Truck dolly saving method and apparatus

An apparatus and method for lessening wear on a dolly on a trailer. The apparatus and method also saves the dolly on the trailer.

BACKGROUND

Semi tractor trailers are loaded and coupled to semi tractors. The semi tractor truck can then be used to move the trailer and the content of the trailer to any desired location. Semi tractors and trailers are used widely in moving commercial goods. Semi tractors and trailers can also be used to move livestock to markets or move a family's personal belongings to a new house hundreds or even thousands of miles away.

Operators of semi trucks, in many instances, disconnect a semi trailer. For example, the operators of semi trucks generally make money while hauling loaded trailers from one spot to another. Therefore, the operator may disconnect a loaded semi trailer when it has reached a destination. The trailer can then be unloaded while the operator of the semi moves another loaded trailer elsewhere. In another instance, the operator may disconnect an empty semi trailer at a location. The trailer can be loaded while the semi tractor is used for other jobs. The operator can then come back and reconnect the now loaded semi trailer and haul it to a selected destination.

Many semi trailers are without a front axle and without front wheels. Generally, the weight of the semi trailer is borne by a fifth wheel on a semi tractor when the semi trailer is attached to the semi tractor. When disconnected, legs known as dollies are used to hold up the end of the semi trailer without the front axle or front wheels. When a full trailer is supported by the legs, a large force is carried on the legs. The semi tractor is generally backed into position where the semi trailer can be attached to the fifth wheel. The chore that remains includes retracting the legs to place the full weight of the semi trailer onto the fifth wheel portion of the semi tractor. A set of gears are turned to retract the legs. When the semi-trailer is loaded, the gears are very difficult to turn. Semi tractor operators can get hurt exerting the amount of force needed to turn the gears to retract the legs. If the semi tractor operator is an employee of a company, workman's compensation claims can result. This can be costly to the owner of a fleet of semi tractors. In addition to potential injuries to semi tractor operators, the large forces needed to turn the gears associated with the dollies can strip the gears. This is again costly in that the parts are expensive and must be replaced before moving the semi trailer. This wastes an operators time in addition to incurring the repair cost. Customers may also be disappointed as the arrival of their freight or cargo in the semi trailer may be delayed. Again, this can result in additional monetary losses if a contract covering the transaction includes penalty costs for delaying shipment. Even if the gears are not stripped, turning the gears under a heavy load wears the gears so that their life is shortened. In other words, the time between stripping the gears associated with the dollies may be shorter than necessary.

SUMMARY

Semi tractor trailers are equipped with a Truck Dolly Saving Method And Apparatus which removes the load on the truck dollies so an operator can easily turn the gears after hitching a semi trailer to a semi tractor.

The description set out herein illustrates the various embodiments of the invention, and such description is not intended to be construed as limiting in any manner.

DETAILED DESCRIPTION

FIG. 1is a schematic diagram of a semi trailer150attached to a semi tractor110that is equipped with a dolly saver140, according to an embodiment of this invention. The semi tractor110includes a frame120. Axels122and124are attached to the frame and carry corresponding wheels. Attached between the axels122,124and the frame120is an air bag130which is inflated or deflated as the semi tractor110tows the semi trailer150. Air bag130is associated with axel122. A similar airbag132is associated with axel124. As shown inFIG. 1, there are two airbags130and132. In actuality there are at least four airbags. The airbags130,132are on one side of the semi tractor and other corresponding airbags are associated with axels122and124on the other side of the semi tractor. The air bags are attached between the axels. The airbag130is attached between the axel122and the frame120. Similarly, the airbag132is attached at one end to the axel124and to the other frame120. The dolly saving apparatus140is attached to the axel122and to the frame120. The semi tractor110includes a cab112. A set of controls142used to operate the dolly saver140is located within the cab112. As a result, the operator of a semi tractor110can control the dolly saver140from the cab. Preferably, the controls142are located on the floor of the cab such that the operator can easily reach the controls from outside the cab. In other words, in order to control the dolly saver140, the operator does not necessarily have to be inside the cab.

