GB725937A - Safety devices for drives for machine parts - Google Patents

Abstract

725,937. Slip-couplings. SULZER FRERES SOC. ANON. Jan. 16, 1953 [Jan. 16, 1952], No. 1372/53. Class 80 (2) [Also in Group IX] An overload coupling for a machine part is arranged to operate, on overload, an indicating device and/or a device for stopping the machine, and is shown applied to a shuttle conveyer drive in a loom of the gripper shuttle type. The main shaft 32, Fig. 1, of the loom is driven by an electric motor through V-belts and a clutch-brake mechanism housed in a drum 34. Weft is drawn from bobbins 29 by shuttles which are shot from left to right and are then returned from a catching box to a picking box 35 by a conveyer 38. In the picking box 35, Fig. 4, a shuttle holder is swung about a shaft 63 to lift a shuttle to the picking position and a cam on a picker shaft 47 cocks a damped torsion bar 49, which actuates a picker to shoot the shuttle through the shed. The shaft 47 is driven through bevel gearing from the main shaft 32. The conveyer 38 comprises a chain 52 driven by a sprocket geared to a shaft 56 on which is slidably splined an element 69, Fig. 5, of the overload coupling, the said element having teeth which are held in engagement with corresponding teeth on a second element 68 by a spring whose pressure is adjusted by moving a collar 74. The element 68 is integral with a gear wheel 67 which is free to rotate on the shaft 56 but is axially held so that normally the wheel 67, which is geared to the shaft 47, drives the shaft 56, and hence the conveyer chain 52, through the overload coupling. On overload (caused, for example, by jamming of a shuttle), the element 69 is moved to the left and thereby displaces an indicator 76 which is attached to a block slidable in a slot in the casing 81. In addition, a lever 84 is rocked and, through a rod 91, moves a shaft 45 which stops the machine-e.g. by actuating a solenoid controlling the clutch-brake drum 34. The stop shaft 45 may also be operated by various other safety devices in the loom. Since, when an overload occurs, the shaft 56 may become out of phase with the shaft 32, the former shaft has a squared end to receive a crank handle for resetting. The splines on the shaft 56 mesh with a freely rotatable toothed ring 97 whose front surface carries a mark visible at a certain position, through a window 99, the spline-tooth ratio being the same as the gear ratio between shafts 56 and 32. A scale is provided on the main shaft 32 and it is arranged that when this reads zero and when a mark on the squared end of shaft 56 is uppermost, then the mark on the ring 97 is visible in the window 99. After an overload cut-out, therefore, the shaft 32 is turned to read zero and the shaft 56 is turned, if necessary, until the marks correspond, and the indicator 76 is moved back to the Fig. 5 position before restarting the machine. It is stated that the overload coupling may operate an acoustic or optical warning device and that it may be applied to the drives for other moving parts of a loom or other weaving or knitting machines, or to any other machinery.