Patent GB-961152-A (GB)
Title: Improvements in or relating to belt lacing machines
IPC: F16G3/00
Filed: 1959-07-08
Abstract: 961,152. Belt-fastening appliances. MASTABAR MINING EQUIPMENT CO. Ltd., B. TEBB, and C. H. PERRY. June 28, 1960 [July 8, 1959], No. 23465/59. Heading F2Q. In an hydraulically-operated clenching machine 36 for inserting fastening hooks into a belt, wherein jaws 10 pivoted in arcuate bearings 26 are actuated, through a rod 22 and links 18, by the ram 24 of an hydraulic cylinder 56, the hydraulic pressure is rendered ineffective at the end of the jaw-closing stroke by a valve 66 in the ram which valve comprises a stem 68 arranged to abut the cylinder end 70 to open the valve and permit free flow through the ram at the end of said stroke. A spring 74 loading the valve 66 permits, during jaw-opening movement of the ram, a restricted flow through the valve to reduce the effective pressure on the ram. Springs 76 impart return movement to the ram to overcome any locking tendency should the links 18 approach deadcentre condition. The machine is mounted on a work-table, together with manual beltcutting and hydraulically-operated clamping means. The jaws 10 provided with inner plates 12 have arcuate bearing grooves 15 co-operating with the bearings 26. To determine the minimum spacing between the jaws in their fullyclosed position the bearings 26 are carried in members 28 pivoted at 34 on the machine casing, reaction stays 38 being provided between said pivots. The ends of the members 28 remote from the bearings 26 are held by springs 40 against a stepped wedge 42 which is longitudinally moved by a hand wheel through a sprocket 50 and a chain-rack 48 to vary the centre distance of the bearings 26. The belt-cutting means is conventional and comprises manually actuated clamp, squaring- up guide and knife means. The belt-clamping means comprises transversely arranged spaced members 108, 102 on pillars 100. The member 102 has depending therefrom hydraulic cylinders 104 fed from a manifold 106. The rods 112 of spring-returned pistons 110 extend through the member 102 to clamp the belt against the member 108. The clenching machine 36 is mounted by wheels 118 on rails transverse of the worktable so that with the belt suitably cut and held by the clamping means the machine 36 may, if the belt is wider than the jaws 10, be shifted across the belt to effect further hook insertion. The work-table is provided at its ends with belt-feeding rollers. The hydraulic control comprises a sump 82, an electric motor-driven pump 84, a relief valve 124 and manually-operable clamp and clench control valves 120, 130 respectively. The clamp valve 120 has two positions, viz. rightward (shown) in which pressure fluid is directed through a line 128 to the valve 130, and leftward in which pressure fluid is directed through a non-return valve 132 to the clamp cylinder manifold 106. The non-return valve 132 prevents clamp release until a valve 134 in an exhaust line 133 is opened. The clench control valve 130 has three positions, viz. central (shown) in which pressure fluid in the line 128 is exhausted to the sump 82, and leftward and rightward in which pressure fluid is directed to opposite ends of the cylinder 56 through lines 140, 142 respectively for closing and opening the jaws 10. At the end of the jaw-closing stroke fluid passing through the valve 66 is exhausted through the line 142. During the opening stroke fluid passing through the valve 66 is exhausted through the line 140.