Meter encoding register with tapered aperture in baffle insert

Claim 1

A multiple shaft meter encoding register for a utility meter having a metering movement responsive to a metering quantity, comprising: a frame; a plurality of shafts rotatably mounted in the frame; means for interconnecting the shafts with an associated metering movement for concurrently rotating the shafts at different predetermined rates in response to actuation by the associated metering movement; means for generating electrical signals responsive to the position of the shafts and including a plurality of code members each fixedly mounted to a separate one of the shafts; the electrical signal generating means comprising an illumination source and a plurality of encoding photosensitive components, each of the code members alternately transmitting and blocking illumination between the illumination source and the photosensitive components in response to rotation of the shafts; baffle means between the illumination source and the photosensitive components for isolating light rays from the source and for avoiding ambient illumination, and the baffle means including tapered apertures aligned with corresponding photosensitive components, each aperture having a smaller end nearer the illumination source and a larger end nearer the photosensitive component.