GB441186A - Improvements in or relating to power-operated tools for tapping, screwing-up and like operations - Google Patents

Abstract

441,186. Screwing-up and unscrewing bolts, nuts, and screws; clutches. BOSCH AKT.-GES., R., 4, Militarstrasse, Stuttgart, Germany. July 19, 1935, No. 20542. Convention date, July 19, 1934. Addition to 429,810. [Class 83 (iii)] [See also Group XXIV] Screwing and tapping.-In a power-operated rotary tool such as a screwing-up and unscrewing machine or a tapping machine &c. the roller clutch described in the parent Specification is modified in details and is combined with a reversing clutch. Oppositely rotating gears a, b are secured against axial movement in a portable machine casing (not shown), and are provided with clutch teeth d<1>, c<1> co-operating with a clutch e secured to the spindle f which is slidable through the gears. A spring g normally maintains the clutch e in engagement with the gear a. A casing h is secured to the lower end of the spindle f and carries rotatably therein a clutch part i carrying a tool socket i<4>, a thrust bearing k being provided between the part i and the casing h. Three rollers s are mounted in radial holes in the part i which is cut away at i<3> to expose the middle portions of the rollers. A plate q, slidably keyed to the casing h by balls r, is provided with clutch teeth q<1> which are pressed into engagement with the exposed portions of the rollers s by means of a spring p abutting on a disc n secured in the casing h and locked by a screw m. In operation, with the gear a rotating the tool in a left-hand direction, the machine is lowered onto the work, whereupon the spindle f is moved axially to cause the clutch e to engage the gear band rotate a stud box, tap, &c. in the socket i<4> in a right-hand direction. On completion of the operation, the clutch i, q slips, whereupon the operator raises the machine and reverses the drive, the roller clutch enabling reversal to be effected without shock to the operator. The disc q may be changed without removing the remainder of the roller clutch to vary the fierceness of the clutch on reversal and so adapt the machine for stud setting, tapping, &c., or alternatively the clutch teeth q<1> may have different inclinations on opposite sides for this purpose.