Patent GB-877186-A (GB)
Title: Improvements in or relating to power cultivators
IPC: B60K28/00
Filed: 1959-04-13
Abstract: 877,186. Change-speed gear. STAUB, G. April 13, 1959 [April 24, 1958], No. 12386/59. Class 80 (2). [Also in Group XXXI] A power cultivator comprises an engine which drives the wheels through a gear-box and a differential gear which incorporates dog clutches for disconnecting the drive to the wheels, the power take, off being drivable either directly from the engine or through the gear-box. The cultivator comprises an engine 3 having an output shaft 54 which drives a shaft 56, Fig. 3, through an overload slip coupling 60 having torque-limiting elements 62 and a shaft 66, rotatable upon shaft 56, through a centrifugal clutch 65. The wheels are mounted upon brake drums 25, Fig. 8, mounted on a shaft 16 driven by pinions 14, 22 which mesh with pinions 28, 29 slidable upon shafts 30 and 31 and which have dog clutch connections to the differential 32 which is driven by a worm 49 rotatable upon the shaft 56 and driven from the centrifugal clutch 65 either directly by engagement of a dog clutch formed by teeth 68 upon the shaft 66 and cooperating teeth in a sliding pinion 69, or through a gearing arrangement comprising sliding pinions 74 and 75 mounted upon a shaft 73 rotatable upon a shaft 72 and a sliding pinion 70 mounted upon a shaft 50 forming an extension of the worm 49. The shaft 66 is provided with teeth 66a with which the pinion 74 may be brought to mesh and the sliding pinion 75 may be brought to mesh with either of the pinions 69 or 70. The pinion 70 may be brought to mesh with teeth 79 upon the shaft 73. There are thus provided four forward gears, one being direct drive. A reverse gear is obtained by bringing a pinion 78 into mesh with the pinions 79 and 70, Fig. 5. The operating handle of the machine may be turned through 180 degrees, and by bringing a pinion 74a, Fig. 4, into mesh with the teeth 66a and pinion 74, there are provided for the new forward direction, three forward and a reverse gear. The shaft 56 has fixedly mounted therein a pinion 114 which meshes with a pinion 112 loosely mounted upon a shaft 107 upon which is slidably but non-rotatably mounted a pinion 110. The pinions 110 and 112 have cooperating dog clutch elements 110 and 113. A pinion 106 is mounted upon an extension of the shaft 50 and the pinion 110 may be brought to engage therewith providing a drive for the power take-off coupling 107a through the gearbox, or by coupling the dog clutch elements 110 and 113 the power take-off coupling 107a is driven directly through the shaft 56 and clutch 61 from the engine. The selector forks 80, 81, 82 for the pinions 69, 70, 78 are mounted on rods 80a, 81a and 82a terminating in the selecting notches 80b, 81b and 82b respectively, the latter being engaged by a ball-ended lever 88 controlled from the handle of the cultivator via the links 96 and 95. The sliding pinion 74 is controlled from the handle 85 via the members 83 and 84 and the sliding pinion 110 is controlled through a fork 110a from a handle operating a shaft 115 (Fig. 6). The pinions 28, 29, forming dog clutches with the differential 32, are slidably moved upon their shafts 30, 31 under the control of forks 35 and members 41, 43 terminating in the pivots 47, 48 operated from the handle through links 47a, 48a; 119, 120. The brake shoes within the brake drums 25 are also operated from the handle through linkages and brake cables 131 and 132. The control handle terminates in a member 98 and is articulated upon a spindle 119 and may be retained in a desired position by engagement of a spring-controlled plunger 102 with a hole 101 in a casing 91. When shifting the control handle through 180 degrees, the brake gear and the gearing links 119, 120 must be disconnected and then re-connected.