Patent Application
20190135060
The invention relates to tow systems for towing one vehicle behind another vehicle, such as towing a passenger automobile behind a motorhome or RV. More particularly, the invention relates to tow systems that easily connect to and tow larger vehicles behind a motorhome or RV.
Due to the size of many motor homes, people elect to tow a smaller automobile or other vehicle behind their motor home such that upon arrival and parking of the motor home, the other vehicle may be unhitched and used while the motor home remains parked. There have been various solutions for towing a secondary vehicle behind a primary vehicle, such as in the case of a motorhome. Many of the solutions are either complex to connect, cumbersome due to size, or difficulty in use when driving.
One solution includes using a tow bar which connects the secondary vehicle to the primary vehicle. The tow bar pulls secondary vehicles while all four wheels remain engaged with the ground. The tow bar typically consists of two elements: the tow bar or wishbone portion that attaches to a trailer hitch, and the base plate which attaches to the chassis of the towed vehicle. Driving can be difficult for the driver and hard on the towed vehicle when the towed vehicle remains on all four wheels.
A second solution includes use of a tow dolly. The tow dolly is a short, two-wheeled trailer that transports the secondary vehicle with two of its wheels off the ground. The dolly is first coupled to the motorhome, then the towed vehicle is driven up ramps on the dolly so that the two drive wheels rest on the dolly and the other two wheels of the vehicle are on the ground. Problems with the tow dollies include the motorhome owner must find a place for the dolly when parked, and most states require licensing of dollies and trailers.
A third solution includes use of a trailer wherein a secondary vehicle is towed with all four wheels off the ground and supported by the trailer. A trailer can be costly, and the trailer would be typically removed requiring storage while not in use. Furthermore, a trailer adds weight so that the total combined weight may be more than the towing capacity of the average motor home.
There are also know mechanical and motorized lifts for cargo, which are connected to a trailer hitch. Such lifts are typically direct connected worm drives to load arms for lifting light weight loads, such as in U.S. Pat. No. 7,798,760 issued Sep. 21, 2010.
A lift tow system is compact and can raise the front wheels of a towed vehicle off the ground for simplified portability, use and storage. The lift tow system is for connection to a primary vehicle having a trailer hitch receiver to tow a secondary vehicle having first and second vehicle ends and an undercarriage frame. The system includes a hitch insert for support within the trailer hitch receiver. A drive support unit is connected to the hitch insert. A movable lift support assembly is movably connected to the drive support unit for moving between an up position and a down position with respect to the hitch insert. A vehicle coupler connects and disconnects the secondary vehicle to the movable lift support assembly in the down position and the vehicle coupler raises the first end of the secondary vehicle when connected to the primary vehicle as the movable lift support assembly moves to the up position for towing the secondary vehicle behind the primary vehicle.
The invention also includes the vehicle coupler including a pintle and a frame mount securely attached to the undercarriage frame of the secondary vehicle. The frame mount includes a coupling arm extending from the secondary vehicle. The vehicle coupler includes a removable tow bar for removable connection to the pintle and to the coupling arm so that the secondary vehicle can be disconnected from the primary vehicle when not being towed by removal of the tow bar between the pintle and the coupling arm.
Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
A tow system 10 for connection to a primary vehicle 12 is shown in
The tow system 10 includes a hitch support arm 28 having a hitch insert 30 for coupling to and being supported within the trailer hitch receiver 14 of the primary vehicle 12. This allows the tow system 10 to be removed as desired from the primary vehicle 12. It also allows the tow system 10 to be used on any primary vehicle 12 having a suitably load-rated trailer hitch receiver 14 without custom modification to the primary vehicle 12.
