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 document for improvements to gearbox control mechanisms.
Identifier | ExFiles\Box 136\4\ scan0152 | |
Date | 21th March 1930 | |
the locking member swings on its pivot and the forward tooth thereon engages with the forward notch on the guide rod. As the spring ball now presses upwards on the locking member to the rear of its pivot axis, the forward tooth of the locking member is maintained in engagement with its notch and the operating lever is also maintained in the corresponding position. When the gear lever is operated to return the mechanism to its neutral position, the initial pressure on the lever causes its lower end to swing the locking member on its pivot against the action of the spring ball and to withdraw the forward tooth of the locking member from engagement with the forward notch on the guide rod, after which the fork may be moved on its guide rod to the neutral position in which it again is engaged by the spring ball, or if desired it may be moved to its rearward position in which the rear tooth on the locking member engages with the rear tooth on the guide rod, and is locked in this position. If the gear lever is swung laterally in the opposite direction to that above described so as to engage with the locking member of the other shifting fork, the latter may be operated so as to be moved into its forward or rearward position and locked in this position in the manner described. By means of my invention, it will be seen that accidental displacement of the gear mechanism in the gear box is effectively prevented and the operation of the gear lever automatically locks and unlocks the control mechanism. My invention may be applied to gear boxes having other numbers of speeds than that above described, and to gear boxes with gate change arrangements. My invention may also be applied to control mechanisms other than for gear boxes. Modifications may be made in the example of my invention above described. Dated the 21st day of March, 1930. WILLIAM BRYSON, Chartered Patent Agent, 29, Southampton Buildings, London, W.C. 2. COMPLETE SPECIFICATION. Improvements relating to Control Mechanism, particularly Reference to Gear Boxes. I, BERNARD THOMSON, of Combe Close, Woldingham, in the County of Surrey, a subject of the King of Great Britain, do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement :— My invention relates to control mechanisms for variable speed gear boxes, and to the type of such mechanisms in which the striking members are locked in positions corresponding to the gear positions for the various speeds so as to prevent their displacement by shocks, vibration or the like, the unlocking and locking of the striking members being effected simultaneously with the gear-changing operations. The object of my invention is to provide an improved construction of control mechanism of the type indicated above. My invention consists in a control mechanism of the type indicated in which the operative connection between the control and striking members is effected through a member which also acts to lock the associated striking member in one or more positions corresponding to speed positions of the variable speed gear, the locking member being released on the operation of the control member to effect a gear change. My invention further consists in improved control mechanisms for gear boxes, to be hereinafter described. Referring now to the accompanying drawings in which similar parts, where desirable, are indicated by the same reference numerals. Figure 1, shows a sectional elevation of a control mechanism constructed according to my invention for the gear box of a motor vehicle, the parts being shown in the neutral position. Figure 2, shows a similar view with the parts locked in an operative position. Figure 3, shows a cross-section through the line III—III, on figure 1. Figure 4, shows a sectional elevation of a modification, the parts being represented in the neutral position. Figure 5, shows a similar view to that illustrated in figure 4, the parts being locked in an operative position. Figure 6, shows a section through the line VI—VI, on figure 5. In carrying my invention into effect, according to one form and as applied by way of example to the gear box of a motor vehicle, in which gear box the changes for the different speeds are effected by a ball-mounted control lever, I arrange the striking forks for positioning the gear wheels for the various speeds, to slide on separate guide rods which are fixed in the gear box casing. In figures 1, 2, and 3, only the lower portion of the control lever, 1, a single striking fork, 2, and a single guide rod, 3, are shown. The boss, 4, of the striking fork, 2, is formed with two diametrically opposite openings 5 and 5a, which are of rectangular section, and in the upper opening, 5, a locking member, 6, is arranged. The locking member, 6, is pivotably mounted on a screwed pin, 7, extending between the side walls, 8 and 9, of the opening, 5, so that the locking member, 6, may swing on an axis at right angles to the axis of the guide rod, 3. The upper portion of the locking member, 6, projects beyond the opening, 5, and is formed with a notch, 10, with which the spherical end, 11, on the lower end of the lever, 1, is adapted to engage. The lower face, 13, of the locking member, 6, is provided with teeth, 14 and 15, the operative faces, 16 and 17, of which form arcs of circles struck from the centre of the pin, 7, while a hemi-spherical recess, 18, is formed centrally on the face, 13. The faces, 19 and 20, of the locking member form parts of circles struck from the centre of the pin, 7. On the guide rod, 3, two notches, 21 and 22, are formed, the operative faces, 23, of these notches being arranged to correspond to the faces, 16 and 17, on the teeth, 14 and 15, respectively of the locking member, 6. Between the notches, 21 and 22, the face, 25, of the guide rod, 3, is flat, as shown in figure 3, and a casing, 26, is rigidly secured in a hole 27, the upper end of which opens on the face, 25. In the casing, 26, a ball, 28, is slidably mounted and is acted on in the upward direction by a spring, 29. One end of the spring, 29, abuts against the ball, 28, while the other end abuts against the face, 30, of the casing, 26. The lower end of the casing, 26, projects through the opening, 5a, in the boss, 4, of the striking fork, 2. In the central position of the striking fork, 2, figure 1, corresponding to the neutral position of the gear, the locking member, 6, is prevented from tilting by the teeth, 14 and 15, which bear on the face, 25, of the guide rod, 3, while the locking member and consequently the striking fork are locked in position by the engagement of the ball, 28, with the recess, 18. If the control lever, 1, is in the neutral position, as shown in figure 1, and it is desired to move the striking fork, 2, into the position shown in figure 2, the control lever, 1, is operated so that its end, 11, is swung to the left of the position in the former figure, whereby the fork, 2, with the locking member, 6, is also moved to the left, the ball, 28, being automatically disengaged from the recess, 18, by the movement of the control lever. When the tooth, 14, registers with the notch, 21, the forces exerted by the control lever and by the spring actuated ball, 28, which now acts at the end of an arm about the axis of the locking member, 6, swing this member in an anti-clockwise direction about its pin, 7, so that the tooth, 14, is forced into engagement with the notch, 21. The striking fork, 2, and also the control lever, 1, are locked in the position in which they have been set, as shown in figure 2, and this position corresponds to that of one of the speed positions of the gear wheels in the gear box. The spring actuated ball, 28, prevents the locking member, 6, becoming accidentally disengaged by vibration or shocks, while disengagement of the end, 11, of the control member, 1, from the notch, 10, laterally, in positions other than the neutral position, is prevented by the usual means. If it is desired to return the mechanism to the neutral position, shown in figure 1, the control lever, 1, is moved in the opposite direction to that above described. The initial movement of the control lever, 1, causes the end, 11, to swing the locking member in the clockwise direction against the action of the spring-actuated ball, 28, and to disengage the tooth, 14, from the notch, 21. The striking fork, 2, may then be returned to the neutral position when the ball, 28, engages again with the recess, 18, or the striking fork, 2, may be moved past the neutral position towards the right and into a position in which the tooth, 15, engages with the notch, 22. The latter position corresponds to another of the speed positions of the gear wheels in the gear box. For a three-speed and reverse gear, two such mechanisms as above described are arranged side by side in the gear box, the notches of the locking members in the neutral position being in alignment with one another so that the control lever may be swung so as to engage with either of the locking members and thereafter swung in either of the directions above described to effect the desired gear change. In figures 4 to 6, I have described a modified form of mechanism in which the striking forks are secured to guide rods. | ||