GB1054156A - - Google Patents

Abstract

1,054,156. Change-speed control; clutches. FORD MOTOR CO. Ltd. Oct. 15, 1965 [Nov. 9, 1964], No. 43741/65. Headings F2C and F2D. A multi-speed vehicle transmission comprising a double planetary gear assembly controlled by hydraulic servo clutches and brakes includes a hydraulic coupling rendered effective during an upshift from first to second gear so that there is a gradual increase of speed during the shift. Transmission details.-The arrangement consists of a torque converter 13, Fig. 1 (not shown), followed by the hydraulic coupling 34 and the planetary gear units 174, 136 controlled by disc clutches 93, 95 and a band brake 186. The coupling output member 54 is connectedby a drum 156 to the sun-wheel 140 of gear unit 136, the sun-wheel being connected to a one-way roller clutch 146. Coupling 34 is controlled by a centrifugal valve 66 which is normally held in the open position shown to allow the coupling to drain through an exhaust port 76, but which can be closed by pressure liquid supplied through a passage 80 to the upper and larger valve land 70 to allow the coupling to be filled through passage 62. Servo clutches 93, 95 are operated by annular pistons 102, 118 engaged by release springs 104, 120, and respectively control the gear units 136, 174. Operation.-For low forward speed the clutch 93 is engaged, the torque converter 13 operating with torque multiplication to drive an intermediate shaft 31 which is clutched to a sleeve 112 which drives the gear unit 136 through a flange 132. Coasting under these conditions may be avoided by engaging brake 186 to hold the sun-wheel 140 stationary. Second gear is engaged by closing valve 66 to fill coupling 34, with brake 186 released but clutch 93 still engaged, the engagement of the coupling causing smooth acceleration of the elements of gear unit 134 until the elements of both units are rotating at substantially the same speed as shaft 31, when clutch 95 is also engaged and coupling 34 emptied. Both gear units are thus locked for direct drive, the torque converter 13 operating in its coupling range. For reverse drive clutch 93 is disengaged and clutch 95 and brake 186 are engaged, the drive then being transmitted through gear unit 174.