GB624183A - Improvements in or relating to a method for actuating the control device of the pressure generator of the hydraulic control of speed change gear mechanism - Google Patents

Abstract

624,183. Change-speed gear. FUSCALDO, O. July 31, 1946, Nos. 22816 and 22817. Convention dates, July 31, 1945 and March 11, 1946. [Class 80 (ii)] The pressure generator 56 of a hydraulicallyoperated change-speed gear is driven by either the driving or the driven shaft of the gear and supplies fluid for the actuation of cone clutches effecting drives of different ratios through a layshaft gear. A driving shaft 10 has integral gears 12, 13, 14, the two latter meshing with gears 28, 29 which are normally free to rotate about a hollow counter-shaft 21, but which may be selectively clutched thereto by the conical clutch members 24, 25, 26 movable against the return springs 50 by fluid pressure admitted from the bore of the shaft 21. A further pressure operated clutch 20 can clutch the driving shaft 10 to a gear 18 integral with the driven shaft 11 and in mesh with a gear 30 rigid with the countershaft 21. The gears 29, 30 mesh with gears 57, 58 respectively, which are freely journalled on a drum 59 in driving connection with the pump 56. Two pairs of pawls 62, 62<1> are pivoted on the drum 59 and are held in contact with the bores of the gears 57, 58 by springs 63 in such a manner that the drum 59 is driven by whichever gear 57, 58 is turning at the higher speed. Oil from the pump passes a spring loaded relief valve and is led to the bore of the piston valve 31 which selectively distributes the oil to the clutches, according to its axial position, bleed holes 48 allowing a constant flow. A reverse gear (not shown) is intermeshed between the gears 12, 27. In modifications to the gears, clutches are shown and described in which the single cone is replaced by opposed cones, and in which a flat plate clutch which may have sector or recessed circular friction facings is used.