Patent ID: 12257945

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

A wheel grid is a device that can be mounted to a tow vehicle to enable towing of another vehicle. The wheel grid is configured to lift the front or rear wheels of the towed vehicle off the ground by engaging the respective front or rear tires of the towed vehicle. This is generally preferable to using a hook to engage the frame of the vehicle, which may cause damage to the towed vehicle or may be more difficult due to the design of the towed vehicle. For the purpose of brevity, the remainder of the present disclosure will discuss wheel grids engaging with the front tires of towed vehicles. However, it should be understood that the embodiments disclosed herein may be used to tow a vehicle by lifting the rear wheels instead.

A wheel grid is generally mounted to a main boom coupled to and extending out from the rear of the tow vehicle. The wheel grid includes a main crossbar, which is generally fixed in position and engages the front sides of the front tires. The wheel grid may include two L-arms configured to rotate from a loading position, in which the L-arms can be inserted between the front wheels of the towed vehicle, to an engaged position, in which the L-arms engage the rear sides of the front tires. The boom then lifts the wheel grid, and the front tires of the towed vehicle are lifted off the ground by the crossbar and the L-arms. Some wheel grids are designed such that the L-arms can rotate into a third, stowed position when no vehicle is being towed. In the stowed position, the L-arms are tucked underneath the tow vehicle so they do not extend beyond the rear of the tow vehicle, creating a potential safety hazard.

An additional concern when designing wheel grids is the wide range of track widths (e.g., the distance between the two front tires) and tire sizes of various vehicles that may need to be towed. For example, compact sedans generally have narrower track widths and tire sizes than full-size pickup trucks. It is advantageous that a wheel grid is able to be used to tow a wide variety of vehicle types.

According to an exemplary embodiment, a wheel grid includes a crossbar configured to be coupled to a main boom of a wheel lift tow vehicle; two L-arms, each coupled to the crossbar at a respective pivot point and including an extension member and a wheel brace member; and a crossbar end coupled to each end of the crossbar and including a cantilevered portion, the crossbar ends each configured to engage a tire of a towed vehicle. The L-arms are configured to rotate into a stowed position in which each L arm is positioned under one of the cantilevered portions.

Referring now toFIGS.1and2, a wheel grid100is shown, according to some embodiments. The wheel grid100includes a mounting bracket102including an opening104. The opening104is configured to receive a pin such that the mounting bracket102can be rotatably coupled to a main boom of a tow truck by the pin. The mounting bracket102is coupled to a crossbar106that extends from a left end108to a right end110. The wheel grid100includes two L-arms112for engaging the front tires of a towed vehicle. Each L-arm112includes an extension member114coupled to a wheel brace member116. The wheel brace member116may be substantially straight and substantially perpendicular to the extension member114. The L-arms112are rotatably coupled to the crossbar106at rotation points118(e.g., pivot points, etc.). Specifically, a proximal end of the extension member114is coupled to the rotation point118and a distal end of the extension member114is coupled to a proximal end of the wheel brace member116. InFIG.1, the wheel grid100is shown in an engaged position, in which the wheel grid100may be engaged with the tires of a towed vehicle. The crossbar106engages the front of the front tires of the towed vehicle, the extension members114extend rearward between the front tires, and the wheel brace members116engage the rear of the front tires. The distance from the left end108to the right end110is shown as width W. The distance from the crossbar106to the wheel brace members116is shown as distance D2.

