Apparatus for stopping a vehicle

An apparatus for externally controlling one or more brakes on a vehicle having a pressurized fluid braking system. The apparatus can include a pressurizable vessel that is adapted for fluid-tight coupling to the braking system. Impact to the rear of the vehicle by a pursuit vehicle, shooting a target mounted on the vehicle or sending a signal from a remote control can all result in the fluid pressures in the braking system of the vehicle being modified so that the vehicle is stopped and rendered temporarily inoperable. A control device can also be provided in the driver's compartment of the vehicle for similarly rendering the vehicle inoperable. A driver or hijacker of the vehicle preferably cannot overcome the stopping action from the driver's compartment.

SCOPE OF THE INVENTION

This invention relates generally to an apparatus for stopping a vehicle moving on a road and, more specifically, an apparatus mountable on a vehicle for applying the brakes of the vehicle to decelerate and stop the vehicle.

BACKGROUND OF THE INVENTION

Hijacked vehicles, such as trucks, are a potentially significant threat to public safety. The potential damage from an explosive or fuel laden truck or other vehicle is great.

A loaded truck is very difficult to stop through external means such as barriers, spikes and patrol cars. Trucks may be damaged through the use of these means but because of momentum may be able to continue on route for a significant distance. Pursuing police officers put themselves in great danger to attempt to shoot either the tires or the driver of a speeding truck. Shooting the hijacker driver, when possible, can result in great danger to the public. Shooting the tires, when possible, is generally not effective because trucks can continue for long distances with a few punctured tires. Either measure typically causes the vehicle to loose control, which may cause the vehicle to detonate in an undesirable location resulting in significant loss of property and life. Law enforcement agencies do not have a workable and safe solution to halt hijacked trucks or other vehicles that can be carried out with the tools and training the agencies have at hand.

BRIEF SUMMARY OF THE INVENTION

An apparatus for externally controlling one or more brakes on a vehicle having a pressurized air or other fluid braking system to halt the vehicle is described. The apparatus can include a pressurizable vessel that is adapted for fluid-tight coupling to the braking system. Light or other impact to the rear of the vehicle by a pursuit vehicle such as an ordinary police patrol car, shooting a target mounted on the vehicle or sending a signal from a remote control can all result in the fluid pressures in the braking system of the vehicle being modified in such a way that the vehicle is stopped and rendered temporarily inoperable. A control device can also be provided in the driver's compartment of the vehicle for similarly rendering the vehicle inoperable. A driver or hijacker of the vehicle preferably cannot overcome the stopping action from the driver's compartment of the vehicle.

DETAILED DESCRIPTION OF THE INVENTION

An apparatus for stopping and/or disabling a vehicle through the application of the vehicle's braking system is described along with a braking system incorporating the apparatus and a method of using the apparatus. In one preferred use, the apparatus is utilized with over the road trucks, especially those having a tractor and one or more trailers attached to the tractor. Several embodiments of the invention apply the brakes via a truck trailer's primary and emergency braking systems simultaneously, although other preferred embodiments activate one or the other of the primary braking system and/or the emergency braking system. Further, embodiments of the apparatus can be utilized with any type of road going vehicle that utilizes a pressurized pneumatic or hydraulic braking system.

The apparatus of the present invention comprises any device or means that facilitates the remote application of the braking system of a vehicle and is referred to herein as a vehicle stopping apparatus (VSA). The VSA can be at least partially mounted to the rear end of a truck or truck's trailer wherein it causes the truck's brakes to be applied when it is lightly impacted or otherwise struck one or more times with sufficient force by the impact of a pursuing vehicle against it or by the impact from a projectile from weapon's fire. The VSA can also incorporate an electromagnetic signal receiver with an associated controller necessary to facilitate the application of the braking system when signaled by a remote transmitter. Further, another VSA can be actuatable only through electromagnetic signals, such as radio or laser signals, from a remote transmitter without utilizing an impact means. Preferably, once activated the VSA cannot be overridden by the driver of the truck without stopping and leaving the cab to either reset or repair the VSA and braking system. The VSA can be actuated be an authorized driver of a vehicle so as to render the vehicle inoperable. Portable versions of the VSA can easily be attached to any vehicle that does not have a permanently installed VSA.

Tractor trailer rigs in the United States typically employ pneumatic or hydraulic fluid braking systems or combinations of both. The normal service or operational brake system on a tractor trailer rig is actuated by the driver who causes increasing air or fluid pressure to be applied to the service braking mechanisms by pressing the brake pedal. However, the emergency brakes on such rigs are designed such that they are automatically applied by the braking system when there is a loss of pressure in the service braking system. The driver can do nothing to stop the automatic application of emergency brakes. Emergency brakes, once applied, are only released when sufficient pressure has been restored in the service braking system.

Tractor trailer rigs are required to have one or more emergency braking subsystems that will automatically apply the brakes to one or more axles of the tractor and/or the trailer when the pressure level in the fluid or pneumatic braking system's supply line(s) falls below a minimum level necessary for safe operation of the rig. These emergency braking subsystems can also be actuated by the truck operator from the tractor's cab by using standard control valves mounted in the cab. Accordingly, the emergency braking subsystem can also serve as the rig's parking brake system.

Referring toFIG. 1, a schematical view of a pneumatic braking system and emergency brake subsystem of a typical truck30having a tractor31and a trailer33is illustrated. An air compressor32that is coupled to the tractor's engine34generates the pressurized air necessary for the operation of the rig. The pressurized air is pumped via a supply line or conduit36to a pressurized air holding tank38. The holding tank is in fluid communication with the primary braking control valve assembly40via a first primary supply line42. Additionally, the tank is fluidly connected to a foot pedal valve44via another supply line46. The foot pedal valve in turn is fluidly connected to the primary tractor braking control valve assembly40through a first pedal valve supply or control line48. Operationally, pressing the foot pedal causes air of increasing pressure, dependent on how much the pedal is pressed, to be delivered to the primary braking control valve assembly40. The brake control valve delivers pressurized air to the tractor brake pots50through the brake pot supply lines53, wherein the pressure of the air being delivered is dependent on the pressure of the air provided to the braking control valve assembly from the pedal valve. The brake pots50of the tractor activate the braking mechanisms52contained at the applicable wheels54with which they are mechanically coupled. The braking mechanisms can include, but are not limited to, drum and disk brake assemblies. The tractor braking control valve assembly can also incorporate more advanced functions such as antilock controls or means wherein the distribution to the braking mechanisms is at least partially apportioned based on the rotation of the associated wheel. For instance, if there is an indication of wheel slippage on the road surface, the braking control valve assembly will reduce the air delivered to the associated brake pot until the wheel regains traction.

Pressurized air from the pedal valve44is also delivered to the trailer braking control valve assembly56through the primary braking control valve assembly40, a second pedal valve control line58, and a third pedal valve control line60, wherein the second and third pedal valve control lines are typically connected through Gladhand or other connectors62. Both the second and third pedal valve control lines58and60are extensions of the first pedal valve control line48and, accordingly, carry air that is pressurized to substantially the same level as that contained in the first pedal valve supply line48when the foot pedal valve44is activated. However, braking control valve assembly40may deliver more air pressure to lines58and60than exists in line48in order to apply more braking force to the trailer33than to the tractor31.

