Wayne E Berndt

US Patent:

55642721, Oct 15, 1996

Filed:

Jul 29, 1994

Appl. No.:

8/282990

Inventors:

Mark J. Warner - North Ogden UT
Wayne E. Berndt - North Ogden UT
O. N. Thompson - Logan UT
Scott W. Lauritzen - Hyrum UT
Kevin W. Davis - Ogden UT

Assignee:

Thiokol Corporation - Ogden UT

International Classification:

F02K 900

US Classification:

60223

Abstract:

The present invention is directed to a novel pressure vessel and process for manufacturing the pressure vessel. In one embodiment, the invention includes a case for a rocket motor which includes a cylindrical, metal shell which has been configured with a plurality of slots positioned in axially extending rows. A fiber reinforced plastic layer is attached to the metal shell. Each slot has a length (L) and is separated by adjacent slots in the same row by an axial distance (A) with adjacent rows of slots separated by a circumferential distance (C) and configured such that L+A. gtoreq. 6C and L. gtoreq. 4A. The method of the invention comprises using a CO. sub. 2 laser to cut a keyhole in the shell and then cutting axially outwardly from the keyhole to form the slot, resulting in slots having a width equal to the cutting width of the laser. The beam is then defocused and used to heat a portion of the metal shell surrounding the ends of each slot to produce a tempered zone.