FIG.2shows the wheel grid100in a stowed position, in which the L-arms112rotate approximately 90 degrees from the engaged position such that the extension members114are substantially parallel and adjacent to the crossbar106and the wheel brace members116extend forward underneath the tow vehicle in a direction substantially perpendicular to the crossbar106. In conventional wheel grids, the distance from the rotation point118to the wheel brace member116, shown as distance D3, may be greater than the distance from the rotation point118to the end108of the crossbar106, shown as distance D1. In these conventional wheel grids, when the L-arms112rotate into the stowed position, the wheel brace members116may be positioned further from the center of the wheel grid100than the end108of the crossbar106. This allows the L-arms112to rotate into the stowed position without the crossbar106interfering. However, in order to tow a wide range of vehicles, it may be advantageous to reduce the distance D2so that the wheel grid can be used to tow vehicles with smaller tires. It is also advantageous to increase the distance D1, and more specifically, the width W of the crossbar106, so that vehicles with wider track widths can also be towed. In order to increase the width W while decreasing the distance D1(thereby reducing the distance D3), the wheel grid100includes a crossbar end120at either end of the crossbar106. The crossbar end120includes a cantilevered portion122that allows the wheel brace members116to rotate under the ends108,110of the crossbar106. Thus, according to some embodiments, the wheel grid100has a distance D3from the rotation point118to the wheel brace member116that is shorter than the distance D1from the rotation point118to the end108of the crossbar106.

Referring now toFIGS.3A and3B, partial cross section views of two wheel grids300a,300bare shown engaging a towed vehicle301, according to some embodiments. The wheel grid300aincludes a crossbar306athat is a distance D4away from a wheel brace member308a. The wheel grid300bincludes a crossbar306bthat is a distance D5away from a wheel brace member308b. Distance D5is greater than distance D4. When wheel grid300aengages the tire302of the towed vehicle300, the tire302sits high enough that there is clearance between the crossbar306aand the oil pan304and other components of the undercarriage of the towed vehicle301. However, because the distance D5between the crossbar306band the wheel brace member308bof the wheel grid300bis larger, the tire302sits lower on the wheel grid300band the crossbar306bmay contact and damage the oil pan304and other components of the undercarriage of the towed vehicle301.FIG.4shows a wheel grid100with an L-arm112that is over-rotated such that the wheel brace member116contacts the tire402of a towed vehicle at a contact point404near the outside of the tire402. It should be understood that “over-rotated” refers to the rotation of the 1-arm112such that the extension member114and the crossbar106form an angle greater than 90 degrees. The contact point404is a distance D6from the crossbar106, which is shorter than the length of the extension member114due to the over-rotation of the L-arm412. This may be necessary to tow vehicles with smaller tires402. The longer the extension member114, the more the L-arm112must over-rotate to contact the tire402at an acceptable distance D6. If the extension member114is too long, the wheel brace member116may contact the tire402at a contact point404that is too close to the sidewall of the tire402or the extension member114may contact the sidewall of the tire402, either of which can damage the tire402.

FIGS.5-11illustrate the wheel grid100with the L-arms112rotated into various operational positions, according to some embodiments. The wheel grid100is coupled to a boom80, which may be coupled to and extend rearward from a tow vehicle.FIG.5shows the wheel grid100in the loading position, with the wheel brace members116are perpendicular to the crossbar106and extending rearward and the extension members114parallel and adjacent to the crossbar106. To engage a vehicle to be towed, the tow vehicle backs up towards the towed vehicle and the wheel brace members116are inserted between the front wheels of the towed vehicle until the crossbar106contacts the towed vehicle. Linear actuators150are configured to rotate the L-arms112to move them between the loading, engaged, and stowed positions.FIG.6shows the wheel grid100with the L-arms112in transition between the loading position and the engaged position. The rods152of the linear actuators150retract into the cylinders154, rotating the linkages160causing the L-arms112to rotate. The linear actuators150may be, for example, electromechanical actuators, pneumatic actuators, or hydraulic actuators that may be controlled via user input. In some embodiments, other actuators or configurations may be used to cause the rotation of the L-arms112. The arrangement of the linkages160allows the linear actuators150to be substantially within the footprint of the crossbar106and enable at least 180-degree rotation of the L-arms112from the stowed position to the loading position. This, combined with the positioning of the rotation points118, allows the extension members114to be substantially parallel and directly adjacent to the crossbar106when in the loading position. When in the loading position, the wheel brace member116may be substantially parallel and directly adjacent to one another. This may allow the wheel brace members116to more easily fit between the tires of the towed vehicle, particularly when the towed vehicle must be engaged by the wheel grid100at an angle.

