Patent GB-1133354-A (GB)
Title: Guide and tension roller for tangential flat belts in spinning and twisting machines
IPC: D01H1/241
Filed: 1966-06-10
Abstract: 1,133,354. Rollers. PALITEX PROJECT-CO. G.m.b.H. 10 June, 1966 [11 June, 1965], No. 25909/66. Heading F2U. [Also in Division D1] A roller for guiding and tensioning the belt which drives tangentially the spindles of a spinning-frame, of which the spindle and tension roller shafts are in fixed positions, comprises a hub capable of revolving freely and a flexible outer surface, the outer diameter of which is capable of increasing and decreasing as a result of radially-acting forces to vary the contact pressure between the roller and belt. In Fig. 1, the roller comprises a hub 2 rotatably mounted by bearings 3 on a shaft 1, the hub carrying an annular chamber comprising a tube 4 enclosed in a cover 5 of which the ends 7 are clamped in the hub. The tube is of trapeziumsection and is inflatable like a tyre. When the roller is rotated by contact with the driving- belt, the side wall of the jacket bulges outwardly, under centrifugal action to press against the belt. The wall of the jacket may have strengthening fins &c. formed, if desired, to hold springs which help to restore the jacket towards its resting shape when the centrifugal force decreases. Magnetic powder may be added to the material of the jacket to supplement the centrifugal effect; this powder is attracted by the driving-whorl and by the belt when the latter also contains magnetic material. In Fig. 2, not shown, compressed air is supplied to the jacket through a stationary tube (15) extending into the hub. Rotatably mounted in air-tight bearings in the tube is a smaller tube which communicates with a transverse tube leading to the inside of the jacket. The interior of the jacket may be subdivided by bellows-shaped partitions (21, Fig. 5, not shown), communicating with the atmosphere to modify the flexibility of the jacket. In Fig. 6, the roller comprises a hub 2 carrying a flexible jacket 9 and rotatably mounted on a shaft upstanding from a housing 28 fixed to the spindle rail 25. Inside the housing is a sleeve-valve 29, which in the position shown, connects, through a passage 16 in the shaft, the interior of the jacket with a source 31 of compressed air, the pressure on the head of the sleeve at 35 overcoming the bias of a spring 30. The pressure inside the jacket can be released through ducts 37, 38 when the sleeve is moved to the right by a handle 36 (which also applies a brake 39 to the whorl 25) the spring then acting to maintain the valve in the release position. At the end of the housing is a venting- valve 41 operated mechanically or when a solenoid 44 is energized by a hand-switch or by a thread feeler on failure of the yarn. In other forms, the hub is formed of two parts, one slidable over the other, each part being connected to one of the end faces of the roller; when the lower part is moved relatively to the upper part, the bulging of the jacket is modified. To move the lower part of the hub, it is connected either by a ball joint (46, Fig. 8, not shown), to a tube movable inside a fixed guide tube, or to a ball (47, Fig. 9, not shown) resting on a foot (51) displaceable by a flexible tube (53) supplied with compressed air. In a modification of these forms, Fig. 11, the lower hub member 2<SP>111</SP> is connected to inwardly-directed partitions 18<SP>1</SP> fixed to the side-wall of the jacket and is movable against the bias of a spring 65 by a plunger 50, through a rod 56. The convexity or concavity of the side wall is initially set by appropriately moving the plunger; when the wall flexes under centrifugal force, the member 2<SP>111</SP> is free to slide on the upper part 2. The inside of the jacket may be filled with foamrubber or have strengthening fins or a lattice of rubber. In Fig. 12, pivoted weights 59 bear under centrifugal action, against the flexible inner walls of a foam-filled annular jacket. Provision is made at starting-up to move the weights outwardly to deflect the jacket walls into contact with the driving-belt and hold it there until centrifugal force takes effect; after an interval the weights are released to allow them to move inwardly or outwardly as the centrifugal effect dictates. To this end, the weights have portions 62 in recesses in the plunger of a dashpot arrangement. The plunger is lowered by pulling a rod 61 downwardly to move the weights outwardly. When the rod is released, until the centrifugal force is sufficient to stop the weights from moving inwardly, they are prevented from doing so by the cushioning effect of the air in a chamber 68 above the plunger. The pressure in this chamber is gradually normalized as air leaks past a ball-valve 67 on an appropriatelyshaped seat until the plunger is freed to move freely under the action of the weights. When the weights move inwardly as the roller slows down, the ends 62 raise the plunger and the rod 61 applying a brake 71 fixed to the rod to the base of the roller. An alternative form of brake may be provided (Fig. 13, not shown). In Fig. 15, the jacket is replaced by a number of radial fins 74 arranged closely together around the hub. In the rest position, the outer ends of these, which form the outer surface of the roller, are curved inwardly; under centrifugal action, they flex outwardly to engage the belt. To brake the roller, the lower of two discs retaining the fins has a flange 79 depending into a recess in a fixed member 81. The recess is filled with a dispersion of metal powder in oil and the brake takes effect when a coil 82 is energized.