Vent stop for window sashes

A two-part motion limiting device for installation in a window assembly, which device consists of

• a housing molded of a resilient plastic material and comprising spaced apart side walls, defining an internal cavity and said cavity having an opening at the top of said housing,
• said housing being configured for reception in a recess or opening in a window sash rail, and
• a tumbler pivotally mounted within said internal cavity for limited pivotal movement about a pivot axis and having first and second pivot limit positions, said tumbler in said first limit position being recessed within said cavity and in said second limit position having a portion extending outward from said cavity,
• said tumbler being molded of a plastic material and having integral, cylindrically shaped pivot pins projecting from opposite sides thereof on a common axis,
• said housing side walls having pivot openings therein located on a predetermined pivot axis and being of a size to closely receive said pivot pins for pivotally mounting said tumbler in said housing,
• said tumbler and said pivot pins having a combined width greater than a width of the internal cavity of said housing,
• said housing side walls being formed on inner surfaces thereof with inwardly opening first vertical slots extending from upper edges of said side walls downward toward said pivot openings along a downwardly and inwardly inclined surface, whereby said pivot pins may be entered into upper portions of said first vertical slots and pressed downwardly therein, progressively displacing said housing side walls outwardly until said pivot pins are seated in said pivot openings,
• integrally molded elements of said tumbler and integrally molded elements of said housing cooperating to form said first and said second limit positions of said tumbler,
• said housing and said tumbler having respective integrally molded detent elements, at least one of which is resiliently deflectable by the other during pivotal movement of said tumbler from one limit position to the other limit position, whereby said tumbler, when moved to a limit position, is resiliently retained in such limit position.