Patent GB-1452869-A (GB)
Title: Method and apparatus for dispensing continuous material
IPC: B65H23/06
Filed: 1975-01-30
Abstract: 1452869 Dispensing strap SIGNODE CORP 30 Jan 1975 [11 March 1974] 4129/75 Heading B8M Continuous filamentary or web material, e.g. steel strap, is dispensed from a coil by sensing demand for the material, applying stored energy to the coil to initiate coil rotation and to dispense material from the coil, sensing termination of material demand, transforming the rotational energy of the coil into storable energy, and storing the storable energy for subsequent use in initiating subsequent coil rotation. In one embodiment, Figs. 1, 2, 4, 8, 10 and 11, a strap dispenser comprises a frame 11, a dancer arm assembly 80 and an axle assembly 31 including a hub 32 carrying a coil 32 of strap. The hub 32, Fig. 8, comprises 132, 132a to support the sides of the coil and three coaxial members 32a, 32b, 32c mounted on an outer axle 33 by bearings 34, 35 with one-way clutches 52 therebetween. The axle 33 comprises segments 33a, 33b keyed to arms 36 supported on a surface 22a of a fixed channel 18 by rollers 37, Fig. 1. Bearings 48, Fig. 8, mount the axle 33 on a hollow axle 38 keyed to arms 39 supported on the surface 22a by rollers 40. A roller 50 is carried at each end of the axle 38 to roll on a fixed vertical rail 20. Each clutch 52, Fig. 10, comprises a smooth outer race surface 52a, formed interiorly of the member 32a or 32c and upon which spindle bearings 53 may freely roll, and an inner surface 52b formed on the segment 33a or 33b and provided with tangential stops. As the hub 32 rotates clockwise relative to the axle 33, the clutch 52 overruns, but when the axle 33 rotates clockwise relative to the hub 32, the bearings 53 move tangentially on the surface 52b and prevent further rotation in this direction. The hub 32 is keyed to the axle 38 by inserts 54, Fig. 11, in the member 32b and which cooperate with keys 55 in the axle 38. The engagement surfaces 54a, 55a of the inserts 54 and the keys 55 are angled to direct a component of the coil's weight towards the centre of the assembly 31 when engaged. The movement of the keys 55 is controlled by a mechanism in the axle 38 and comprising bearings 60, Fig. 8, each mounted in a slidable housing 61, axially slidable spools 62 and a cam member 63. Rollers 66 are interposed between the cam 63 and the keys 55. Upon demand for strap, the cam 63 is moved to the position of Fig. 8 from that of Fig. 9 (not shown), and the component of the coil's weight directed towards the centre of the assembly 31 forces the rollers 66 into pockets (65), Fig. 12 (not shown), in the cam 63 to disengage the keys 55. Upon cessation of demand for strap, the cam 63 is moved to the right of Fig. 8 and the rollers 66 are forced out of the pockets (65) to force the keys 55 into engagement with the inserts 54. The movement of the spools 62 and the cam 63 is effected through an over-centre spring-loaded mechanism 86, Figs. 1, 2 and 4, actuated by the dancer arm assembly 80 comprising a roller 82 carried by arms 81 pivoted by pins 84 to the frame 11. A shaft 87, Fig. 4, having a hemispherical end portion 88 is received in a slot in a portion 85 of each arm 81 and is pivoted by a pin 89 to a member 90 pivoted to the frame 11 by a pin 91. A portion 92 of the member 90 bears against one of the bearings 60 to operate the cam 63 as the members 90 are pivoted. To provide energy for operating the members 90, one shaft 87 is provided with a sleeve 94 loaded adjustably by a spring 93. Upon demand for strap, the arms 81 are pivoted upwardly by the pull on the strap passing under the roller 82 and the shaft 87 is pivoted counterclockwise against the spring 93 and as the shaft 87 passes over an imaginary line extending between the pins 89, 91, the assembly 86 snaps into the Fig. 4 position and axially shifts the cam 63 to the Fig. 8 position. When strap demand ceases, the arms 81 pivot downwardly to pivot the shaft 87 clockwise until it passes over the line between the pins 89, 91 and snaps into the Fig. 2 position to return the cam 63. The members 90 are interconnected through links 100, 101, 103, Fig. 2, the link 103 being pivoted at 105. For intermediate braking of the coil during dispensing, the arms 81 are attached to a rim braking system comprising a pivoted lever 110, Fig. 1, having a brake shoe 112 to bear against the coil rim. The lever 110 is attached to one arm 81 by a spring 113 and a cable 114 so that, upon decrease in strap demand, as the arms 81 rotate clockwise, the lever 110 is raised to provide braking. In operation, in the stopped position, the hub 32 and the axles 33, 38 are supported, in an elevated position, with the rolls 37, 40 resting on the surfaces 22a with the arms 36, 39 being approximately horizontal and the hub 32 being constrained from rotation about the arms 39 by the engagement of the keys 55 with the inserts 54 and about the arms 36 through the clutches 52. Upon demand for strap, the