GB117279A - Improvements in or relating to Electrical Measuring Instruments. - Google Patents

Abstract

117,279. Rogers, R. H., Dorer, P. O., and Smith & Sons, S. May 12. 1917. Bases; contacts; indicators.-Switches for use on motor-cars &c. are contained in a casing with a rotatable bezel, which is used both as the switch handle or actuating-means and as a position indicator for the switch. The casing may contain electric or other instruments, or may be simply a switch casing. As shown in Fig. 2, the bezel B has an attached dial F, which rotates behind an apertured plate D carried by the instrument body A. The dial carries switch bushes J wiping over sets of contacts H. Spring studs K engage holes in the shell C to ensure definite positions of the bezel. As the latter is rotated, different connexions are made by the brushes J, which are indicated by lettering on the dial F appearing at the apertures D<1> in the plate D. The instrument may be a combined volt and ammeter and the switch used in a battery-charging and electriclighting plant. The instrument A, dial, and bezel are removably held to the base of the casing by the single screw G<1>. In a modification, spring blades M, Fig. 3, carried by posts on 'the base wipe over contact segments O<1> on the outside of a sleeve 0 carried by the dial F. The leads from the blades are taken to terminals L on bars of insulating-material on the base G. In a further modification, the indications are effected by a pointer driven through gearing hidden behind the dial by a toothed segment attached to the rotatable bezel; or the indications may be obtained by a mark on the bezel or casing coming opposite lettering on the casing or bezel respectively.