Fully pressurized air is delivered to the trailer braking control valve assembly56from the first primary supply line42through the primary braking control valve assembly40, the second primary supply line64and the third primary supply line66, wherein the second and third primary supply lines are also typically connected through a connector62. Both the second and third primary supply lines are extensions of the first primary supply line and accordingly, carry fully pressurized air. In a manner similar to the operation of the primary braking control valve assembly, the trailer braking control valve assembly delivers pressurized air to the trailer's brake pots based on the pressure of the air received through the third pedal valve supply line60. The brake pots50, which are coupled to the trailer braking control valve assembly56through brake pot supply lines68and70, activate the associated brake mechanisms52to which they are coupled. As with the primary braking control valve assembly40, the trailer braking control valve assembly56can also incorporate advanced features such as antilock control.

Most newer tractors and trailers have emergency braking subsystems that utilize conventional means such as spring brake pots72to mechanically activate associated brake pots50which are automatically activated in emergency situations or manually activated for parking the vehicles. The spring brake pots typically contain a mechanical biasing mechanism, such as a spring (not shown), that is activated when the pressure in associated spring brake air line(s)74drops below a predetermined level, thereby applying the associated braking mechanisms52through the brake pots50. The spring brake air lines74are typically fluidly coupled with shunt lines or conduits76and78that are coupled to one of the primary air supply lines such as line66. Accordingly, if pressure is lost in any one of the primary air supply lines, the pressure level will simultaneously drop in the spring brake air lines74, thereby releasing the biasing mechanism which mechanically causes the spring brake pots72to activate the associated braking mechanisms52. It is to be appreciated that by providing a release valve (not shown) fluidly coupled with the shunt line74in the cab of the tractor, an operator may engage the emergency braking subsystem as desired. If utilized when the vehicle is stopped, the spring brake pots permit the emergency braking system to be utilized as a parking brake.

In the first preferred embodiment of the invention, a first type of VSA80is installed between the shunt lines76and78that feed pressurized air to the spring brake pots72so that they are not activated when the truck is operating normally. Operationally, a first type VSA is a device or means configured to exhaust any pressurized air contained in either or both of the shunt lines76and78, that is in the emergency spring braking system of the vehicle, when remotely activated. In the first preferred embodiment, such remote activation is achieved by an impact of sufficient force against the VSA. Preferably, at least a portion of the VSA80is mounted on the rear of a tractor or trailer, such as a bumper, where it may be easily impacted and where it cannot be repaired or reset without the vehicle operator having to leave the tractor or other operation compartment of the vehicle. Various embodiments of the first type VSA are described in greater detail below.

FIGS. 2,3, and4illustrate different first type VSA embodiments that are mountable to the bumper81of a vehicle and utilize a hinged impact plate configuration to exhaust the air in associated spring brake shunt lines76and/or78. Each includes mounting plates82for connection with a bumper. Each are pivotally connected to an impact plate84along their top edges by way of a hinge86. Other types of movable members can be used as well. The plates are typically fabricated from steel although aluminum or other materials could be utilized as well. A spring88is provided to position the impact plate away from the mounting plate a predetermined distance. Further, the spring, which can comprise any suitable design such as a coil or leaf spring, is sufficiently stiff to prevent the impact plate from pivoting about the hinge when subject to incidental contact. In a preferred configuration, the spring load required to fully compress the impact plate is at least 200 lbs.

Referring toFIG. 2, the first embodiment of a first type VSA80includes a brake actuation device such as a lever operated ball valve90mounted on the mounting plate82with a lever92extending from the valve downwardly and towards the back surface of a remotely operable mechanism such as an impact plate84. The valve is adapted for fluidly coupling to the shunt lines of the braking system, such as shunt lines76and/or78of tractor trailer30. Proximate the bottom edges of the impact and mounting plates respective stop blocks94and96are mounted to the facing surfaces of the plates. The blocks prevent the impact plate from being pushed too far and causing damage to the lever valve. In its first (or home) position as shown inFIG. 2, the valve lever92is in the closed position preventing pressurized air in the coupled shunt lines76and/or78from exhausting. When the impact plate is hit with sufficient force, such as might result from the bumper or other implement of a law enforcement vehicle striking the impact plate, the impact plate pivots towards the mounting plate82to a second or actuated position. Lever push block97that is attached to the impact plate, moves the end of the lever92towards the mounting plate and downwardly, thereby rotating the valve from the closed position to an open position wherein the pressurized air from the shunt lines76and/or78is exhausted out of the valve's exhaust port98. As described above for tractor trailer30ofFIG. 1, the emergency braking subsystem is activated to decelerate and stop the truck. The truck can not be operated by the driver until valve90in VSA80is reset to the normal position.

VSA80is normally mounted on a truck or trailer bumper so that any standard police patrol car can easily impact the impact plate84. Large numbers of law enforcement officers drive ordinary passenger cars with no special bumper equipment. Any one of these law enforcement officers may be called upon to stop a hijacked truck at any time. To minimize the probability of undesirable activations of the first type VSA, several other solutions are possible. For instance, the VSA can be mounted in high or lower positions wherein the bumper of a typical vehicle can not easily impact the VSA by bumping the VSA equipped vehicle. To facilitate activation of repositioned VSA by law enforcement officials, law enforcement vehicles can be equipped with an activation fixture that includes a ram or other appropriate implement attached thereto to impact the VSA. This fixture (not shown) can be permanently affixed to law enforcement vehicles or it could be removeably attached when the need arises.

In a second embodiment first type VSA80′ shown inFIG. 3, a section of the shunt line or conduit78is extended through the mounting plate82and the impact plate84and is capped by a plug100on its end to prevent the leakage of air therefrom. Preferably, the line is also fixedly secured to both the mounting and impact plates. Additionally, it is desirable that the section of the shunt line78passing through the VSA may be of a suitable material to facilitate its cutting, breaking or puncturing when the VSA is impacted. A knife edge102is preferably installed on plate82so that conduit78is cut cleanly when impact plate84is moved forward by impact. Suitable materials for conduit78are rubber or plastic hose that can be cut cleanly to provide a large opening for air to escape rapidly from cut conduit78. A cut conduit78made of rubber or plastic can be easily repaired in the field by simply reinstalling cap100on the cut end. However, the truck driver must get out of the cab of the truck to make such repairs. Once breached, the pressurized air in line78is released and the emergency braking system is activated.

By mounting the first type VSA on the bumper of a truck or other vehicle, it is conceivable that someone other than law enforcement officials could accidentally or even purposefully activate the VSA. Police may desire evidence of those vehicles that either intentionally or accidentally activate another vehicle's VSA and then leave the scene. Accordingly, a marking device or indicator means is provided on VSA80′. The marking device comprises a crushable container104that is mounted to the mounting plate82and includes a nozzle106facing generally outwardly. The container is typically filled with a dye or paint for marking the impacting vehicle. When the impact plate84is pivoted inwardly by an impact, it crushes the container sending dye or paint from the nozzle, through a nozzle hole108in the impact plate and onto the impacting vehicle. A marking system of similar construction can be used on all VSA embodiments that are activated by rear impact.

In a third embodiment first type VSA80″ shown inFIG. 4, a pressure release valve110is not mounted within the impact and mounting plates84and82. Rather, the brake actuation device includes a transducer112mounted between the plates and electrically, mechanically, pneumatically or hydraulically connected to a pressure release valve110mounted within the chassis of an associated vehicle. By mounting the release valve in the chassis, modifying or tampering with the valve becomes more difficult and time consuming reducing the chances that a potential hijacker can disable the VSA before taking to the road. Further, the risk of damage to the valve is also reduced, as it is removed from the bumper of the vehicle where it would have been subjected to the elements. Operationally, when the impact plate is pivoted forwardly the transducer112is activated. The transducer then sends a signal to the valve through conduit114and/or wire connecting the valve with the transducer causing the valve to switch from a closed to open position thereby exhausting an attached shunt line78through an exhaust port116.

