Definitions

• the field of the present invention relates generally to devices for securing a trailer in place so as to prevent theft of the trailer. More specifically, this invention relates to devices for securing trailers by preventing movement of one or more of the trailer's wheels. Even more specifically, this invention relates to theft deterrent devices used to prevent unauthorized movement of a trailer by preventing air from reaching, and thereby releasing, the trailer's air brakes.
• trailer owners typically use mechanical locking devices, such as the gladhand and kingpin locks, that are designed to physically prevent hook-up to those trailer components.
• mechanical locking devices such as the gladhand and kingpin locks
• experience has proven that these devices can be overcome relatively easily by the determined and resourceful thief.
• the devices are useless if the truck driver forgets to set the locks. Even when the driver does set the locks, problems can arise if the next authorized driver does not have the key and is forced to break the lock to move the trailer, thereby rendering the security system useless.
• the typical trailer utilizes spring-biased parking brakes which require the introduction of air pressure to release the brakes.
• the parking brake system is configured such that the brakes are engaged by a spring to lock the trailer's wheels when there is no air pressure in the air line to release the brakes.
• the tractor or truck used to haul the trailer includes an air compressor that provides compressed air to the trailer through a brake air line in order to release the brakes so as to allow movement of the trailer. When the driver releases the trailer from the truck, the disconnect of the brake air line from the compressor biases the spring to lock the wheels to prevent movement of the trailer.
• the Gustafsson patent describes a vehicle theft device that utilizes a series of three-way valves and check valves to interact with the main and parking brake systems to prevent movement of a vehicle, primarily the tractor portion of a truck.
• the valves direct air pressure away from the drive axles and routes it to acuate the front brakes only.
• a major limitation with this type of device is that if there is a malfunction, then the front wheels can lock-up while the vehicle (and trailer) is moving. Vehicle accidents have resulted from such a malfunction.
• the Harless patent describes a valve assembly that interacts with a trailer's air brake system to prevent movement of the trailer until someone manually releases the valve from inside the trailer. This system is primarily designed to prevent injury to workers while loading the trailer.
• the trailer locking device of the present invention solves the problems identified above. That is to say, the present invention discloses a new and useful trailer locking device that effectively prevents theft of a trailer.
• the trailer locking device of the present invention is adaptable to new and existing trailers, is easy for the truck driver to engage and is difficult for the thief to overcome or disable.
• the trailer locking device of the present invention is a separate unit having a housing, a controller unit mounted in the housing, a control valve mounted in the housing and a control mechanism located outside the housing.
• the controller unit is connected to a power supply, such as a battery, which can be located in the housing and adapted for connection to an external power source, such as the electrical take-off from the tractor or truck pulling the trailer.
• a charging regulator can be used to ensure the battery is kept in a charged condition without overcharging.
• the control valve is electrically connected to the controller unit.
• the control valve inlet is configured for connection to a supply of compressed air and the outlet is in fluid communication, selectively, with the inlet so as to allow compressed air to vent from the control valve.
• the control valve has a mechanism for activating the valve by selectively opening and closing the interior chamber between the inlet and the outlet.
• the activating mechanism can be an electric motor operatively connected to a shaft that is slidably disposed in the control valve.
• One or more limiting switches, electrically connected to the controller unit, are used to monitor and limit the movement of the shaft in the control valve.
• Pressure sensors are operatively engaged with the control valve and electrically connected to the controller unit.
• the control mechanism which can be a keypad, keylock, radio controlled or other similar mechanisms, is electrically connected to the controller unit for selectively controlling the control valve.
• the trailer locking device is configured for use with a trailer having an internal cavity and a brake line connected to one or more compressed air-operated brakes.
• This locking device has a housing which is disposed in the internal cavity of the trailer, a controller unit mounted in the housing, a control valve mounted in the housing and a control mechanism (i.e., keypad, key lock, etc.) on the outside of the housing.
• the controller unit is connected to a power supply, which is preferably located inside the housing, and the control valve is electrically connected to the controller unit.
• the control valve inlet is pneumatically connected to the brake line between the supply of compressed air (i.e., from the tractor or truck) and the brakes.
• the control valve outlet is in fluid communication with the inlet so as to allow the compressed air to vent from the control valve to place the brakes in a locked condition when desired.
• the control mechanism is operatively connected to the controller unit for selectively controlling the control valve so as to change the condition of the control valve from the locked to the unlocked condition.
