Wheel lift towing device

A wheel lift towing device includes a boom for mounting to a towing vehicle and having a cross bar connected to its rear end. A pair of wheel retainer arms are each rotatably mounted offset from one end of the cross bar and devices are provided for rotating each wheel retainer arm which includes motive devices operatively connected to the wheel retainer arm by elongated flexible devices. Each wheel retainer arm cooperates with a wheel retaining plate and an end of the cross bar to cradle and support a wheel.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a wheel lift type vehicle lifting and 
towing device and, more particularly, to such a device having elongated 
flexible means for rotating wheel retainer arms from a fully closed 
position to a fully opened position. 
2. Description of the Related Art 
It has been conventional to lift vehicles for towing by means of a winch 
and a cable having a hook at its end or by use of a sling system whereby a 
vehicle is lifted by a sling suspended from a boom at the rear of a tow 
truck. With the current designs of automobiles, however, it is no longer 
possible to lift many of such vehicles with either a conventional winch 
and a cable or a sling system without damaging the vehicle. Accordingly, 
wheel lift types of lifting and towing devices wherein a vehicle is lifted 
by engaging its wheels with some form of wheel retaining assembly have 
become common and well known in the art. 
While such prior wheel lift types of lifting and towing devices generally 
have been satisfactory, they nevertheless have been found to have certain 
disadvantages. In many such prior devices, rotatable wheel retaining arms 
are not able to be rotated to a fully open, non wheel engaging position or 
a fully closed storage position wrapped around the ends of a cross bar. In 
other such prior art devices, the wheel receiving or retaining assemblies 
have arms which must be pivoted from a position outside of the wheels of 
the vehicle to a position adjacent the wheels. This can make it difficult 
to position the wheel retaining devices in a wheel cradling position when 
one or more of the wheels is against an obstacle such as a curb. Still 
other such prior wheel retaining assemblies have removable arms which must 
be manually inserted or connected for lifting and towing and manually 
disconnected for storage. This is time consuming, cumbersome and requires 
heavy lifting and handling. Moreover, devices with such manually connected 
arms cannot be readily adjusted to vary the tightness with which a wheel 
can be gripped. Accordingly, such manually operated devices can not easily 
grip a deflated tire. Other prior wheel lift devices can not be moved to a 
horizontal storage position adjacent the end of a towing vehicle but must 
be rotated to a vertical position for storage. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved wheel lift 
towing device having wheel retainer arms automatically rotatable from a 
storage position wherein the ends of the arms are wrapped around the ends 
of a cross bar to a fully opened position wherein the arms are retracted 
to a position adjacent the rear end of a cross bar to permit insertion of 
the arms between the wheels of a vehicle and then to rotate the arms 
outwardly back to a wheel engaging position wherein the arms securely 
cradle the wheels of a vehicle from between or inside of the wheels. 
It is another object of the present invention to provide an improved wheel 
lift device having wheel retainer arms automatically rotatable from the 
inside outwardly to engage the inside, front and back faces of the wheels. 
It is still another object of the present invention to provide a wheel lift 
towing device having wheel retaining arms which are automatically rotated 
by hydraulic means having elongated flexible means connected to the arms 
which permit the arms to be rotated between a fully opened position to be 
positioned conveniently between two wheels of a vehicle and a fully closed 
horizontal storage position wherein the ends of the arms wrap around the 
ends of a cross bar. 
It is a further object of the present invention to provide a wheel lift 
towing device having automatically rotatable wheel retainer arms which 
remain fixedly attached to the device while being rotated from a storage 
position to a fully opened position and then to a wheel retaining position 
whereby the wheels of a vehicle are cradled from the inside face thereof. 
It is another object of the present invention to provide a wheel lift 
device having automatically rotatable wheel retainer arms whereby the 
tightness of the grip on a vehicle's wheels may be readily adjusted to 
tightly grip a deflated wheel or wheels of different sizes. 
It is a still further object of the present invention to provide a wheel 
lift device with automatically rotatable wheel retainer arms whereby the 
arms may be rotated to a storage position wrapped around the ends of a 
cross bar so that the cross bar can be stored in a horizontal storage 
position adjacent the rear end of a towing vehicle from where the device 
may be quickly automatically moved to a vehicle hook-up position. 