A fourth embodiment first type VSA80′″ is illustrated inFIG. 5that is mountable on a bumper of a vehicle but does not utilize the hinged impact plate configuration of the first three first type VSA embodiments80,80′ and80″. Rather, the fourth embodiment VSA80′″ comprises one or more pressurized vessels118that are fluidly coupled with sections of the shunt lines76or78. In a preferred configuration, the pressure vessels are similar to small oil cooler radiators that can withstand pressures upwards of 200 psi, but can be relatively easily crushed and punctured when hit by a chase vehicle or when hit by a projectile such as from weapons fire. Once punctured, the shunt line78is exhausted and the emergency brakes are applied as described above for the braking system of the tractor trailer30ofFIG. 1.

As will be described below, all the vehicle stopping apparatus inFIGS. 2,3, and4can also be used to apply the regular service brakes as well as the emergency brakes of a vehicle such as a truck30shown inFIG. 1.

Many older tractor trailer rigs do not utilize the spring brake pot of more modern rigs. Rather, they utilize an emergency braking system based upon a reserve supply of pressurized air that is supplied to the brake pots50, if the pressure within the primary supply lines drops below a predetermined level. A schematical representation of the braking system of an older style trailer200is illustrated inFIG. 6. Pressurized air is provided to the trailer braking control valve assembly56through the third primary supply line66and a primary supply shunt line202. Pressurized air from the foot pedal valve44is received by the trailer braking control valve assembly56through the third pedal valve control line60. Based on the pressure of the air received from the third pedal valve supply line, air pressurized to a level proportional to the air from the third pedal valve supply line66is provided through brake pot supply lines68and70to the respective brake pots50thereby causing the braking mechanisms52to be activated.

The old-style emergency braking subsystem shown inFIG. 6comprises an emergency reserve air tank204that is fluidly coupled to the third primary supply line66. A one way check valve206is provided inline with the third primary supply line66just upstream of the reserve air tank204. The valve permits air to flow into the tank but does not permit pressurized air to flow out of the tank back to the third primary supply line66. Accordingly, if the primary supply lines are depressurized, the reserve air contained in the pressurized reserve air tank204remains under pressure. A reserve tank air supply line208extends from the reserve tank204to the trailer braking control valve assembly56to supply pressurized air to the emergency braking system when required.

Operationally, when the pressure of the air in the primary supply line66drops below a predetermined level, the trailer braking control valve assembly56automatically directs pressurized air from the emergency reserve tank204to the brake pots50through the associated supply lines68and70, thereby effectively activating the braking mechanisms52. The emergency braking mechanism will remain activated until the air in the primary supply line66is restored to its minimum operational pressure level, usually at least 60 psi. As with the spring brake pot based emergency braking subsystem of truck30, an operator of the truck hauling trailer200may cause the emergency braking subsystem ofFIG. 6to be activated by exhausting the air in the primary supply lines through a release valve (not shown) typically provided in the tractor's cab. Accordingly, the emergency braking subsystem can also be utilized as a parking brake system.

Any one of the first type VSA embodiments80,80′,80″ and80′″ can be fluidly connected to the third primary supply line66upstream of the one-way check valve206through the supply shunt line76. Accordingly, when the first type VSA is activated in any suitable manner, the pressurized air in the primary supply lines42,64, and66is exhausted, causing the pressure in the primary lines to drop. Once the pressure has dropped a predetermined amount, the trailer braking control valve assembly56directs air from the emergency reserve tank204to the brake pots50, thus causing the brake pots50and the associated braking mechanisms52to be activated.

In many tractor trailer rigs the emergency braking subsystem is only applied to a fraction of the vehicle's total number of axles. In tractor trailer30ofFIG. 1, for example, only the rearmost axle has the emergency braking feature. Accordingly, the distance required to stop a truck is potentially greater than when the tractor trailer's braking mechanisms on all wheels are applied by the foot pedal valve44. In the braking system of trailer300ofFIG. 7, a second type VSA380is utilized in conjunction with a modified trailer braking control valve assembly334so that both the emergency braking subsystem and the primary service brakes, preferably on all wheels, are applied simultaneously to maximize the stopping power and minimize the stopping distance. It is to be appreciated that a similar braking control valve assembly could be utilized in the tractor portion of a rig to ensure that activation of the second type VSA applies the tractor's brakes as well. The second type VSA380advantageously is configured to exhaust pressurized air from the spring brake pots72and also redirect maximum supply air pressure to the braking control valve assembly to apply the service brakes of the vehicle.

The second type VSA380of trailer300inFIG. 7, in a manner similar to the first type VSA80, causes the pressurized air provided to the spring brake pots72through shunt line78and spring brake supply lines74to be exhausted, thereby releasing the biasing mechanism in the spring brake pots72to activate associated braking mechanisms52by acting through the brake pots50.

In the braking system of trailer300inFIG. 7, the third pedal valve control line60is fluidly coupled with the trailer braking control valve assembly334through the first control port314. Another service brake activation control line310extends between the second type VSA380and the trailer braking control valve assembly334. Line310is coupled with the trailer braking control valve assembly334through a second control port312. Line310allows the VSA380to activate the trailer's service brakes, that is not only the braking mechanisms52operable by spring brake pots72but also other and preferably all of the other braking mechanisms52of the vehicle, just as the driver can activate the service brakes with the pedal valve in the cab of the truck. As described above concerning trailer30inFIG. 1, the pressure level of the air directed from the braking control valve assembly to the brake pots50through the brake pot supply lines68and70is dependent on the pressure of the air supplied to the braking control valve assembly334through the first control port from the third peddle valve control line60. The second control port312is similarly connected to the trailer braking control valve assembly334in a manner similar to the first control port, wherein the pressure level in the air passed through the port from the service brake activation supply line310determines the pressure level of the air supplied to the brake pots.

Operationally, when the second type VSA380is activated the pressurized air from the shunt line76is directed through the VSA and the brake activation supply line310and into the second control port312. The trailer braking control valve assembly334then supplies pressurized air to the associated brake pots50to apply the associated braking mechanisms52. Since the pressurized air is routed from a primary air supply line66, the air supplied to the trailer braking control valve assembly is at its full (or maximum) operating pressure. Accordingly, the service braking mechanisms52on all wheels will be applied with maximum force, the same force as when an operator fully depresses the brake foot pedal valve44to slam on the brakes.

In a standard air brake system, the air in the pedal valve control lines48,58,60inFIG. 1is normally exhausted to atmosphere when the foot pedal valve44is not being depressed. No residual pressurized air remains in these lines that could act to cause the braking control valve assembly334to continue to activate the braking mechanisms once an operator is no longer pushing the pedal valve44. The exhaust port for the pedal control lines is typically located within the associated pedal control valve. Accordingly, it is not possible to directly connect the VSA brake activation line310into the third pedal valve control line60, since any pressurized air passing through the VSA brake activation line310would simply flow out of the pedal valve exhaust port through the pedal valve supply line62and not activate the braking system as desired.

A schematical representation of one preferred trailer braking control valve assembly334for use with the braking system of trailer300ofFIG. 7is shown inFIG. 8. The braking control valve assembly334is part of the brake actuation device and incorporates a shuttle valve316connected with the first and second control ports314and312. The shuttle valve316isolates line310from pedal valve control line60so that air pressure in line310cannot be exhausted by line60. It acts to direct either the air from the foot pedal valve supply line60or the brake activation supply line310to the pressure apportioning valve hardware318of the control valve334through an internal air passage320. Normally, the shuttle valve316permits pressurized air of varying pressures to pass therethrough as received through the first control port314. However, when air of sufficient pressure is provided through the second control port312, the connection between the first control port and other parts of the trailer braking control valve assembly334is closed. Accordingly, the actions of the operator relative to the brake foot pedal valve44have no effect on the control of the braking system by the VSA through line310.

