GB1163933A - Improvements in or relating to Hand-Tools - Google Patents

Abstract

1,163,933. Pruners. WILKINSON SWORD Ltd. 16 Feb., 1967 [18 Feb., 1966], No. 7138/66. Heading B4B. [Also in Division B3] A pruner comprises a body portion 12 to which is secured a fixed blade 10 and to which is pivoted, at 31, a movable blade 11, the body portion having an integral handle 18 and having pivoted thereto, at 32, a movable handle 34, the blade 11 being biased to the closed position by means of a spring 55 and having on the rear face thereof a projection 44 which is engaged by a hooked pawl member 40 when the blade 11 is closed, a further pawl member 46 having a tooth 48 engageable with teeth 50 on a rack-bar 51 pivoted to the blade 11 and having a projection 49 engageable by a cam-like stop 54 on a cranked portion of the rack bar, the pawl members 40, 46 being connected to each other by a flexible wire link 47. The pawl member 40 is integral with a spring-influenced trigger 42, operation of which engages the pawl 41 with the projection 44. The invention is also applicable to secateurs and spanners. Operation.-When the handles 18, 34 are squeezed together, the blade 11 is moved away from the blade 10 to grip an item, e.g. a branch, to be cut. The spring 55 acts through the rack bar 51 to clamp the branch between the blades. Thus, although the handle 34 can now be released, the blades continue to engage the branch to be cut. In this condition, the link 47 operates to retract the pawl 41 from the projection 44 on the blade 11 and force the tooth 48 into engagement with one of the teeth 50 of the rack bar 51. Squeezing of the handles 18, 34 causes the rack bar to be moved forwardly, thus forcing the blade 11 further into the branch to be cut. When the pressure on the handle 34 is relieved, the blade 11 is again maintained in contact with the branch to be cut by the action of the spring 55 on the rack bar. The tooth 48 is disengaged from the rack bar and re-engaged with a succeeding tooth immediately pressure is re-applied. Further pressure on the handles 18, 34 causes the rack bar to inch a further distance and the blade 11 cuts further into the branch to be cut. On completion of the cut, the blades are held in a closed position by the action of the spring 55 on the rack bar but the link 47 again acts to retract the tooth 48 from the rack teeth and engage the pawl 41 with the projection 44. The stop 54 on the rack bar biases the pawl 41 into engagement with the projection 44 through the link 47. The stop 54 engages the projection 49 on the pawl member 46.