Patent GB-361808-A (GB)
Title: Improvements in or relating to electrically driven vehicles
IPC: A01B3/74
Filed: 1930-10-08
Abstract: 361,808. Arrangements of winding- apparatus on motor vehicles. SACERDOTI, C., 30, Via Castelvetro, Milan, Italv. Oct. 8, 1930, No. 12553/31. Divided on and addition to 348,527. [Class 78 (v).] In an electrically-driven tractor vehicle of the type described in the parent Specification in which the vehicle is supplied with electrical energy through a trailing cable adapted to be wound on a drum driven through a friction clutch device, a differential transmission is interposed between the friction clutch and the driving motor. Means are also provided for automatically regulating the clutch friction by the cable tension. The driving motor is placed in a low position in the vehicle frame. The cable is guided with respect to the winding drum by an eccentric device or by a member having two crossed threads of opposite pitch arranged to control a guiding device. Joints are provided in the supply cable to permit relative rotation of adjacent sections. In the construction shown in Fig. 1, the vehicle comprises a motor 5 arranged as low as possible in the frame. A revolving support 2 for the supply cable 1 is mounted in a hollow standard 10, and a pulley 8 guides the cable to a winding drum 4. The pulley 8 is carried by a forked collar 11 which is axially slidable on the standard 10. The collar 11 is formed with a screw-threaded lug 12 through which passes a screw-threaded shaft 14 rotatable in either direction' and mounted on the vehicle frame. Bevel wheels at the lower end of the shaft 14 mesh with a bevel wheel 15 carried on a shaft 16 and driven by gearing 17 from the winding drum 4. As the drum 4 revolves to wind or unwind, the pulley 8 is respectively raised or lowered, thus guiding the cable. The motor 5 drives one element 21 of a friction clutch; the element 22 of the clutch being secured to the drum 4. An adjustable spring 23 allows of adjustment of the pressure between the elements 21, 22 of the clutch. The movements of the guide pulley 8 may be controlled by an eccentric 25, Fig. 2, arranged to operate a rod 26 mounted firmly on the collar 11. The eccentric 25 may be driven from the drum 4 by gearing 27, 28. The guide pulley 8 may be controlled by a rod 29, Fig. 3, formed with double-inverted quick-pitch interconnected screw threads. The rod 29 is rotated from the winding drum 4 and engages a finger 30 carried by the collar 11. Fig. 4 shows a rotatable joint for the cable. The ends of a pair of elements 11, 1<11> are respectively provided with coupling heads 31<1>, 31<11> which interengage as shown. Collecting rings 32<1> and brushes 32<11> are fixed to the respective parts of the joint to ensure electrical continuity. Fig. 5 shows a device for obviating stress on the supply cable due to excessive pull. The support pulley 2 for the supply cable 1 is mounted on an arm 2<1> pivoted to a support 3. A rod is hinged to the arm 2<1> and connects it to an oscillating beam 32 connected to one element 33 of a friction clutch 33, 34 so that the pulley 2 controls the movement of the element 33 relatively to the element 34. A control spring 35 is attached to the arm 2<1>. Fig. 6 shows a differential mechanism included in the gear driving the drum 4 and designed to allow slip in the clutch 33, 34. The element 33 is driven by a shaft 36 carrying a differential gear wheel 37. A gear wheel 38 is driven by a shaft 39 from the motor. The gears 37, 38 are interconnected by planet wheels rotably mounted on a casing 40. A helicoidal crown wheel 41 mounted on the casing 40 meshes with a worm 42 driven by bevels 43 and spur gears 44 which are rotated by the drum 4. The pinion of the gears 44 is loosely mounted on a shaft 45 and is adapted to be connected for driving in one direction by a ratchet wheel 46 which engages a pawl pivoted on the shaft 45. A ratchet 47 is mounted loosely on the shaft 45 and engages a pawl on the engine frame to prevent rotation of the shaft in the other direction. In operation, when the vehicle approaches the main supply terminals, the cable is wound in by the drum 4 rotated by the shaft driving the clutch element 33. The gears 37, 38 revolve, the casing 40 being held stationary as the helicoidal gear 41, 42 is nonreversible and is held by the ratchet 47. When the vehicle recedes from the main supply terminals, the pinion 44 is rotated and the drive 45, 43, 42, 41 and the casing 40 is rotated so that the shaft 36 is slowed down or stopped.