Shuttle valve316is illustrated in its normal and VSA-activated position inFIGS. 9 and 10, respectively. The shuttle valve comprises a shuttle member322slidably contained within a cylindrical cavity323. The shuttle member has a plunger protrusion324and326extending from each of the top and bottom sides thereof. Three ports are provided into the cavity: the aforementioned first control port314at one end of the cavity; the aforementioned second control port312at the other end; and an outlet port321in a sidewall of the cavity323coupled with the internal air passage320shown inFIG. 8. Pressure seals328are provided between the surface of the shuttle member and the sidewall of the cavity to prevent the passage of pressurized air from one side of the shuttle member to the other. Further, a spring325is provided within the cavity and is configured to actively bias the bottom side of the plunger324into the second control port312to seal the second control port as shown inFIG. 9. In the normal configuration of shuttle valve316shown inFIG. 9, pressurized air from the pedal valve control line60flows freely from the pedal valve44through outlet port321and passage320to the pressure apportioning valve hardware318ofFIG. 8.

When the second type VSA380is activated as shown inFIG. 10, air line310supplies full operating pressure into the shuttle valve316pushing the shuttle member322upwardly to seal the first control port314This permits maximum pressurized air from the brake activation control line310to flow freely to output port321and on to the pressure apportioning valve hardware318, thereby activating brake pots50and associated braking mechanisms52.

An optional one way check valve327may be provided along the brake activation supply line310in trailer300ofFIG. 7. This check valve permits the flow of pressurized air into second control port312but not out of the second control port. The check valve327serves primarily to prevent a quick and easy reset of the braking system after VSA380has been activated. Once the VSA380is activated and the brake activation supply line310has been pressurized, the air trapped between the check valve327and the braking control valve assembly334acts to hold the service brakes in the applied position. This makes it more difficult for a hijacker to release the brakes in order to operate the truck. Even if the hijacker is able to release the service brakes by bleeding the pressurized air holding tank40, he will still not be able to operate the vehicle's braking system since the shuttle valve316continues to be in the VSA-activated position ofFIG. 10preventing the use of the brake pedal valve44. The check valve327and the portion of the supply line to the braking control valve assembly334are preferably located within the chassis of the trailer and are not easily accessible by an operator. By providing a one-way check valve327, an operator cannot merely cut or break the brake activation supply line310at its junction with the VSA380to release the pressure at port312and restore operability to the brake foot pedal valve44.

In a variation of trailer300ofFIG. 7, the second type VSA380may not be connected to the spring brake pots72, since the braking mechanisms52associated with the spring brake pots will be activated more strongly anyway by the brake pots50when the service brake activation supply line310is pressurized. The use, however, of the redundant application of the braking mechanisms as provided for inFIG. 3increases the difficulty of someone deactivating the VSA380and/or resetting or repairing the braking system once the VSA has been activated. For instance, where an emergency braking subsystem is connected to the VSA, a hijacker cannot merely disconnect or block the brake activation310line prior to hijacking the truck to disable the VSA. The VSA can still activate the emergency brakes. Disconnecting the emergency braking subsystem is difficult since positive pressure must be maintained in the spring brake pots to prevent them from activating. For instance, if the shunt line76is blocked or cut, the pressurized air to the spring brake pots72is released and the associated braking mechanisms are applied. To effectively disable the VSA380concerning the emergency braking subsystem, a hijacker must first disconnect the shunt line76from the VSA and effectively splice it into one of the spring brake pot supply lines74and seal any leaks that might develop. In the time necessary to perform such an operation, law enforcement officials will have ample time to arrive on the scene to thwart the hijacking or prevent a VSA-disabled hijacker from completing a repair and continuing underway.

FIG. 11illustrates a first embodiment second type VSA380that is configured to both exhaust the pressurized air in the spring brake pot supply lines74of the braking system of trailer300ofFIG. 7and also pressurize the brake activation supply line310causing the all the service brakes to be applied as well. The apparatus380also includes a impact counter402that is configured to require two or more impacts to the VSA before the braking system is activated.

The second type VSA380includes a bumper mounted portion404and a chassis mounted portion406. The bumper mounted portion comprises an L-shaped mounting bracket408with a hinged edge410that is pivotally coupled with a remotely operable mechanism in the form of an impact plate412. A spring414is provided spanning the distance between the plates and holding the impact plate in its first unactivated position. The spring is sufficiently stiff so that the impact plate will not pivot due to incidental contact between two vehicles or by a pedestrian bumping or being knocked into the VSA380. One end of a flexible load transferring control cable416extends outwardly from the vertical portion of the mounting bracket proximate its bottom edge. The end of the cable can include an impact pad418to receive the force of the impact plate when it is pivoted. A stop block420may also be provided to forwardly limit the pivotal movement of the impact plate. A semi-rigid load transferring cable housing422is braced against and affixed to the backside of the vertical portion of the L-shaped mounting bracket. The cable housing extends to and is affixed to a metal bracket424that is attached to the trucks chassis426. A hole extends through the metal bracket through which the other end of the control cable passes.

In addition to the metal bracket424, the chassis mounted portion includes a brake actuation device having a valve assembly428that is fluidly coupled with shunt line76, the spring brake pot supply lines74through shunt line section78, and the brake activation supply line310. In a preferred configuration the valve assembly includes an impact counter402, one or more pressurized air redirection valves430for directing the flow of pressurized air, and a solenoid actuator432. The impact counter includes a first shaft434that is attached to the end of the control cable through a coupling436. Based on the configuration of the impact counter any number of hits against the impact plate that are transferred to the impact counter through the control cable may be required before the one or more valves are actuated to activate the braking system.

It can be appreciated that an impact counter402can be constructed from a great variety of pneumatic, hydraulic, or electrical components. For instance, pneumatic or hydraulic spool valves can be connected to perform any logical or arithmetic operation such as counting and actuating a mechanical device to produce a differential displacement of a mechanical shaft. Electronic logic circuits can be used to do the same.

A mechanical impact counter402that is particularly rugged and robust is shown inFIGS. 12 and 13. Counter402utilizes a spiral ratchet mechanism. A cylindrical cartridge442is slidably contained within a cylindrical housing444. From a left opening in the housing, the first shaft446extends outwardly and is coupled with the end of the control cable416shown in the VSA380ofFIG. 11. The first shaft and a corresponding second shaft448that extends outwardly of the other end of the housing are fixedly attached to the cartridge, sharing a common axis of rotation therewith. The cartridge and the two shafts are typically made from a metal and can be integrally fabricated. A continuous groove450is formed in the surface of the cartridge around its circumference, at13—13inFIG. 12and as shown inFIG. 13, to receive a control pin452that is fixedly attached to the housing444as shown inFIG. 13. A spring454contained in the housing biases the cartridge to the left.

The positioning of the pin452in the continuous groove450controls the longitudinal displacement of the cartridge442and its associated shafts446and448within the housing. The spiral ratchet and its operation is described in detail in U.S. Pat. No. 5,445,230, entitled “Downhole Drilling Subassembly and Method for Same,” issued on Aug. 29, 1995, which is hereby incorporated in its entirety. As shown herein, shaft446must receive two impacts before it will move to the right and lock in place to actuate the air redirection valves430. The movement of the pin and the operation of the impact controller are best described with reference toFIG. 13, which illustrates the circumferential spiral groove450linearly. As noted above, it should be appreciated that the ends of the view ofFIG. 13are joined together as the spiral groove extends around the cartridge442.

