Patent GB-1013113-A (GB)
Title: Improvements in or relating to a motor vehicle
IPC: B60K17/10
Filed: 1961-12-08
Abstract: 1,013,113. Tractors; controlling vehicles. C. VAN DER LELY N.V. Dec. 8, 1961 [Dec. 9, 1960], No. 44034/61. Heading B7H. [Also in Division F2] A tractor frame comprises a transmission housing 5'and beams 6, 7 and 8 upon which is mounted the engine 4. A seat 11 is carried by an arm 12 from a rotary mounting which includes a notched plate 19 which co-operates with a spring-loaded plunger 29 for locating the seat at a given angle. The seat includes a housing 13 in which levers 45 and 53 are mounted for rotation about shafts 46 and 43 at rightangles to one another, the two levers 45 and 53 being connected to a common actuating shaft 50 upon which is mounted a sleeve 51 which is slidable on a pin 55 carried by a crank 56 of a linkwork 56, 57, 63, 64, 65, 66, Fig. 12, which has a pin and slot connection with the actuating arm 72 of an hydraulic steering mechanism, Fig. 11, comprising valve members 80, 81, supply pipe 95 and return lines 96, 97, a fixed piston 101 and a movable cylinder 104, to which is attached a rack 109 engaged by a pinion 111 on the steering shaft 110 which is connected to the mounting 112 of a single steerable front wheel. A gearshift lever 113 which may be for varying the swashplate angle of an hydraulic pump/ motor transmission, is operative through members 128, 130, 132 and has an upper part 117, Fig. 9, bent to engage an inclined sleeve 120 carried by a lower portion 118, the parts 117 and 120 having a number of alternative pin-andslot connections so as to vary the position of the operating handle to suit the position of the driver's seat, the parts being held together by the pressure of a spring 122. The steering arrangement is such that a movement of the levers 45 and 53 to the left transversely of the tractor causes steering to the left, the levers 45 and 53 having " changed places" by rotation of the seat through 180 degrees. Similarly if the seat is rotated through 90 degrees, movement of the levers 45 and 53 to the left again produces steering to the left, the levers now pivoting about the shafts 43 instead of the shafts 46. The tractor may comprise a braking system to provide differential braking upon steering which comprises a pedal 151, a master cylinder 158, and a fluid reservoir 161 having an output line to a cylinder 164 from which ducts 178 and 179 lead to the back wheel brake cylinders respectively. A pair of valve members 165 and 166 is located in the cylinder 164 and each is connected respectively to a piston 169 and 170. A valve spool 183, 184 is connected to a follower 192 acting in a cam groove 193 in a member 194 connected to a rod 195 connected to the steering linkage. Pressure fluid is supplied through a duct 190 to the space between the valve pistons 183, 184. When the vehicle is being braked while being turned, the cam member 194 is moved by the steering system and the valve pistons 183, 184 moved in one direction or the other, so that pressure fluid is admitted from the duct 190 to either the duct 175 or 176 according to the direction of steer with consequent movement of the piston 169 or 170 acted upon, and throttling or cessation of the supply of pressure fluid in the line 178 or 179 by the valve member 165 or 166 whereby the braking effect upon the outer wheel is reduced or removed. In an alternative mechanical system for differential braking, the brakes are actuated by levers 215, 216 through rods 213, 214 which have sliding connections 207, 208 with a rod 204 connected by a rod 203 to the brake pedal 199. The rod 204 is connected to the steering system so that upon turning, the connection 205 between the rods 203 and 204 is nearer one or other of the rods 213 or 214 with consequent increase of the braking force in the one and decrease in the other. The tractor may also be equipped with a differential lock.