Patent GB-646604-A (GB)
Title: Improvements in method of and mechanism for tying flexible members
IPC: A01F15/14
Filed: 1948-04-29
Abstract: 646,604. Knot-tying devices. MCKAY MASSEY HARRIS PROPRIETARY, Ltd., H. V. April 29, 1948, No. 11803. Convention date, May 2, 1947. [Class 112] A method of tying two flexible members comprises forming a U-shaped bend in one member, laying the second member above and between the arms of the bend of the first member mechanically carrying one arm of the bend to form the bend into a turn around the second member, and mechanically carrying a part of the second member spaced from the bend to form a turn around the other arm of the bend. A device for tying by the method is mounted on the compression chamber of a portable hay baling press and includes a guide (not shown), an oscillatory loopformer 16, retractable jaws 31<SP>1</SP>, 32<SP>1</SP>, and a rotary gripper 22. As shown in Fig. 15, the free end of a wire T from a spool is held in a notch in the flange 22<SP>1</SP> of the gripper and the wire is passed around the jaws to form the bend T<SP>1</SP> in the first member. The wire extends from the bend, around the compression chamber, passes between the jaws and through notches in the flanges 22<SP>1</SP>, 22<SP>2</SP> of the gripper to a roller 35, and extends from the roller to the spool: The portion T<SP>2</SP> of the wire passing between the the jaws and notches forms the second member, and the portion T<SP>3</SP> extending from the roller to the spool is held away from the tying mechanism by the guide. The device is now started on the tying cycle, the member T<SP>2</SP> being resiliently gripped and retracted by the jaws. After this operation the loop-former starts to rotate clockwise, an arcuate arm 16<SP>2</SP> on the loop-former passing above the member T<SP>2</SP> and below the lower arm of the bend T<SP>1</SP>. When the loopformer reaches the position shown in Fig. 16, the gripper is rotated by half a notch to release the free end of the wire and to grip the member T<SP>2</SP> by co-acting with a projection 28<SP>2</SP> on the guide member. On further rotation of the loop former the upper arm of the bend T<SP>1</SP> is engaged by a projection 16<SP>4</SP> on the arcuate arm so that the bend T<SP>1</SP> is formed into a turn around the member T<SP>2</SP>. As rotation of the loop-former continues the arcuate arm passes over the lower arm of the bend T<SP>1</SP> and shortly afterwards, as shown in Fig. 18, the member T<SP>2</SP> is engaged and held between a spring 20 and the tip of the arcuate arm. The member T<SP>2</SP> is then severed by a further half notch rotation of the gripper in co-operation with a cutter 28<SP>3</SP> on the guide. Soon after passing the position shown in Fig. 18 the loop-former is rotated in an anticlockwise direction back to its initial position. During this movement the loop-former carries the member T<SP>2</SP> to form a turn around the lower arm of the bend T<SP>1</SP> and thus complete the knot shown in Fig. 20. The device is operated by reciprocating a slide 11, Fig. 9, a knot being formed for one complete reciprocation of the slide. A cam in a slot 11' in the slide oscillates a rocker 30 to give gripping and retracting movement to the jaws, the arrangement being that the jaws close at the beginning of the cycle and open at the end of the cycle. The loop-former is oscillated by a rack 12 on the slide and a pinion 13, the connection between the pinion and the loop-former permitting initial movement of the slide and closing of the jaws without corresponding rotation of the loop-former. A cam groove 11<SP>1</SP> in conjunction with a link 26 and a ratchet 23 imparts rotary motion to the gripper so that it rotates by half a notch twice duripg the inward stroke of the slide.