It is still another object of the present invention to provide a wheel lift 
device having automatically rotatable wheel retainer arms which may be 
rotated to a fully opened position whereby when the cross bar is rotated 
to a sharp angle to a vehicle's wheels, a relatively large amount of space 
is available for the arms to fit between the wheels. 
The present invention achieves the above and other objects by providing a 
wheel lift towing device for attachment to the rear of a towing vehicle. 
The wheel lift device includes an extensible boom pivotally mounted to the 
vehicle for up and down movement and a cross bar pivotally attached to the 
rear end of the boom. A pair of wheel retainer arms are rotatably mounted 
offset from the ends of the cross bar and means are provided for rotating 
the wheel retainer arms comprising motive means operatively connected to 
the wheel retainer arms by elongated flexible means. Mounting means 
symmetrically and rotatably mount the wheel retainer arms to the cross bar 
with the mounting means being offset from opposing end portions of the 
cross bar. 
The motive means for each wheel retainer arm may be a hydraulic cylinder 
device having a barrel movable along a fixed rod with a pair of elongated 
flexible means in the form of chains connected between the barrel of the 
hydraulic cylinder and the wheel retaining arm. The rod and barrel are 
mounted at a fixed angle of approximately 15.degree. to a longitudinal 
axis of the cross bar. One end of each elongated flexible means is 
attached to the wheel retainer arm, the other end of one of the elongated 
flexible means is attached to one end of the barrel and the other end of 
the other of the elongated flexible means is attached to the other end of 
the barrel. 
Each wheel retainer arm is substantially L-shaped and has an arm portion 
and a transverse wheel engaging portion and is rotatable through a radial 
path from a horizontal storage position wherein the wheel engaging portion 
is wrapped around an end of the cross bar to a fully opened position 
wherein a back of each arm portion is adjacent the cross bar and the wheel 
engaging portion of one wheel retainer arm is adjacent the wheel engaging 
portion of the other wheel retaining arm. Each retainer arm further has an 
intermediate position in the radial path wherein the arm portion is 
transversely oriented to the cross bar whereby the wheel retainer arm 
cooperates with an end of the cross bar to form an outwardly directed 
substantially U-shaped frame for engaging a wheel. 
These, together with other objects and advantages which will be 
subsequently apparent, reside in the details of construction and operation 
as more fully hereinafter described in claimed, reference being made to 
the accompanying drawings forming a part hereof, wherein like numerals 
refer to like parts throughout.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings, shown in FIG. 1 is a towing vehicle or truck 10 
having a conventional crane or hoist 12 pivotally mounted to the back top 
portion of the truck and which may be raised and lowered. Attached to the 
understructure of the body of the tow truck adjacent the rear end thereof 
is a wheel lift vehicle lifting and towing device according to the present 
invention, generally indicated by the numeral 14. In FIG. 1, the wheel 
lift device is shown with an extensible boom 16 in a downwardly extended 
position. When in a retracted storage position, the back portion of the 
wheel lift device is in a substantially horizontal position adjacent the 
rear end of the truck. 
Referring to FIGS. 2-7, the wheel lift device 14 includes a cross bar 20 
pivotally attached at pivot point 21 to the end of the boom 16. The cross 
bar 20 includes generally straight sections 24 and 25 extending the length 
of the cross bar along its longitudinal axis. An angular section 26 
protrudes forwardly and outwardly from each side of the center of the 
cross bar at an angle of approximately 15.degree. to the cross bar's 
longitudinal axis to enclose and position motive means 44 for rotating 
wheel retainer arms 36. This non-parallel orientation of angular section 
26 with respect to the longitudinal axis allows the motive means also to 
be mounted in a fixed, non-parallel orientation with respect to the 
longitudinal axis of the cross bar whereby the fixed motive means can 
provide a sufficient stroke to rotate the wheel retainer arms to a fully 
closed and a fully opened position. 
A bent plate 28 is provided at each end of the cross bar to support an 
outer face of a wheel. As best shown in FIG. 3, the upper end of bent 
plate 28 is fastened to a plate 30 upstanding from the upper surface of an 
end portion of the cross bar. Attached to the front of each plate 30 are a 
pair of hooks 32 to accommodate tie down chains or straps. Another 
upstanding plate 34 is attached to the front of each angular section 26 of 
the cross bar. 
