GB295063A - Improvements in speedometer - Google Patents

Abstract

295,063. Marks, E. C. R., (A. C. Spark Plug Co.). May 9, 1927. Magnetic speed indicators; transmission mechanism; registering distance upon counters. -In a speedometer of the eddy-current type, the indicating drum is arranged coaxially with a fixed annular magnet, and between the magnet and the rotor. The indicating assembly is axially adjustable with reference to the magnetic field. Improvements relating to the internal transmission mechanism and the general transmission mechanism and the general arrangement of parts are described. A C-shaped permanent magnet 35 is clamped by screws 37 in a groove in a platform 4 projecting from a main frame 1 made of aluminium. Within the magnet is arranged a spider-shaped rotor 21 having upturned lugs 22 on each arm, and the cylindrical flange 57 of the drag element 55 is disposed between the magnet and the rotor. The drag element, which is preferably formed of an alloy of aluminium and magnesium, is mounted on a spindle 54, movement of which is restrained by an adjustable spring 60. The spindle 54 is supported in jewel bearings in a cup 50 and a cap 52 both of which are carried by a frame 38. The frame 38 is secured to the frame 1 by screws 43, 45 so that the position of the indicating assembly may be readily adjusted axially with reference to the magnetic field. The speed indicators marked on the flange 57 of the drag element are visible through the gap in the C-shaped magnet 35. The rotor 21 is mounted on a vertical shaft 20 which is connected to an inclined vehicle-driven shaft 8 by a flexible shaft 25. Lubricating pads 23. 80, 81 and a packing washer 82 are provided. The mileage counters 70 are driven by a worm 15 on the shaft 8 through a cross shaft 72. They are mounted in a frame 73 which is secured to the main frame 4 by screws 76. The outer casing 3 is preferably formed of steel.