FIG. 2is an illustration of a dolly250on a semi trailer150with a handle252engaged with the dolly250. The dolly has a foot254which is essentially a curved plate capable of adapting to several different surfaces. The foot254is also relatively large so as to lessen the pressure on the plate and prevent the trailer end supported by the dolly250from sinking into a surface on which the dolly foot254is placed. The dolly250is basically a stand used to hold up the end of the tractor trailer150which is devoid of wheels. The dolly250holds the free end or end of the semi trailer150devoid of wheels up in a substantially level position when the semi trailer150is unattached or disconnected from the semi tractor110. The dolly250is retractable so as not to interfere with hauling operations when the semi trailer150is attached to the semi tractor110. It should be noted that there are typically two dollies250. One dolly is located on one side of the semi trailer150, and another dolly (not shown inFIG. 2) is located on the other side of the semi trailer150. The dolly250includes a set of gears. Turning the handle252turns the gears which in turn place the dolly250in its retracted position. It will be appreciated that many times the trailer150is detached from the semi tractor110when the trailer150is empty. The trailer150is then loaded, which in turn places a large force on the dolly250. When the large force is placed on the dolly250, many times it is very difficult or nearly impossible to turn the handle252. In other words, loading the dolly also loads the gears associated with the dolly250.

FIG. 3is a schematic of an air leveling system that includes the dolly saver340, according to an example embodiment. Leveling system300includes the airbag130, which is attached between the axel122and the frame120and the airbag132, which is attached between the axel124and the frame120of the semi tractor110. Attached to the frame120is a fifth wheel trailer hitch320. The fifth wheel320is capable of receiving the A hitch associated with the semi trailer150. The leveling system also includes an air supply310and a control mechanism330. The leveling system300also includes an air leveling valve301, an actuator arm302(FIG. 7), and the dolly saver340. The dolly saver340is a variable length rod. The dolly saver includes a rod342and an air cylinder341. The dolly saver is attached to the axle of the tow vehicle on one end. The other end of the dolly saver340is attached to the actuator arm302of the air leveling system300. The air leveling system300also includes air lines312and314that are attached to the air leveling valve301, and, when the valve is opened, supply air to the airbags130and132, respectively, with compressed air. The controller330opens and closes an air valve associated with the air supply310. In one embodiment, the air supply310is the same air supply for the seat in the cab of a semi tractor trailer truck. The air supply line is provided with a T-fitting and then to an air valve309controlled by the control mechanism and further detailed below. The controller330receives input or a call for air from the individual air bags130and132. In response to the inputs, the controller opens the air valve309with respect to the air supply310to either add more air to the air bag or remove air from a particular air bag. In actuality, as mentioned previously, for a particular air leveling system300are actually four air bags. Two airbags are associated with each axel122and124. The airbags are located on each end of a particular axel122,124. The air leveling system300allows the trailer150to remain engaged with the fifth wheel hitch320. In addition, the airbags130,132and the others not shown also absorb shock or dampen shocks that may be otherwise transferred from the semi trailer150to the semi truck110.

The air leveling system300also includes a variable length rod340. The variable length rod340includes an air cylinder341. The air cylinder341is attached to the air supply310and controlled by a separate controller142(FIG. 9A). While hauling the tractor trailer150, the variable length rod340is maintained at a fixed length. The variable length rod340is attached at one end to the frame120of the truck and at the other end to the air leveling system. The fixed length associated with the variable length rod maintains a specified distance between the frame120and the axel or axels122,124. The variable length rod340is not supplied with air during hauling operations. As a result, the variable length rod stays at its shortest length during hauling operations so as to maintain a manufacturer's specified distance between the axels122,124and the frame120of the semi tractor110(shown inFIGS. 1 and 2). The controller142supplies air to the air cylinder341only under certain conditions, such as when the parking brake on the semi tractor is engaged. When the parking brake is not engaged, the controller330is also disengaged, which in turn deflates or makes sure that there is no air in the air cylinder341of the variable length rod340. Thus, the changeable length or air cylinder341can be used to change the length only under certain conditions, such as when the parking brake is on.

FIG. 4is an illustration of a portion of the air leveling system300or a semi tractor truck110, according to an example embodiment of the invention.FIG. 4shows the semi tractor110and its frame120. Also shown is the fifth wheel hitch320. An airbag132is located on one side of an axel124, and another airbag432is attached to the other end of the axel124. The axel124is not shown inFIG. 4. However, the wheels424and424′ are attached to the axel.

