Patent GB-191216149-A (GB)
Title: An Improved Hydraulic Change Speed Gear for Power Vehicles.
Inventor: HAMMER LUDWIG
IPC: B60K17/10
Filed: 1912-07-10
Granted: 1913-10-10
Abstract: 16,149. Hammer, L. July 10, 1911, [Convention date]. F i x e d - abutment type; movable-abutment type; governing and regulating pumps etc.; packing drums &c.-A hydraulic change-speed and reverse gear for power vehicles comprises (1) a pump element with variably eccentric casing, (2) a member depending upon the instantaneous eccentricity of this casing and positively controlling the fuel supply in such a manner that the amount of fuel delivered corresponds to the power requirements, this amount being also automatically varied by a hydraulic piston acted upon by the pressure in the pump element, (3) a speed-regulating device acting upon the fuel pump, (4) by-pass devices for allowing the road-wheel motors to run light and for the braking of these wheels, and (5) a self-starting device for the apparatus. Fig. 1 shows a general arrangement of the apparatus, and Figs. 2 and 3 sectional views of the pump element. The driving- shaft 1 carries a piston head 2, in radial slots in which vanes or pistons 3 work. The vanes are surrounded by an eccentric casing 4 provided with ports 8, 9 working against a face in which are the ports 10, 11 of the delivery and suction pipes 12, 13. The casing is provided also with an extension lever 5 secured to a rotatable shaft 6, the turning of which regulates the eccentricity of the casing. Plates 15 are placed at each side of the piston head 2, which plates are pressed by a spring ring 16. The pressure space of the pump is located at the side of the rotating piston head adjacent the cover, so that the hydraulic pressure serves to keep the valve face of the inner casing against the joint surfaces of the cover. In the form shown in Fig. 1, the displacement of the casing 4 is obtained by the movement of the lever 17 attached to the shaft 6. This lever is pressed by a spring 18 against a stop 19 and is raised by a rod 23 through the lever 22 and the forked rod 20. The upward movement of the lever may also be limited by a stop. To keep the fuel supply always proportional to the instantaneous power req nirements. the lever 17 is connected to the operating- lever 27 of an exactly similar but smaller pump element 29 driven off the shaft 1, which pump supplies fuel through a pipe 30 to the carburettor 37. A branch from the pipe 30 leads to a needle valve 32, which is used to adjust the delivery of the fuel by by-passing a portion to the suction pipe 31. To prevent the working pressure of the system from rising above a certain limit, a pipe 43 leading from the delivery pipe 12 allows pressure liquid to act upon a piston 42, which is connected to the fuel-pump lever 27 through levers 25, 26. The lever 25 is also acted upon by a spring 49 through the medium of a lazy-tongs mechanism 46, 47, 47<1>, 48, 48<1>, so that the pull to be overcome by the piston is constant however strongly the spring is tensioned. To prevent the speed of the engine from falling too low, or in the case of a light load, rising too high, a speed regulator is provided consisting of a small pump element 53, Fig. 4. also driven bv the shaft 1 and delivering liquid to a cylinder 60, within which is a double-ended piston valve 61. This valve is loaded by compressed air or a spring. In the cylinder 60 are four ports, two leading by a pipe 65 to the suction pipe of the system, and two by pipes 63, 64 to a small hydraulic motor 52, of which the piston member carries the nut for the spindle 51 on which the spring bracket 50, 44 is fixed. According as to whether the pressure in the pipe 59 is too low or too high, the motor 52 is rotated in one or the other direction to increase or diminish the eccentricity of the fuelpump. The pump element 53 is set by means of a by-pass 5'6. The liquid delivered by the system passes through a reversing-valve 74 and pipe 78 to the distribution box 86, whence it is led by pipes 78', 78<11> to the wheel motors. The liquid, on returning from the wheel motors, enters a distribution box 87 and passes by a pipe 81 to the valve 74 and back by the pipe 13. If the car is running light, the liquid driven by the wheel motors operates a piston 66 and by-passes the pipes 12, 13 through the valve 73. A piston 70 in the cylinder 69 loaded by air pressure in the vessel 72 permits the movement of the piston 66. If braking is to be effected, the valve 73 is closed down by the rod 23 from the driver's seat. In some cases, a positive connexion is provided between the speed-regulator 52 or 46 and the valve 73 to produce automatic braking. To prevent the pressure of liquid in the wheel-motor circuit from rising too high, liquid may pass by a pipe 88 through a non-return valve 89 to a vessel 90 containing oil under pressure. If the pressure in this vessel becomes excessive, liquid flows into the chamber 93, where the oil is under approximately atmospheric pressure. To prevent the formation of air spaces in the wheelmotor circuit, a pipe 98 leads from a chamber 97 back to the circuit. Reversal of the wheel motors is effected by turning the cock 76 through ninety degrees. The pressure liquid in the chamber 90 may be led by a pipe 99 to the suction pipe 13 for the purpose of starting- up the main engine. When this is accomplished, the liquid delivered through the pipe 12 moves the piston 66 and finds its way through the pipes 98, 102 and cock 100 to the vessel 93. When the engine works with sufficient power, the cock 100 is closed. The Specification as open to inspection under Section 91 (3) (a) comprises also (1) a modified form of pump and (2) a construction of road wheel motor. (1) In the form of pump shown in Fig. 7 (Cancelled), the casing 4 is displaced by the rod 131 and co-operates with the truly-ground cover 7, pressure between the surfaces being maintained by the spring 138. Fig. 9 (Cancelled) shows another form without the outer casing, journals being provided at 131 and 142. The regulating of the working pressure, speed and fuel supply may be also carried out by the apparatus shown in Figs. 7 and 8 (Cancelled). The eccentricity of the piston casing is here obtained by the rotation of the lever 135 and screw 133, which causes the lateral movement of the nut 132 and rod 131. The end of the lever 135 is connected by a pin-and-slot mechanism to lever 27 operating the casing of a fuel pump 29. The nut 132 is connected by a lever 136 with the spindle 51 of the speed-governor 52, so that, bv the rotation of the nut, the eccentricity of the casing 4 is varied. The regulation of the working pressure in this case is effected by the pistonrod 40 acting upon a lever 139 secured to a screw similar to the screw 133. The spring arrangement 44, 47, 48, 49 may be replaced by ordinary springs 141. (2) The wheel motors are of the form shown in Figs. 5 and 6 (Cancelled). Liquid arrives in the hollow plug 105 and through the axle head 109 to the eccentric chamber formed by the wheel hub 112. Vanes 117 carried by the hub take the liquid thrust. The axle head is provided at each end with annular grooves forming journals into which grooves project extensions of the casing. Between the bottoms of the grooves and the cover and casing extensions a packing-ring 160 is placed. The end of the tube 105 is closed by a cover 123 and the axle part 106 is prevented from rotating by a screw 107. The pressure of the entering liquid is opposed to pressure exerted by the weight of the car on its bearings. This subject-matter does not appear in the Specification as accepted.