GB900712A - Clutch, for reversible drives - Google Patents

Abstract

900,712. Friction clutches; reverse gearing. WARMAN, C. P., and MOSS, J. W. Oct. 29, 1958 [Nov. 4, 1957; Sept. 16, 1958], No. 34664/58. Class 80 (2). Twin pneumatically-controlled friction disc clutches for use with marine reverse gearing comprise a driving housing 43, 45, Fig. I, containing a pair of diaphragms 6, 8 selectively inflated by the admission of compressed air thereto to engage presser plates 18, 20 with driven friction discs 14, 16 in toothed engagement with nested driven shafts 34, 36, passages 48, 42, 44, 22, 24, 50, 52, 54, 56 allowing free flow of cooling air over and through the clutch parts. Friction discs 10, 12 on each side of the driven discs 42, 44 are in toothed engagement with the driving housing 43, 45 and are biased apart by springs 26, 28. The passages 22, 24 are formed in the presser plates 18, 20, which are made from heat-insulating material. The diaphragms 6, 8, made of elastomeric material, may either be annuli, or may be closed at each end, as shown in Fig. 5, such a shape facilitating their removal and replacement without complete dismantlement of the clutches and gearing. The friction facings 10 &c. may be discs, or may be segments as shown in Fig. 11, this form again facilitating replacement of the discs. Compressed air is fed to the clutches through passages 80, 82 within the nested driven shafts 34, 36 and thence through a pipe 84 to the diaphragm 6, and through pipes 92, 96, 98 to the diaphragm 8. Control is effected by a conventional manually-operated valve (not described). The nested shafts 34, 36 carry gears 60, 62, Fig. 6, the former meshing directly with a gear 64 fast upon a propeller shaft 5, and the latter meshing through an idler gear 3 with a gear 68 fast upon the propeller shaft. In the event of failure of one or other of the clutches, bolts 15 can be passed through radial holes in the housings 43, 45 to engage with the driven clutch discs and lock the parts solidly together. In a modified construction, Figs. 8 . . . 10 (not shown), the pressure discs adjacent the inflatable diaphragms are secured to bolts surrounded by springs which bias the pressureplates to the clutch disengaged positions. The faces of the pressure-plates are provided with radial cooling passages 200, 202, Fig. 11, as are also the faces of the discs in toothed engagement with the driving housing and lying adjacent to the driven clutch discs. The clutch discs are made from an asbestos composition material.