Encoder having first and second housing portions and guide means

摘要: An encoder includes a casing having an open end and base which fits in the end. Trapezoidal cutouts are arranged to receive partly trapezoidal projections on base. The contains optical sensor, circuit board for operation of timing disc mounted rotary hub. hub has passage drive shaft motor, is register with opening During assembly, passed through motor urged towards one another push into casing. When enters casing, received guide surface engages centering Once cutouts, rotated relative each other secure Due shape projections, moves direction away from during rotation. This causes disengage