The rotatable wheel retainer arms 36 are pivotally mounted by suitable 
means such as pins 38 to the cross bar at offset points from each end 
thereof. Each wheel retainer arm is substantially L-shaped in 
configuration and has a first arm portion 40 and a second wheel engaging 
portion 42 transverse to said arm portion. As best shown in FIGS. 5-7, 
each arm portion 40 is slightly bent outwardly at the mid-point thereof. 
This bend in the arm portion 40 permits the arms to be more closely 
together when in the fully opened position shown in FIG. 6. Each arm 
portion 40 further has a pivotal base portion 41 rotatably mounted to the 
cross bar, with the base portion having a radial surface at its front end. 
Each wheel engaging portion 42 of each wheel retainer arm is bent inwardly 
at approximately the mid-point thereof. This bend not only permits wheel 
engaging portion 42 to more closely simulate the curved surface of a wheel 
but also permits automatic adjustment for different sized tires. For 
example, when the wheel retainer arms are in a wheel engaging position as 
shown in FIGS. 2 and 6, a tire with a smaller diameter will have a smaller 
track width and would be positioned closer to the connection between the 
arm portion 40 and the wheel engaging portion 42 whereas a wheel with a 
larger diameter will have a wider track width and would be positioned 
closer to the outside of the wheel engaging portion 42 of the wheel 
retainer arm. 
In the embodiment best shown in FIGS. 3 and 4, each motive means 44 
comprises a hydraulic cylinder means having a barrel 46 and a fixed rod 48 
with the barrel being slidable along the rod. Each barrel has an I-beam 49 
attached to its back side. Each hydraulic cylinder means is rigidly 
mounted within and along angular section 26 at a fixed angle of 
approximately 15.degree. to the longitudinal axis of the cross bar. The 
15.degree. non-parallel orientation of the cylinder means is necessary to 
provide sufficient stroke to move the wheel retainer arms through a full 
range of motion from a fully closed position to a fully opened position. A 
parallel relationship between the cylinder means and the longitudinal axis 
such as shown in Russ et al, U.S. Pat. No. 4,564,207 would not provide 
sufficient stroke to move the wheel retainer arms through their full range 
of motion. 
Each end of fixed rod 48 has a hollow central chamber 51 therein supplied 
with hydraulic fluid from either end through hoses 50 as shown in FIG. 4. 
The fixed rod 48 of each hydraulic means has a piston 55 mounted on its 
center thereof and the hollow chamber 51 at each end of the fixed rod has 
an opening 57 adjacent to the piston whereby fluid injected through the 
opening acts against the piston and an end of the barrel to cause the 
barrel to move along the length of the rod. 
As most clearly shown in FIG. 3, a pair of elongated flexible means such as 
chains 52, 53 are connected between the hydraulic cylinder means 44 and 
each side of a wheel retainer arm 36. The chains comprise an upper chain 
52 and a lower chain 53. The first upper chain 52 is attached at one end 
to the outside of arm portion 40 of each wheel retainer arm and is 
attached at the other end to an end of I-beam 49 adjacent an end of the 
barrel 46 of the hydraulic cylinder means. The second lower chain 53 is 
attached at one end to the inside of the arm portion of each wheel 
retainer arm and is attached at its other end to the opposite end of the 
I-beam 49 adjacent the opposite end of the barrel 46. A separator flange 
54 may be provided on the radial end of the arm portion 40 to provide a 
support for the upper chain 52. The bottom flange of I-beam 49 supports 
the lower chain 53. With this construction, when the barrel 46 is moved by 
hydraulic pressure in one direction, it causes one of the chains to rotate 
a wheel retainer arm in one direction and movement of the barrel in an 
opposite direction causes the other of the chains to rotate the wheel 
retainer arm in an opposite direction. 
While in the preferred embodiment shown in the drawings, the elongated 
flexible means are shown as chains, other suitable means may be utilized 
such as a cable, a strap or a band. 
As most clearly shown in FIG. 3 the cross bar 20 preferably has an 
upstanding bent plate 56 on the backside in the center thereof. Moreover, 
as shown in FIG. 2, the device preferably has a top plate 58 extending 
over the central portion of the cross bar. In addition, each angular 
section 26 preferably has a top plate 60 thereon. 
