Solid block of propellant with a plurality of propulsion stages and methods of manufacture

• US 3,926,697 A
• Filed: 10/15/1969
• Issued: 12/16/1975
• Est. Priority Date: 10/15/1968
• Status: Expired due to Term

• Current Assignee: Gerard Yvan Brut, Jean Jacques Humbert, Jean Marie Joseph Elie Gounou, Jean Pierre Francis Thomas
• Original Assignee: Gerard Yvan Brut, Jean Jacques Humbert, Jean Marie Joseph Elie Gounou, Jean Pierre Francis Thomas
• Inventors: Humbert, Jean Jacques, Thomas, Jean Pierre Francis, Brut, Gerard Yvan, Gounou, Jean Marie Joseph Elie
• Primary Examiner(s): Sebastian, Leland A.
• Application Number:
  US04/866,621
• Time in Patent Office: 2,253 Days
• Field of Search: 149/14,97,98 264/3R 102/100,101,103 156/286,287
• US Class Current: 149/14
• CPC Class Codes: C06B 45/12 having contiguous layers or zones
• CPC Class Codes: F02K 9/12 made of two or more portions burning at different rates or having different characteristics
• CPC Class Codes: F02K 9/24 Charging rocket engines with solid propellants; Methods or apparatus specially adapted for working solid propellant charges

Abstract

A solid propellant block comprises several successive powder layers, whose principal ingredient is nitrocellulose, burning in sequence and having planar, cylindrical or other contact surfaces, the layers being sealed to one another at the contact surfaces by gelatinization of the nitrocellulose by nitroglycerine, a polyalcohol nitrate or an explosive oil base molding solvent, which is another ingredient of at least one of the powder layers.

Claims

1. A METHOD OF PRODUCING A SOLIDPROPELLANT BLOCK COMPRISING A PLURALITY OF SUCCESSIVE CONCENTRIC ADJACENT LAYERS OF DIFFERENT COMPOSITIONS ADAPTED TO BURN IN SEQUENCE TO PROVIDE SUCCESSIVE STAGES OF LIFT, EACH LAYER BEING BONDED TO ADJACENT LAYERS BY GELATINIZED NITROCELLULOSE, WHICH COMPRISES FORMING A PLURALITY OF CONTACTING ADJACENT LAYERS OF DIFFERENT COMPOSITIONS IN A MOLD, EACH LAYER CONSISTING OF A PROPELLANT COMPOSITION COMPRISING NITROCELLULOSE AS THE PRINCIPAL INGREDIENT, AT LEAST ONE OF SAID ADJACENT LAYERS CONSISTING OF GRANULES OF A BASE POWDER OF A PROPELLANT COMPOSITION THE PRINCIPAL INGREDIENT THEREOF BEING NITROCELLULOSE, INTRODUCING A MOLDING AGENT COMPRISING NITROGLYCERINE OR A POLYALCOHOL NITRATE AS THE PRINCIPAL INGREDIENT, UNDER VACUUM INTO AT LEST SAID LAYER CONSISTING OF SAID BASE POWDER TO CAUSE AT FIRST FLOW OF SAID NITROGLYCERINE OR SAID POLYALCOHOL NITRATE INTO THE INTERSTICES BETWEEN THE GRANULES OF SAID BASE POWDER AND HEATING IN THE MOLD AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO CAUSE MOLDING OF SAID BASE POWDER IN SITU AND GELATINIZATION OF THE NITROCELLULOSE OF SAID BASE POWDER AND AT THE CONTACT SURFACE OF THE ADJACENT LAYERS THEREOF, WHEREBY SAID LAYER FORMED FROM SAID BASE POWDER IS SEALED TO ITS ADJACENT LAYERS BY MEANS OF SAID GELATINIZED NITROCELLULOSE.

2. The method according to claim 1 wherein said contact surface is planar.

3. The method according to claim 1 wherein said contact surface is cylindrical.

4. The method according to claim 1 wherein heating is carried out at 45*C for 24 hours foLlowed by heating at 65*C for 96 hours.

5. The method according to claim 1 wherein one of said adjacent layers is a double base cast powder and the other is an extruded double base powder.

6. A method of producing a propellant block in accordance with claim 1 wherein a plurality of adjacent layers are molded in situ from dissimilar base powders and said adjacent layers are formed by placing a separating partition in the mold to form separate chambers for said adjacent layers, pouring the base powder composition of each layer into the respective chambers, removing the partition while leaving the contact surface between the adjacent layers undisturbed, introducing said molding agent under vacuum and thereafter heating the layers to effect gelatinization and sealing.

7. A method of producing a propellant block in accordance with claim 5 wherein said molding agent is introduced simultaneously into all said layers.

8. A method of producing a propellant block according to claim 1 wherein at least one of the adjacent layers is a preformed block, which comprises introducing said preformed block into a mold, the preformed block being of such size that vacant regions remain in the mold, introducing a different composition the principal component of which is nitrocellulose in granular form into the vacant regions of the mold, to form said adjacent layer, with said pre-formed block serving as a form for a chamber for said adjacent layer, whereafter introducing a molding agent for said adjacent layer into said mold and heating the entire mass to effect the gelatinization of nitrocellulose and sealing at the contact surfaces.

9. The method according to claim 8 wherein heating is carried out at 45*C for 24 hours followed by heating at 65*C for 30 hours to achieve partial gelatinization of said preformed layer and in the final step heating is carried out at 45*C for 24 hours followed by heating at 65*C for 96 hours.

10. The method according to claim 8 wherein said preformed block is a composition containing said molding agent.

11. A method of producing the block of claim 8 wherein a plurality of said blocks are pre-formed and placed in said mold.

12. The method as claimed in claim 11, wherein the molding agent comprises 72-78% nitroglycerine, 21-27% triacetin and 0.5-1% stabilizer.

13. A solid block of propellant prepared by the method of claim

14. A solid block of propellant prepared by the method of claim 6.

15. A solid block of propellant prepared by the method of claim 8.