From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Patent specification for a preselector self-selecting gear control mechanism.
Identifier | ExFiles\Box 136\4\ scan0154 | |
Date | 7th July 1934 guessed | |
PATENT SPECIFICATION This specification relates to developments in preselector control, in which the gears are self-selected - from neutral to top - to facilitate getaways. Improvements in and relating to Change-Speed Gear Control I, ARTHUR ALLTREE, Rydal Dene, Pilling Lane, Preesall, near Fleetwood, in the County of Lancaster, British subject, do hereby declare the nature of this 5 invention to be as follows:— My invention relates to improvements in change-speed gear control mechanism of the type in which a gear can be preselected in advance of the actual gear 10 change, my invention relating in particular to the change-speed gears employed in the transmission systems of motor vehicles. In such mechanisms pre-selection is obtained by means of a selector 15 shaft formed with slots or cams that permit any desired link or equivalent to link or couple a control member, such as a brake element in the case of epicyclic gears or a gear shift lever in the case of 20 constant mesh or sliding gears, to a self-change or equivalent shaft that actuates the brake element or gear shift lever for the gear change. The object of the present invention is 25 to provide means by which the self-change or equivalent shaft can itself actuate the selector shaft so that gear changes can be made without the need for using the normal selector shaft control lever. 30 According to my invention I provide a pawl, arm, or equivalent that has one end pivoted upon the self-change or equivalent shaft and its other end adapted to engage ratchet teeth, pins, or the like on 35 the selector shaft the arrangement being such that when the self-change shaft is given a partial turn in one direction the pawl acting on one of the ratchet teeth gives the selector shaft a partial turn 40 equal to a change from one slot or cam to the next one. Assuming the self-change shaft to be linked or coupled to a control pedal or lever movement of the pedal or lever in one direction has the effect above 45 described and the return movement of the pedal or lever effects the gear change to the gear corresponding with the new position of the selector shaft. A suitable spring tends to keep the pawl 50 in the path of the ratchet teeth and also allows it to overrun on the return movement. [Price 1/-] Means are provided to put the pawl, or its equivalent, out of action so that the normal selector shaft control lever can be 55 employed when desirable. In one construction such means comprise a crank, cam, or the like, so mounted adjacent to the pawl that it can be turned to remove the pawl from the 60 path of the ratchet teeth and this crank or cam may be controlled by means of a lever conveniently placed for the driver to use. Alternatively the crank or cam may be controlled by means of the normal 65 selector shaft control lever by forming the latter in two parts hinged together in a manner that permits the lever to be raised clear of the notched quadrant, or its equivalent, over which it normally moves 70 to select the gears the movable portion of the lever being connected, by a rod or equivalent and such cranks or links as may be desirable, to the crank or cam that controls the position of the pawl. 75 In one construction a rigid part of the normal control lever is secured to the upper end of a hollow rod or tube which has its lower end suitably coupled to the selector shaft or to a member that turns 80 the selector shaft and within this hollow rod or tube I provide a rod that is free to be moved lengthwise in the tube and has its upper end coupled to the hinged part of the control lever and its lower end suit- 85 ably coupled to the crank or cam that controls the position of the pawl. The central rod may be coupled to the hinged part of the lever by providing a slot in the rod into which a movable end of the 90 lever projects, or by any other convenient construction. A spring or spring-loaded plunger may be provided to keep the movable part of the lever in its different positions. The 95 arrangement is such that the control lever in its normal position on the quadrant is used to control the selector shaft in the usual manner, the pawl being inoperative, but by raising the hinged member of the 100 lever the pawl is made operative enabling a driver to start his vehicle from rest in first forward speed and to pass through the different speeds to top direct drive with- | ||