Tamper resistant lock

• US 8,250,887 B2
• Filed: 05/26/2010
• Issued: 08/28/2012
• Est. Priority Date: 05/26/2010
• Status: Active Grant

• Current Assignee: J.J. MacKay Canada Limited (137954 Canada Ltd.)
• Original Assignee: J.J. MacKay Canada Limited (137954 Canada Ltd.)
• Inventors: MacKay, George Allan, Fievet, Michael Glenn
• Primary Examiner(s): Gall, Lloyd
• Assistant Examiner(s): Adeboyejo, Ifeolu
• Application Number:
  US12/788,100
• Publication Number:
  US 20110289985A1
• Time in Patent Office: 825 Days
• Field of Search: 701/20, 701/18, 701/09, 704/19, 704/22, 70493-495, 703/78, 701/03, 701/14, 701/16, 70/15, 70416-418
• US Class Current: 70/1.5
• CPC Class Codes: E05B 17/2084 Means to prevent forced opening by attack, tampering or jimmying E05B15/1614 takes precedence; for ignition or steering locks B60R25/023
• CPC Class Codes: E05B 27/0007 Rotors
• CPC Class Codes: E05B 27/0014 Stators cylinder lock casings in general E05B9/04
• CPC Class Codes: E05B 65/0075 for safes, strongrooms, vaults, fire-resisting cabinets or the like safes, closures and fastenings therefor E05G
• CPC Class Codes: E05B 65/0082 with additional locking responsive to attack, e.g. to heat, explosion in general E05B17/2092
• CPC Class Codes: G07F 9/06 Coin boxes
• CPC Class Codes: Y10T 70/20 Attack-actuated defeating mechanisms
• CPC Class Codes: Y10T 70/50 Special application
• CPC Class Codes: Y10T 70/5208 Multiple dead bolts
• CPC Class Codes: Y10T 70/5252 Sliding and swinging
• CPC Class Codes: Y10T 70/5261 Key operable only
• CPC Class Codes: Y10T 70/527 Sliding
• CPC Class Codes: Y10T 70/5279 Key operable only
• CPC Class Codes: Y10T 70/7605 Pin tumblers
• CPC Class Codes: Y10T 70/7915 Tampering prevention or attack defeating
• CPC Class Codes: Y10T 70/7949 Yielding or frangible connections

Abstract

A tamper resistant lock is provided. The tamper resistant lock comprises a primary locking mechanism for locking and unlocking the tamper resistant lock with an appropriate key. A secondary locking mechanism is engaged and prevents unlocking when a sufficient force is applied to the tamper resistant lock. The force may be the result of driving a screwdriver into a keyway of the lock in an attempt to forcefully unlock the lock.

Claims

1. A tamper resistant lock comprising:

a primary locking mechanism having a longitudinal cylinder within a housing, the longitudinal cylinder rotatable within the housing, the longitudinal cylinder coupled to an actuator that is rotatable between a locked position and an unlocked position when an appropriate key is received within the longitudinal cylinder;

a secondary locking mechanism to prevent rotation of the actuator when a tampering force parallel to a longitudinal axis of the longitudinal cylinder is applied to the primary locking mechanism, the secondary locking mechanism, when engaged, coupling the actuator to the housing of the primary locking mechanism.

2. The tamper resistant lock of claim 1, wherein the secondary locking mechanism comprises:

a first interacting component coupled to the longitudinal cylinder;

a second interacting component coupled to the housing, longitudinally spaced from the first interacting component and aligned for engaging the first interacting component; and

an engaging component allowing longitudinal movement of the first interacting component relative to the second interacting component, whereby the first interacting component engages with the second interacting component when the tampering force is greater than a threshold.

3. The tamper resistant lock of claim 2, wherein the engaging component further prevents longitudinal movement of the first interacting component relative to the second interacting component when the tampering force is less than the threshold.

4. The tamper resistant lock of claim 2, further comprising a backing plate, wherein the engaging component is coupled to the housing of the primary locking mechanism and mounts the primary locking mechanism apart from the backing plate.

5. The tamper resistant lock of claim 4, wherein the engaging component comprises a mounting plate displaced from the backing plate by one or more members and wherein the housing of the primary locking mechanism is secured to the mounting plate.

6. The tamper resistant lock of claim 4, wherein the first interacting component is located off of a center of rotation of the longitudinal cylinder and the second interacting component is located on the backing plate.

7. The tamper resistant lock of claim 6, wherein the first interacting component comprises a hole and the second interacting component comprises a pin sized to be received in the hole when the first interacting component is engaged with the second interacting component.

8. The tamper resistant lock of claim 6, wherein the first interacting component comprises a pin and the second interacting component comprises a hole sized to receive the pin when the first interacting component is engaged with the second interacting component.

9. The tamper resistant lock of claim 5, wherein the mounting plate deforms under the tampering force to longitudinally move the primary locking mechanism towards the backing plate.

10. The tamper resistant lock of claim 2, wherein the actuator comprises a cam plate attached to the longitudinal cylinder, and wherein the first interacting component is located on the cam plate.

11. The tamper resistant lock of claim 10, further comprising one or more locking bars coupled to the cam plate for retracting or extending from the tamper resistant lock when the longitudinal cylinder is rotated within the housing.

12. The tamper resistant lock of claim 10, wherein the cam plate is coupled to the longitudinal cylinder to allow the longitudinal cylinder to rotate when a sufficient torque is applied to the longitudinal cylinder with the secondary locking mechanism engaged.

13. The tamper resistant lock of claim 2, wherein the engaging component comprises one of:

a deformable mounting plate;

a mounting plate having a breakable connection;

a collapsible member mounting a mounting plate above a backing plate;

or

shearable pins of the primary locking mechanism.

14. A securable device comprising:

a body having an interior space to be secured;

an access panel in the body; and

a tamper resistant lock according to claim 1 preventing forceful opening of the access panel.

15. The securable device of claim 14, wherein the securable device comprises:

a parking meter;

a vending machine;

an electrical cabinet;

or

a telecommunications cabinet.