Patent GB-808202-A (GB)
Title: Improvements in or relating to manually and power operated steering mechanism for motor vehicles
IPC: B62D5/24
Filed: 1955-06-27
Abstract: 808,202. Vehicle power steering. ROSS GEAR & TOOL CO. Inc. June 27, 1955 [July 7, 1954], No. 25238/57. Divided out of 808,201 [Group XXIV]. Class 79(5) In vehicle power steering mechanism the steering shaft carries an externally toothed gear C, Fig. 4, meshing with an internally toothed gear C<SP>1</SP> connected to the input component of the steering gear, torque reaction between the gears C, C<SP>1</SP> actuating valve means to energize a fluid operated motor. As further shown in Fig. 4 the shaft B connected to the steering wheel (not shown) is pivotailly mounted at B<SP>1</SP> in a casing A and carries at its lower end the gear C meshing with gear C<SP>1</SP> rotatably mounted at M in the casing A and connected to a shaft D. The shaft D is connected by balls F to a piston E slidable in cylindrical portion A<SP>3</SP> of the casing A and connected to a rack G meshing with a gear segment H carried on a shaft H<SP>1</SP> extending out of the casing A to be connected to the steering linkage (not shown). Manual rotation of the shaft B causes axial movement of the member E and hence rotation of the shaft H<SP>1</SP> to steer the vehicle. Manual rotation of the shaft B also causes planetary movement of the gear C relative to the gear C<SP>1</SP> due to the torque reaction, such movement causing movement of the shaft B about its mounting B<SP>1 </SP>to operate valves I, P thus selectively pressurizing the faces of the piston E to give power assisted steering. As shown in Fig. 6 the valves I, P each comprise a fixed sleeve I' and a piston I<SP>3</SP> slidable within the sleeve, the sleeve having channels d, f<SP>1</SP> and the piston channels a, b, g. The channels d of the valves I, I' are connected by channels d\ e to opposite sides of the pistom E and the channels f<SP>1</SP> are connected by channels f, J\ J<SP>2</SP> to a nipple J in the casing A connected to the output of a pump (not shown). The channels a, g in each valve are separated by a corrugated rib whereby the nipple J is normally connected to the channels e, hence connecting the pump output to both faces of the piston E. The channels a, b are separated by a rib c having an opening c<SP>1</SP> into a bore i in each piston P. The bore i houses a spring I' and a recessed plug I<SP>4</SP> whereby the spring I<SP>5</SP> urges the pistori I<SP>3</SP> against a collar K on the shaft B and the plug P against a head J<SP>3</SP>. The connection of the pump output through the opening c<SP>1</SP> to the bore i further urges the piston P against the collar K. The channel b has on its outer side a corrugated rib h permitting fluid flow from the channel b to a space h at the end of the piston, the spaces h being connected to a nipple J<SP>4</SP> connected to a fluid return circuit (not shown), whereby in the normal positions of the pistons P the inlet nipple J is connected to the exhaust nipple J<SP>4</SP>. Bearing against the collar K is a piston L subject to the fluid pressure in the inlet nipple J and serving to mesh the gears C<SP>1</SP>, C<SP>1</SP>. Reference has been directed by the Comptroller to Specification 705,372 [Group XXIX]