Wire thread cast insert
AssigneeAvia Instrument Company
InventorFrank William Hauser
Life of this patent
Estimating the term…
Abstract
A threaded opening is formed in a plastic or metallic body formed by molding or casting by providing a wire in a helical configuration supported on a core member and then molding or casting the material about the helical configuration. This helical configuration or insert is initially provided with a thread pitch greater than that desired for the final threaded opening so that shrinkage of the material as it hardens adjusts the greater thread pitch of the helical insert to the desired final value.
Claims7
A method of providing a threaded opening of given thread pitch in a cast body of material having a predetermined shrinkage upon solidification comprising the steps of:
- a. forming a wire of given cross-sectional shape into a helical configuration wherein the pitch of the helical turns is adjusted over a major length of the configuration to a given value greater than said given thread pitch;
- b. introducing an internal support into said helical configuration of outside diameter corresponding substantially to the inside diameter of the helical configuration;
- c. casting material around said helical configuration and support until the material hardens into a solid body;
- d. removing said internal support to leave a threaded opening in said body;
- and, e. cooling said body so that the shrinkage of said body during said cooling reduces the pitch of said helical configuration from said given value to said given thread pitch so that the final threads in the opening have said given thread pitch.
Dependencies are inferred from the claim text.