Patent GB-1016438-A (GB)
Title: Frictional and positive progressive engagement clutch
IPC: F16D23/06
Filed: 1964-02-03
Abstract: 1,016,438. Positive clutches. TWIN DISC CLUTCH CO. Feb. 3, 1964 [Feb. 27, 1963], No. 4409/64. Heading F2C. The fluid-pressure engagement of a positive clutch for use in aeroplanes, boats, gas turbines &c. is synchronized by the prior engagement of a parallel-arranged friction clutch, the force engaging the friction clutch then being eased to permit slipping so that the positive clutch can slide readily into the fully engaged position. In one form, a driving (or driven) shaft 10 carries a clutch sleeve formed with teeth 14 which can be engaged by teeth 31 formed around the periphery of an axially-slidable clutch sleeve 30 mounted for rotation with a driven (or driving) shaft 15. In parallel with the positive clutch 14, 31 is a synchronizing friction disc clutch 13, engaged by sliding leftwards a ring R. The ring is fast with radial flanges 24, 25 and a ported hub, to form oil-receiving chambers C, 49, 51, C1. Leftwards movement of the ring R for engagement of the synchronizing clutch 17 is effected on the admission of oil under pressure through shaft ducts &c. 40, 41, the ring at the same time carrying leftwards the clutch sleeve 30 until the teeth 14, 31 are in abutting relationship. The synchronizing clutch 13 is now fully engaged, and the driving and driven shafts 10, 15 are brought to the same speed of rotation. Oil under pressure is next admitted by manual or other external means (not described) through shaft ducts, ports &c. 46, 45, 43, 42 to the chamber C1. The pressure face of the chamber C1 is of greater area than the pressure face of the chamber C. Accordingly, the ring R is slidden rightwards in the clutch-disengaging direction, to ease the friction clutch 13, which now slips, simultaneously with leftward movement of the clutch sleeve 30 to slide the clutch teeth 14, 31 into full engagement. To disengage the clutch, the chambers C, C1 are vented to exhaust, and oil under pressure is supplied through a shaft duct 48 to the chamber 49, thus biasing the ring R rightwards, oil passing through a port 50 from the chamber 49 into the chamber 51, to bias the clutch sleeve 30 rightwards. In another form, a driving (or driven) housing 100, Fig. 4 (not shown), is formed with clutch teeth 105 engageable by clutch teeth 120 upon a sleeve 117 rotating with a driven (or driving shaft) 102. A friction disc synchronizing clutch 103 connects the driving housing 100 to the driven shaft 102. Clutch engagement is effected by admitting oil under pressure through a port 110 to a chamber C3, to slide a ring R1 leftwards for engagement of the synchronizing friction clutch 103. As the ring R1 slides leftwards, it exposes a port 112 through which oil under pressure in the chamber C3 now passes into a chamber 115 formed within the clutch sleeve 117. The clutch teeth 105, 120 are thereby slidden into engagement, the rightwards reaction upon a flange 116 of the ring R1 biasing the latter rightwards, to allow partial disengagement and slipping of the friction synchronizing clutch 103. Disengagement of the clutch teeth 105, 120 is effected by venting the chamber C3 to exhaust and instead supplying oil under pressure through shaft ducts and ports 134, 133 to a chamber 130. A one-way valve 104<SP>1</SP> permits quick return flow of oil from the chamber C4 to the chamber C3.