FIG. 5is an illustration of a variable length rod540used to provide feedback to the air leveling system300of a semi tractor truck110, with respect to the distance between the frame110and the axel or axels of the semi tractor truck110, according to an example embodiment. The changeable length rod540includes a fixed rod510(FIG. 7) and an air cylinder520. The air cylinder520includes an air inlet522. The air cylinder also has an attachment end524. The fixed rod510includes a first attachment end512and a second end524, which is unattached as part of the dolly saving or air leveling system300. The fixed rod510is what is found on many trucks. The fixed rod510is of a specific length so that the distance between the frame and the axels is maintained. According to an embodiment of the invention, the air cylinder520is attached to the fixed length rod510. The end514of the fixed length rod510is detached and the end524of the air cylinder520is reattached to the axel or transmission. In other words, the air cylinder is reattached to the semi tractor at the same point as where end514was previously attached. It should be noted that air cylinder520is attached to the fixed rod510so that the attachment end524is approximately the same length as the distance between the attachment end512and the end514of the fixed rod510.

FIG. 6is an illustration of another embodiment of a variable length rod640used to provide feedback to the air leveling system300of the semi tractor truck110with respect to the distance between the frame120and the axels of the semi tractor truck110, according to another example embodiment. The variable length rod640includes an air cylinder620and a fixed rod portion610. The fixed rod portion610has an attachment end612and a threaded end616, as well as a fastener618. The cylinder has an attachment end624and an end626which attaches to the fastener618. The fastener618attaches to the end626in a secure fashion. The fixed length rod610can be adjusted by screwing or unscrewing the rod610into and out of a threaded opening in the fastener618. In this fashion, slight adjustments can be made to the overall length of the changeable length rod640. The air cylinder620also includes an air inlet622. As shown, an air tube from an air supply310(shown inFIG. 3) is also attached to the changeable length rod640.

FIG. 7is an illustration of a variable length rod540as attached to an axel122and to a portion of the air leveling system300. The end524is attached to the axel122. The end514is unattached. The air cylinder520is attached to the fixed rod510along the length of the rod. The end512is attached to the actuator arm302of the air leveling system300. The actuator arm302is attached to an air leveling valve301which supplies air to the air bags, such as132and432, of the air leveling system300. The changeable length rod540is at its shortest point or shortest length when the air cylinder520is not provided with air. When it is at its shortest length, the distance between the frame120of the truck and the axel122will be maintained at a specified distance. If the frame is too low with respect to the truck or axel122, the relative distance causes a lever arm associated with the air leveling system to be moved to a position where it signals to the air leveling system that the frame is either too high or too low. The actuator arm302is an actuator that, when moved, either inflates the various bags such as airbags132,432or deflates the various air bags132,432to raise or lower the frame120with respect to the axel122. At the particular position where the distance is substantially correct, or substantially the selected distance, the actuator arm302is not in a position where it will engage the air leveling system to pressurize or depressurize or provide air or release air from the airbags132,432.

FIG. 8is a flow diagram of a method800for removing the load from the dolly, such as dolly250, according to an example embodiment. A semi tractor is backed under a loaded trailer, as depicted by reference numeral810, and the park brake is applied as depicted by reference numeral812. The dolly saver is then lengthened to raise the rear suspension or rear portion of the frame of a tow vehicle, such as a semi tractor trailer truck, as depicted by reference numeral814. Raising the rear suspension or the frame removes the load from the dollies. As a result, the dollies are then cranked up, as depicted by reference numeral816. The dollies are cranked up with little or no effort because the weight has been removed from them. The park brake is then released to return the tractor trailer to its normal height, as depicted by reference numeral818. The dolly saver is lengthened by providing air to the air cylinder of the dolly saver. For example, looking at the dolly saver540, air is provided to the cylinder520to add an additional length to the variable length rod540. This additional length moves the lever arm (seeFIG. 7) of the air leveling system300. Moving the lever arm signals the air leveling system300that the distance between the frame120and the axel122of the semi tractor110is too low. In actuality, it is not too low but by lengthening the cylinder the air leveling system300is signaled that it is too low and inflates the air bags, such as air bag130to lift the frame120. Lifting the frame120also lifts the semi trailer150and, when the fifth wheel is positioned below the semi trailer150, also lifts the dollies250off the ground so that there is little, if any, load on the dolly other than its own weight. With the load on the dollies removed, the dollies can then be cranked using the handle252to turn the internal gears and retract the dollies250and place them in their retracted position. The dollies can be cranked up then without having to place excessive torque on the handle252, which lessens the wear and tear on the dollies. In addition, it no longer will require excessive force to crank up the dollies so many more people will have the capability to move the crank up the dollies. The dolly saving system also reduces the number of injuries to workers. Other advantages include a time savings to the operator since the dollies can be cranked up with less effort.

