| 摘要 |
1,151,171. Screen-printing apparatus. INTERNATIONAL BUSINESS MACHINES CORP. 15 March, 1967 [18 March, 1966], No. 12128/67. Heading B6C. [Also in Division F2] In a lock mechanism (see Division F2) for a revolving carrier 32 holding six workpiece holders 33 of a screen printing apparatus, a detent engagement means formed by a locator detent contact surface 81 and a locking detent contact surface 82 is adapted to be engaged by a longitudinally slidable locator detent 83 having a positioning surface 85, the lock mechanism including a lug 86 for limiting longitudinal movement of the locator detent, a longitudinally slidable locking detent 88 having a wedging surface 89 adapted to selectively contact the locking detent contact surface 82, support means 84 for slidably supporting the locator detent 83 and the locking detent 88 and detent actuating means (not shown) acting through a cross bar 94 to urge the locator detent 83 into engagement with the locator detent contact surface 81 in an advance of moving the locking detent 88 into wedging engagement with the locking detent contact surface 82. The wedging surface 89 is inclined at a greater angle (5 degrees) relative to the longitudinal axis of the locking detent 88 than the positional surface 85 relative to the axis of the locator detent 83 (3 degrees) the detents 83, 88 are received in hardened steel inserts 80 provided in the revolving carrier 32. Spring-biased ball bearing assemblies 95-100 are provided at each end of the locator detent 83 and the locking detent 88. Springs 92 are located against slide elements 91 associated with the cross bar 94 and the length of the locator detent 83 is greater than the length of the locking detent 88 such that the locator detent 83 comes into engagement with the detent abutment means in advance of moving the locking detent 88 into wedging engagement with the locking detent contact surface 82 by this means as the cross bar 94 is advanced, spring 92 in the detent 83 is compressed while spring 92 in the detent 88 is not because the detent 88 has not encountered any significant opposition. As the advancing movement of the cross bar 94 continues the wedging surface 89 will come into wedging contact with the contact surface 82 on the insert 80 to urge the surface 81 of the insert 80 against the surface 85 of the detent 83 so that both detents are firmly placed in engagement with the respective surfaces of inserts 80 to ensure accurate positioning of the carrier 32 in the index position. |
