Patent GB-190716101-A (GB)
Title: Improvements in or connected with Transmission or Variable Speed Gear.
Inventor: WOODFIELD SYDNEY
Filed: 1907-07-12
Granted: 1908-07-13
Abstract: 16,101. Woodfield, S., and Hewer, F. July 12. VariabLe speed and reversing gearing. - In a variable - speed transmission gearing applicable to motor road vehicles, boats, &c., ribs or projections upon a driving-part frictionally engage the driven part during a period of each revolution, the speed ratio depending upon the number of ribs &c. in action. In the arrangement shown in Fig. 3, the driving-shaft a carries a slidable drum h having a number of ribs h<5> of different lengths upon its periphery. The driven shaft b is out of alinement with the shaft a and terminates in a cylindrical casing b<1> within which is mounted a lining b<2>, which is thus eccentric to the drum h and is adapted to be frictionally driven by one or more of the ribs h<5> according to the extent to which the drum is slid into the lining. The lining is supported by springs or by a pneumatic cushion c, adjustably compressed by means of a screwed collar b<5>, which is normally locked by a pin b<6>. The lining transmits rotation to the cylinder and shaft, through a collar b<4> with notches engaging pins b<3> in the cylinder. The cylinder b<1> runs upon ball bearings upon fixed supporting &c disks d, e, which are rigidly connected together by a barf, and to the fixed frame &c. by a lug &c. g. The shaft a passes through the disks eccentrically, and its eccentricity with reference to the cylinder &c. may be adjusted to take up wear &c. by eccentric sleeves d', e<2>. With this arrangement, the cylinder may form an oil-retaining casing ; moreover, by means of the couplings a', b<*1>, the device may be detached and removed. The drum h is controlled by a lever &c. acting through a bar h<4> loosely engaging a collar h<3>. A positive drive and a reverse are also provided. When the drum h is slid to the left into the enlarged part of the lining b<2>, it becomes clutched to a loose pinion i upon the driving-shaft continuously in mesh with a corresponding annular wheel b<7> attached to the boss of the cylinder b<1> ; this gives a positive drive at a slightly reduced speed. When moved to the outer end of the cylinder b<1>, the drum h becomes clutched to a pinion j<1>, giving a reverse through an idle pinion j carried by a stud on the disk d, and an annular wheel b<8> formed within the cylinder. The ribs may be arranged in inclined grooves, so as to be adjustable for wear. In a modification, the ribs are carried by the cylinder which then becomes the driving-member. In the arrangement shown in Figs. 12 and 13, the shafts instead of being out of alinement are slightly inclined to one another, and the studs or projections are upon the face of a disk carried by the driving-shaft, and drive a relatively tilted resiliently mounted disk upon the driven shaft. The studs h<5> carried by the driving-disk h are normally retracted by springs &c., and one or more are raised into driving position by suitablyarranged cam surfaces or ridges m<5> of different lengths upon a regulating-disk m, which normally rotates with the driving-shaft a, but which, for purposes of varying or reversing the speed, may be rotated relatively thereto by means of a sliding key &c. m<9> engaging a straight groove or slot in the shaft and an inclined groove in the boss of the disk m. A reverse is obtained by means of a pinion j<1>, slidably mounted upon the boss of the disk m and carrying studs j<1*>passing through it and adapted to co-operate with reversing-cam ridges upon the driving-disk h as shown. Thus, when the disk m is rotated relatively to the disk h for a reverse, the pinion is pushed into engagement with an idle pinionj upon a fixed stud and engaging the bevelled edge of a cylindrical extension to the driven disk b<1>. In another modification studs, similar and similarly operated to the above, are arranged upon the periphery of a drum in an eccentric arrangement as described with reference to Fig. 3. In a further modification the drive is effected by means of rollers h<*5> carried in L-shaped slots in side plates and resting upon shoes h<5> as shown in Fig. 20. The rollers are normally drawn by springs h<*7> to the base of the slots, but may be raised so as to catch the cylinder and be drawn to the end of the slots into driving engagement therewith. This is done by lifting one or more of the corresponding shoes h<5> by means of cam-ridges m<5> upon a regulating- disk arranged and operated as in the preceding construction. According to the Provisional Specification, the device may be applied to transmit rotation at a single or fixed speed ratio.