The tow system 10 includes an upright or vertical drive support unit 32 connected to the hitch support arm 28 and a movable lift support assembly 34 movably connected to the drive support unit 32 for moving between an up position and a down position with respect to the drive support unit 32, the hitch insert 30 and hitch support arm 28. The movable lift support assembly 34 includes a vehicle coupler 36 for connecting and disconnecting the secondary vehicle 16 so that the vehicle coupler 36 can be attached to the secondary vehicle 16 in the down position while the front wheels 24 of the secondary vehicle 16 rest on the ground. The vehicle coupler 36 lifts the front wheels 24 of the secondary vehicle 16 are raised and is supported by the vehicle coupler 36 as the movable lift support assembly 34 moves to the up position so that only the rear wheels 26 rest on the ground. With certain type of vehicles, the secondary vehicle 16 may be rotated so that the rear wheels 26 are lifted with the front wheels 24 on the ground.
The drive support unit 32 includes an electro-mechanical drive system 38 for moving the lift support assembly 34 between the up and down positions. Such drive system 38 may be in the form of a motorized worm gear, a hydraulic pump device, or any other drive systems as commonly known in the art. In the preferred embodiment, the drive system 38 is operated by a wired controller 40, as shown, though a wireless controller is also contemplated. The drive system 38 may also be solely mechanically driven as commonly known in the art.
The drive support unit 32 includes a fixed vertical, first inner shaft 42 fixedly connected to the hitch support arm 28 and a second outer shaft 44 sliding with respect to the inner shaft 42. The drive system 38 is attached between the first shaft 42 and second shaft 44 to extend and retract the first shaft 42 with respect to the second shaft 44 causing the tow system 10 to move between the up and down positions. The drive support unit 32 remains substantially vertical when the hitch insert 30 is connected to the primary vehicle 12 and while moving between the up and down positions. This provides a compact design allowing the support drive unit 32 and movable lift support assembly 34 to remain on the primary vehicle 12 even when not towing a secondary vehicle 16.
The lift support assembly 34 includes a sliding support post 46 extending parallel to the drive support unit 32 for moving between the up and down positions. The lift support assembly 34 includes a locking clamp 48 fixedly connected between the sliding support post 46 and the second shaft 44 of the drive support unit 32 so that the sliding support post 46 moves with the second shaft 44. The outer or second shaft 44 may include a circular flange 50 to further secure the locking clamp 48 to ensure a fixed and solid mechanical connection between the locking clamp 48, sliding support post 46 and second shaft 44. Also included is a u-shaped stop bracket 52 welded or otherwise fixedly connected to the outer shaft to provide a stop for limiting the upward motion of the sliding support post. The sliding support post 46 includes a lower end 54 and an upper end 56. The upper end 56 is connected to the locking clamp 48. The upper end 56 includes a clamp hole 58 therethrough and the locking clamp 48 includes a connector hole 60 wherein a bolt 62 can be secured through aligned clamp hole 58 and connector hole 60 to secure the locking clamp 48 to the sliding support post 46.
The hitch support arm 28 has a hitch end 64 and a mount end 66. The hitch end 64 forms the hitch insert 30 for coupling to and support within the trailer hitch receiver 14 of the primary vehicle 12. The mount end 66 includes mount receiver 68 for fixedly receiving and connecting to the drive support unit 32, and more particularly the first shaft 42 thereof. A positioning collar 70 is fixedly connected to the mount receiver 68 for receiving the sliding support post 46 therethrough such that the support post 46 slides within the positioning collar 70 while maintaining the support post 46 parallel with the drive support unit 32. The positioning collar 70 has a locking hole 72 therethrough. The lower end 54 of the support post 46 includes a limit hole 74 therethrough, such that when the lift support assembly 34 is moved to the up position, the limit hole 74 aligns with the locking hole 72 and a locking pin 76 is pushed through the holes 72, 74 to physically support the lift support assembly 34 in the up position. This provides mechanical support by the locking pin 76 allowing the drive system 38 to release its gearing while the secondary vehicle 16 raised and towed, reducing the load on the drive system 38.
The support post 46 includes an extending pivot support member 78 fixedly attached to the lower end 54 of the support post 46. The extending pivot support member 78 includes a support aperture or hole 80 therethrough to receive a bolt 82, acting as a pivot, therethrough, as subsequently described. The pivot support member 78 may be welded or otherwise permanently attached to the support post 46.
