Patent GB-403363-A (GB)
Title: Improvements in devices for compensating the speed of bobbins and the like, more particularly in the winding of artificial silk
IPC: B65H59/38
Filed: 1932-03-18
Abstract: 403,363. Variable -speed driving - mechanism. FABRIQUES DE SOIE ARTIFICIELLE D'OBOURG SOC. ANON., Obourglez-Mons, Belgium. March 18, 1932, No. 8147. Addition to 379,295. Void [Abridged as open to inspection under sect. 91 of the Acts, March 20, 1932]. [Class 120 (ii).] In mechanism for varying the rate of rotation of a bobbin-holder shaft inversely with the radius of the winding, a single belt co-operates with two extensible pulleys, the diameter of one of which is reduced or increased in accordance with the increase or diminution of the diameter of the other which drives the bobbin, and the diameter of which is controlled by one or more revolutions at a constant speed of a rotating member. A driving shaft 5 is rotated by a chain wheel 6 in bearings 4 in a frame 1. A pulley 7 on the shaft 5 comprises two conical plates 8, 9, one of which 8, is keyed to the shaft while the other is axially displaceable thereon. The pulley 7 drives by a belt a similar expansible pulley 10 on a shaft 11 which rotates in bearings 12 and drives the bobbin shaft through a wheel 13. The movable portions of the expansible pulleys are connected by a lever 16 pivoted at 17 so that increase in the diameter of one pulley corresponds to decrease in the diameter of the other. The movable portion of the pulley 10 is displaced on the shaft 11 by a lever 26 pivoted at 29 and acted upon by a cam 31 mounted on a shaft 32 rotated by gearing 33, 34, 37, 38, 41, 42, 46. This transmission gear is so arranged that the cam 31 makes one complete revolution during a specified time, e.g. the time of winding. One of the transmission gear wheels is mounted in the slot of a lever pivoted on the shaft 32 and may be changed. A spring 48 keeps the roller 47 on the lever 26 pressed against the cam 31. A disc 49 on the end of the shaft 32 enables the amount of the rotation of the shaft 32 to be ascertained. The expansible pulleys comprise conical segments e.g. 14, 15 urged apart by an internal spring and provided with slides 54 for guiding segments 55 each constituting part of the circumference of the pulley. When the roller 47 is at the lowest point of the cam 31, the internal spring urges the members 14, 15 apart and the pulley 10 has the maximum diameter. When the apparatus is in use for winding bobbins, the gears connecting the shafts 5, 32, and the cam 31 are suitably chosen to suit the length of the winding and the thickness of the thread. In order that a cycle of variations may be carried out the cam 31 as shown in Fig. 6 is provided with a displaceable portion 57 which co-operates with a cam 58 fixed on a support 59. The profile of the cam 58 corresponds with that of the cam 31 so that at the end of one cycle, the portion 57 leaving the projection 59 on the cam 58 is suddenly displaced in the direction of the arrow 60 to bring its face 61 level with the lowest portion 62 of the cam 31. The same result may be obtained as shown in Fig. 8 by rendering the movable member 57 of the cam 31 integral with a cylinder or tube 63 provided with a groove 64 engaged by a lever 66. In this case at the end of a cycle the spring 48 moves the member 57 back to the initial position, and during the next cycle the lever 66 displaces the sleeve 63 to bring the member 57 to the position shown. If the period of variation of speed is to comprise several rotations of the shaft 32, a screw is arranged on the shaft 32 and the cam 31 is replaced by a nut engaging this screw. The nut is integral with a toothed wheel which meshes with another toothed wheel rotatable by hand so that the nut may be easily returned to the starting position after a cycle of variation.