Trailer locking device

• US 6,634,721 B2
• Filed: 06/01/2001
• Issued: 10/21/2003
• Est. Priority Date: 06/02/2000
• Status: Active Grant

• Current Assignee: John P. Holt
• Original Assignee: John P. Holt
• Inventors: Holt, John P.
• Primary Examiner(s): RODRIGUEZ, PAMELA
• Application Number:
  US09/872,512
• Publication Number:
  US 20010050509A1
• Time in Patent Office: 872 Days
• Field of Search: 303/89, 303/7, 303/9, 303/13, 303/DIG.3, 303/DIG.4, 188/3.H, 188/3.R, 188/265, 188/353, 180/287
• US Class Current: 303/89
• CPC Class Codes: B60R 25/08 operating on brakes or brake systems
• CPC Class Codes: B60T 17/16 Locking of brake cylinders
• CPC Class Codes: B60T 17/18 Safety devices; Monitoring

Abstract

A locking device for immobilizing trailers to prevent unauthorized movement or theft of the trailer by venting the compressed air that is used to release the brakes. The locking device has a controller unit, a control valve and power source mounted inside a housing. A control mechanism, such as a keypad or key lock system, is located outside of the housing, preferably on a trailer wall. The inlet on the control valve connects to the brake line that delivers compressed air to the trailer'"'"'s compressed air-operated brakes. In the locked condition, the control valve is set so compressed air vents out the control valve'"'"'s outlet, preventing release of the brakes. When the proper lock code, key or other signal is received, the control valve closes the outlet to stop the venting and allow the brakes to be released.

Claims

1. A trailer locking device for use with a trailer having a brake line configured to pneumatically interconnect a supply of compressed air to one or more air-operated brakes on said trailer, said trailer locking device comprising:

a controller unit connected to a power supply;

a control valve electronically connected to said controller unit, said control valve having an inlet and an outlet selectively in fluid communication with said inlet, said inlet pneumatically connected to a brake line outlet pneumatically disposed in said brake line between said supply of compressed air and said brakes, said control valve configured to open in response to an open signal from said controller unit so as to allow compressed air from said brake line to vent from said outlet and maintain said brakes in a locked condition until a close signal is received from said controller unit to close said control valve so as to prevent compressed air from venting through said outlet and place said brakes in an unlocked condition; and

control means operatively connected to said controller unit for selectively controlling said control valve.

2. The trailer locking device of claim 1, wherein said control valve further comprises an electric motor operatively connected to a shaft slidably disposed in said control valve to selectively open and close the communication between said inlet and said outlet and one or more limiting switches to monitor and limit the movement of said shaft in said control valve.

3. The trailer locking device of claim 2, wherein said one or more limiting switches is electrically connected to said controller unit.

4. The trailer locking device of claim 2, wherein said control valve further comprises one or more pressure sensors operatively engaged with said control valve electronically connected to said controller unit so as to measure the air pressure at said control valve, at least one of said pressure sensors configured to communicate with said controller unit to open said control valve when the pressure in said brake line drops below a pre-determined level and to maintain said control valve in a closed condition when the pressure in said brake line is above said pre-determined level.

5. The trailer locking device of claim 4, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

6. The trailer locking device of claim 1, wherein said control valve further comprises one or more pressure sensors operatively engaged with said control valve, said one or more pressure sensors electronically connected to said controller unit so as to measure the air pressure at said control valve, at least one of said pressure sensors configured to communicate with said controller unit to open said control valve when the pressure in said brake line drops below a pre-determined level and to maintain said control valve in a closed condition when the pressure in said brake line is above said pre-determined level.

7. The trailer locking device of claim 6, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

8. The trailer locking device of claim 1, wherein said control means comprises a keypad entry system.

9. The trailer locking device of claim 1, wherein said control means comprises a key lock system.

10. The trailer locking device of claim 1, wherein said power supply is a battery disposed inside of a housing, said battery operatively connected to an external electrical source and means for changing said battery.

11. The trailer locking device of claim 1, wherein said control valve further comprises an electric motor operatively connected to a shaft slidably disposed in said control valve to selectively open and close the communication between said inlet and said outlet and one or more limiting switches to monitor and limit the movement of said shaft in said control valve.

12. The trailer locking device of claim 1, wherein said controller unit has a multiple tier code system for allowing modification of one or more controls of said controller unit.

13. The trailer locking device of claim 1, wherein said controller unit can be programmed with one or more time settings.

14. The trailer locking device of claim 13, wherein said controller unit has a multiple tier code system for allowing modification of one or more controls of said controller unit.

15. A trailer locking device for use with a trailer having an internal cavity and a brake line connected to one or more compressed air-operated brakes, comprising:

a housing disposed in said internal cavity of said trailer;

a controller unit in said housing, said controller unit connected to a power supply;

a control valve in said housing and electronically connected to said controller unit, said control valve having an inlet pneumatically connected to a brake line outlet disposed in said brake line between a supply of compressed air and said brakes, said control valve having an outlet selectively in fluid communication with said inlet, said control valve configured to open in response to an open signal from said controller unit so as to allow compressed air from said brake line to vent from said outlet and to maintain said brakes in a locked condition until a close signal is received from said controller unit to close said control valve so as to prevent compressed air from venting though said outlet and place said brakes in an unlocked condition; and

control means operatively connected to said controller unit for selectively controlling said control valve so as to change between said locked condition and said unlocked condition, said control means located outside of said housing.