The lift support assembly 34 includes a pivot arm 84 secured to the sliding support post 46, and more particularly, the pivot arm 84 is connected to the extending pivot support member 78. The pivot arm 84 pivots between a tow position and a lowered position. The pivot arm 84 has a pintle end 86 and a locking end 88. The pintle end 86 of the pivot arm 84 moves up in the tow position and storage position, and pivots down in the lowered position and secondary vehicle coupling and de-coupling position.
The pivot arm 84 includes a pivot hole 90 therethrough centrally located between the pintle end 86 and locking end 88. The pivot hole 90 is shown near the middle of the pivot arm 84. However, other positions are possible which may depend on leverage and/or locking needed. The pivot hole 90 is secured to the support hole 80 of the pivot support member 78 by the connector or bolt 82 so that the pivot arm 84 pivots with respect to the extending pivot support member 78 and therefore the support post 46. The pivot arm 84 includes a bent elbow 94 extending from the locking end 88 at an angle from the pivot arm 84 to engage the hitch support arm 28 in the up position and to force the pivot arm 84 to pivot to the tow position by raising the pintle end 86. This pivoting allows the tow system 10 to raise the secondary vehicle 16 higher than the travel of the drive system 38 and further elevates the pintle end 86.
The pintle end 86 of the pivot arm 84 includes a mounting block 96 secured thereto. The mounting block 96 is secured to the pivot arm 84 at an angle, shown as approximately 45 degrees, so that the mounting block 96 is substantially vertical in the tow position. The mounting block 96 may be fixedly connected to the pivot arm 84 by suitable fasteners or other permanent means, such as welding. A pintle hitch or hook 98, as commonly known in the art, is fixedly secured to the mounting block 96 by suitable connectors 98 so that the pintle hitch 98 is raised with the pivot arm 84.
The vehicle coupler 36 includes a frame mount 102 securely attached to the undercarriage frame 22 of the secondary vehicle 16. The frame mount 102 includes a coupling arm 104 extending along the undercarriage 22 from the secondary vehicle 16. The coupling arm 104 typically extends for a distance less than the front edge 18 of the secondary vehicle 16 so as not to extend beyond the vehicle 16 but allow easy access by a user thereof. The vehicle coupler 36 includes a removable tow bar 106 for removable connection between the pintle 98 and to the coupling arm 104 so that the secondary vehicle 16 can be disconnected from the primary vehicle 12 when not being towed by removal of the tow bar 106. The removable tow bar 106 includes a lunette ring 108 for connection to the pintle 98, and a locking receiver end 110 with a lock hole 112. The frame mount 102 includes a cross bar or plate 114 for directly connecting to the undercarriage 22 of the secondary vehicle 16 and the coupling arm 104 is connected and extends out perpendicular to the cross bar 114. The cross bar or plate 114 would be bolted to the undercarriage of the secondary vehicle 16, usually by a mechanic. The coupling arm 104 has a mounting hole 116 therethrough, the coupling arm 104 being received within the locking receiver end 110 of the tow bar 106 so that the lock hole 112 aligns with the mounting hole 116 to receive a removeable connector pin 118 therethrough.
In operation, a user would initially have the frame mount 102 fixedly attached and positioned on their secondary or passenger vehicle 16. The frame mount 102 would remain permanently attached to the secondary vehicle 16 at all times or during the traveling season since it will take access to under the secondary vehicle 16. The hitch support arm 28 is mounted on to the hitch receiver 14 of the motor home or other primary towing vehicle 12. The locking pin 76 can be removed and the drive support unit 32 operated to draw the second shaft 44 down and further over the first, inner shaft 42 which slides the support shaft 42 downward to lower the lift support assembly 34 which causes the pivot arm 84 to move to a horizontal position near ground level. The user can connect the tow bar 106 to the coupling arm 104 of the frame mount 102, then slightly raise the lunette ring 108 for engagement with the pintle 98. The pintle 98 can then be locked. Thereafter, the drive system 38 is operated to raise the support post 46 causing the elbow 94 to engage the hitch support arm 28 to pivot the pivot arm 84 to a further raised, tow position such that the locking hole 72 and limit hole 74 align so that the locking pin 76 can be placed therein.
The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.
