Ersted

The appellant holds patent No. 1,625,769, issued to him on April 19, 1927, for a clutch engaging device, especially adapted for hoisting machines. Alleging infringtement thereof by defendant, he brought this suit for an injunction and accounting.

As is usual, the clutch side of the drum in such hoisting machines is normally held out of operative engagement with the drive gear by a coil spring. By means of a lever, the operator effects engagement by causing two helix members or “erowders,” resembling opposed saw-tooth collars, to rotate or climb one upon the other, thus forcing, the drum into operative contact with the drive gear. The problem was to provide a means of indicating to the operator the force to be applied, in an amount sufficient to effect the engagement, but not so much as to overstrain the parts. This object appellant attains in his invention by means of a partially depressed coil spring mounted upon a bolt adjustably secured at one end to the drum housing. The other end of the bolt, after passing through an eye in the end of an arm on one of the helix members, is fitted with a threaded nut, by means of which the arm is held in contact with the spring, and the…