Patent GB-1224225-A (GB)
Title: Improvements in or relating to hydraulically operated cable cutter tools
IPC: H02G1/00
Filed: 1968-09-13
Abstract: 1,224,225. Shearing. DYNAMIC TOOLS Ltd. 13 Sept., 1968, No. 43758/68. Heading B3W. An hydraulically operated hand cutting tool, particularly for cutting cable, comprises a ram housing 12 connected to a jaw support 13 by means of a connector element 120 which includes a flange 127 which engages a resilient projection such as a split ring 126 located in a groove 125 in the jaw support 13 and is screwthreaded to engage threads 121 on the housing 12. As the element 120 is screwed on to the housing 12 planar reference surfaces 122, 124 on the housing and on the support respectively are brought together to align the two parts. Integral with the housing 12 is a sleeve 20 in which is rotatably mounted a portion 30 of a handle 11 which includes a crank 32. The crank 32 through a stem 96 co-operates with a pushrod 98 (Fig. 3) to allow opening movement of the cutter jaws. Also integral with the housing 12 is an arm 21 on which is pivoted at 42 the other handle 10 in the form of a bell-crank. The piston 58 of an hydraulic pump is pivotally secured to the short arm 41 of the bell-crank. The pump cylinder 52 communicates with a fluid reservoir 71 surrounding the ram cylinder 70 and with interior of the ram cylinder 70 via a valve assembly 80, the arrangement being as follows. Rotation of the handle 11 to the Fig. 3 position in which push-rod 98 is withdrawn from ball 91, movement of the handle 10 away from handle 11 causes a suction stroke of the pump. The ball 91 is moved away from its seat 90 and fluid is drawn from the reservoir 71 through bores 100 and 99 into the pump cylinder 52. As the handle 10 is moved towards the handle 11 fluid is pumped into bore 99 causing ball 91 to move on to its seat 90 and a second ball 84 to be moved, against the action of spring 92, away from its seat 83 to put the bore 99 in communication with a bore 101 leading to the ram cylinder 70 to extend the ram (78), (79), Fig. 2 (not shown). An adjustable cap (111) on the ram cylinder limits the stroke of the ram so that the cutters do not cross each other. When the ram has been extended the required amount the handle 11 is rotated in the reverse direction and the crank 32 through the push-rod 98 and spacer 95 causes balls 91 and 84 to be lifted off their seats 90 and 83, respectively. Fluid then flows from the cylinder to the reservoir through bore 101, valve passage 80 and bore 100. A relief valve comprising a spring-loaded ball valve (105), (106) connects the portion 82 of the valve passage 80 with a bore (109) leading to the reservoir 71. The cutter jaws 141, 144 are mounted by means of links 136, 137 on a crosshead (134), Fig. 2, secured to the upper end of the ram piston-rod (79) and are pivoted on the support 13 at 146, 147. The cutter jaws are opened by the action of a spring 135. For cable cutting, cable gripping jaws 161, 163 are pivoted on extensions of the pins 146, 147 and are connected by links 158, 159 to a handle 150 pivoted about a stud 151. Closing movement of the handle is limited by a stop 153. Gripper elements 170, 171 are rotatable to present gripping faces of different configurations.