• the control mechanism is located outside of the housing and attached to an outer wall of the internal cavity.
• the control mechanism can be radio controlled with the receiver in or near the housing to receive transmissions from other sources to lock or unlock the trailer.
• the trailer lock device is incorporated into a trailer having a brake line pneumatically connected to one or more compressed air-operated brakes.
• the housing could be eliminated if the controller unit, power supply and control valve are incorporated into the trailer itself.
• the control valve is electrically connected to the controller unit and it has an inlet that is pneumatically connected to the brake line between a supply of compressed air and the brakes.
• the control valve outlet is in fluid communication with the inlet so as to allow compressed air to vent from the control valve to place the brakes in a locked condition.
• the control mechanism is operatively connected (i.e., by coaxial cable, other wiring, radio connection or etc.) to the controller unit for selectively controlling the control valve so as to change between the locked condition and an unlocked condition.
• the control valve can have an activating mechanism for activating the control valve by selectively opening and closing the communication between the inlet and the outlet.
• the activating mechanism can comprise an electric motor that is operatively connected to a shaft which is slidably disposed in the control valve.
• One or more limiting switches can be used to monitor and limit the amount of movement of the shaft in the control valve.
• Pressure sensors are operatively engaged in the control valve to signal the controller unit to vent air through the control valve.
• the primary objective of the present invention is to overcome the disadvantages associated with presently available trailer theft deterrent devices and to provide a trailer theft deterrent system that is easy to use and effective to prevent theft of a trailer. It is also an important objective of the present invention to provide a trailer locking device that prevents compressed air from getting to the air-operated brakes by utilizing a valve disposed between the source of compressed air and the brakes to vent the compressed air when locking of the trailer is desired. It is also an important objective of the present invention to provide a trailer lock device having a controller unit and control valve mounted in a housing with an external control mechanism to allow the user to lock and unlock the device.
• FIG. 1 is a cut-away side view of a typical trailer showing installation of the present invention
• FIG. 2 is a front view of the trailer in FIG. 1 ;
• FIG. 3 is a schematic view of the components of the present invention.
• FIG. 4 is an perspective view of the preferred embodiment of the present invention.
• FIG. 5 is a cut-away side view showing use of the invention with a trailer not having cavity between the outside and the interior bulkhead;
• FIG. 6 is a cut-away side view showing use of the present invention with a flatbed trailer
• FIG. 7 is a perspective view of a control valve preferably suitable for use with the present invention.
• FIG. 8 is a cross-sectional view of the control valve in FIG. 7.
• the trailer locking device designated generally as 10
• device 10 generally comprises a control mechanism 14 connected to housing 16.
• the housing 16 can be made out of a variety of materials and, in the preferred embodiment, should have one or more vent holes or be otherwise sufficiently vented to vent discharge air (as described below).
• control mechanism 14 is an electronic keypad mounted on and accessible from the outside of trailer 12, as shown in FIG. 1 (as also shown in FIG. 1 and set forth in more detail below, housing 16 is located inside the wall of trailer 12).
• Control mechanism 14 can also be a padlock dial type lock, key lock, radio controlled lock and card swipe type of lock.
• inside housing 16 is a controller unit 20 having microprocessor board and associated electronic circuitry, charging regulator 24, power supply 26 (i.e., battery), control valve 30 and one or more pressure or pneumatic sensors 32. Radio and electrostatic interference protection should be designed into controller unit 20 according to automotive safety standards.
• control valve 30 can be a solenoid actuated latching dump valve.
• inlet hose 40 which connects at one end to T-splice 28 disposed in pressure brake line 34.
• the other end of inlet hose 40 connects to the inlet 42 of control valve 30.
• outlets 44 for venting compressed air from control valve 30 to maintain the brakes in a locked condition (as explained in more detail below).
• outlet 44 vent air to the inside of housing 16 where the air can pass outside the housing through the vent holes or other venting mechanism.
• a discharge hose can be used to connect outlet 44 with the exterior of housing 16 or the exterior of trailer 12.
• Brake line 34 interconnects gladhand coupler 46, located on the outside of trailer 12 and configured to received compressed air from the truck or tractor used to haul trailer 12, and the trailer's braking system (not specifically shown).
