, co-operative clutch parts, a power-driven reversing gear, a lost-motion connection between said reversing gear and the first of said clutch parts at one side of the gear, a friction slip device interposed between said reversing gear and said first clutch part at the other side of the gear, the second of said clutch parts being connected with said shaft and capable of being moved axially thereof to transmit rotational movement thereto when engaged with said first clutch part and when said reversing gear is in operation. The workcarrying table 17 of a surface-grinding machine has tracks 18 moving in trackways 16 on a saddle 14 which has tracks 15 moving in trackways 13 on the machine frame 10; cross movement of the saddle 14 is effected intermittently by any known means. For effecting reciprocation of the table 17 it is provided with a rack 47 engaged by a gear 48, carried by the saddle 14, which meshes with a cylindrical gear 44 having at one end a gear 45 meshing with a gear 46 secured to a shaft 55. The shaft 55 may be rotated by means of a hand crank 61 having clutch teeth 67 which, by axial movement of the hand crank, are made to engage clutch teeth 68 on the shaft. Power actuation is by means of electric motor 20 through belt drive 22, toothed gearing 26, 27, a reversing mechanism 34, automatically operated in any known manner to effect reversals of the table, and a bevel gear 41 meshing with a bevel gear 100 mounted on the hubs 75 of a clutch member 71 mounted on the shaft 55 for rotation relative thereto. A second clutch member 80 is keyed to sleeve 72 which is keyed to shaft 55; the sleeve 72 is retained on the shaft 55 by nut 74 and serves to locate the clutch part 71 axially. The clutch part 80 is movable axially on the shaft 55 by means of a pin 90 eccentrically positioned in a disc 88 rotated by a handle 91 having a spring-pressed detent to locate it in either of its two operative positions. There is a lost-motion connection between the bevel gear 100 and clutch part 71 comprising a tongue 106 on the latter projecting into a slot 103 in a flange 102 on the hub of the former; additionally there is a friction drive between the gear 100 and part 71 by means of a friction plate 110 and spring washer 111, the pressure of which can be adjusted by nuts 112, 113. The object of the construction is to reduce shock at reversals of the table. U.S.A. Specification 2,010,366 is referred to.