Electronic apparatus for determining the wear of a gun tube

• US 3,914,996 A
• Filed: 04/30/1974
• Issued: 10/28/1975
• Est. Priority Date: 04/30/1974
• Status: Expired due to Term

• Current Assignee: Harry J. Davis, Thomas W. Smith
• Original Assignee: Harry J. Davis, Thomas W. Smith
• Inventors: Davis, Harry J., Smith, Thomas W.
• Primary Examiner(s): Aegerter, Richard E.
• Assistant Examiner(s): Schmidt, Frederick R.
• Application Number:
  US05/465,642
• Time in Patent Office: 546 Days
• Field of Search: 73/35,91,167 89/14R,135 235/151.3 346/38
• US Class Current: 73/167
• CPC Class Codes: F41A 19/01 Counting means indicating the number of shots fired
• CPC Class Codes: G01L 5/14 for measuring the force of explosions; for measuring the energy of projectiles
• CPC Class Codes: G01N 2203/0623 using piezoelectric gauges
• CPC Class Codes: G01N 3/56 Investigating resistance to wear or abrasion

Abstract

Electronic apparatus for determining the wear of a gun tube of, for example, an artillery weapon. The apparatus counts the number of rounds fired from the weapon, distinguishes the zone level of the round being fired, provides a weighted signal depending upon this zone level, and accumulates successive weighted signals in a memory unit which may provide instantaneous read-out of a number that corresponds to the amount of wear experienced by the barrel of the gun tube. The strain produced in the gun tube when a round is fired is sensed by transducer means. The transducer delivers a signal proportional to the sensed strain. The signal is first tested to determine if a valid firing has occurred. If so, a weighing circuit provides a weighted signal, for example in digital form, which is processed through a logic circuit to the memory. Successive firings are similarly weighed and counted to provide a running total inversely proportional to the remaining life of the gun tube. The memory means may comprise in one embodiment a non-volatile MNOS memory which requires associated compatible complementary logic circuitry. Alternatively, in another embodiment, the memory may comprise a current integrating electrolytic cell.

Claims

1. Electronic apparatus for determining the wear of a gun tube of an artillery weapon, which comprises:

a gun tube which develops a strain upon the firing of an artillery round therefrom;

transducer means connected to said gun tube for generating as an output a firing signal in response to said strain, the magnitude of said firing signal being proportional to the charge used to fire said round;

means automatically responsive to the magnitude of said firing signal for electrically generating a weighted digital signal also proportional to the charge used to fire said round;

memory means for storing said weighted signal and for accumulating successive weighted signals whereby the total stored in said memory means is indicative of the wear of said gun tube;

signal processing means connected to receive said output from said transducer means for electronically discriminating against the passage of each output which falls below a predetermined minimum value which corresponds to an actual firing of said round from said gun tube, said signal processing means comprising threshold detecting circuit means which produces an output only in response to those firing signals whose amplitude exceed a predetermined value, and signature detecting circuit means which produces an output only in response to those firing signals whose rise time and duration exceed predetermined values; and

logic means responsive to the outputs of said threshold detecting circuit and said signature detecting circuit for causing said weighted signal to be fed to said memory means.

2. The electronic apparatus according to claim 1 wherein said logic means comprises:

shift register means for receiving and storing as its contents said weighted signal from said weighted signal generating means;

clock pulse generating means; and

gating means connected to said clock pulse generating means and to said signal processing means for effectuating the transfer of said contents of said shift register means to said memory means.

3. The electronic apparatus according to claim 2 wherein said memory means comprises an MNOS memory.

4. The electronic apparatus according to claim 3, wherein said logic means further comprises:

a plurality of one shot circuits for providing restoration signals to said MNOS memory;

anD an MNOS flip-flop circuit means connected to said one shot circuits for changing its output between two alternative states in response thereto;

wherein said shift register means comprises first and second parallel-in, series-out shift registers and wherein said gating means is further responsive to said alternative outputs from said MNOS flip-flop circuit means for alternatively gating said clock pulses to said first and second shift registers.

5. The electronic apparatus according to claim 1 wherein said memory means comprises electrolytic cell means for integrating the current of said weighted signal.

6. The electronic apparatus according to claim 5 wherein said logic means comprises:

first and second timing circuits respectively responsive to said threshold detecting circuit means and said signature detecting circuit means for providing first and second timing signals; and

first and second gating circuits respectively responsive to said first and second timing signals for grounding said weighted signal generating means and for causing said weighted signal to be fed to said electrolytic cell means, respectively.

7. The electronic apparatus according to claim 6, wherein said first and second gating circuits are comprised of field effect transistors.