FIG.7shows the wheel grid100with the L-arms112rotated into an engaged position such that the wheel brace members116are roughly parallel to the crossbar106. The wheel brace members116may engage the rear side of the front tires of the towed vehicle. The boom80can then lift the wheel grid100causing the crossbar106and the wheel brace members116to lift the front of the towed vehicle by engaging the front tires. It should be understood that one or more of the crossbar106or the wheel brace members116may not contact the tire until the wheel grid100is partially lifted.FIG.8shows the wheel grid100in an over-rotated engaged position. As discussed above, for towing vehicles with smaller tires, a small amount of over-rotation may be necessary to reduce the distance D6from the crossbar106to the contact point404of the tire on the wheel brace member116.FIG.9shows the wheel grid100with the L-arms112in transition between an engaged position and a stowed position. The rods152of the linear actuators150continue to retract into the cylinders154, rotating the linkages160causing the L-arms112to rotate further.

FIG.10shows the wheel grid100with the L-arms112in a stowed position such that the extension members114are adjacent the crossbar106and the wheel brace members116extend forward toward the tow vehicle. The wheel brace members116pass under the cantilevered portions122of the crossbar ends120. As discussed above, this allows the distance D3from the crossbar106to the wheel brace members116to be reduced while maintaining the width W of the crossbar106. Because the wheel brace members116pass under the cantilevered portions122of the crossbar ends120, the crossbar106does not interfere with the rotation of the L-arms112into the stowed position.

FIGS.11A and11Bshow the wheel grid100rotated zero degrees and ninety degrees, respectively, about a rotation pin1104inserted into the opening104in the mounting bracket102, according to some embodiments The rotation pin1104rotatable couples the wheel grid100to the main boom80to allow the tow vehicle to engage the tires of a towed vehicle from an angle. For example, it may not be possible to load a car parallel parked between two other cars with the crossbar106in a static position perpendicular to the main boom80. Rotation of the wheel grid100allows the towed car to be engaged and pulled out of the parking spot at an angle. In some embodiments, the wheel grid100may be inserted under the center of a parallel-parked vehicle from the side, and the crossbar106may engage the rear of the front tires while the wheel brace members116engage the front of the front tires. The towed vehicle can be pulled out of the parking spot, set back down, and reengaged from the front to be towed away. In some embodiments, the rotation of the wheel grid100relative to the main boom80may be actuated (e.g., electrically, hydraulically, or pneumatically actuated). In some embodiments, the wheel grid100rotates when it comes in contact with a tire of a towed vehicle. The tire pushes the wheel grid100left or right causing the rotation as the tow vehicle backs toward the towed vehicle. The wheel grid100may be able to rotate at least 90 degrees in either direction (clockwise or counterclockwise) from the neutral position in which the crossbar106is perpendicular to the main boom80.

FIG.12shows a detent assembly1200that resists the rotation of the wheel grid100relative to the main boom80, according to some embodiments. The detent assembly1201may be mounted to the crossbar106by two fasteners1202(e.g., threaded fasteners, screws, shoulder screws, etc.). The fasteners1202each extend through a respective clearance hole in a detent bracket1204, such that the detent bracket1204is slidably coupled (e.g., not threadedly coupled) to the fasteners1202. A spring1206is positioned around each of the fasteners1202and biases the detent bracket1204toward the main boom80. The fasteners1202may be threadedly coupled to the crossbar106, and a locknut1208may be threadedly coupled to each fastener1202to hold the fastener1202in position relative to the crossbar106. When the wheel grid100is in the neutral position (e.g., when the crossbar106is perpendicular to the main boom80), the springs1206bias the detent bracket1204such that the detent bracket1204engages a detent flat82in the main boom80. This configuration resists the rotation of the wheel grid100until a rotational force on the wheel grid100overcomes the force of the detent assembly1100. The towed vehicle may thus be kept substantially in line with the tow vehicle unless a relatively strong rotational force overcomes the force of the detent assembly1100. The detent assembly1201may also prevent or resist the rotation of the wheel grid100when the wheel grid100is in the stowed position to stop the wheel grid100from swinging and potentially contacting the rear wheels or other components of the tow vehicle. The main boom80includes a left portion84and a right portion86, each with a circular profile, which the detent bracket1204contacts when the wheel grid100is rotated out of the neutral position.FIG.13shows a perspective view of the detent assembly1200.