In its normal reset or home position pin452is biased by the spring454against a first right slot456in the groove450. When a first impact is transferred to the first shaft446, the cartridge442moves to the right with pin452being forced along a first sloped surface458in the groove. As the pin rides along the first sloped surface it causes the cartridge to rotate accordingly. The rightwardly motion of the cartridge is stopped when the pin impacts the left wall of a first left slot460. The longitudinal displacement between the first left and right slots is not sufficient to actuate the one or more valves and the braking system is not activated by the VSA380. Next, the cartridge is biased leftwardly by the spring454once the first impact force is removed. The pin rides along the second sloped surface462causing the cartridge to rotate until it is seated in the second right slot464. If a second impact of sufficient force is received, the cartridge is again move rightwardly with the pin riding against the third sloped surface466rotating the cartridge accordingly until being stopped when the pin impacts the left wall of the second left slot468. The displacement between the second left and right slots is sufficient to cause the valves to be actuated and cause the braking system to be applied. When the impact force subsides, the spring attempts to bias the cartridge back to it leftmost position but the cartridge is held in place by the pin impinging against a right substantially vertical wall470of the second left slot468, thereby effectively locking the impact counter in the valve actuating position.

As provided in the illustrated impact counter ofFIG. 13, the one or more valves430are actuated after two impacts. However, by modifying the configuration of the continuous spiral groove it is possible to increase the minimum number of impacts before the cartridge and the second shaft448are displaced to the right a sufficient distance to actuate the one or more valves. Depending on the diameter of the cartridge, the groove450can be configured to include upwards of at least 8 complete cycles on a small diameter cartridge before actuating the one or more valves.

Once the predetermined number of hits is recorded by the impact counter, the valves430are actuated to activate both the service brakes and the emergency braking subsystem. Simply stated, the air redirection valves430when actuated cause the spring brake pot supply lines74to be exhausted to atmosphere causing the spring brakes72to apply the associated braking mechanisms52, and cause the brake activation line310to be pressurized to cause the service brakes to be fully applied. Two valve configurations are described in greater detail below.

FIGS. 14 and 15illustrate two coupled gate valves472and474that can comprise one or more pressurized air redirection valves430to activate the emergency braking subsystem and the service brakes of the braking system of trailer300ofFIG. 7. Gates valve levers476and478pivotally couple the valves with an actuating rod480. The left end of the actuating rod interfaces with the right end of the second shaft448of the impact counter402to transfer the longitudinal displacement of the counter once the impact plate has been hit with sufficient force the requisite number of times, for example, two for counter402. Each valve includes three ports. The first port of each valve is an exhaust port482and484. The second port486and488is coupled to a coupling air line490that joins the two valves together. The third port492on the first valve472is coupled to shunt line section78, which leads to the spring brake pots72, while the third port494on the second valve474is coupled to the brake activation supply line310. The coupling air line in turn is fluidly connected to the shunt line76.

FIG. 14is an illustration of the two valves when the second type VSA380is in its normal non-activated state. The shunt line section78is fluidly coupled with the primary shunt line76through the first valve472, permitting pressurized air into the spring brake pots72thereby preventing activation of the emergency braking system. Further, the brake activation supply line310is exhausted to atmosphere through the second valve474, such that the operator of the tractor trailer rig has full control of the service brakes through the foot pedal valve44.

When the second shaft448of the impact counter402is displaced longitudinally to the right putting the VSA380in the activated state, the actuator rod480pushes the levers476and478of the gang valves into their second position as illustrated inFIG. 15. In this position the first valve472exhausts the shunt line section78, which is connected to the spring brake pot supply lines74to atmosphere causing the spring brake pots72to activate along with the emergency braking subsystem. Further, the brake activation supply line310is coupled with the primary shunt line76, through the second valve474causing the service brakes to be activated. It is appreciated that although the first and second gate valves are shown as two separate valves they could be combined into a single valve housing with a single actuating lever and perform the same function.

In one configuration of the valve assembly428utilizing the gate valves ofFIGS. 14 and 15, the second shaft448and the actuator rod480are longitudinally coupled together such that movement of one longitudinally results in movement of the other. Accordingly, when the impact counter402is reset, the gate valves move back into their normal position as well, causing the service brakes and the emergency brakes to be released. In another configuration, the actuator rod480is not fixedly connected to the second shaft448. Rather, they merely abut each other when the VSA380is activated. Accordingly, resetting the impact counter does not pull the actuator rod back into in a position wherein the gate valves return to their normal non-actuated position. The brakes remain applied until both the impact counter and the gate valves are both independently reset. In this configuration, resetting the VSA380is very time consuming and could prevent a hijacker from re-enabling the braking system before law enforcement authorities are able to apprehend the hijacker.

In other variations, the gate valves472and474can be enclosed in a locked box contained in the chassis to prevent tampering or resetting by anyone who does not have the key or know the combination to the lock. The gate valves ofFIGS. 14 and 15have been described for use in valve assembly428of the first embodiment second type VSA380as illustrated inFIG. 11in conjunction with an impact counter402. It is appreciated that the gate valves ofFIG. 14could also be used in an embodiment of the second type VSA wherein no impact counter is utilized and the actuator rod480is directly coupled with the control cable416.

A spool valve assembly can also be utilized in place of the two gate valves in the valve assembly428ofFIG. 11described above to accomplish the activation of both the service brakes and the emergency braking subsystem of the trailer300shown inFIG. 7. One air redirection valve assembly430incorporating a spool valve is illustrated inFIGS. 16 and 17.

The spool valve includes a substantially cylindrical valve body496slidably contained within a valve housing498. A plurality of air cavities500,502,504and506are formed between the outside surface of the valve body and the inside surface of the valve housing. Flanges508,510and512that extend radially beyond the nominal surface of the air cavities separate the air cavities. The flanges have a diameter just slightly smaller than the inside diameter of the valve housing. Seals514are provided at the circumferential sides of the flanges to seal each air cavity so that pressurized air from one cavity does not bleed into another cavity. Left and right shafts516and518are fixedly attached to the ends of the valve body and extend outwardly from the valve body through openings provided in the ends of the valve housing. Seals520are provided at the openings to prevent pressurized air in the adjacent cavities from bleeding through the opening. Preferably, the right shaft518is comprised of a ferromagnetic material, such a steel or iron, to facilitate activation of solenoid432, which is described in detail below. A spring522is provided within the housing to the right of the valve body and acts to bias the valve body leftwardly.

An air supply inlet524is provided into the leftmost first air cavity500. Inlet524is connected to a bypass air supply line526that is coupled with the brake activation supply line310. A manually actuatable bypass valve528is provided inline along the bypass air supply line526to permit or hinder the flow of pressurized air from the brake activation line into the first cavity500. Further, an auxiliary port530may be provided between the inlet port524and the bypass valve to permit pressurization of the first cavity by alternative means. Normally, a cap532seals port530.

The second air cavity502is separated from the first air cavity500on its left by the first flange508and associated seals514and from the third air cavity504on its right by the second flange510and associated seals514. In the normal position, a port533connected to shunt line76opens into the third cavity504and pressurizes shunt line78also connected to third cavity504.

