GB191421742A - Improvements in Screw and Nut Mechanism for use in connection with Presses and other like purposes. - Google Patents

Abstract

21,742. Brinjes & Goodwin, Titterton, F., and Savage, J. E. Oct. 29. [Cognate Application, 6293/15.] Screw - and - nut mechanism. - Screw-andn u t mechanism f o r presses for baling or cheese - making, filterpresses, and other purposes is arranged to give a quick advance of a spindle, followed by a slow movement with heavy pressure. A spindle a, Fig. 1, formed with a coarse thread, is turned by a hand-wheel f and moves through a nut b until the wheel contacts with the end of the nut, which is then rotated either frictionally or through connexions g, h. A fine thread b<1> on the outside of the nut engaging a stationary sleeve c gives the final slow movement to the spindle. The nut has a collar b<2> at one or both ends to limit its movement, and an adjustable stop e may also be provided. The engaging faces of the nut and hand-wheel may be coned or toothed. A collar may be formed on the spindle a to engage the collar b<2> and return the nut to its initial position when the wheel f is turned back.. Fig. 4 shows a modification in which the nut b is turned by a separate hand-wheel m and works on an inner nut n, which is held against rotation by a square head n<1> sliding in the support c. The final slow movement is due to a slight difference in pitch of the inner and outer threads on the nut b. Fig. 7 shows a device for preventing rotation of the spindle a until the wheel m has been moved back to its initial position. A spring-pressed key r carried by the support c projects through a slot in the head n' into a slot p in the spindle a, which is thus held against rotation until the key is removed. When the wheel m is screwed back, the nut n moves to the right, and a projection u on the head n<1> engages a bell-crank lever t, which raises the key r. Specification 23,723/98 is referred to.