High security lock

• US 6,073,469 A
• Filed: 06/07/1995
• Issued: 06/13/2000
• Est. Priority Date: 06/01/1993
• Status: Expired due to Fees

• Current Assignee: National Technologies Incorporated (Network Connex)
• Original Assignee: National Technologies Incorporated (Network Connex)
• Inventors: Julien, Gerald J.
• Primary Examiner(s): BARRETT, SUZANNE LALE DINO
• Application Number:
  US08/482,972
• Time in Patent Office: 1,833 Days
• Field of Search: 292/DIG. 66, 70/2, 70/6, 70/7, 70/18, 70/20-22, 70/24-26, 70/35, 70/38 A, 70/38 C, 70/51-54, 70/277, 70/278, 70/416, 70/417, 403/404
• US Class Current: 70/38.00A
• CPC Class Codes: B60R 25/023 Countermeasures against the physical destruction of the steering lock
• CPC Class Codes: E05B 15/1614 of hard materials, to prevent drilling E05B67/04, E05B67/38 take precedence
• CPC Class Codes: E05B 37/14 in padlocks
• CPC Class Codes: E05B 47/0009 with thermo-electric actuators, e.g. heated bimetals
• CPC Class Codes: E05B 51/005 by a bimetallic or memory-shape element heated by electricity E05B47/0009; for panic door actuation E05B65/104
• CPC Class Codes: Y10T 70/459 Both legs engaged
• CPC Class Codes: Y10T 70/463 Long leg engaged
• CPC Class Codes: Y10T 70/7921 Armoring

Abstract

A high security lock includes a shackle having two ends and a lock body having openings for receiving the ends of the shackle. A latch in the lock body has a catch movable into engagement with the shackle for securing at least one end of the shackle in the body. The latch is releasable to allow the one end of the shackle to move clear of the body to open the lock. The shackle is made of a shape memory effect alloy having a characteristic that its yield strength increases when work is impressed on it, so that cutting or breaking the shackle with common tools is more difficult and time consuming than with other shackle materials. The lock thus provides a level of security substantially superior to conventional locks.

Claims

1. A high security lock, comprising:

a shackle having a middle portion and two ends;

a lock body having openings therein for receiving said ends of said shackle;

a latch having a catch movable into engagement with said shackle for securing at least one end of said shackle in said body and which is releasable to allow said one end of said shackle to move clear of said body;

wherein said shackle is a U-shaped rod of primarily monolithic shape memory effect metal having a yield strength that increases when work is impressed on said shape memory effect metal and said shackle is accordingly difficult to cut or break with common tools.

2. A lock as defined in claim 1, wherein said shape memory effect metal is Nitinol.

3. A lock as defined in claim 2, wherein:

said catch is made of Nitinol.

4. A lock as defined in claim 1, further comprising:

a catch actuator for operating said catch to release said shackle and open said lock, said catch actuator bearing on said catch to move said catch to a disengaged position to release said shackle when said catch actuator is actuated.

5. A lock as defined in claim 4, wherein:

said catch actuator includes a key operated lock tumbler having a cam engaged with said catch for moving said catch to said disengaged position.

6. A lock as defined in claim 4, wherein:

said catch actuator includes an element, made of shape memory effect material having a transition point, disposed in opposition to a spring, and a heater arranged to heat said shape memory effect element such that said shape memory effect element will overpower said spring when said heater heats said shape memory effect element to above said transition point and said shape memory effect element moves said catch to said disengaged position.

7. A lock as defined in claim 4, wherein:

said catch engages both legs of said shackle to positively lock both shackle legs in said lock body when said catch is engaged with said shackle.

8. A lock as defined in claim 4, further comprising:

a spring operatively engaged with said catch for biasing said catch into an engaged position with said shackle.

