Inventors:
Richard L. Patterson - South Euclid OH
Jyoti Mukherjee - North Royalton OH
Edward L. Slaby - West Farmington OH
Robert A. Furmanek - Maple Heights OH
Assignee:
The Warner & Swasey Company - Cleveland OH
International Classification:
B23B 1300
Abstract:
A tool force sensor assembly (20) generates an electrical signal which is related to the change in force applied by a tool (24) to a workpiece (28) and is indicative of the wear condition or failure of the tool (24). The sensor assembly (20) is mounted in force transmitting relationship between a movable tool support (30, 36) and a nut member (44, 45) which is driven by screw shaft (40, 41). The sensor assembly (20) comprises a plurality of ring-shaped piezoelectric transducers (48) which are held in preselected, circumferentially spaced relationship to each other around the screw shaft (40, 41) by a retainer ring (56, 58) which is sandwiched between a pair of load distribution plates (52, 54). Fasteners (46) extend through each of the transducers (48) and mount the sensor assembly (20) between the nut member (44, 45) and the tool support (30, 36). An alternate form of the retainer ring (80) is formed by molding the transducers (48 ) within a layer of flexible molding material which allows the transducers (48) to seat properly against the load distribution plates (52, 54).