Systems and methods for casting propellant grain

Patent metadata

Field	Value
Publication number	US-12350864-B2
Application number	US-202318545882-A
Country	US
Kind code	B2
Filing date	Dec 19, 2023
Priority date	Sep 16, 2020
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

Systems and methods for casting solid propellants include a mandrel for forming geometric features in a perforation of a propellant grain. In various embodiments, the mandrel includes a frangible portion that is removed from the propellant grain after the propellant grain has cured around the mandrel. A second portion of the mandrel may be left behind in the propellant grain. The mandrel may include a support structured disposed in the through hole of the mandrel. The support structure may include a plurality of longitudinal channels for directed exhaust gasses through the mandrel upon ignition of the propellant grain.

First claim

What is claimed is:

1. A method for casting a solid propellant, comprising:
disposing a mandrel with respect to a casting tube, wherein a cavity is formed between the mandrel and the casting tube;
moving an uncured propellant grain into the cavity;
curing the propellant grain around the mandrel, wherein a perforation is formed in the cured propellant grain via the mandrel;
breaking a first portion of the mandrel apart from a second portion of the mandrel; and
removing the first portion from within the propellant grain, while leaving the second portion embedded in the cured propellant grain.

2. The method of claim 1 , further comprising coupling a first end cap to the casting tube.

3. The method of claim 2 , further comprising coupling a second end cap to the casting tube.

4. The method of claim 1 , further comprising:
breaking a third portion of the mandrel apart from the second portion of the mandrel; and
removing the third portion from within the cured propellant grain, while leaving the second portion embedded in the cured propellant grain.

5. A mandrel for forming a solid propellant, comprising:
an elongated body;
a through hole disposed in the elongated body; and
a support structure disposed in the through hole, wherein the support structure comprises a plurality of longitudinal walls extending from an inner surface of the elongated body in a transverse direction across the through hole, wherein each of the plurality of longitudinal walls connects at a first side and a second side to the inner surface.

6. The mandrel of claim 5 , wherein the support structure comprises a plurality of longitudinal channels.

7. The mandrel of claim 6 , wherein the support structure and the elongated body are monolithically formed with each other.

8. The mandrel of claim 7 , further comprising a non-longitudinal feature disposed on an outer surface of the elongated body.

9. The mandrel of claim 7 , further comprising a protuberant surface disposed on the elongated body.

10. The mandrel of claim 7 , further comprising a helically extending ridge disposed on an outer surface of the elongated body.

11. The mandrel of claim 5 , wherein a first wall of the plurality of longitudinal walls intersects with a second wall of the plurality of longitudinal walls.

Assignees

• Goodrich Corp

Inventors

• Wilson Brian
• Rodriguez Jean C

Classifications

• B29C33/448

  destructible (B29C33/52 takes precedence; in particular used in injection moulding B29C45/4457) · CPC title

• F02K9/24 Primary

  Charging rocket engines with solid propellants; Methods or apparatus specially adapted for working solid propellant charges · CPC title

• B29K2901/12

  Thermoplastic materials · CPC title

• B29C39/36

  Removing moulded articles · CPC title

• B29K2009/00

  Use of rubber derived from conjugated dienes, as moulding material · CPC title