Patent GB-480312-A (GB)
Title: Improvements in and relating to machines for tensioning and binding wires around cases and the like
IPC: B65B13/28
Filed: 1936-08-17
Abstract: 480,312. Wiring boxes &c. GERRARD WIRE TYING MACHINES CO. PROPRIETARY, Ltd. Aug. 17, 1936, No. 22572. Convention date, Aug. 26, 1935. [Class 45] A machine for tensioning wire round a box &c., twisting overlapping portions together and cutting off the excess wire, comprises wire-gripping slides 8, 9, Fig. 3, which are moved longitudinally substantially equal amounts in opposite directions by cams 16, 17 on a mainshaft 6, the cams being located on opposite sides of a twisting mechanism 51, and the machine so functioning that all the operative mechanisms such as the tensioning, twisting &c. gear, perform cyclical movements in positive mechanical sequence as the mainshaft is driven continuously in one direction. Tensioning mechanism. The cams 16, 17 are splined on the shaft 6 and are resiliently urged apart by springs 24, whose compression may be adjusted by nuts 28, so that excessive wire tension is avoided. Motion is imparted to the wire-gripping slides along guides 13 by pins 14 engaging in grooves in the cams, the slide 9 having an eccentrically pivoted jaw 42, Fig. 22, which clamps the free end of the wire against a co-operating surface 37, and the slide 8 having its driving pin 14 mounted in a lever 32, Fig. 13, which is pivoted at 33 in the slide and has an eccentric actuating a gripping jaw 34 co-operating with a jaw 36 on the slide. Twisting mechanism. Twisting is effected by a slotted pinion 46, Fig. 9, driven by a gear 56 rigid with a pinion 53 adapted to be driven by a gear segment 52 on the mainshaft 6. A cam 58 on the segment 52 locks a cam 59 on the pinion 53 so that the twisting pinion is held stationary during the wire tensioning operation, after which, on further motion of the shaft 6, the cams 16, 17 maintain the tensioning slides stationary while the cam 59 is released allowing the twisting pinion to be actuated. As the shaft 6 continues to rotate the twisting pinion applies a slight overtwist, but at this stage the teeth on the segment 52 disengage from the pinion 53 which is then reversed to take up this overtwist, by the cam 58 as it moves into locking engagement with-the cam 59, Cutting-mechanism. The wire is severed by pivoted cutters 69, Fig. 3, actuated by cams 63 on the shaft 6, and moving past the wire guides 61. Mounting and driving machine ; wiredbox ejecting mechanism. The mechanisms of the machine are mounted on a baseplate 2, Figs. 1, 2 carried by arms 111 mounted in a cross-bar 113 which is pivoted on a slide 116 vertically adjustable as by worm and rack gearing 119 on a standard 117. The arms 111 support a motor 72 which drives the machine through a spring-loaded clutch 127 and a shaft 73, having square ends to facilitate the separation of the machine from the driving motor. The slide 116 is adjusted so that the baseplate 2 is slightly inclined to the top of the case 157 to be wired, a spring 122 tending to lift the machine and a buffer spring 124 being provided to cushion movement of the frame 111. A layshaft 78 which may be clutched to the shaft 73 has a crank disc 143 driving a rod 146 adjustably coupled to a frame 152 which is pivoted at 153 to the cross-bar 113 and has a member 156 adapted to discharge the case 157 after it has been wired. Driving and control mechanism. The mainshaft 6 is driven from the motor shaft 73 by spur and bevel gearing 76, 77, 79, 81, Fig. 2, and a one-revolution clutch comprising a spring-pressed dog 84, Fig. 6, which can engage a number of recesses 88 in the hub of the wheel 76, when released by axial movement of a cam 94 having a spiral recess 96. The cam 94 is moved to release the dog 84, and so couple the mainshaft 6 to the driven wheel 76, by a lever 89, Fig. 4, which is rocked about a pivot 91 against the pressure of a spring plunger 93 by a cam 102 on a shaft 97 controlled by a handle 101, Fig. 3. On release of the handle 101 the sleeve 94 returns axially so that the large radius of its spiral recess moves over the dog 84 whereby, on continued movement of the shaft 6, the spiral recess retracts the dog from driving engagement with the wheel 76, the drive being interrupted after one revolution of the shaft 6. A pin 108, Fig. 4, may be provided on the shaft 6, to engage a cam 107 on the sleeve 94, and so effect positive movement of the sleeve to declutch, if the handle 101 is not released in time. The mainshaft 6 has a cam 128 at its left-hand end, Fig. 4, which slides a rod 131 near the end of each revolution of the shaft 6, thus causing a one-revolution clutch member 135, similar to the mainshaft clutch, to couple the shaft 78 to the driven wheel 77 and thereby actuating the wired-case ejecting mechanism. An adjustable brake 159 is provided to prevent over-running of the shaft 78. To ensure that the shaft 6 is not driven when the ejecting mechanism is in operation, a disc 137 on the shaft 6 has a steep-sided recess into which a roller on a lever controlled by a spring plunger 141 may press to complete the final movement of the shaft 6 after declutching, and to maintain the shaft 6 in final position.