| 摘要 |
Apparatus (10) comprising rotatable feed belts (16,18) driven by a reversible electric servo-motor (20) which is operated by a pre-programmed electronic controller (30) feeds accurately measured lengths of a wire strand (12), regardless of wire slippage which may occur relative to the feed belts. Controller (30) receives feedback signals from an encoder (22) indicative of the distance and direction wire (12) actually moves, compares the feedback signal with stored data and recognizes the amount and direction of any wire slippage. Wire movement less (or more) than the desired length results in forward (or reverse) operation of servo-motor (20) and feed belts (16,18) to move the wire forward (or in reverse) until the desired length is reached. Encoder (22) is operated by a measuring wheel (24) which engages and is rotated by wire strand (12) itself during forward or reverse movement. Either "run-out" of wire strand (12) or too large a "following error" shuts down the apparatus. Measuring wheel (24) is movable by a positioning cam (28) into direct engagement with feed belt (18) for set-up and test of apparatus (10) before a wire strand is present. The feed belts (16,18) are adjustably movable by a pneumatic actuator (26) relative to each other to tightly engage a wire strand regardless of wire diameter. A tachometer (21) on servo-motor (20) counts the lengths fed. |
