Abstract: A counterforce spring assembly for printed circuit board test fixtures is provided. A number of counterforce spring assemblies are provided in an array between the top plate and probe plate of the test fixture. Each counterforce spring assembly includes a support cup residing in an aperture through the probe plate. A compression spring resides in the support cup and provides spring-biasing of the top plate to the probe plate during the UUT testing cycle. Each counterforce spring assembly includes a circumferential flange to limit downward travel of the top plate toward the probe plate. Each assembly is small enough to fit between probe apertures corresponding to component leads of the UUT. The counterforce spring assemblies can be freely placed underneath the top plate to provide even spring-biasing thereof to prevent bowing and bending of the top plate which often causes errors in the testing of printed circuit boards.

Abstract: An apparatus is disclosed for the feeding of oval-shaped open end wire links seriatim, from an open-link feeding bar magazine, to a groove in a movable link-forming slide tool. Subsequent upward movement of the link-forming slide tool carries the open oval-shaped wire link into internal surface contact with a fixed position link center-forming anvil. Closed chain links or findings are mounted over the ends of the open wire links at this point, and further upward movement of the link-forming slide tool results in the closure of the previously open wire link to a desired configuration such as oval or round, and its assembly with the preformed ornamental objects is completed. The present device may be employed in various power driven modes.