Apparatus for measuring the temperature of chambered projectile

Patent metadata

Field	Value
Publication number	US-10267582-B2
Application number	US-201514676793-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 1, 2014
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A system, device, and method for measuring the temperature of a chambered projectile within a firearm are provided. A test ammunition round may include a projectile, a sleeve, and a case including a first end coupled to sleeve, and a second end coupled to the projectile. A thermocouple may be located within the projectile, and an electronic coupler may be coupled to the thermocouple, and extends through the case and the sleeve and exits the sleeve through a slot for coupling to a data acquisition system.

First claim

The invention claimed is:

1. A method of manufacturing a test ammunition round, the method comprising the steps of:
providing a projectile that is compatible with a firing chamber for a firearm under test;
boring a receiving cavity in a proximal end of the projectile;
providing a case that is compatible with the chamber of the firearm under test, the case including a case passageway extending from a proximal end to a distal end;
boring a case opening into in the proximal end of the case;
providing a thermocouple and a lead wire electrically coupled to the thermocouple;
one of brazing and soldering the thermocouple into the receiving cavity of the projectile;
running the lead wire from the thermocouple, and through the case passageway of the case;
pressing the proximal end of the projectile into the distal end of the case;
providing a sleeve including a cylindrical outer side wall defining an axially extending sleeve passageway;
forming a radially extending slot within the proximal end of the sleeve;
running the lead wire axially into the sleeve passageway and radially out through the slot in the sleeve; and
pressing the distal end of the sleeve at least partially into the proximal end of the case.

2. The method of claim 1 , wherein the step of boring the receiving cavity includes drilling into a solid copper projectile.

3. The method of claim 1 , wherein the step of one of brazing and soldering includes using silver solder to secure the thermocouple within the receiving cavity.

4. The method of claim 1 , wherein the step of boring the case opening includes drilling the proximal end of the case.

5. The method of claim 4 , wherein the step of pressing the distal end of the sleeve includes press fitting a ⅜ inch tube into the proximal end of the case.

6. The method of claim 1 , wherein the step of pressing the proximal end of the projectile includes using a reloading press to crimp the distal end of the case to the proximal end of the projectile.

7. The method of claim 1 , wherein the case has a maximum outer diameter less than 10 millimeters.

8. The method of claim 7 , wherein the combined length of the case and the projectile is less than 60 millimeters.

9. The method of claim 8 , wherein the case and the projectile include dimensions of a standard 5.56 mm ammunition round.

10. A method of measuring the temperature of a chambered projectile in a firearm using a test ammunition round, the method comprising the steps of:
providing a firearm including a firing chamber;
instrumenting a test ammunition round projectile with a projectile thermocouple;
coupling the projectile thermocouple to a data acquisition system, wherein said data acquisition system is external to the firearm;
firing a first plurality of rounds of ammunition through the firearm under test to heat the firing chamber;
inserting the test ammunition round into the firing chamber;
recording a first temperature profile of the projectile through the projectile thermocouple with the data acquisition system;
removing the test ammunition round from the firing chamber;
firing a second plurality of rounds of ammunition through the firearm under test to heat the firing chamber, the second plurality of rounds of ammunition being greater than the first plurality of rounds of ammunition;
inserting the test ammunition round into the firing chamber; and
recording a second temperature profile of the projectile through the projectile thermocouple with the data acquisition system.

11. The method of claim 10 , further comprising the step of comparing the first temperature profile and the second temperature profile to known deformation temperature of the ammunition round to predict a maximum number of successive rounds of ammunition that may be fired before reaching the deformation temperature.

12. The method of claim 10 , further comprising the steps of instrumenting the firearm with a plurality of thermocouples, and coupling the plurality of thermocouples to the data acquisition system.

13. The method of claim 12 , wherein the step of instrumenting the firearm includes thermally coupling a muzzle thermocouple to a barrel muzzle of the firearm, thermally coupling a gas port thermocouple to a barrel muzzle of the firearm, and thermally coupling a chamber thermocouple to the chamber of the firearm.

14. The method of claim 10 , wherein the step of instrumenting a test ammunition round projectile with a projectile thermocouple includes the steps of:
providing the projectile that is compatible with the firing chamber for the firearm;
boring a receiving cavity in a proximal end of the projectile;
providing a case that is compatible with the chamber of the firearm under test, the case including a case passageway extending from a proximal end to a distal end;
boring a case opening into in the proximal end of the case;
providing a thermocouple and a lead wire electrically coupled to the thermocouple;
one of brazing and soldering the thermocouple into the receiving cavity of the projectile;
running the lead wire from the thermocouple, through the case passageway of the case;
pressing the proximal end of the projectile into the distal end of the case;
providing a sleeve including a cylindrical outer side wall defining an axially extending sleeve passageway;
forming an axially extending slot within the proximal end of the sleeve;
running the lead wire axially into the sleeve passageway and radially out through the slot in the sleeve; and
pressing the distal end of the sleeve at least partially into the proximal end of the case.

15. The method of claim 14 , wherein the case has a maximum outer diameter less than 10 millimeters.

16. The method of claim 15 , wherein the combined length of the case and the projectile is less than 60 millimeters.

17. The method of claim 16 , wherein the case and the projectile include dimensions of a standard 5.56 mm ammunition round.

Assignees

• Us Navy

Inventors

• Englert Stefan L

Classifications

• F42B8/02

  Cartridges {(F41A33/02, F42B7/12 take precedence)} · CPC title

• Y10T29/49119

  Brush · CPC title

• F42B8/08

  Dummy cartridges, i.e. inert cartridges containing neither primer nor explosive or combustible powder charge · CPC title

• F42B5/24

  for cleaning; for cooling; for lubricating {; for wear reducing} · CPC title

• G01K1/026

  arrangements for monitoring a plurality of temperatures, e.g. by multiplexing · CPC title