An outlet port534is provided into the second cavity that is exhausted to atmosphere. In the actuated position of the valve body496within the valve housing498that is achieved after the VSA380has been activated as shown inFIG. 17, shunt line78that normally feeds the spring brake pot supply lines74opens into the second cavity now connected to the exhaust port534. Thus, the emergency brakes are applied when the VSA is activated.

The third air cavity504is separated from the fourth air cavity506on its right by the third flange512and associated seals514. Inlet port533connected to the primary shunt line76extends through the valve housing and opens into the third cavity504in both the normal position and in the VSA activated position of the valve body496. When the valve body496is in its normal or rest position, shunt line78opens into the third cavity permitting pressurized air from the shunt line76to be supplied to the spring brake pots72during normal braking system operation. When the valve body496is in its actuated position as shown inFIG. 17, service brake control line310opens into the third cavity and is pressurized by shunt line76. Shunt line78is exhausted through the second cavity now connected to the exhaust port534.

The fourth air cavity506is bounded on the right by the right end of the valve housing498and contains the spring522that biases the valve body leftwardly. An exhaust outlet port536to atmosphere is provided into the forth cavity in both the normal and activated positions of the valve body. When the VSA380is in its normal state as shown inFIG. 16, the brake activation supply line310opens into the fourth air cavity connected to the exhaust port536, thus exhausting all pressure in the VSA service brake activation line310.

FIG. 16illustrates the spool valve in normal or rest position when the second type VSA380has not been activated and the trailer300ofFIG. 7is in its normal operating mode. Pressurized air from the third primary supply line66of the trailer300is fed to the primary shunt line76. Line78is connected by the third air cavity504of the spool valve to the shunt line section78to feed pressurized air to the spring brake pots72through the spring brake pot supply lines74. Additionally, the brake activation supply line310is vented to atmosphere through the fourth air cavity506and the associated exhaust port536.

The spool valve is actuated when the second shaft448of the impact counter402is driven to the right when the VSA380has been hit the requisite number of times. The second shaft of the impact counter pushes the left shaft516of the valve body to the right as well, thereby compressing the biasing spring522and moving the valve body into its rightmost position as illustrated inFIG. 17. In the actuated position, pressurized air flows from the primary shunt line76through the third cavity504and into the brake activation supply line310to cause the automatic activation of the service brakes. If the bypass valve528is opened, pressurized air is also directed through the bypass air supply line526into the first air cavity500so that the pressurized air holds the valve body in its actuated position. If the bypass valve is closed, no pressurized air will enter the first cavity to hold the spool valve in the actuated position. Rather, the spool will remain in the actuated position so long as the impact counter402is in the actuated position with the second shaft448holding the valve body496in its rightmost position. Once the impact counter402is reset, the valve body will return to its normal position. As discussed above concerning the two gate valves, it may be desirable to require both the impact counter and the spool valve to be independently re-settable thereby increasing the difficulty and time required to restore the braking system to its normal configuration. As can be appreciated in a variation of the first embodiment second type VSA380without an impact counter, the pressurization of the first cavity500is necessary to hold the spool valve actuated.

When the spool valve is in the actuated position as shown inFIG. 17, the shunt line section78that feeds pressurized air to the spring brake pots72is vented to atmosphere through the second air cavity502and exhaust port534. Accordingly, the emergency braking subsystem is also activated.

The solenoid432is provided at one end of the spool valve as shown inFIGS. 16 and 17. The solenoid comprises a housing538containing a solenoid coil540therein. An opening is provided in the left end of the housing through which the right ferromagnetic shaft518of the spool valve passes. Two electrical connections542and544of the coil extend from the solenoid housing for connection to a DC power source and a control circuit. When a current is passed through the coil, the magnetic attraction between the coil and the ferromagnetic left shaft518pulls the valve body into the position illustrated inFIG. 17, thereby causing the service brakes and the emergency braking subsystem to be activated. It is appreciated that by providing a radio or laser receiving device to control the application of power to the solenoid a second method of remotely applying the vehicle's brakes, other than impacting the bumper mounted portion of the second type VSA380ofFIG. 11, is provided. Further, the solenoid may be coupled with a operator accessible switch in the cab or other location on the truck to permit the operator to disable the vehicle so as to thwart a hijacker or other unwanted operator.

Referring toFIG. 18, a schematical illustration of the solenoid control circuit is provided showing both a switch operated and a remote perpetrated solenoid actuating means. Both of these means may be included with a particular valve assembly430of the second type VSA380ofFIG. 11or only one of the two means may be coupled with the solenoid432. In the switch operated means, a switch552is typically located in the cab of the vehicle or in another location known to the operator of the vehicle. The switch is coupled electronically to a delay circuit556that delays applying direct current power to solenoid432until after a predetermined delay time span has passed. Then delay circuit556activates an internal relay (not shown) that connects the positive current power supply line554to connector542which activates solenoid432. The delay circuit is coupled with a direct current power supply. The power supply may be the primary electrical system of the vehicle or the delay circuit may be powered by its own battery that cannot be easily accessed by or disabled by a potential hijacker. Typically, the negative connectors of the solenoid and the delay circuit are grounded on the chassis558of the vehicle.

A delay circuit is utilized to permit a truck operator whose vehicle is being hijacked to activate the disabling circuit prior to being forced from the vehicle without the hijackers being made aware of his action. Presumably, the operator can escape from the scene before the delay circuit activates and renders the vehicle inoperative, thereby avoiding the hijacker's retribution. The switch552, or an additional switch, may also be located on the outside of the vehicle as well.

Additionally or alternatively, the solenoid432can be electrically coupled with a radio or laser signal receiver560. The receiver is coupled to its own or the vehicle's direct current power source and is adapted to receive radio or laser signals562from a remote source. Preferably, the signals are coded and signal receiver560includes a decoder for decoding the signals and, accordingly, activating the braking system.

It is appreciated that coupling the switch552and/or delay circuit556to the solenoid would normally require at least one electrical line554to be run from the cab where the switch and/or delay circuit might be located to the solenoid, which is typically located in the trailer33of a tractor trailer rig. Adding extra electrical lines to all the trucks on the road is not reasonable or practical. An alternative solution is illustrated inFIG. 19, wherein control signals, such as a signal to activate the VSA spool valve430, in the form of alternating current can be sent from the tractor31to the trailer33over the direct current power lines564already connecting the tractor with the trailer, which direct current electrical lines for lights and accessories are standard on all trucks, trailers and other vehicles.

InFIG. 19, the main power direct current line564of a tractor is connected to the main power lines566of the trailer through a standard connector plug568. An alternating signal generator and coding device570is coupled to truck direct current power line564. Alternating signal578is impressed on line564. Signal578appears on the trailer power line566where it is received by decoder576. A relay inside decoder receiver576closes its contacts whenever the coded signal578is received by decoder576. This relay (not shown) can be used to activate any electrical device such as the solenoid432ofFIG. 18.

A switch in the truck cab can be used to activate the signal generator570inFIG. 19. For example, the signal generator and receiver combination570and576ofFIG. 19can be inserted between switch552and solenoid432orFIG. 18to active the VSA spool valve ofFIG. 16.

Operationally, the vehicle driver triggers the delay circuit556by activating the associated switch552. After the predetermined period of time, the delay circuit556activates the coding device570, which generates a code and sends an alternating current signal578carrying the code over the positive power line564. The decoding device576, which continuously monitors the positive power line for signals, identifies and decodes the signal. If the code matches the activation code of the device, the associated relay is tripped and power is supplied to the solenoid432causing the associated VSA380to be activated. It is appreciated that alternating current signaling and decoding devices are well known, inexpensive and reliable.

