GB731288A - Improvements relating to bale-banding machines - Google Patents

Abstract

731,288. Bale-tying machines. SAQUET, A. Sept. 24, 1952 [Sept. 28, 1951], No. 23987/52. Class 45. A mechanism for a bale - banding machine, which is effective, through a single control to feed forward the banding strip L to a length necessary to encircle the package and, after the strip has been trained around the package to feed back and tension the strip to an adjustable predetermined tension and also to set in action moans for sealing the tensioned strip into a band, comprises a drive shaft 4, a pair of coacting banding strip feed rollers 26, 46, the hub 11 of one of which 46 is rotatable on the shaft 4, and clutch controlled gears 6-8 for selectively rotating the roller 46 either forwardly or backwardly from the drive shaft 4. As shown, a housing 25 supports the shaft 4 which is driven by a pulley 6. The pulley is connected to the shaft through a disc 2 and a ring 3 which form an overload clutch. The shaft 4 is surrounded by a tubular layshaft 9 to which it is connected through a reversing mechanism consisting of a dog clutch member 5 which is slidably but non-rotatable mounted on the shaft 4 and which can engage either the two gears 6, 7 or take up a neutral position between them. The gear 6 is free to rotate on the shaft 4 and the gear 7 is integral with the layshaft 9, and both engage with the third gear 8. Hence the layshaft can be rotated in either direction by the pulley 6. The layshaft drives the hub 11 through a plate 10 and friction ring 12; the hub 11 and its roller 46 are formed integrally with a gear-wheel 47 and a ratchet wheel 13. The roller 46 is grooved and the roller 26 is serrated where they engage the banding strip L. They feed the banding strip forwardly so that it can be trained round a package and subsequently by operation of the reversing mechanism retracted to draw it closely around the package and then to tension it. The tensioning mechanism comprises a roller 30 which engages the strip in its passage between a sealing mechanism and the nip of the feeding rollers 46, 26. This roller 30 is carried by a cranked lever 29 which is pivotally mounted, is connected to a damper 42 and engages a slidable yoke 43 which is connected by springs 45 to a lever 52. The lever 52 can be positioned by means of a button 68 in one of a number of positions relative to a scale 69 and serves to adjust the degree of tension applied to the strip since during its withdrawal the strip tends to straighten out between the sealing mechanism and the nip of the rollers 46, 26; this straightening lifts the roller 30 against the resistance of the yoke 43 caused by the springs 45. During the first part of the rotation of this lever 29 caused by the lifting of the roller 30, a stop 33 on the end of the lever remote from the roller engages a latch 34 which releases a support 37 pivotally mounted on the housing coaxially with the shaft 4. The support 37 carries a gripper 35 and a pawl 36 which when the support is engaged by the latch 34 are held inoperative by stops 38, 39 respectively. When the support 37 is released the gripper 35 engages the strip and the pawl 37 locks the support to the roller 46 by engaging one of the teeth of the gear-wheel 47, hence the grip between the roller 40 and the strip is increased. After this has taken place the increase in tension in the strip causes the drive of the roller 46 through the friction ring 12 to slip and the drive is then taken over by an arrangement comprising the ratchet wheel 13 and a pawl 16. The pawl is connected to a lever 18 which is rocked by a cam 14 on the layshaft 9. Reverse rotation of the ratchet wheel is prevented by a pawl 22. As the tension in the strip increases the roller 30 continues to raise the lever 29 until eventually an electric contact 49 on the lever engages a fixed electric contact 50, to complete a circuit for the sealing mechanisms which joins overlapping parts of the strips to complete a loop around the package. At the completion of the sealing operation the clutch member 5 is returned to a neutral position so that the various parts of the mechanism may regain their initial positions. The clutch member 5 is moved to any one of its three positions by a fork 24 which is controlled through a quadrant by a foot pedal. The fork 24 is also provided with a member clutch 23 which holds the pawls 16, 22 out of contact with the ratchet wheel 13 while the rollers 46, 26 are feeding the strip forwardly for training round the package. Specification 698,181 is referred to.