In some embodiments, the main boom80may include stops88to limit the overall rotation of the wheel grid100in either direction. The stops88may be positioned such that the heads of the fasteners1202contact the stops. Fine control of the maximum amount of rotation of the wheel grid100can be achieved by adjusting the extension of the fasteners1202away from the crossbar106. For example, the fasteners1202can be loosened such that the heads of the fasteners1202are farther from the crossbar106. The heads of the fasteners1202will then contact the stops88on the main boom80at a lower amount of rotation. Conversely, the fasteners1202can be tightened such that the heads of the fasteners1202are closer to the crossbar106, and the wheel grid100will be able to rotate further before the fasteners1202contact the stops88.

FIGS.14-16show the wheel grid100with overlaid alternatively shaped L-arms1412, to emphasize the advantages of the shape of the L-arms112. The L-arms1412are designed with extension members1414that are not able to rotate into a parallel and adjacent position relative to the crossbar106. The L-arms1412may also include wheel brace members1416that have a straight portion1417and an angled end1418. The angled ends1418cause the combined width W2of the wheel brace members1416in the loading position to be larger than the width W1is the combined wheel brace members116in the loading position. This makes it more difficult to fit the wheel brace member1416between the tires of the towed vehicle.FIGS.15and16show the wheel grid100and the alternatively shaped L-arms1412in a loading position engaging a large tire401and an over-rotated loading position engaging a small tire403, respectively. As shown inFIG.15, because the straight portion1417of the wheel brace member1416is not perpendicular to the extension member1414, an area1501of interference is created. When engaging a towed vehicle with large tires401, the area1501requires that the wheel grid is more centered on the towed vehicle. If the wheel grid is not centered, the straight portion1417of the wheel brace member1416can contact the sidewall of the tire401. As shown inFIG.16, when towing a vehicle with small tires403, the straight portion1417of the wheel brace member1416may contact the sidewall of the tire403at a contact point405rather than making contact at the back of the tire at contact point404. To avoid contact at the contact point405, the L-arms1412cannot over-rotate as much as the L-arms112, which causes a towed vehicle with small tires403to drop lower into the wheel grid, potentially causing contact between the wheel grid and the undercarriage of the towed vehicle. Thus, in the case of a small tire403or a large tire401, the L-arms112provide advantages over the alternatively designed L-arms1412.

Crossbar Belting

In certain situations, it may be difficult or impossible to tow a vehicle by engaging the tires with a wheel grid (e.g., wheel grid100). For example, if the tires of the towed vehicle are damaged or the wheels or tires are removed, the crossbar and L-arms may not be able to properly engage and lift the vehicle. Instead, one or more chains coupled to the crossbar may be used to lift the vehicle. The tow vehicle may back toward the towed vehicle until the crossbar is approximately aligned with the front bumper of the towed vehicle. Then, a chain may be coupled to a hook on one side of the crossbar, coupled to the axle of the towed vehicle, and then coupled to a hook on the other side of the crossbar. Alternatively, a separate chain may be coupled to each side of the crossbar and the axle. When the wheel grid is lifted, the chains lift the vehicle and the crossbar contacts or nearly contacts the front bumper. In this towing arrangement, the crossbar may cause damage to the bumper if there is no protection in place between the bumper and the crossbar, which is generally made of metal, such as steel or aluminum.