A second embodiment second type VSA380′ that in most respects is similar to the first embodiment second type VSA380ofFIG. 11is illustrated inFIG. 20. The impact plate412ofFIG. 11is replaced with a “radiator-style” pressure vessel438of the type similar to the pressure vessel118described for the first type VSA80′″ ofFIG. 5. A preferred pressure vessel440is approximately one-foot square and an inch thick. The pressure vessel is hingeably connected to the mounting plate408and is fluidly coupled to the shunt line78of the third embodiment braking system ofFIG. 3. Accordingly, the pressure vessel permits activation of the VSA380′ through a suitable number of impacts to cause the impact counter402and the valve assembly430to apply both the emergency braking system and the service brakes, and through the release of pressure to the shunt line76when the pressure vessel is punctured by weapons fire, thereby causing the emergency braking subsystem to be activated. In a preferred configuration, the face of the pressure vessel includes a hazardous waste placard438to help conceal the pressure vessel from view and provide law enforcement officials with a highly visible target.

The braking system of trailer600inFIG. 21functions in essentially the same manner as the braking system of trailer300inFIG. 7in that both the service brakes and the emergency braking subsystem are activated when a vehicle stopping apparatus is activated. However, unlike the brake activation line310of trailer300ofFIG. 7, the brake activation line section610is pressurized and is fluidly coupled with the shunt line78at one end. Accordingly, activation of the VSA80exhausts the pressurized air from the brake activation line610opposed to pressurizing the line as in the trailer300ofFIG. 7. The other end of the brake activation supply line610is fluidly coupled to a standard inverter valve602. A second brake activation supply line604extends from the inverter valve to the second control port312of the trailer braking control valve assembly334. Further, a second shunt line606extends from the third primary supply line66to another port in the inverter valve. A simple first type VSA80, such as those provided inFIGS. 2–5, can be utilized with this trailer wherein the VSA80merely exhausts the pressurized lines78and610that are coupled with it when activated. However, using a simplified valve as in VSA80requires the addition of the inverter valve602in order to accomplish all the functions of VSA380inFIG. 11.

Operationally, inverter valve602supplies no air pressure at it is output port604when there is air pressure at its input port line610. Inverter valve602supplies maximum air pressure at its output port604when there is no air pressure at its input line610. The inverter valve602supplies pressurized air to the brake activation supply line section604via the second shunt line606whenever the pressure in the first brake supply line610is exhausted by the activation of the VSA80. The trailer braking control valve assembly334is similar to the braking control valve assembly of trailer300ofFIG. 7, wherein pressurized air is provided to the brake pots50via the brake pot supply lines74when pressurized air is provided to a shuttle valve (not shown) through the second control port312.

A third type vehicle stopping apparatus780for use in connection with a braking system of a truck or other vehicle having a hydraulic braking system (not shown) is illustrated inFIGS. 22 and 23. “Air over hydraulic” braking systems are common in medium sized trucks with the service brakes being activated by hydraulic means and the emergency and parking brakes being activated by a pneumatic system utilizing spring brake pots such as described above in reference to trailer30ofFIG. 1. As can be appreciated any of the previously described VSA embodiments can be utilized to activate the emergency braking system, however a modified VSA is required to activate the hydraulic service brakes.

InFIG. 22, an impact device700is adapted for mounting behind on a mounting plate82of a bumper-mounted VSA such as the first embodiment first type VSA80ofFIG. 2. Accordingly, when activated through an impact with an impact plate84hingeably connected to the mounting plate in a manner similar to VSA80as shown inFIG. 2, the hydraulic brakes are activated and held in the activated position. As shown inFIG. 22, an impact block701is provided to ensure good contact with the front face of an impact plunger702of the impact device700. The plunger702is slidably mounted in a front portion of a cylindrical impact device housing704. Outwardly biased plunger stop latches706are mounted on the outside of the plunger and are configured to permit unhindered rearward movement of the plunger in the housing. Mating housing stop latches708are mounted on and protrude from the inside of cylindrical housing's bore. The plunger stop latches706are biased outwardly by springs710such that these latches will recess into the interior of the plunger702, allowing the plunger latches to pass freely by housing latches706as plunger702moves into housing after an impact. Once the plunger latches have slid past the housing latches, the plunger latches are configured to spring outwardly. The rear face of the plunger is in contact with a force transfer spring712that is in contact with a hydraulic piston714at its other end. Stop blocks730are rigidly attached to the cylindrical housing704. Stops blocks730prevent piston714from moving backward in housing704under the normal hydraulic pressure in cavity716, thus not relieving the hydraulic pressure in the braking system connected to cavity716by line722. The force transfer spring is typically in a lightly biased or unbiased in its normal inactivated state as shown inFIG. 22. The backside of the hydraulic piston is in contact with a fluid reservoir716containing hydraulic brake fluid. Seals718are provided around the outside of the piston to prevent hydraulic fluid from seeping out of the reservoir. At the back end of the housing a port720is provided that is coupled with a hydraulic supply line722which in turn is coupled to the associated braking mechanisms.

In the normal inactivated position of the impact device700no pressure is transferred from the device to the hydraulic brake mechanisms through the hydraulic brake line722. However, when the impact plunger702through the impact block701is pushed forward in the housing, the force transfer spring712is biased. The force associated with this bias is applied to the piston714and ultimately the incompressible hydraulic fluid, which causes the brakes to be applied. It is appreciated that the force required to push the plunger702into its locked position ofFIG. 23is dependent on the force transfer spring. Ideally, to prevent the unwanted or incidental locking of the vehicle's brakes, a force of at least about 200 lbs is required to lock the plunger in the activated and locked position ofFIG. 23. Once the impact force subsides the force transfer spring attempts to bias the plunger back into its normal inactivated position, however, vertical surfaces of the housing and plunger stops706and708contact and abut each other holding the plunger in its activated position. Accordingly, the force transfer spring remains in a biased condition as shown inFIG. 23. It continuously exerts a force on piston714which acts to hold the displaced fluid from the reservoir716in an associated reservoir of the braking mechanisms effectively locking the braking mechanisms of the service brakes in an activated condition. The service brakes are not released until the impact device700is reset. To reset the brakes, two apertures724are provided through the housing just above the plunger stop latches when the plunger is in the activated position. By inserting a wire into the apertures724and using the wire to depress the plunger stop latches706so as to permit the latches to pass by the housing stop latches708, the plunger702can return to its normal inactivated position shown inFIG. 22.

In a variation of the impact device ofFIG. 22designed for remote activation upon receipt of a radio or laser signal, the impact plate can be replaced with a suitable solenoid which is activated in much the same manner as described above with respect to the second type VSA380ofFIG. 11.

The utility of any of the various vehicle stopping apparatus80described herein, that is at least partially mounted to a bumper81of a vehicle, is enhanced if there is some visible signal to law enforcement officials that the VSA is operable and ready to stop the truck when activated by someone outside the truck.FIG. 24illustrates a VSA80mounted on the bumper81of a truck or trailer33with a visible flag650or lighted status indicator that signals when the VSA80is operable and ready to be activated by any means. Alternatively, the light or flag may only be visible when the VSA80is not operational. The flag indicator650can be actuated by positive air pressure inside the VSA thereby verifying that shunt line76is providing a pressurized supply air to the VSA and has not been cut, blocked, or otherwise disconnected by someone who wants to disable the VSA. Ideally, law enforcement can view the flag indicator from a distance (like a license plate) and determine whether the VSA is operable.

