Moving-coil electrical instruments with bearing structure

A moving-coil electrical instrument comprising a frame member defining a pair of aligned apertures, a spindle, a pair of bearings mounted in said apertures in which respective ends of the spindle are rotatably mounted, each of said bearings having a part mounted in the respective said aperture for movement between first and second angular positions about the axis of the spindle, one of said bearings having a supporting surface against which the respective end of the spindle bears, an electrical coil, means mounting the electric coil on the spindle for angular displacement about the axis thereof, a core member of a magnetic circuit embraced by said coil, and first and second means engageable by respective ones of said bearing parts to constitute bayonet mountings to mount those parts in their respective said apertures in said frame member when in said first angular positions with the said supporting surface of the said one bearing located at a predetermined and fixed position within the said one bearing, and to permit removal of those parts from their respective said apertures when in said second angular positions.

A moving-coil electrical instrument comprising a frame member defining a pair of aligned apertures, a spindle, a pair of bearings mounted in said apertures in which respective ends of the spindle are rotatably mounted, each of said bearings having a part mounted in the respective said aperture for movement between first and second angular positions about the axis of the spindle, one of said bearings having a supporting surface against which the respective end of the spindle bears, an electrical coil, means mounting the electric coil on the spindle for angular displacement about the axis thereof, a core member of a magnetic circuit embraced by said coil, and first and second means engageable by the said part of said one bearing and the said part of the other bearing respectively to constitute bayonet mountings to mount the said parts in their respective said apertures when in said first angular positions with the said supporting surface of the said one bearing located at a predetermined and fixed position within the said one bearing, and to permit removal of those parts from their respective said apertures when in said second angular positions, the said first and second means being constituted by a second part of the said one bearing and the frame member respectively.

A moving-coil electrical instrument comprising a frame member defining a pair of aligned apertures, a spindle, a pair of bearings mounted in said apertures in which respective ends of the spindle are rotatably mounted, one of said bearings having a part mounted in the respective said aperture of the frame member for movement between first and second angular positions about the axis of the spindle, the said one bearing having a supporting surface against which bears the respective end of the spindle, a carrier member mounted on the said spindle, an electric coil mounted on the carrier member with the coil being radially displaced from the spindle, a body mounted on the carrier member to counter-balance the coil, the center of mass of the said body being spaced from the plane which includes both the center of mass of the coil and the longitudinal axis of the spindle, a core member of a magnetic circuit embraced by said coil, and means engageable by said part of said one bearing to constitute a bayonet mounting to mount the said part in the respective said aperture when in said first angular position with the said supporting surface located at a predetermined and fixed position within said one bearing and to permit removal of the said part from the respective said aperture when in said second angular position.