Abstract: A latch bolt mechanism for tilting window sashes includes an actuating spring that is integrally molded of plastic material in one piece with the latch bolt. The spring has a transversely corrugated configuration, comprised of at least two transversely disposed wave-like spring sections. Each spring section includes a pair of oppositely oriented U-shaped sections having spaced apart semi-cylindrical portions at opposite sides joined by transverse connecting sections. In a relaxed configuration of the spring, the several connecting sections are substantially parallel to each other and are longitudinally spaced apart. In a compressed configuration of the spring the connecting elements lie at an angle to each other and the several semi-cylindrical portions are closely spaced or in contact providing for the required spring compression without excessively stressing the plastic material. Significant production economies are realized with the one-piece, molded construction of the latch bolt and spring.

Abstract: A fully functioning, pivoting vent stop for sliding windows has only two parts, a housing and a pivoting tumbler, both formed of injection molded plastic material. The tumbler is pivotally mounted in the housing and has integral detent elements cooperating with detent elements on the housing walls to position the tumbler in recessed or extended limit positions. The cooperating detent elements also provide an over-centering spring action as the tumbler is actuated between its limit positions. Assembly of the two-part device is achieved in a highly simplified and economical manner by configuring an internal cavity in the housing with inclined slots in the internal side walls of the housing. This enables the tumbler to be resiliently pressed into the cavity, temporarily displacing the housing side walls outwardly, until the cooperating pivot and detent elements are fully engaged.

Abstract: A sash lock mechanism of all-plastic construction incorporating a plastic detent spring arrangement having operating characteristics equal or superior those of conventional metallic springs while providing a more economical manufacture and assembly. The detent spring is of closed rectangular form, with inwardly bowed side elements positioned to act on opposite sides of a detent cam positioned between them, and connected at their ends by integral end and corner elements. The end and corner elements are closely confined against outward movement, causing the inwardly bowed side elements to be significantly more resistant to outward displacement by the detent cam when operating the lock. The arrangement provides a superior “feel” and snap-action effect than expected from all-plastic detent mechanisms for the purposes intended.