The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 29, 1988
Filed:
Sep. 03, 1987
Robert W Milton, Huntsville, AL (US);
Lawrence B Thorn, Madison, AL (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
The hot spall tester comprises a tube furnace portion adapted for retaining a magazine portion for containment of a plurality of steel ball bearings which are heated and individually dropped through a feed tube member to a programmed or manually operated carrousel portion having a plurality of sample cups for receiving and containing individual solid propellant samples to be spall tested in accordance with the method. A torque rod is employed to facilitate rotation of the magazine portion and carrousel portion in a vertically aligned relationship with the magazine portion so that the heated steel ball is delivered by gravity through a feed tube to a sample cup of the carrousel portion positioned below the magazine portion. In operation the magazine portion and carrousel portion are aligned and vertically positioned to provide a calculated transit time for the steel ball bearing to drop by gravity to the propellant in the sample cup. Subsequent rotation of the carrousel of about 22.5 degrees positions the cup containing the propellant sample and hot steel ball bearing under a piston having about 0.0001 inch clearance with the carrousel whereby because of its close tolerance, the piston retains the propellant and hot steel ball bearing in a confined pressure relationship during any pressure buildup. For an eight unit capacity of the magazine portion and carrousel portion the sequence can be repeated either manually or automatically eight times to evaluate a solid propellant composition reaction to a hot spall.