GB686909A - Improvements in or relating to means for transmitting impact forces - Google Patents

Abstract

686,909. Driving trench shuttering. RICE, C. J. Jan. 11, 1951 [Jan. 19, 1950], No. 1464/50. Class 68(ii) In a device for imparting impact forces, a cap is provided to rest on the surface to which impact is to be applied and an arm in adjustable engagement with the cap extends in a direction parallel with the line of impact, the arm having a foot adapted to receive percussive blows. As shown, a cap 2, shaped to fit on the top of a shutter 3, has a spherical depression 6 which co-operates with a dome-like projection on a carrier 8 mounted on a guide-member 11 through which passes a channel - sectioned arm 12 having a foot 15. A latch 13 engages holes 14 in the arm 12 and thus allows the foot to be adjusted at the most suitable height for receiving percussive blows, e.g. from a tool such as that described in Specification 647,500, [Group XXIII]. In a modification, Fig. 3 (not shown), a swinging arm may engage notches in the 'arm 12, unrestricted movement of which mav be prevented by a spring urged catch, Fig. 6 (not shown). The cap 2 may be clamped to the shutter by a liner and adjustable. screwed pins which may be prevented from unscrewing by vibration by a toggle arrangement, Fig. 11 (not shown). Specification 681,018, [Group XXIII], also is referred to.