Importance

Loading Importance Indicators...

Abstract

In an automatic fastening machine for installing fasteners in a workpiece provided with a hole for receiving a fastener having a longitudinal axis, wherein a work axis extends through the hole and wherein the fastener is held in a holding position prior to installation in the hole so that the fastener is oriented with the longitudinal axis thereof parallel to the work axis, a method and apparatus for detecting tipped or mis-oriented fasteners while in the holding position and prior to being upset in the workpiece, the method and apparatus utilizing at least one beam of energy which is influenced by the fastener orientation. Energy is radiated along at least one path intersecting the fastener when in the holding position and the radiated energy is received and a response is given to the amount of energy interrupted by the fastener in a manner providing an indiction if the fastener longitudinal axis is not parallel to the work axis. Preferably, the energy is radiated along two paths disposed at angles to each other and intersecting in a manner such that when the fastener longitudinal axis is parallel to the work axis, equal amounts of energy are interrupted, and when the fastener is mis-oriented unequal amounts of energy are interrupted thereby providing an indication of fastener mis-orientation. The energy comprises a laser beam in the form of a band having a width extending between longitudinally extending edges of the band. Two laser beam bands are disposed at angles and with an edge of each band intersecting the longitudinal axis of the fastener whereby in any mis-oriented disposition of the fastener, unequal amounts of the beams are interrupted thereby providing an indication of the mis-oriented fastener. The indication of a tipped or mis-oriented fastener is immediately signaled to the machine control to stop the machine or take whatever corrective action is appropriate to avoid damage to the workpiece. The accuracy and effectiveness of the method and apparatus of the present invention provides a level of confidence in tipped fastener detection thereby avoiding any need to slow the fastnener insertion cycle and even allowing an increase in fastener insertion speed so as to increase the overall production rate.

Loading the Abstract Image...

First Claim