Patent GB-711414-A (GB)
Title: Mechanism for forming the shed in looms
IPC: D03C5/02
Filed: 1952-05-16
Abstract: 711,414. Looms. SULZER FRERES SOC. ANON. May 16, 1952 [May 23, 1951], No. 12471/52. Classes 142(2) and 142(4) Shedding motions, pattern mechanisms. In a loom in which the heddles are actuated by a set of cams to produce a weave, a different set of cams is brought into operation either automatically after a certain number of picks, or manually when desired, in order to change the weave. In an embodiment in which two heddles are used to produce two weaves, one heddle is actuated by cams 52, 53 on a shaft 39 for one weave, and by cams 56, 57 on a shaft 40 for the other weave. The other heddle is similarly actuated. Cams 52, 53 co-operate with follower rollers 60, 61 which positively actuate the associated heddle, and follower rollers 62, 63 similarly co-operate with cams 56, 57 to actuate the same heddle for the alternative weave. The follower rollers 60-63 for each heddle are mounted in frames 68 pivoted on a common shaft 70. Shaft 70 is mounted in a yoke 72 pivoted about a shaft 73. To change the weave a locking bolt 77 is disengaged from a part 44 of a clutch which then engages, resulting in the rotation of an eccentric 74 through 180 degrees, the clutch being automatically disengaged after it has made one complete revolution. The rotation of the eccentric changes the yoke 72 from the left to the right hand position in which follower rollers 62, 63 co-operate with cams 56, 57. Bolt 77 may be disengaged either manually or automatically after any 'desired number of picks, thus automatically changing from one weave to another. Automatic change means comprises a changeover disc 92 driven from the main loom shaft 23 through a gear train 91. Cams 93, 94 are adjustably mounted on the disc 92 and in one position of the disc close a circuit thereby energizing a solenoid 107 to lower 'bolt 77. To interrupt weaving during change-over, a cam 87 is driven by.a chain drive 43 which also drives the eccentric 74. A cam follower is connected to a clutch 22 on the main shaft 23 through a system of levers, rotation of cam 87 disengaging the clutch, and thus stopping weaving, until the cam has practically completed a revolution, when the clutch is re-engaged. In the meantime roller frame 68 has completed its change-over movement. In another embodiment four heddles are used, and two sets of cams are mounted on each cam shaft to enable four different weaves to be produced. The sets of cams on one shaft are mounted on a sleeve keyed to that shaft so as to permit longitudinal movement. When one set of cams is in operation the set on the other shaft for producing the next succeeding weave can be moved along its shaft into a position opposite the device for transmitting the cam motions to the heddles. In a further embodiment six cam shafts 155 are mounted in a carrier 163 which is rotatable about a shaft 162. A chain drive actuates a sprocket 166 to which six sprockets 167 are connected, sprockets 167 driving sprockets 169, 170, 171 through chains. The four sprockets 169 have the same diameter as the sprockets 167, while sprockets 170, 171 have a larger diameter to obtain the speed reduction ratio necessary for the respective weaves. The sets of cams 156-161 are continuously driven during weaving, the carrier 163 being locked in one of the six positions in which a set of cams engages a roller frame 151. To change the weave, the carrier is released, rotated and locked in a fresh position, either manually, or automatically by means similar to those previously described.