• One or more sensors 32 are operatively connected to control valve 30 and electronically connected to controller unit 20 to indicate whether there is compressed air in brake line 34 (and, therefore, inlet hose 40). If any one of the sensors 32 determines that the pressure in brake line 34 is greater than a predetermined level (i.e., 60 psi, which is a typical minimum level needed to activate trailer brakes), then controller unit 20 will not open control valve 30, will not vent air through outlet 44 and, therefore, will not lock the trailer's brakes.
• a predetermined level i.e. 60 psi, which is a typical minimum level needed to activate trailer brakes
• the sensors 32 are also used to automatically lock the trailer's brakes. Once the sensors 32 indicate to the controller unit 20 that the pressure in the brake line 34 has dropped below the predetermined level (such as when the driver stops the truck or disconnects the air supply), then the controller unit 20 signals control valve 30 to open and allow air to be vented through the outlet 44, thereby preventing the trailer's brakes from being unlocked. If desired, a second sensor 36 can also be used to determine if compressed air is flowing in line 34 beyond T-splice 28 to the brake system.
• housing 16 is sealed at the manufacturing stage to prevent unauthorized tampering and to prevent water, salt and other material from entering the components inside housing 16.
• the various components that are located inside housing 16 should be mounted therein to prevent unwanted movement of the components during transit of trailer 12.
• housing 16 is best located inside the structural components of trailer 12 where it is inaccessible to a thief and protected from the environment.
• Many trailers 12 are constructed to have interior cavity 48 between the outer wall 50 and inner bulkhead 52.
• housing 16 is installed in cavity 48 and control mechanism 14 is installed such that it faces outward from outer wall 50 so the keys 54 (for the keypad versions of control mechanism 14) can be accessed by the truck driver or other person needing to move trailer 12.
• Brake air lines 34 which connect to T-splice 28, are located between the deck plate 58 and the floor 60 of trailer 12 and travel rearward to connect to the trailer's brakes.
• housing 16 can be installed in cavity 48 by cutting an opening in deck plate 58 with a disk grinder or similar tool and then sealing the opening by welding or other processes. Once installed, it would be very difficult for a thief to access housing 16 because use of a cutting torch or like equipment would likely result in cutting the brake lines 34 or inlet hose 40, which would disable the brake system altogether.
• housing 16 can be installed in the interior cavity 48 between deck plate 58 and floor 60, with cable 18 located on the outside of outer wall 50.
• flatbed trailers and the like will likely require the housing 16 to be installed in cavity 48 between deck plate 58 and floor 60 with cable 18 connecting to control mechanism 14 (i.e., keypad).
• control mechanism 14 connects directly to controller unit 20 such that the proper numerical entry on keys 54 will unlock device 10 (by closing control valve 30) and allow trailer 12 to be moved.
• Electrical communication between keypad 14 and controller unit 20 is coded such that is not possible to "hot wire” the system, even if the potential thief can access the wires from control mechanism 14.
• Power coupling 64 which connects to the external electrical source (such as the power supply system on the truck or tractor), delivers power to charging regulator 24, via power supply line 66, to maintain battery 26 in a charged condition. Power from battery 26 operates device 10.
• power supply line 66 can connect to the trailer's power source.
• the air line 34 from gladhand coupler 46 connects to T-splice 28, which branches off to inlet hose 40, to deliver compressed air to valve 30 and to the air brakes on trailer 12.
• Sensor 32 connects to controller unit 20 so that the microprocessor therein can determine if coupler 46 is connected to the compressed air system of the truck or tractor. If the controller unit 20 receives a signal from sensor 32 that the compressed air supply line is not connected, it will open control valve 30 or lock it in an open position to prevent compressed air from being delivered to the brakes, thereby preventing movement of trailer 12.
• the driver sets the trailer's brakes, causing a drop in the air pressure in brake line 34.
• the pressure sensors 32 constantly measure, with controller unit 20, the pressure in the brake line 34 to determine a measured pressure amount.
• the controller unit 20 signals the control valve 30 to open so that air will be vented through outlet 44, thereby automatically placing the trailer locking device 10 in a locked condition and preventing any movement of trailer 12 until the device 10 is placed in an unlocked condition.
• any compressed air delivered to brake line 34 will follow the path of least resistance and be vented out control valve 30 through outlet 44.