After cranking up the dollies, the driver can then get into the truck or tow vehicle and release the park brake. The park brake release also disengages the controls to the dolly saver or variable length rod540,640. Releasing the air and the controls returns the semi tractor110to its normal height. Essentially, the variable length rod is lengthened so as to temporarily lift the back end of the semi tractor110and specifically to lift the frame120of the semi tractor to lift the semi trailer slightly using the air leveling system300. This allows an operator or anyone else to crank up the dollies with little effort and with little opportunity for getting injured. The controls for lengthening the dolly saver or variable length rod540,640are tied to an electrical signal for a light associated with engagement of the parking brake. Therefore, the controls such as control142that is within the cab112of the semi tractor110, can only be used when the parking brake is engaged. Furthermore, when the parking brake is disengaged, the electrical signal is removed, therefore removing the controls and deflating the air cylinder520,620to the dolly saver540,640, respectively.

Stated simply, the air leveling system of a tow vehicle is overridden for a short time while the vehicle is substantially stationary. The air leveling system is provided with an amount of air to lift the rear portion of the tow vehicle. For example, when the tow vehicle is a semi tractor trailer, the air leveling system raises the rear portion of the semi tractor trailer truck (which includes the fifth wheel) by as much as 2 inches. It should be understood, that this amount is within the normal operating range of the air leveling system while the semi tractor trailer truck is towing a trailer. As a result, the air bags of the air leveling system are not being over inflated. If the semi tractor trailer is positioned to hook up to a trailer, the 2 inch elevation lifts the trailer and removes the load from the dollies of the trailer so that they can be cranked up with less effort. Upon an indication that the tow vehicle will be moving or is moving, the override of the air leveling system is removed to allow the normal operation of the air leveling system. Such an indication can include a release of the parking brake, an engagement of a clutch, or placing a truck into gear, or the like. The override is removed in response to such indications.

FIG. 9Ais a schematic diagram of the operator control mechanism142associated with the dolly saver, according to an example embodiment. The operator control mechanism142associated with the dolly saver, is typically placed in the cab of the tow vehicle. For example, in a semi tractor trailer truck, the control mechanism142can be placed under the seat so that the operator can operate the control either from within the cab or from outside the semi tractor trailer. In another embodiment, the control mechanism142can be placed into the dash board of a tow vehicle. The control mechanism142includes a relay910, a pilot light920, an air valve930, and a momentary switch940. In an unpowered position the air valve930remains closed. The air valve930remains closed and therefore disallows from an air source or air supply from being sent to the dolly saver540,640. The relay910is enabled from a power source. The power source used to enable the relay is the emergency park brake light on the dash of the semi-truck110. Thus, when the parking brake is engaged, the light for the emergency brake is turned on. The power to the emergency light is then used to enable the relay and the control system or the controls142. Thus, when the parking brake is engaged the controls142for the dolly saver are enabled and when the emergency brake is released power to the relay is disabled and thus the relay910and the controls142are disabled. The air valve930is shut when the controls are disabled. The controls also include a pilot light920and an air valve930and a momentary switch940. The momentary switch controls power to the air valve930. The momentary switch must be depressed in order to have the air valve open and allow air to go to the dolly saver. Air from the air supply line or air supply310is then delivered to the dolly saver. The air cylinder associated with the dolly saver, such as520and620(shown inFIGS. 5 and 6) lengthens the dolly saver thereby lifting up the frame120of the semi-tractor110. The length of travel or the amount of lengthening that can be accomplished is fixed so as to prevent the air bags, such as130,132,432(shown inFIGS. 1,3, and4) are not over inflated. In one example embodiment the maximum length that the air cylinders can extend the variable length rod is approximately three inches. Of course, it should be understood, that for other applications the amount of extra travel or amount of extra length produced can be different. It should also be noted that, once invoked the dolly saver extends to its maximum length. When air is removed from the dolly saver, a spring within the air cylinder returns the dolly saver to its minimum length.

