Efficient piezoeletric-triggered time delay module

• US 7,804,223 B1
• Filed: 04/16/2007
• Issued: 09/28/2010
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: Ensign-Bickford Aerospace & Defense Company (Incitec Pivot Limited)
• Original Assignee: Ensign-Bickford Aerospace & Defense Company (Incitec Pivot Limited)
• Inventors: Teowee, Gimtong
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): ROSENAU, DEREK JOHN
• Application Number:
  US11/787,377
• Time in Patent Office: 1,261 Days
• Field of Search: 310/317, 310/318, 310/339, 333/141
• US Class Current: 310/318
• CPC Class Codes: F42C 11/02 with piezo-crystal
• CPC Class Codes: F42C 9/147 Impact fuze in combination with electric time fuze
• CPC Class Codes: H02N 2/183 using impacting bodies high voltage generators in spark lighters F23Q

Abstract

An efficient piezoelectric-triggered time delay module may be provided with separate firing and logic capacitors, and may also have corresponding separate piezoelectric transducers. Further, separate firing and logic capacitors may be impedance-matched to corresponding separate piezoelectric transducers. Optionally, the capacitors may be made of the same materials as the corresponding piezoelectric transducers. Further alternately or additionally, low-value, high-voltage rated capacitor(s) may be employed. Further alternately or additionally, the piezoelectric transducer(s) may be selected to offer high charge output within the intended operating temperature range. Further alternately or additionally, the piezoelectric transducer(s) may be constructed with multiple wafers.

Claims

1. An efficient piezoelectric-triggered time delay module for use with a percussive primer or shock device, comprising:

a) a logic capacitor and a firing capacitor that are separate from each other;

b) control electronics;

c) a firing switch;

d) an initiator; and

,

e) two piezoelectric transducers that respectively correspond to said logic capacitor and to said firing capacitor;

wherein

each said piezoelectric transducer is impedance-matched to the respective corresponding capacitor and is made of the same material as the respective corresponding capacitor resulting in a close tracking of impedance over a range of temperatures.

2. The time delay module of claim 1, wherein said capacitors are rated at greater than 250V.

3. The time delay module of claim 1, wherein said piezoelectric transducers comprise a d₃₃ greater than 500×

10<sup>−

12</sup> m/V.

4. The time delay module of claim 1, wherein said piezoelectric transducers comprise a g₃₃ greater than 0.015 Vm/N.

5. The time delay module of claim 3, wherein said piezoelectric transducers comprise a g₃₃ greater than 0.015 Vm/N.

6. The time delay module of claim 1, wherein said piezoelectric transducers have multiple wafers.

7. The time delay module of claim 6, wherein each of said multiple wafers of said piezoelectric transducers have a different Curie point.

8. The time delay module of claim 1, wherein said piezoelectric transducers include a tuned transformer.

9. The time delay module of claim 1, wherein said piezoelectric transducers are also capable of generating electricity pyroelectrically.

10. An efficient piezoelectric-triggered time delay module for use with a percussive primer or shock device, comprising:

a) at least one piezoelectric transducer;

b) at least one storage capacitor;

c) control electronics;

d) a firing switch; and

,

e) an initiator;

wherein said at least one storage capacitor is impedance-matched to said at least one piezoelectric transducer and is made of the same material as the at least one storage capacitor resulting in a close tracking of impedance over a range of temperatures.

11. The time delay module of claim 10, wherein said at least one piezoelectric transducer includes a piezoelectric transducer having multiple wafers.

12. The time delay module of claim 10, wherein said at least one storage capacitors is rated at greater than 250V.

13. The time delay module of claim 10, wherein said at least one piezoelectric transducer comprises a d₃₃ greater than 500×

10<sup>−

12</sup> m/V.

14. The time delay module of claim 10, wherein said at least one piezoelectric transducer comprises a g₃₃ greater than 0.015 Vm/N.

15. The time delay module of claim 13, wherein said at least one piezoelectric transducer comprises a g₃₃ greater than 0.015 Vm/N.

16. The time delay module of claim 11, wherein each of said multiple wafers of said at least one piezoelectric transducer have a different Curie point.

17. The time delay module of claim 10, wherein said at least one piezoelectric transducer includes a tuned transformer.

18. The time delay module of claim 10, wherein said at least one piezoelectric transducer is also capable of generating electricity pyroelectrically.