Patent GB-193489-A (GB)
Title: Machine for manufacturing wire straps
IPC: B21F1/06
Filed: 1921-11-23
Abstract: 193,489. Lurcott, W. N. Nov. 23. 1921. Fastenings. - In a machine for making wire straps of the kind described in Specification 184,011, [Class 94 (i), Packing &c.], having coiled loops B at one end, as shown in Fig. 11, wire is fed forward so that an unsupported length projects beyond a guide, which length is then bent up at an angle of approximately 90‹ to the body over a steady rest and is then coiled round the body of the wire by a rotary member. Standard lengths of wire A, Fig. 5, are fed through a perforated plug 20 in a sliding carrier tube 15, which is provided with a mandrel 19 and is mounted in a fixed guide tube 16, by a pair of rollers 58, 59, Fig. 2, of which the roll 58 is mounted on the main shaft 39 and the roll 59 on a shaft having an eccentric extension 65<a> supported on a bearing 64. The shaft carrying the roll 59 is rocked against the action of a spring 61 by an adjustable cam 63, 62 on a shaft 32 engaging a roller 67 on an arm projecting from the shaft of the roll 59 so as to raise the roll out of contact with the wire during the coiling operation. The wire and mandrel pass through a hook-shaped coiling-member 22, which is secured to a head 18 rotated by gearing 46, 44 from a shaft 40 driven by bevel gear from the main shaft. The wire is fed bv the rolls between a pair of shear blades, the fixed blade 26 of which is secured to a block 27 pivoted in a boss 33 and the movable blade of which is reciprocated on the block 27 by an eccentric on the shaft 32 so as to sever the previously-completed blank from the stock. The shaft 32 is rotated by gearing 43, 45 from the shaft 40 at a slower speed than the head 18 to suit the number of turns of the coil. After the blank has been severed, the length of wire between the guide tube 16 and the shear blades is bent up at right-angles by a curved arm 34 on the shaft 32 over a finger 35, which together with a finger 37 forms part of a steady rest 36, Fig. 7. The steady rest is pivoted to brackets 53 carried by a rod 52 and is provided with a spring 55 to hold the heel thereof in contact with a cam 56 on the framing. The bent wire is coiled over the mandrel and body of the wire by the rearwardlyinclined portion 38 of the coiling-hook. During coiling the wire and mandrel and also the steady rest are traversed by a cam rib 48 on a drum 47 secured to the shaft 32, which engages a roller 50 secured to a plate 51 which is screwed to the carrier tube 15 and also to the rod 52. The wire at the bend is held by the finger 35 until the coiling is completed, when the spring 55 presses the heel of the rest into a recess 57 in the cam plate 56 so as to release the coil, whereupon the roll 59 is lowered and feeds the wire at increased speed through the machine previous to severing the completed blank from the stock. In a modification, Figs. 12 and 12<a>, the wire A is fed continuously from a reel C through guide rolls 69, 70, 71 and two sets of straightening-rolls 72, 73 by a pair of rolls 75, 76, the roll 76 being mounted in a similar manner to the roll 59 and the roll 75 being driven by a chain 85 from the main shaft 39. In order that the wire may be fed intermittently through the coiling-mechanism, as described in the previous form, it is arranged, after passing through the rolls 75, 76 to loop round a fixed drum 87 and then pass to the coiling- mechanism through guide rolls 79, 80, 81, 82. The shafts 40, 32 described in the previous form are driven from the main shaft through gearing 89, 90, 91, of which the gear 90 is carried by a slotted link so as to be replacable for varying the length of the strap produced. The feed rolls 59, 58 are arranged as in the previous form, the roll 59 being pressed into contact with the wire when required by a spring 88, Fig. 22. The main shaft is driven from a loose pulley 94, connected to a prime mover, the pulley being pressed against a driving shoe 95 on the shaft by a spring 96 operated by a hand lever 99, which is pivoted at 100. The hand lever carries a spring-controlled plunger 102, the latch head 101 of which engages a notch 103 in a latch bar 104 pivoted at 107 so as to hold the lever in operative position. The latch bar which is heavier at its inner end and also pressed down by the spring 88 has projections 109 resting on the cam 62, one on each side of the roller 67 by which the roll 59 is raised. In order that the main shaft may be disengaged from the pulley when the wire is exhausted, the shaft 65 carrying the roll 59 is provided with flying weights 112 carried on levers connected to a sleeve 113 provided with a flange 116. If the operation is normal the weights fly out due to rotation of the roll 59 and bring the flange 116 under a bracket 114 on the latch bar and so prevent the bar from falling and thus from disengaging the hand lever 99, but if no wire is present the rolls are out of contact and the flange 116 thus remains in the position shown in Fig. 22 and thus the bar is allowed to fall to disconnect the drive. The drive may be disconnected at any time by pushing down the plunger 102. The completed straps prior to severing, may be discharged into a box-like guide 122, Fig. 12<a>, one side of which is pivoted at 124 and opened, after each strap is severed, by a cam on the shaft 32. The straps drop when the box is opened and their coiled ends are guided by a pair of rods 123 which pull them forwardly, the blanks being received on members 118 projecting from supports 117. In order that bundles of straps C may be obtained each having a determined number of straps, the straps in passing to the members 118 pass thereto on either side of guides 120, which are carried by a shaft 119 rocked at intervals by a rod 129, Fig. 12, which is connected by an arm 128 to a counting-mechanism. This mechanism comprises a shaft 138, Fig. 23, which is rotated step by step bv a ratchet wheel 141 and pawl 143 carried bv a lever 142 which is connected by a rod 144, Fig. 12<a>, to the bar which opens the guide shoot. The shaft 138 drives by worm gear a segmental disc 134 which is connected by a boss 132 to a rod 127. A doubleacting spring 130 is connected to the boss 132 and also to a boss 131 through which the rod 127 may slide. The arm 128 is secured to the boss 131 which carries a slide 133 having two lugs 136 with projections 136<a> and 136<b>. The spring is alternately compressed and expanded by the movement of the disc and is alternately released when the straight edges 137 of the disc are in alignment with the projections on the lugs so as to allow the spring to move the slide backwards and forwards after the delivery of a definite number of straps and so rock the rod 119. The shaft 138 carries an adjustable mutilated disc 145 engaging a lug 146 on the slide 133 so as to ensure movement of the slide at the correct time.