When the air bags raise the frame of the truck with respect to the axles the air bags also lift the semi-trailer off the ground and disengage the dolly250from the ground. This allows the dollies250(shown inFIG. 2) to be easily raised to the retracted position. The operator then jumps in the truck and disengages the emergency brakes before moving the truck. Disengaging the parking brake also disables or turns off the electrical signal to the brake light. In response to the brake light turning off, the controls142to the dolly saver are also disengaged. The air valve930returns to its default position where it turns off or shuts off the air supply to the dolly saver and the dolly saver (and more specifically the air cylinder520,620of the dolly saver) bleeds off air allowing the trailer to return to its normal operating position. Using the parking brake light and the power that is fed to it as the power source for the controls142for the dolly saver also acts as a safety feature and prevents the operators from driving off with the dolly saver engaged or in an extended position. Generally trucks are not meant to operate at other than the minimum length between or non-extended length of the dolly saver,640.

It should also be noted that the air supply can be simple T-fitting which is also shown inFIG. 9A. The simple T-fitting can be used to tap into an existing air supply line, such as an air supply used to supply air to the operator's seat. The air supply line is lengthened slightly by the T-fitting. Also attached to the T-fitting is an air supply lines that supplies the air cylinder520,620associated with the dolly saver540,640, respectively. The T-fitting carries the reference number999inFIG. 9A. In some embodiments, the operation of the dolly saver can be implemented using a computing device such as a general purpose computer or a microprocessor that executes a set of instructions in the form of computer software or firmware associated with a device.

FIG. 9Bis a schematic diagram of another operator control mechanism a tow vehicle9001, such as a semi tractor trailer truck, according to an example embodiment. The tow vehicle9001has a rear portion and a forward portion9003. The tow vehicle also has a frame9005and axles. The semi tractor trailer truck9001also includes an air leveling system which include an air bag1912and an air bag1914. Typically, each axle includes at least two air bags. Two air bags1912and1914are shown in this schematic since the truck9001is shown as a side view. The control mechanism includes a control box or control housing1900which may be placed in the cab of the tow vehicle9001. For example, in a semi tractor trailer truck, the control box or control housing1900can be placed under the seat so that the operator can operate the control either from within the cab or from outside the semi tractor trailer. A relay1910, a pilot light1920, an air valve1930, and a momentary switch1960are placed in the control box or control housing1900. The relay1910is attached to a power source. The control mechanism also includes a variable length rod1942that connects between the frame9005of the semi tractor trailer truck9001and an actuator of the air leveling system. The variable length rod1942includes an air cylinder. The air valve1930is attached to the air cylinder of the variable length rod1942. The air valve1930is also attached to an air supply. In this embodiment, the air supply is a source of compressed air for the seat within the cab of the truck9001.

In the embodiment shown, the power source is the electrical system through the wire attached to the parking brake light. When the parking brake is disabled there is no power for the relay1910. When the parking brake is set, power is delivered to the parking brake light and this same source of power is used to power the relay1910. In an unpowered position the air valve1930remains closed and disallow air from an air source or air supply from being sent to the variable length rod1942. The relay1910is enabled when the parking brake is set. As mentioned, the power source used to enable the relay is the emergency park brake light on the dash of the semi-truck9001. Thus, when the parking brake is engaged, the light for the emergency brake is turned on. The power to the emergency brake light is then used to enable the relay1910and when the emergency brake is released, power to the relay1910is removed and thus the relay1910is disabled along with the air valve1930. Thus, when the power to the emergency light is removed, control of the air leveling system through the control mechanism is prevented. The control mechanism is for a period during which the truck is substantially stationary. When the truck is underway, the control of the air leveling system defaults to the controls associated with normal operation.

In operation, the momentary switch1960is switched on when the tow vehicle is stationary because, otherwise there is no power delivered to the control box or control housing. The relay1910then delivers power to open the air valve1930. The momentary switch1960must be depressed in order to have the air valve1930open and deliver compressed air to the air cylinder of the variable length rod1942. The air cylinder associated with the variable length rod1942lengthens the rod and moves an actuator to invoke the air leveling system and to cause the air leveling system to lift or elevate the frame9005of the tow vehicle9001. The length of travel or the amount of lengthening that can be accomplished is fixed so as to prevent the air bags, such as1912and1914, from being over inflated. In one example embodiment the maximum length that the air cylinders can extend the variable length rod is approximately two to three inches. This value is within the normal operational range of the air bags. Of course, it should be understood, that for other applications the amount of extra travel or amount of extra length produced can be different The truck stays in a position with the elevated or lifted rear portion until power to the relay1910and the air valve1930is removed. In this embodiment the power to the relay is controlled by the power to the parking brake indicator light. When either of these events occurs, the controls default to the controls associated with normal operations. The truck is positioned to hook up to a trailer. Then, when the truck9001is stationary, the air leveling system is used to lift the truck and the trailer. This also removes the load of the trailer from the dollies. The dollies can then be cranked up with less effort and more quickly than when loaded. The truck is returned to level after the dollies are cranked up. This is done either by actuating the momentary switch or receiving an indication that the truck will or may be moving, such as when the parking brake is released, or the truck is placed in gear or the like.

