Abstract: A mechanical cycle counter incorporates a cast aluminum, thermal isolating upwardly open connector coupled to a steam powered cyclic actuator depending stainless steel cylinder closed off at opposite ends by stainless steel end caps. A disk-like piston slides interiorly of the cylinder and is extended by a piston rod upwardly through the cylinder and through a hole within the bottom of the connector. A mechanical counter oscillation arm rotates approximately sixty degrees and is mounted to a shaft bearing a plurality of rotary wheels. A horizontal portion of the oscillation arm is in the path of the projecting end of the piston rod. A chamber beneath the piston and above the lower end cap receives steam. A stainless steel coil spring concentrically surrounds the piston rod and has one end abutting the piston and the opposite end abutting the upper end cap.

Abstract: A toggle linkage over-center mechanism employs first and second solid, metal links having facing axial ends pivoted to each other for pivoting about a first axis, the first link is pivotably coupled at one end to the fixed support for pivoting about a second pivot axis. The second link has an opposite axial end pivotably coupled about a third axis to an element for causing over-center movement of the pivotably coupled first and second links through a center line defined by the first and third pivot axes. Tension coil springs having opposite ends are pivotably coupled to respective outboard ends of the pivotably coupled first and second links. One of the rigid metal links is adjustable over its length to preload the tension coil springs to a sufficient magnitude to maintain preload tension within the over-center toggle linkage mechanism over the full range of movement of the toggle links between oppositely oblique over-center positions.