Patent GB-1466984-A (GB)
Title: Lfiting mechanism
IPC: B65H54/52
Filed: 1974-05-28
Abstract: 1466984 Linkwork ZINSER TEXTILMASCHINEN GmbH 28 May 1974 [28 May 1973 12 Oct 1973] 23678/74 Heading F2K [Also in Division D1] The invention relates to a lifting mechanism actuable when an element thereof is in any position along a path followed by that element, to displace said element by a predetermined amount along said path. A bobbin lifting mechanism shown in Fig. 1 has a cylinder 2 that is urged by a pressure medium to slide along a piston rod 2 in the direction of the pivot 50, the force being insufficient to cause the bobbin or package 4 to be lifted off the frictional drive roller 6. As the package increases in diameter the force of the pressure medium is increased by cam means 5 acting on a pressure control valve D. When the package 4 is to be lifted off the drive roller 6 the cylinder 7 is locked against motion along the rod 2 and a piston 13, Fig. 2, that is coupled to the piston rod 1 is then biased to the left in Fig. 2 to cause the piston 13 to move through a predetermined stroke displacement and so lift the package 4 off the drive roller 6 by a substantially fixed amount irrespective of the setting of the cranked arm 3 at the moment of lift-off. In Fig. 2 the cylinder 10 normally travels along the rod 2 by means of a pressure medium entering opening 14 and acting on a partition 23 joined to the cylinder 10. The piston rod 1 has a peg 24 that is trapped in a compartment 57, the peg 24 normally engaging the right-hand wall of the compartment 57 so that the rod 1 is constrained to move to the left with the cylinder 10.  When the yarn package 4 is to be lifted off the drive roller 6, a pressure medium enters the cylinder 10 at 15 to drive a piston 12 carrying conical gripping elements 19 into locking engagement with a conical gripping surface 55 carried by the cylinder 10. This locks the cylinder 10 against the movement relative to the piston rod 2 and causes the piston 12 to uncover an opening 17 leading to a space between the piston 13 and the housing 40 of the compartment 57. The pressure medium now acting on the piston 13 now moves the piston 13 to the left until the peg 24 engages the left-hand wall 61 of the compartment 57. The piston rod 1 thus moves by a constant amount and lifts the package 4 accordingly. In Fig. 7 (not shown), illustrates a modification of the embodiment of Fig. 2 in that a compression spring takes the place of the pressure medium between the piston 11 and the partition 23. In Fig. 7 the cranked lever 3 is in the form of an acute angle such that the effective lifting force of the apparatus is not reduced on the package increase in diameter. Fig. 8 (not shown) is an embodiment similar to that of Fig. 7 except that a special linkage arrangement causes the effective length of the upwardly directed arm (65) of the crank (3<SP>11</SP>) to be increased with increasing package diameter. Fig. 9 shows an embodiment similar to Fig. 2 except that when an electromagnet 32 is energized the armature 33, and thereby the piston 12 carrying conical gripping elements 19, is moved to the left to lock the cylinder 10 and piston rod 2 against relative motion. When the armature 33 is de-energized a spring 35 cancels the gripping action. Similarly an electromagnet 32<SP>1</SP> is used to cause a predetermined displacement to the left of an armature 33<SP>1</SP> that is rigid with the rod 1. In Figs. 10 and 11 the cylinder 100 is pivotally mounted at 115. A piston rod 102 extends right through the cylinder and in coupled to the cranked lever 3. Fig. 10 has been drawn the wrong way round, compared with Fig. 11, but during normal package growth the rod 102 slides from left to right through the cylinder 100 in Fig. 10. When the package 4 is to be lifted off the drive roller 6 a pressure medium is passed into the cylinder 100 at 123 and the piston 103 moves to the right in a manner clamping the balls 111 against the rod 102. This locks the piston 103, 105 to the rod 102 and the pressure medium then moves the rod 102 to the right until the piston 105 abuts against the stops 107. This causes a predetermined lift-off of the bobbin 4 from the drive roller 6. Figs. 12 and 13 (not shown), illustrate further embodiments that function in a manner similar to Fig. 10.