In another embodiment, portions of the control mechanism, such as the relay1910, the pilot light1920, the air valve1930, or the momentary switch1960can be placed into the dash board of a tow vehicle.

In another embodiment, lifting of the rear portion of the semi trailer may not involve moving the actuator arm or adding compressed air to a cylinder associated with the dolly saver. The inflation and the deflation of the air bag or air bags of the air leveling system will be controlled directly to lift a trailer thereby removing the load from the dolly or dollies associated with the trailer, such as a semi trailer.FIG. 10is a schematic diagram of an apparatus for lifting a semi tractor trailer is associated with a semi tractor truck, according to an example embodiment. The apparatus1000includes a source of a compressed air or pressurized air1010, and a delivery apparatus1012for selectively placing compressed into at least one airbag1014of an air leveling system1016. The apparatus1000also includes a controller1020that only allows delivery of the compressed air to the airbag1014of the air delivery system1016when there is an indication that the tow vehicle or semi tractor trailer is substantially stationary, such as when a parking brake on the semi tractor truck has been set. In one embodiment, the controller1020releases another amount of air from the at least one bag1014of the air leveling system1016in response to an indication that the tow vehicle will be moved or is moving. One example of an indication that the tow vehicle will be moving includes the release of the parking brake on the semi tractor truck. The controller1020monitors the amounts of compressed air placed into and released from the at least one air bag1014of the air leveling system1016. For example, the controller1020monitors the air leveling system1016so that the air leveling system1016operates within a normal operating range even when the air leveling system is being overridden to raise the rear portion of the tow vehicle. In one embodiment, the delivery apparatus1012includes a device for changing the length of a connecter between the air leveling system1016and a frame of the semi tractor trailer truck.

In operation, the controller1020controls the addition of air into the air bag1014of the air leveling system1016. Air is placed into the airbag or airbags1014only after the parking brake of the truck has been set and the momentary switch has been activated. Air is removed from the airbags1014after the parking brake is released and the truck or tow vehicle controls default to the controls associated with normal operations. This substantially prevents an overriding of the air leveling system while the truck is underway. The controller1020also monitors the air leveling system during the override to assure that the amount of air added to the air leveling system1016does not go beyond a range associated with normal operating conditions of the air leveling system while the truck is underway. This assures that the air bag1014or air bags associated with the air leveling system1016will not be over inflated or blown. Once the load on the dolly or dollies is reduced, the dolly or dollies may be retracted by hand, or placed in a traveling position. Before the truck operator is able to get underway, the parking brake must be released. In response to the parking brake being released, the air bag1014or air bags are deflated or the compressed air in the air bags is reduced to a position near the initial position when the truck was unloaded. Again, the controller1020monitors the air leveling system1016to assure that the amount of air removed from the air leveling system1016does not go beyond a range associated with normal operating conditions of the air leveling system1016while the truck is underway.

In still other embodiments, the control is accomplished with a purely mechanical system. An electronic controller, such as a microcontroller or microprocessor does not come into play.

