GB768039A - Improvements in indexing mechanism for machine tool and like tables - Google Patents

Abstract

768,039. Machine tool details; indexing. SCHOLIN, H. W., and SCHOLIN. C. W. Nov. 1, 1954, No. 31471/54. Class 83 (3). Indexing apparatus comprises a plate or table 23, Fig. 2, rotatable about a fixed pivot 40 and having mechanism for indexing it contained in a casing 21, Fig. 3, having wings 27 for attachment to a support such as a machine-tool structure. The table 23, Fig. 2, carries a number of pins 48 around its edge which extend above and below the plate and are equally spaced according to the number of indexed positions required. Any form of work-support may be secured to the plate and the upper ends of the pins 48 may be used as locating dowels for such supports. The lower ends of the pins are used in the indexing mechanism. A latch 52, Fig. 3, pivoted at 53 to the casing has a slot 55 which engages a pin 48 to hold the plate in an indexed position. The latch 52 is connected at 57 to a link 58, Fig. 6, which is in turn pivoted at 60 about a pin secured to a quadrant 42 rotatable about the central axis of the device. The indexing movement may be performed by hand by pushing a rod 68, or may be fluid-operated by a piston 103. Alternatively, the indexing and return of the mechanism may be effected automatically by a single electric switch. As described, the piston 103 pushes the rod 68 which carries a pin 66 engaging a slot 65 in a quadrant 43 which lies under the quandrant 42 and is also rotatable about the central axis. As the quadrant 43 rotates clockwise, a connecting-link 70 pivoted to it at 69, rotates a dog 72, an opening 77 in which is brought into engagement with one of the pins 48. The dog 72 is pivoted at 73 to a spacing-piece 74 on a third quadrant 44 which is again rotatable about the central axis of the device and underlies the quadrant 43, Fig. 2. A projection 85, Fig. 9, on the dog 72 engages an end-piece 59 on the link 58 and withdraws the latch 52 at the same time as the dog 72 engages the pin 48 (D-1). Further rotation of the quadrant 43 rotates the table, and plates 43, 44 are automatically locked together to move into the newly indexed position, Fig. 6. Quadrant 44 engages a stop-piece 91 in this position and a projection 102 engages a contact 101 to operate a switch-and-solenoid gear to reverse the fluid-supply to the piston 103. On reverse movement of the quadrant 43, which is now disengaged from quadrant 44 (held against rotation for a short interval), a cam-piece 100, Fig. 6, on the dog 72 pushes a guided link 62 pivoted to the quadrant 42 by a pin 61 and rotates the quadrantnticlockwise to engage the latch 52 with the newly-positioned pin 48 adjacent thereto. Thus the plate 23 is held while the dog 72 is released and returns with the other parts of the mechanism to the original position shown in Fig. 3. In this arrangement a valve 109 is operated by an adjustable stop 112 in lieu of the switch operated by the projection 102.