16. The trailer locking device of claim 15, wherein said control valve further comprises an electric motor operatively connected to a shaft slidably disposed in said control valve to selectively open and close the communication between said inlet and said outlet and one or more limiting switches to monitor and limit the movement haft in said control valve.

17. The trailer locking device of claim 15, wherein said control valve further comprises one or more pressure sensors operatively engaged with said control valve, said one or more pressure sensors electronically connected to said controller unit so as to measure the air pressure at said control valve, at least one of said pressure sensors configured to communicate with said controller unit to open said control valve when the pressure in said brake line drops below a pre-determined level and to maintain said control valve in a closed condition when the pressure in said brake line is above said pre-determined level.

18. The trailer locking device of claim 17, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

19. The trailer locking device of claim 15, wherein said control means is disposed on a wall of said cavity external to said cavity.

20. The trailer locking device of claim 15, wherein said control means is a radio controlled device.

21. A trailer locking device for use in a trailer having a brake line configured to pneumatically interconnect a supply of compressed air to one or more air-operated brakes, said trailer locking device comprising:

a controller unit connected to a power supply;

a control valve electronically connected to said controller unit, said control valve having an inlet and an outlet selectively in fluid communication with said inlet, said inlet pneumatically connected to a brake line outlet pneumatically disposed in said brake line between said supply of compressed air and said brakes, said control valve configured to open in response to an open signal from said controller unit so as to allow compressed air from said brake line to vent from said outlet and maintain said brakes in a locked condition until a close signal is received from said controller unit to close said control valve so as to prevent compressed air from venting through said outlet and place said brakes in an unlocked condition;

one or more pressure sensors operatively engaged with said control valve, said one or more pressure sensors electronically connected to said controller unit so as to measure the air pressure at said control valve, at least one of said pressure sensors configured to communicate with said controller unit to open said control valve when the pressure in said brake line drops below a pre-determined level and to maintain said control valve in a closed condition when the pressure in said brake line is above said pre-determined level; and

control means operatively connected to said controller unit for selectively controlling said control valve so as to change between said locked condition and said unlocked condition.

22. The trailer locking device of claim 21, wherein said controller unit and said control valve are disposed in a housing.

23. The trailer locking device of claim 22, wherein said housing is located in an internal cavity of said trailer.

24. The trailer locking device of claim 21, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

25. The trailer locking device of claim 21, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

26. A method of operating a trailer locking device for locking the brakes of a trailer having a brake line configured to pneumatically interconnect a supply of compressed air to one or more air-operated brakes on said trailer, comprising the steps of:

a. intercepting the pressure in said brake line at a brake line output disposed between said source of compressed air and said air brakes;

b. delivering the pressure in said brake line to a control valve having an inlet and an outlet;

c. measuring the pressure in said brake line with one or more pressure sensors operatively engaged with said control valve and electronically connected to a controller unit to obtain a measured pressure;

d. comparing said measured pressure to a pre-determined pressure amount;

e. transmitting an open signal from said controller unit to said control valve to open said control valve when said measured pressure is less than said pre-determined pressure; and

f. venting air from said brake line through said outlet in said control valve to automatically place said brakes in a locked condition.

27. The method of claim 26, wherein air is vented from said brake line until said control valve receives a close signal from said, controller unit.

28. The method of claim 27 further comprising the step of closing said outlet so as to allow air from said brake line to place said brakes in an unlocked condition.

29. The method of claim 26, wherein at least one of said one or more pressure sensors measure the pressure inside said control valve between said inlet and said outlet.

30. A method of locking the brakes of a trailer having a brake line pneumatically interconnect a supply of compressed air to one or more air-operated brakes on said trailer, comprising the steps of:

a. intercepting the pressure in said brake line at a brake line output disposed between said source of compressed air and said air brakes;

b. delivering the pressure in said brake line to a control valve having an inlet and an outlet;

c. measuring the pressure in said brake line with one or more pressure sensors operatively engaged with said control valve and electronically connected to a controller unit to obtain a measured pressure, at least one of said one or more pressure sensors measuring the pressure inside said control valve between said inlet and said outlet;

d. comparing said measured pressure to a pre-determined pressure amount;

e. transmitting an open signal from said controller unit to said control valve to open said control valve when said measured pressure is less than said pre-determined pressure, said controller unit communication with said control valve configured to prevent opening of said control valve if said measured pressure is greater than said pre-determined pressure; and

f. venting air from said brake line through said outlet in said control valve so as to automatically place said brakes in a locked condition, said controller unit configured to operate said control valve so as to vent air through said outlet until said controller unit receives a close signal from a control means operatively connected to said controller unit.

31. The method of claim 30 further comprising the step of closing said outlet so as to allow air from said brake line to place said brakes in an unlocked condition.