GB1222136A - Improvements in or relating to toothed wheel change speed gears - Google Patents

Abstract

1,222,136. Change-speed gearing. SACHSENRING AUTOMOBILWERKE ZWICKAU VEB. 6 June, 1968, No. 27053/68. Heading F2D. A four forward speed and reverse speed transmission, Fig. 1, for vehicles having frontwheel drive and an in-line, transversely disposed engine, and which reduces the difference in length of the drive shafts, comprises parallel input and output shafts 1, 26 and two layshafts 7, 14, the shafts 14 and 26 each carrying a pair of wheels 12, 13 and 24, 25 alternatively clutched to their respective shafts by known synchronizing clutch sleeves 18, 30 controlled by a single manual gear lever controlling a sliding and turning shaft 44, Fig. 2; the clutch sleeve 18 being moved directly by rocking the shaft 44 to slide a shift rod 70 carrying a fork 73, and the sleeve 30 being moved by a shift rod 61 carrying a fork 66 and moved by fluid pressure 40 from an output driven gear pump 36, 37, against a spring 63, the fluid pressure 40 being controlled by a reduced diameter portion 45 in the shaft 44 which, in one axial position of the shaft, connects the fluid pressure to an exhaust 47 to lubricate the gearing, a positive interlock plate 68 between rods 70 and 6] prevents movement of rod 61 except when rod 70 is in neutral. A pressure relief valve 50 limits the maximum fluid pressure. The plate 68 is formed near one end with a slot 69 through which the rod 70 passes. The rod 70 is formed on its side furthest from the rod 61, with a trapezoidal projection (71), Fig. 5 (not shown), and on its side nearest the rod 61, with a trapezoidal recess (72) directly opposite the projection. The opposite end of the plate 68 has a semi-circular recess which may engage in a slot 67 in the rod 61. Axial movement of the rod 70 in either direction from its central neutral position in which the plate is withdrawn from the rod 61 by riding up the projection (71), causes the plate to move down the side of the projection and up the side of the recess to project either into the path of the rod 61 or into its slot 67 depending on whether the rod 61 is in its left-hand position as shown, or has been moved to the right by fluid pressure, to positively prevent axial movement of the rod 61. A shift rod 83 carries a fork 80 engaging an idler gear (not shown), to mesh wheel 8 and external teeth 21 on clutch sleeve 18 for reverse, a known interlock 86 being provided between shift rods 83 and 70, and a spring- biased ball detent 55 engaging the shaft 44 in its reverse position.