GB599807A - Improvements in or relating to arrangements for operating clutches - Google Patents

Abstract

599,807. Operating clutches. PESCO PRODUCTS CO. Dec. 18, 1944, No. 25366. Convention date, Dec. 24, 1943. [Class 80(ii)] [Also in Group XXIX] In a fluid-operated clutch having a cylinder mounted concentrically with the clutch axis and a tubular piston slidable therein under fluid pressure to cause clutch disengagement, means are provided which compensate for changes in the position of the piston due to wear of the clutch members. As shown, applied to the operation of a conventional type of friction clutch 10, Fig. 2, interconnecting driving and driven shafts 20, 32 respectively and released by movement of levers 36 acting on a presser plate 24, an annular piston 50 carrying a ball race 56 which operatively engages the levers 36 reciprocates in a fixed annular cylinder 44 formed from a base member 40 and inner and outer tubular members 38, 42 respectively. Rotary movement of the piston is prevented by a guide shoe 62 mounted thereon and co-acting with a guide rod 58 which also carries a spring 58b acting on the shoe 62 to hold the piston 50 firmly against the levers 36 at all times. Air vents 72, 76 are provided for the cylinder and for the space enclosed by a flexible boot 66 protecting the exposed working surface of the piston 50. Remote control of the clutch is effected by a pedal 13b, Fig. 3, acting through a plunger 13d on the fluid trapped in a master cylinder 13f which communicates with the clutch cylinder 44 through a power intensifier which acts purely as a fluid link until a predetermined working pressure is attained when it operates as a follow-up relay. To compensate automatically for wear in the clutch friction facings, the cylinder 44 is given such initial capacity that movement of the levers 36 and therefore of the piston 50 to the right due to such wear still allows sufficient working volume to operate the clutch, the excess fluid thus expelled from the cylinder 44 escaping into a reservoir 13a through a port 13e uncovered by the plunger 13f when the pedal 13b is retracted by a spring 13c. The reservoir 13a is initially filled to a level 13m by unscrewing a vented closure plug 13g, a check valve 130 being provided to indicate the attainment of the correct level. The Specification as open to inspection under Sect. 91 comprises also subjectmatter abridged in Group XXIX and describing the construction and operation of the power intensifier. This subject-matter does not appear in the Specification as accepted.