Patent GB-778045-A (GB)
Title: Improved digger and scraper apparatus
IPC: E02F3/65
Filed: 1955-08-26
Abstract: 778,045. Motor vehicles. GENERAL MOTORS CORPORATIONS. Aug. 26, 1955 [Sept. 14, 1954], No. 24564/55. Classes 79(2), 79(3) and 79(5). [Also in Group XXI] Digger and scraper apparatus comprises a frame 10 supporting a scraper bowl 15 and supported by pairs of front and rear wheels 18 and 14 which are connectable to be driven from a common engine 16 mounted on the frame. The frame 10 is pivotally connected at 12 to a front frame 11 having arms 20 which extend on either side of the scraper bowl 15. The frame 10 and bowl 11 are raised or loweredby the action of fluid pressure operated jacks 24. The front wheels 18 are pivotally mounted at 30, 31, on a frame 26 which is steerable about a substantially vertical axis 27. The pivotal joint 30, 31, permits oscillation of the axle of the wheels 18 in a transverse plane. The member 26 has upper and lower portions 26b, 26a journalled respectively in extension arms 22b, 22a of a member 22 forming part of the frame 11. The member 22 and arms 20 are joined by a cross tube 21 of polygonal cross section. The member 26 is steerable relative to the member 22 by means of a pair of fluid-pressure operated jacks as described in Specification 764,513. The drive from the motor 16 passes through a fluid coupling or torque converter 32, and a three speed gear box 33, to a combined two speed gear box and torque divider 34. One output shaft 36 of the torque divider 34 is connected to a differential gear driving the rear wheels 14. The other output shaft 35 of the torque divider 34 extends laterally to a bevel gear 40 which transmits the drive via a longitudinally extending shaft x and universal joints 44, 45, 46, and 47 to bevel gearing 41. The latter connects with a laterally-extending shaft leading to further bevel gearing in a gear casing 42 mounted between the arms 22a, 22b. An output shaft 50, Fig. 4, from the casing 42, is connected by a universal joint 51 to a shaft 50<SP>1</SP> which extends within and is concentric with the bearing of the portion 26a on the arm 22a. The shaft 50<SP>1</SP> is connected to a double universal coupling 52 which is in horizontal alignment with the pivotal joint 30, 31, and is connected to a differential gear 43 connected to the front wheels 18. The input shaft 33a of the torque divider 34, is rigid with an internally toothed gear 62 in mesh with planet pinions 64 themselves in mesh with a sun gear 63 rigid with a shaft 72. The planet pinions 64 are journalled in a planet carrier 65. The shaft 72 may be moved axially by the action of a shift fork 75 to withdraw the sun wheel 63 from engagement with the planet pinions 64 and bring it into engagement with internal gear teeth 67a carried by the planet carrier 65. At the same time, teeth 73a carried by a collar 73 rigid with the shaft 72, are drawn out of engagement with corresponding teeth formed on the housing 60 of the torque divider. The planet carrier 65 carries a further set of planet pinions 82 which are in mesh with a sun gear 80 rigid with a hollow shaft 86 connected by bevel gearing 87, 88, to the output shaft 35 leading to the front wheels 18. Each planet pinion 82 is rigid with a further pinion 82a in mesh with an internal gear 81 which is itself in mesh with a gear 85 on the output shaft 36 leading to the rear wheels 14. A brake shoe, Fig. 5 (not shown), is adapted to act upon a brake drum 90, carried by the shaft 36, to an extent dependent on the degree to which the wheels 18 are turned more than 45 degrees in either direction from the straightahead position. A cam rigid with the member 26 bears on a follower which is connected to the operative member of a valve disposed in a fluid pressure line leading from a reservoir to a cylinder for actuating the brake shoe. The gearing of the torque divider 34 is so selected to divide the torque from the motor between the wheels 14 and 18 in a ratio proportional to the average weight distribution on each pair of wheels.