Referring now toFIGS.17-19, the wheel grid100is shown with a protective belt1700, according to some embodiments. The belt1700is positioned around the crossbar106and provides a barrier between the crossbar106and the bumper1802of the towed vehicle1800. The belt1700may be made of a flexible, relatively soft material that may reduce scratches, dents, and other damage to the bumper1802that may occur if the bumper1802directly contacted the crossbar106. For example, the belt1700may be made from a rubber, plastic, or composite material. The material may also be selected to provide a non-slip surface so that the bumper1802does not slide across the crossbar106, which may further reduce the damage to the bumper. The belt1700may also protect the wheel grid100itself. For example, as shown inFIG.19, the belt may be positioned around the L-arm actuator linkages160, protecting the linkages160as well as the crossbar106itself from damage caused by lifting the bumper1802.

When a vehicle1800requires a chain lift (e.g., due to damage to the tires1804), the L-arms112are rotated into the stowed position, as shown inFIGS.17-19. A belt1700is then installed on each side of the crossbar106. The belt1700includes an elongated body1702long enough to wrap around the crossbar106. The belt1700further includes a narrow portion1704that widens to a tab1706at one end of the belt1700. At the other end of the belt1700is a slot1708sized to receive and retain the tab1706. The slot1708may be, for example, a T-shaped slot with a vertical portion1710and a horizontal portion1712. To install the belt1700on the crossbar106, the belt1700is first positioned around the chain hooks111near an outer end of the crossbar106, as shown inFIG.18. In this area, the crossbar106may be relatively narrow, allowing for more room to install belt1700. Next, the tab1706is inserted into the vertical portion1710of the slot1708by turning the tab end of the belt1700ninety degrees from its natural position. Because of the shape and flexible material of the belt1700, a user may rotate the tab1706by hand. Once the tab1706has been fully inserted, the tab may be rotated ninety degrees back to its natural position, and the narrow portion1704may be moved into the horizontal portion1712of the slot1708. Because the tab1706is wider than the horizontal portion1712of the slot1708, the tab1706cannot be pulled through the horizontal portion1712, and the belt1700is retained around the crossbar106. Finally, the belt1700can be slid toward the center of the crossbar106into an installed position around the linkages160, as shown inFIG.19. Because the crossbar106is wider in this position, the belt1700may fit snugly around the crossbar and be held in place by friction. A second belt1700may be installed on the other end of the crossbar106.

Once the belts1700are in the installed position, the tow vehicle can back the wheel grid100up to a towed vehicle until the crossbar is roughly aligned with the bumper. Then, a user can install the chain1720by coupling a first end of the chain1720to the hooks111on a first side of the crossbar106, coupling the chain1720to the axle or other structural component of the towed vehicle, and coupling the other side of the chain1720to hooks111on the other side of the crossbar106. In some embodiments, separate chains1720may be used on each side of the crossbar106. Once the chains1720are installed, the wheel grid100can be lifted, causing the chains to lift the vehicle1800. As shown inFIG.17, the belts separate the bumper1802of the towed vehicle1800from the wheel grid, protecting the bumper1802, the crossbar106, and the linkages160from damage. To remove the belt1700, the process is reversed. The vehicle is lowered to the ground and the chains1720are removed. The belts1700are slid toward the end of the crossbar, and the tab1706is turned ninety degrees and pulled back through the vertical portion1710of the slot1708. The tab1706may include an opening1707that can be used to pull the tab1706when installing or removing the belt1700or can be used to hook the belt1700in a storage location.

As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

The hardware and data processing components used to implement the various processes, operations, illustrative logics, logical blocks, modules and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, particular processes and methods may be performed by circuitry that is specific to a given function. The memory (e.g., memory, memory unit, storage device) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present disclosure. The memory may be or include volatile memory or non-volatile memory, and may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. According to an exemplary embodiment, the memory is communicably connected to the processor via a processing circuit and includes computer code for executing (e.g., by the processing circuit or the processor) the one or more processes described herein.

The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data that cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above. Such variation may depend, for example, on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations of the described methods could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.

It is important to note that the construction and arrangement of the wheel grid100and the systems and components thereof as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.