arms 81 pivot upwardly actuating the mechanism 86 to move the cam 63 to the Fig. 8 position to disengage the keys 55 so that the hub 32 is free to fall vertically, the hub being guided by the rollers 50 running on the rails 20. As the hub 32 falls, the clutches 52 remain engaged. The hub 32 is forced to rotate about the points of contact of the rollers 37 and the surfaces 22a. The coil C continues to fall until the arms 39 have moved into vertical alignment with the axles 33, 38 and then the hub 32 begins to overrun the arms through the clutches 52. The hub 32 is continually accelerated by the arms 81 and if, during the feed cycle, the hub speed exceeds the demand speed, the shoe 112 is brought into contact with the hub rim to slow the hub down. Upon cessation of strap demand, the hub 32 tends to continue to rotate and feed off strap due to rotational inertia. The arms 81 pivot downwardly moving the shoe 112 into contact with the hub rim and subsequently reach their stop position in which the mechanism 86 is again actuated to move the cam 63 and force the keys 55 outwardly to engage the inserts 54 so that rigid contact is again initiated between the axle 38 and the hub 32. The arms 39 act as pivot arms between the hub 32 and the surfaces 22a and the hub 32, in attempting to rotate the axle 38, creates a moment about the point of contact between the rollers 40 and the surfaces 22a thus causing the hub 32 to pivot upwardly about these arms. As the hub 32 moves upwardly, the arms 36, 39 move away from each other and the coil C continues to rise until all of the rotational energy is dissipated and the coil is locked in the up position, the weight of the coil C being supported by the arms 36 through the clutches 52 and the arms 39 through the engaged keys 55 and inserts 54. The dispenser also includes a mechanism 130, Fig. 8, for clamping the inner diameter of a coil and which is adjustable for different inner diameters and different coil widths. Four clamping shoes 131 are each movable between coil retaining rims 132, 132a and have follower tabs 155 to bear against guides 154 during movement. To alter the effective diameter of the hub, the shoes 131 are movable inwardly and outwardly by linkages 134 pivoted by pins 160 to the member 32b. Each linkage 134 is operated by rotation of a shaft 154 to move a cradle (140), Figs. 14 and 15 (both not shown), therealong. The cradle (140) comprises plates 141, 143 between which are held rollers 139 mounted upon a pin 138 of the linkage 134. Thus movement of the cradle (140) pivots the linkage 134 about the pin 160 to move the shoe 131 inwardly or outwardly. The shafts 154 are interconnected by sprockets 156 and chains 157 and one shaft 154 is operated by a key in a socket 158. In another embodiment, Figs. 16 and 17, the axle 38 contains a single spool 62, the cam 63, and a spring-loaded return system 200 including a block 201 locating a tube 202 in which the left-hand portion of the cam 63 is slidably received. A compression spring 204 biases a piston 203 against the cam 63. A second compression spring 206 opposes movement of a guide block 67 to the left of Fig. 16. To act on the bearing 60, Fig. 16, an over-centre mechanism 210, Fig. 17, has an actuator portion 211 on a pivoted plate 212 fixed to a shaft 213 provided with an actuator arm 216 rotatable counterclockwise by a spring-loaded mechanism 230 controlled by one arm 81 and primed by the axle assembly as it falls. The mechanism 230 comprises a slide 235 carrying a roller 236 engageable with the arm 216. A spring-loaded cylinder 240 operates the slide 235 and includes a compression spring 242 designed to generate a force sufficient to overcome the force of the springs 204, 206. A spring 242 acts on a piston 243 having a reduced diameter portion 245 on which a collar 235a of the slide 235 is slidably mounted. The cylinder 240 is maintained in the primed state of Fig. 17 by a toggle linkage 250 comprising a Y-shaped link 251 pivoted by pins 260, 254 to a second link 253 and fixed blocks 255, respectively. A roller 261 is also carried by the pin 260. The linkage 250 is operated by an inclined surface 270c on a slide 270 acting on the roller 261. To operate the slide 270, one arm 81 is provided with an actuator linkage 280 including a cam roller 282 engageable with a vertical link 285 pivoted to a link 287 pivoted to the rail 20, the link 287 abutting against the bearing 50. The link 285 bears against a roller 290 mounted on the slide 270. A latch mechanism 300 is provided to maintain the slide 235 in the actuating position when the cylinder 240 has been primed and comprises a pair of pivot links 301 the upper ends of encompass rollers 305 mounted in cut-outs 235d in the slide 235. Cam rollers 306 on the links 301 are engageable with locking surfaces 311 on latches 310 to maintain the slide 235 in the dispensing position, Fig. 18 (not shown). Two pivot levers 312<SP>1</SP> are provided on the linkage 280 to lift the latches 310 from the roller