A visible operational status indicator above can easily be incorporated in all the truck stopping apparatus embodiments described for this invention. Further, a non-visual indicator may also be incorporated in to one or more of the VSA embodiments. For instance, a pressure transducer could be coupled to a radio transmitter that would indicate to someone in another vehicle that tunes into the right frequency whether the VSA is operational or not.

Each of the vehicle stopping apparatus described heretofore can be permanently incorporated into the braking system of the vehicle and are actuated at least in one mode by impacting a portion of the apparatus, whether from another vehicle hitting a portion of the VSA or by weapons fire puncturing a pressure vessel of the VSA. Under certain circumstances, it is preferable to have a remotely activated portable VSA that can be easily attached to a tractor trailer rig and immediately provide the ability to remotely stop the vehicle.

FIG. 25is an illustration of one embodiment of a portable VSA actuatable from a remote source. Portable VSA800is coupled to the air brake lines of a truck or other vehicle by interfacing with the standard Gladhand connectors62customarily utilized to connect the brake lines of a tractor802to a trailer804. As illustrated inFIG. 26, the primary brake air supply line64from the tractor802is coupled to a corresponding primary line838passing through the VSA800. The other end of the primary line is coupled to the second primary brake air supply line66. Similarly, the first pedal valve supply line58from the tractor is connected to a corresponding control line836of the apparatus800and the other end of the primary control line is coupled with the second pedal valve supply line60going to the trailer804. Preferably the VSA is enclosed in a lock box890that is securely fastened to the tractor802. Strong plastic and/or fiberglass-reinforced boxes permit the antenna to be mounted inside the box since the box is transparent to radio waves. It is preferable that the Gladhand connections be made inside the box as shown inFIG. 26such that the VSA is not easily disconnected by persons without the key or combination to the lock on the box890. A security box of no larger than 1 cubic foot has been found to be suitable to house all the hardware of the apparatus800.

As shown inFIG. 26, a remotely operable mechanism such as receiver892, which includes a controller, is provided with a suitable antenna893to receive radio signals895from a suitable remote source such as triggering device850. The receiver is electronically coupled to two electronically activated valves894and896. The receiver's controller includes a processor, memory and associated logic necessary to decode the received signals and to control the activation of the brakes on truck802and/or trailer804. First valve894is configured to exhaust the air from the primary line838to atmosphere and second valve896is configured to redirect pressurized air from the primary line838to the control valve line836through a shuttle valve316that is essentially identical in function to the shuttle valve316of trailer300inFIG. 7. Valves894and896are included within the brake actuation device of VSA800. Typically, the VSA800includes its own batteries to supply power to it.

When VSA800is in its normal operating configuration, air from the supply line64passes unhindered to line66, and the foot pedal valve control line58passes unhindered to line60so that the braking system of the truck operates in a completely conventional fashion. However, if a coded signal895is received directing the VSA to apply the brakes, the receiver892can open the first valve894, exhausting the air in the primary brake air supply lines838, causing the pressure therein to drop, wherein the emergency brakes of the trailer are applied in the manner described with reference to the braking system of trailer300ofFIG. 7. Further, the second valve896can be activated to direct pressurized air to the shuttle valve316causing air at maximum pressure to be directed to the trailer braking control valve assembly through the second foot pedal supply line60, wherein the control valve assembly applies the service brakes with maximum force. In normal operation, only the service brakes are activated. However, the remote operator can send out another differently coded signal that cause application of only the emergency brakes or that causes both sets of brakes to be applied simultaneously. It is to be appreciated that if the vehicle's driver attempts to disable the service brakes when they have been applied by the VSA by cutting off the main air supply in line66, the emergency brakes on at least the trailer are activated as the pressure in the associated spring brake pots is released.

The remotely controlled apparatus800can be utilized in at least a positive control mode, and a negative control mode. In the positive control mode, the VSA800is only activated when a coded signal is received from a remote source, causing one or more of the electronically controlled valves894and896to be activated. In the negative control mode the receiver is configured to receive continuously broadcast coded deactivation signals in order to prevent the VSA from being activated. If the VSA fails to receive a deactivation signal for a set period of time, such as several seconds, the receiver causes either or both of the electronically activated valves894and896to be activated, thereby applying the vehicle's brakes.

In general, the use of a VSA and the modified braking systems incorporating a VSA have been described in terms of stopping a hijacked vehicle as it is driven down the highway. It is appreciated, however, that radio controlled vehicle stopping apparatus380, such as the VSA ofFIG. 11and the remotely controlled VSA800ofFIG. 26, can be utilized to protect critical facilities, structures and areas by automatically disabling any VSA controlled vehicle that breaches a safety or controlled zone around the facility or structure. A remotely controlled portable VSA such asFIG. 26can be installed on any truck entering or operating within a controlled zone in a matter of minutes as shown inFIG. 25.

In one embodiment shown inFIG. 27, a plurality of radio control transmitters902are situated proximate the access roads904to a control or critical zone such as a critical facility906. Each transmitter has an effective range908capable so that all the transmitters effectively cover the access roads as they lead to the facility. They transmit a coded signal910over their effective range that will remotely activate any radio controlled VSA passing into range of the signals to stop the vehicle912. In a first operational mode, the transmitters902are continuously broadcasting the coded activation signal910so that no VSA-equipped vehicle may enter the safety or critical zone906. In a second operational mode, the coded signals are only transmitted when security personal or surveillance equipment identify or perceive a threat. As also shown inFIG. 27, the surveillance equipment can include electric fences914with sensors to indicate an object passing through associated gates915and/or radar speed detectors916. For instance, if a truck or other vehicle passes through an electrical fence914guarding critical facility906, a signal is sent to the transmitters to transmit the coded signal to activate the VSA on this truck or on all trucks. If the truck exceeds a maximum allowable speed, the radar speed detectors trigger the transmitters to activate the VSA in the truck and stop it.

In another operational mode, the truck is permitted to operate within a protected or critical zone so long as it is receiving a coded deactivation signal from one or more transmitters902. If the truck fails to receive the deactivation signal for any reason, the VSA is activated. This negative control mode has desirable anti-tamper or fail-safe features. An approaching truck912is stopped by the VSA mounted on the truck anytime the driver or any other source, such as a deliberate jamming transmission or random radio interferences, blocks the reception of proper radio signals from transmitters902longer than some specified time. Negative control can also be used to define a safety zone by placing transmitters902far enough away from the safety zone such that trucks entering the safety zone cannot receive coded radio signals. In this case, trucks with installed radio controlled VSA apparatus can only operate in an area in which they can receive a proper radio signal from the transmitters.

For the purposes of explanation, numerous specific details have been set forth in the foregoing description in order to provide a thorough understanding of the present invention. The detailed description and embodiments discussed herein are not intended to limit the scope of the invention as claimed. To the contrary, embodiments of the claims have been contemplated that encompass the full breadth of the claim language. Accordingly, the present invention may be practiced without some of the specific detail provided herein.

For example, the VSA ofFIG. 11is described in terms of use with the braking system of trailer300ofFIG. 7. It is appreciated, however, that by simply modifying the routing of the air lines into and out of the described valve assemblies (seeFIGS. 14,15,16, and17), one can adapt the VSA for use with the other types of braking systems. Additionally, although the solenoid432and associated remote radio and or laser signal control of a VSA was discussed only concerning the valve assembly of the VSA ofFIG. 11that incorporates a spool valve430, remote control features using the solenoid can be incorporated into most if not all of the VSA embodiments as desired with appropriate modification. It is to be further appreciated that many of the features, components, and methods of use described in relation to a particular embodiment or variation of the invention may be utilized with other embodiments of the invention as well.