Renishaw: RGA22 plunger - M9535-0151
The applicator body has a retractable spring loaded plastic plunger that, during operation, applies a tacking force to the scale. The plunger is raised and lowered by means of the release knob shown and is held in both positions by detents. The plunger is retracted for setup purposes and lowered when scale application takes place. The release knob is shaped in arrowhead form such that if access or view is restricted it is possible to both determine the position of the plunger and raise or lower it.

Scale guide: The scale guide locates into the applicator head beneath the plunger knob and is retained by detents. In operation the scale guide guides the scale into the applicator whilst simultaneously removing the scale backing paper. It is detachable from the applicator body to enable easy loading of the scale and also incorporates a locking mechanism to prevent the scale falling out during initial setup. The lock is a pinch roller which is activated by tightening the extension handle. The release paper is separated from the scale by a blade within the guide and ejected to one side.