Lifting hook with load indicator - includes compression coil spring in case, with rack and pinion transmitting relative movement to indicator needle

摘要

The lifting hook with a load indicator includes a box through which a rod carrying the actual hook passes. Inside the box is a coil spring which is compressed by the action of the load on the hook. The movement of the rod inside the box is connected to an indicating needle on the outside by a multiplying linkage to show the amount of the load. A toothed rack is moved by the rod, and this in turn acts on a pinion. This pinion is connected with a second pinion to move the needle on the indicating dial. The length of the connecting rod between the two pinions is variable. Reference marks are movable behind a window in the box to facilitate the display of a load in excess of a preset value.