Probe locking washer

A probe locking washer (10) for substantially preventing unwanted loosening of a probe mounted on a receiver unit of an animal training device in which the receiver unit is mounted on an animal collar. The probe locking washer (10) of the present invention includes a disk member (25) having an upper surface (30) and a lower surface (35) and a centrally disposed hole member (40) which allows the probe locking washer (10) to be mounted on the mounting post (20). The probe locking washer (10) also includes a countersink member (45) disposed in the lower surface (35) of the disk member (25) and which includes a plurality of internal radial spline teeth (50) for providing radial resistance to any untightening force caused by vibration or other untightening force. Additionally, the upper surface (30) of the disk member (25) carries a raised rib (55) that is configured so as to surround and register with the external shape of the probe (15) thus engaging the probe (15) in a manner that substantially prevents rotation of the probe (15) within the rib (25). Thus, the rib (55) locks the probe (15) to the probe locking washer (10) and radial spline teeth (50), which are disposed in the countersink member (45), substantially lock the probe locking washer (10) to the mounting post (20) on which the probe is secured. In this manner, unwanted rotation of the probe is substantially prevented.