• the automatic locking by device 10 can be subject to any delay time (i.e., not automatically lock for 30 minutes to allow for a restroom or lunch break). In this manner, the operation of device 10 is not dependent on the truck driver remembering to set the controller mechanism 14 lock (code, key or etc.) after he or she disconnects from trailer 12.
• device 10 can be configured to require the driver or owner to manually operate the control mechanism 14 to place the trailer locking device 10 in a locked condition. For instance, with a keypad system, a lock code would be entered on keys 54 of the keypad control mechanism 14 to send a signal to microprocessor 20 to open valve 30.
• any compressed air that comes into the system i.e., from an unauthorized hook-up
• the truck driver can be provided with the proper code, key or etc. so that he or she may deactivate the trailer locking device 10.
• controller unit 20 When the proper code is entered, the controller unit 20 sends a close signal to control valve 30 to close outlet 44, which allows compressed air to flow to the brakes, thereby releasing the brakes and allowing trailer 12 to be moved.
• the keypad or other device on controller unit 14 should be illuminated so that it can be seen and any operational or status indicators on controller unit 14 can be read.
• Control valve 70 has valve body 72 with inlet 74, outlets 76 and interior chamber 78.
• Inlet 74 is configured to attach to inlet hose 40, which connects to brake line 34, and connect to chamber 78.
• Outlets 76 are in fluid communication with inlet 74 by way of chamber 78 so as to vent compressed air from valve 70 to prevent the trailer brakes from being released.
• Chamber 78 is configured to slidably receive shaft 80 therein.
• An activating mechanism, such as electric motor 82 is attached to valve 70 to move shaft 80 in chamber 78.
• Motor shaft 84 connects to an end of shaft 80 to slide shaft 80 in chamber 78.
• the inlet 74 and outlets 76 are alternatively moved from being in communication with each other to where there is no communication between inlet 74 and outlets 76.
• Pressure sensors 32 attached to valve body 72 are used to monitor the pressure inside chamber 78.
• multiple pressure sensors 32 can be used (i.e., two are shown in FIG. 3.).
• one or more limiting switches 86 can be mounted on valve body 72 and connected to shaft 80.
• microprocessor 20 allows user-specific requirements to be programmed into device 10 to make the device more functional for the particular driver or trucking company using device 10.
• microprocessor 20 can be programmed to allow entry of a delay time or time function that locks the brakes for a specific amount of time (i.e., 8 hours) or automatically unlocks the brakes at a specific time of day and/or date (i.e., 7:00 a.m. on Monday morning).
• Microprocessor 20 can also be programmed to recognize different codes from different drivers so the trucking company can verify who has moved trailer 12 (and even when).
• device 10 can have a three tier code system where the driver's code and the amount of delay time can be modified only be a person having a management code, which code can only be modified by someone having the executive or top-level code.
• the factory can set the executive code, allowing the purchaser to set and modify the management and driver codes.
• device 10 can utilize a mechanical locking system, such as a key lock, instead of the electronic keypad 14.
• a key lock system reduces the dependence on electronics and the amount of electricity (battery) power required to operate device 10.
• the use of a key to unlock device 10 allows the trucking company or driver to control who can unlock device 10 (i.e., only a person with a key).
• the use of a key lock does have several disadvantages with regard to how easy it is to have a second driver unlock device 10 after the first driver sets device 10 in a locked condition.
• control mechanism 14 is the use of a radio receiver located in the housing 16 or in connection with controller unit 20 that can receive a radio transmission from a central location or from the truck or tractor pulling trailer 12.
• Various other control mechanisms 14 can be used.
• various control mechanisms 14 can be combined (i.e., keypad, key lock and radio transmission) so as to provide increased security, redundancy or the ability to have a master override.
• the device 10 can be incorporated into a trailer 12 without the use of any housing 16.
• the controller unit 20, control valve 30 and power supply (battery 26) can be incorporated directly into the trailer 12, such as in an interior cavity 48.
• These components would have to be mounted to one or more of trailer walls. This eliminates the need for a separate housing 16 component.
• the control mechanism 14, such as keypad, could be mounted on the outside of the trailer wall and connect directly to controller unit 20, as described above.
• the control valve 30 and other components would operate the same as described above. In order for this embodiment to be practical, the various components would have to be sealed inside the trailer 12 and mounted so as not to break loose during movement of trailer 12.

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• 2001
  • 2001-06-01 EP EP01941785A patent/EP1409271A1/de not_active Withdrawn

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