FIG. 11is a flow diagram of another method1100, according to an example embodiment. The method1100is performed while a tow vehicle is substantially stationary. The method1100includes inflating the airbags of an air leveling system from a first position where the tow vehicle is substantially level to a second position where the rear portion of the tow vehicle is elevated1110, and returning the tow vehicle to a substantially level position before moving the vehicle1112. The method1100may also include receiving an indication that the tow vehicle will remain stationary1114. In one embodiment, this may include setting a parking brake of the tow vehicle. The method1100may also include returning the tow vehicle to a substantially level position1112in response to receiving an indication that the tow vehicle is about to move or is moving1116. In one embodiment, releasing the parking brake is an indication for returning the tow vehicle to a substantially level position. Other indication for returning the tow vehicle to a substantially level position include other events or placing the towing vehicle in gear. Inflation the airbags of an air leveling system to move the frame from the first, substantially level position, to the second position1110is accomplished within a range associated with the normal range of operation of the air leveling system. This prevents over inflation of the air bags. In one embodiment, inflating the airbags of an air leveling system includes changing the length of a rod attached between the axle of the tow vehicle and an actuator arm of the air leveling system. Changing the length of a rod includes elongating an air cylinder associated with the rod. This method is employed in hooking up a trailer to a tow vehicle, such as a semi tractor trailer. The tow vehicle is positioned to attach to a trailer. The tow vehicle then remains substantially stationary during the hook up operation. For example, the parking brake will be set during the hook up operation. After the tow vehicle is correctly positioned with respect to the trailer, the method can be employed to raise the rear portion of the tow vehicle which in turn raises the dollies off the ground. The dollies can then be cranked up to a travel position. The tow vehicle is then returned to a substantially level position before moving the tow vehicle either by an automatic shutoff or by manually disengaging a system. The air leveling system then operates normally as it would during travel of the tow vehicle or semi tractor trailer truck.

The controller1020may also be the control mechanism or controller330described and set forth inFIG. 3above. The controller1020(shown inFIG. 10) may include one or more processors for implementing the instructions associated with all or a portion of the methods discussed above.FIG. 12illustrates an example embodiment of a system2000that functions as a controller.FIG. 12is a block diagram of a computer system that executes programming for performing all or a portion of the above algorithm or methods, according to an example embodiment. A general computing device in the form of a computer2010, may include a processing unit2002, memory2004, removable storage2012, and non-removable storage2014. Memory2004may include volatile memory2006and non-volatile memory2008. Computer2010may include, or have access to a computing environment that includes, a variety of computer-readable media, such as volatile memory2006and non-volatile memory2008, removable storage2012and non-removable storage2014. Computer storage includes random access memory (RAM), read only memory (ROM), erasable programmable read-only memory (EPROM) & electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD ROM), Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium capable of storing computer-readable instructions. Computer2010may include or have access to a computing environment that includes input2016, output2018, and a communication connection2020. One of the inputs could be a keyboard, a mouse, or other selection device. The communication connection2020can also include a graphical user interface, such as a display. The computer may operate in a networked environment using a communication connection to connect to one or more remote computers. The remote computer may include a personal computer (PC), server, router, network PC, a peer device or other common network node, or the like. The communication connection may include a Local Area Network (LAN), a Wide Area Network (WAN) or other networks.

FIG. 13is a schematic diagram of a computer readable medium1300that includes a set of instructions1310. The computer readable medium can be a memory module, a memory stick, a floppy disk, a hard disk, an internet connection to a remote server, or the like. Computer-readable instructions stored on a computer-readable medium are executable by the processing unit2002of the computer2010. A hard drive, CD-ROM, and RAM are some examples of articles including a computer-readable medium. For example, a computer program2025capable of providing a generic technique to perform access control check for data access and/or for doing an operation on one of the servers in a component object model (COM) based system according to the teachings of the present invention may be included on a CD-ROM and loaded from the CD-ROM to a hard drive. The computer-readable instructions allow computer system2000to provide generic access controls in a COM based computer network system having multiple users and servers.

In some instances, the controller may operate in accordance with a machine readable medium. A machine-readable medium comprising instructions, which when implemented by one or more processors perform the following operations: determining that a parking brake of a semi tractor trailer is set, and inflating the airbags of an air leveling system of a semi tractor trailer to move the airbags from a first position to a second position thereby placing a loading force from the trailer onto the air leveling system. When inflating the airbags of an air leveling system of a semi tractor trailer the air leveling system is operated within a normal range of operation. The first position and the second position are within the normal range of operation of the air leveling system. The machine-readable medium further causes the one or more processors to perform the following operations: determining that the parking brake of the semi tractor has been released, and deflating the airbags of an air leveling system of a semi tractor trailer in response to the parking brake being released. This moves the airbags from the second position to another position near the first position. Deflating the airbags of an air leveling system of a semi tractor trailer includes operating the air leveling system within a normal range of operation. In one embodiment, the instructions cause a connector between the air leveling system and the frame of a semi tractor trailer to elongate. In another embodiment, the machine-readable medium includes instruction for pumping a compressed air to a cylinder to elongate a connector between the air leveling system and the frame of a semi tractor trailer.