9. A lock as defined in claim 8, wherein:

said shackle has a beveled end and said catch has a beveled surface, said beveled end and said beveled surface being axially aligned in the direction of said bores in said lock body, whereby pushing said shackle into said bores cams said beveled catch against said spring biasing force until said catch is aligned with said notch in said shackle, whereupon said catch snaps into said notch to engage said shackle and lock said shackle in said lock body.

10. A high security lock, comprising:

a shackle having a middle portion and two ends, said shackle being made of a shape memory effect alloy having a yield strength that increases when work is impressed on said shape memory and said shackle is accordingly difficult to cut or break with common tools;

a lock body having openings therein for receiving said ends of said shackle;

a latch having a catch movable into engagement with said shackle for securing at least one end of said shackle in said body and which is releasable to allow said one end of said shackle to move clear of said body;

a catch actuator for operating said catch to release said shackle and open said lock, said catch actuator bearing on said catch to move said catch to a disengaged position to release said shackle when said catch actuator is actuated;

said catch actuator includes a shape memory effect element disposed in opposition to a spring, and a heater arranged to heat said shape memory effect element such that said shape memory effect element will overpower said spring when said heater heats said shape memory effect element to above its transition point and said shape memory effect element moves said catch to said disengaged position;

a secondary shape memory effect actuator and a secondary locking member operated by said secondary actuator, said secondary actuator having a secondary shape memory effect element having a lower transition temperature than said catch actuator shape memory effect element, whereby said secondary actuator will operate before said catch actuator if said lock is heated with a torch to engage said secondary locking member with said shackle before said catch actuator operates to disengage said catch from said shackle, so said lock will remain locked.

11. A high security lock, comprising:

a shackle having two ends, said shackle being made of a metal rod consisting primarily of nickel and titanium having a characteristic that the yield strength thereof increases when work is impressed on said metal, whereby cutting or breaking said shackle with common tools is more difficult and time consuming than with conventional shackle materials;

a lock body having openings therein for receiving said ends of said shackle;

a latch having a catch movable into engagement with said shackle for securing at least one end of said shackle in said body and which is releasable to allow said one end of said shackle to move clear of said body;

wherein said lock provides a level of security substantially superior to conventional locks.

12. A high security lock as defined in claim 11, wherein:

said metal rod is made of Nitinol.

13. A high security lock as defined in claim 11, wherein:

said metal rod is made of 55 Nitinol.

14. A high security lock as defined in claim 11, wherein:

said shackle is primarily solid monolithic Nitinol.

15. A high security lock, comprising:

a U-shaped shackle having two ends, said shackle consisting essentially of a Nitinol rod having a characteristic that the yield strength thereof increases when work is impressed on said Nitinol;

a lock body having openings therein for receiving said ends of said shackle;

a latch having a catch movable into engagement with said shackle for securing at least one end of said shackle in said body, said latch being releasable to allow said one end of said shackle to move clear of said body;

whereby cutting or breaking said shackle with common tools is more difficult and time consuming than with conventional shackle materials, providing said lock with substantially superior resistance to unauthorized opening by cutting and breaking said shackle compared to conventional locks.

16. A high security lock as defined in claim 15, further comprising:

a notch adjacent at least one of said ends of said shackle for engagement by said catch.

17. A high security lock as defined in claim 16, wherein:

said notch is a cylindrical recess opening in one side of said rod.

18. A high security lock as defined in claim 17, wherein:

said catch includes a circular cross-section portion movable into engagement with said cylindrical recess in said rod to lock said shackle in said body, and movable out of engagement with said cylindrical recess in said rod to release said shackle for opening movement in said body.

19. A high security lock as defined in claim 18, further comprising:

a lock tumbler having a portion engagable with said catch and movable by rotating a key in said tumbler to release said circular cross-section portion of said catch from said cylindrical recess in said rod to open said lock.

20. A high security lock as defined in claim 15, wherein:

said Nitinol shackle has a yield strength that increases from about 8-25 KSI to at least about 250 KSI when subjected to cold working imposed by efforts to cut or break said shackle.