GB918937A - Fluid controlled tension winding and unwinding device - Google Patents

Abstract

918,937. Variable-speed gear. HOBBS MANUFACTURING CO. March 7, 1961, No. 8278/61. Class 80 (2). [Also in Groups IX, XVI and XXXIV] A variable-speed gear for use with wire, paper &c. winding and unwinding apparatus comprises a driving shaft 17 fast on which is a carrier supporting a bevel planet pinion 20 meshing a reaction side gear 23 driving through a train 22, 27 to a pump 26 which forces liquid through an adjustable orifice 69, and also meshing a side gear 25 driving through a train 24, 31 to a driven shaft 29. A simple reverse gear 39, 45, 44; 36, 46 between the driven shaft 29 and a layshaft 42 is manually controlled by means of a knob 52 and links &c. sliding a positive clutch collar 32 on the layshaft to rotate the latter always in the same direction, independently of reversal of the direction of rotation of the driving shaft 17 for winding and unwinding operations. The layshaft 42 drives through a train 46, 63 to the side gear 62 of a second differential having its planet pinion 61 driven by an electric motor 59, the second side gear 64 of this differential driving an auxiliary pump 67 supplying liquid through a pipe 73 to a cylinder 68 containing a free floating piston 70. The pump 26 supplies liquid through a pipe 28 to the opposite side of the free floating piston 70 from a sump 14, whence it returns through the orifice 69, partially closed by the piston. When the driving shaft 17 is rotated in one direction for winding, decreasing speed of the driven shaft 29 causes the pump 26 to supply more liquid to the cylinder 68 and thereby tend to slide the piston 70 rightwards of Fig. 2, this action being opposed by the change in speed of rotation of the auxiliary pump 67 which works harder and supplies a higher pressure to the opposite side of the piston, so that the latter remains in the same position and maintains a constant size of the orifice 69, whereby the material is wound at a constant tension. When the driving shaft 17 is rotated in the opposite direction for unwinding, and following change-over of the reverse gear 32 &c., increasing speed of the driven shaft 29 causes the auxiliary pump 67 to slow down, thus allowing the free floating piston 70 to move to the right of Fig. 2 and increase the size of the orifice 69 through which the pump 26 is forcing liquid, reducing the torque applied to the driven shaft. The tension in the wound material can be adjusted by a needle valve 75 through which liquid supplied from the auxiliary pump 67 returns to the sump 14. The electric motor 59 may have its speed of rotation controlled by the operations of the main process machine containing the gear, to vary the speed of rotation of the driven shaft 29. The sump 14 is formed in the upper part of a casing 10 containing the gearing.