Abstract: An improved chain motor drive controller is provided for a chain hoist. The system employs a position encoder including a position sensor located within the casing of the chain hoist to producing encoded electrical position signals. A motor pulley is mounted on the chain motor rotary drive shaft and is coupled by a cogged belt to rotate an encoder pulley that is mounted on the same shaft as the position sensor. A mechanical coupling is thereby provided entirely within the casing of the chain hoist to transmit rotary motion from the rotary drive shaft directly to the position sensor. Also, tracking circuitry, likewise located entirely within the chain hoist casing, receives electrically encoded destination signals and compares these to signals from the position sensor.

Abstract: An improved chain motor drive controller is provided for a chain hoist. The system employs a position encoder including a position sensor located within the casing of the chain hoist to producing encoded electrical position signals. A motor pulley is mounted on the chain motor rotary drive shaft and is coupled by a cogged belt to rotate an encoder pulley that is mounted on the same shaft as the position sensor. A mechanical coupling is thereby provided entirely within the casing of the chain hoist to transmit rotary motion from the rotary drive shaft directly to the position sensor. Also, tracking circuitry, likewise located entirely within the chain hoist casing, receives electrically encoded destination signals and compares these to signals from the position sensor.

Abstract: A chain hoist having a casing into which and with respect to which a chain travels is provided with an externally mounted position encoder assembly. A releasable connector, such as a ratchet strap, is employed to firmly but removably couple the position encoder assembly housing externally on the chain hoist casing. The releasable connector holds the position encoder assembly housing in a fixed position relative to the chain hoist casing. The position encoder assembly has a chain gear that is rotatably mounted relative to the position encoder assembly housing proximate to the chain access opening in the chain hoist casing. The precision encoder assembly chain gear engages the portion of the chain that is maintained under tension at a location externally of the chain hoist casing and rotates as the chain travels relative to the chain hoist casing.