Patent GB-160315-A (GB)
Title: Improvements in or relating to the automatic control of variable speed gears for self-propelled vehicles
IPC: F16H61/02
Filed: 1920-01-07
Abstract: 160,315. Oddie, F. A. Jan. 7, 1920. Automatic speed or power control; controlling-apparatus, arrangements of hand, foot, and transmission gear in connection with. - Comprises automatic speed control in which a constantly reciprocating member is adapted to operate a selector member to change the gear up or down whenever a centrifugal governor driven from the primemover shaft interposes a connection between the reciprocating member and the selector member. The change - speed gear shown is of the kind described in Specification 17706/14, in which a rod A sliding within the driving and driven shafts B, E and having an enlargement A<2> adapted to operate radially-acting clutches to grip the gear-wheels in turn to the shaft E, is moved from the neutral position shown (1) to the right for a reverse drive, and (2) to the left for the low and successive higher forward speeds. The direct drive is obtained by clutching the shafts B, E together by a final movement to the left of the rod A the countershaft through which the other speeds are obtained being then de-clutched by the action of a reduced part A<3> of the rod on a clutch B<2>. The rod A is rigidly connected with a cylinder C<2> on a slider C which is normally locked by double pawls E<1> engaging with fixed teeth F<1>. A spring-loaded plunger G carried by a slidable bar H works within the cylinder C<2> and has a pin G' with rollers G<4> adapted to engage one or other of the pawls and lift it clear of the teeth. Thus, when the bar H is operated, the plunger is moved against the action of one of its springs and lifts the corresponding pawl, whereupon the slider C is released and the spring moves the slider and the gear-changing rod A through the space of one tooth to change the gear. A box K is constantly reciprocated along the bar H by link-work Land gearing driven from the shaft B, and is formed with pawl teeth K<1>, K<2>, adapted to engage teeth formed on the bar H, so that whenever the box is moved laterally across the bar H by a centrifugal governor N, also driven from the shaft B, one of the pawl teeth is engaged with the teeth on the bar H and the next stroke of the box K in the corresponding direction is imparted to the bar H, thus changing the gear. The gear can be locked in the neutral position shown by means of a hand-operated cam-slot which passes over a bar K<3> in the governor connection to the pawl box K and holds it against lateral movement. For the reverse, the cam-slot is moved further and presses the box K to one side until one of its pawls engages an extra tooth H<4> on the bar H, after which the bar H is moved further to the right and the reverse gear is engaged. A spring-controlled rod S normally prevents the reverse gear from being engaged, and a hand-lever S<3> which operates this rod to allow the reverse to engage may also control the cam-slot effecting the reverse. The main clutch (not shown) is controlled by a pedal Q<3>, and is also automatically disengaged whenever the gear is changed by means of a bar P which has teeth engaged by the box K and is so connected to the clutch pedal by links P<3>, P<4>, and stops P<5>, P<6>, that the pedal is depressed whether the bar P moves to the right or the left. The bar P is also connected through a spring device to the throttle pedal Q<7> so that the latter can be independently operated, but the throttle is partially closed by the bar P during a change up in the gear and is opened during a change down. In order to modify the action of the governor when the throttle is actuated, a spring T forms a connection between a. throttle link T<2> and a lever O through which the governor controls the box K.