Patent GB-397321-A (GB)
Title: Improvements in or relating to spur wheel variable speed gears
IPC: F16H3/08
Filed: 1932-02-26
Abstract: 397,321. Variable-speed gearing ; claw clutches. MOLDENHAUER, E., 85, Graf Adolfstrasse, Dusseldorf, Germany. Feb. 26, 1932, No. 28634. Divided on 383,827. [Class 80 (ii).] In a spur-wheel variablespeed gear, for motor vehicles the drive is transmitted between adjacent wheels 3, 6, 9 on the main shaft 10 by means of positive clutches 5a, 6a, and 8a, 9a and between adjacent wheels 4, 12, 13 on the layshaft 11 by means of bidirectional clutches 16, 26 which can only engage when the driving part is rotating more rapidly in the driving direction than the driven part but which can be disengaged at any time, the bidirectional clutch between two adjacent layshaft wheels being engaged and disengaged alternately with the positive clutch between corresponding main shaft wheels. The bidirectional clutch between the layshaft wheels 4, 12 comprises an axially movable clutch sleeve 16 having facial teeth 15,17, Figs. 4 and 5, engaging respectively teeth 14 on the wheel 12 and teeth 18 on the wheel 4. Parts of the driving sides of the teeth 15 and the driven sides of the teeth 17 are helically inclined as shown. A friction sleeve 19 surrounds the claw-sleeve 16 and has inclined slots 20 engaged by pins 21 on the claw-sleeve. The arrangement is such that on moving a freely mounted operating sleeve 24 to the left, a spring 22 acts to thrust the coned end of the friction sleeve 18 into frictional engagement with the wheel 4, thus causing the friction sleeve to rotate and its inclined slots 20 to bear on the pins 21. If the driving wheel 4 is rotating more rapidly in the driving direction than the driven wheel 12 the claw-sleeve 16 will then be moved to the left to engage the clutch teeth 17, 18. The torque of the drive so instituted then causes the inclined sides of the teeth 14, 15 to thrust the teeth 17, 18 into full engagement, Fig. 5. In a temporary intermediate position the inclined sides of the teeth 17, 18 permit the driven member to overrun the driver. The claw-sleeve 16 is disengaged from the wheel 4 by sliding the operating collar to the right against the pins 21 to take along also the clawsleeve. The collar 24 and the sleeve 5 of the main-shaft positive clutch 5a, 6a are actuated by a common fork 25. The clutch between the layshaft wheel 12, 13 differs from that described above in that its claw-sleeve 26 is surrounded by a directly-operated friction sleeve 27 splined to it, although in a modification the sleeve 27 is loose on the claw-sleeve and has a recess with one inclined side engaging pins 79 on the claw-sleeve to initiate its engaging movement. Instead of providing inclined teeth 14, 15 on the claw-sleeves and gear wheels the clawsleeves may be mounted on helical splines on the layshaft. The corresponding claw-sleeves 26, 8 on the lay- and main-shafts are separately operated through forks 30, 32 which bear on opposite sides of a cam selector 34, Fig. 2, the single fork 25 for the other claw-sleeves 5, 16 bearing on adjacent cam 33. Reversing means comprise an additional slidable countershaft 37 carrying wheels 35, 36 engageable simultaneously with the wheels 3, 9 respectively.