In operation of the wheel lift device of the present invention, the boom is 
extended and the wheel retainer arms are opened from the closed position 
shown in FIG. 5 to a fully open position as shown in FIG. 7 wherein the 
back of the arm portions of the wheel retainer arms contact the back 
central portions of the cross bar and the wheel engaging portions 42 are 
adjacent to each other in a generally parallel relation. The boom is then 
lowered and the towing vehicle is positioned so that the wheel retainer 
arms are close to the wheels of a vehicle to be towed. While backing the 
towing vehicle up into position, the wheel engaging portions 42 of the 
wheel retainer arms may serve as guides for an operator of the vehicle to 
properly position the wheel retainer arms to the center of the vehicle 
being towed. The wheel retainer arms 36 are then positioned between the 
wheels 62 of a vehicle and rotated outwardly to engage the wheels as shown 
in FIG. 2. When the wheel retainer arms 36 are in the wheel retaining 
position, the wheels 62 of the vehicle are cradled between the arm 
portions 40, the wheel engaging portions 42 of each arm, the bent plates 
28 and the ends of the cross bar 20. 
While in FIGS. 2 and 6 the arm portions 40 of the wheel retainer arms 36 
are shown as being generally perpendicular to the cross bar when in a 
normal wheel engaging position, the wheel retainer arms may be rotated 
farther outwardly to an angle greater than 90.degree. to more securely 
grab a tire by hydraulically controlling the grip. This is a particularly 
advantageous feature if a wheel is deflated or underinflated. 
The construction of the wheel lift device of the present invention permits 
the wheel retainer arm to be moved to a fully opened position as shown in 
FIG. 7 which provides a relatively large amount of space available for the 
arms to fit between the wheels of a vehicle when the device is at a sharp 
angle to a vehicle's wheels 62 as shown in FIG. 8. This is a particularly 
useful feature when direct access to the wheels of a vehicle is blocked by 
an obstacle such as another vehicle. 
Some prior art devices employing a hydraulic cylinder directly connected to 
the wheel retainer arms only permit the arms to be partially opened to the 
extent shown in FIG. 9. See, for example, the prior art device shown in 
FIG. 14 of U.S. Pat. No. 4,674,943. This does not permit as large a space 
for the arms to fit between the wheels of a vehicle when the device is at 
a sharp angle to the wheels. As shown by comparing the cross hatched areas 
of FIG. 8 and FIG. 9, the cross hatched area of FIG. 8 is over twice as 
wide as the cross hatched area of FIG. 9 showing the space available with 
some prior art devices employing hydraulic cylinders directly connected to 
the wheel retainer arm. 
While the prior art Russ et al device of U.S. Pat. No. 4,564,207 does 
permit as large a space as shown in FIG. 8, the Russ et al device has 
other disadvantages. Thus, the Russ et al device does not provide 
sufficient cylinder stroke for a full range of motion of the wheel 
retainer arms as previously discussed due to the parallel relationship of 
the hydraulic cylinders with the cross bar. Moreover, because the 
cylinders of the Russ et al device are exposed, the hoses providing 
hydraulic fluid to the cylinders are also exposed. Accordingly, during 
extension and retraction of the boom and the rotation of the cross bar, 
the exposed hoses can be tangled or pinched which can cause rupture. 
The use of elongated flexible means such as chains between the motive means 
and the wheel retainer arms as taught by applicant permit the wheel 
retainer arms not only to be pivoted to a fully closed, horizontal storage 
position wherein the ends of the arms wrap around the ends of the cross 
bar as shown in FIG. 5 but also permit the arms to be fully opened as 
shown in FIG. 7 to provide a greater amount of space for the arms to fit 
between the wheels of a vehicle when the device is at a sharp angle to the 
wheels of a vehicle as shown in FIG. 8. Moreover, the ability of the cross 
bar and arms to be positioned horizontally adjacent the rear end of a 
towing vehicle when in a storage position, permits the boom and the cross 
bar and arms to be quickly extended out to a position to engage the wheels 
of a vehicle. This is particularly advantageous in situations where speed 
is of the essence, such as when repossessing a vehicle. 
In addition, the ability of the arms to wrap around the ends of the cross 
bar when in a fully closed or storage position is advantageous because the 
arms do not protrude beyond the end of the vehicle to any significant 
extent. This feature further is an advantage when the wheel lift device is 
used in car carrier applications, since the arms will not interfere with 
the ground when the bed is in a tilted position. 
Moreover with the device of the present invention, the hoses which are 
connected to the ends of each fixed rod of the hydraulic cylinder means do 
not move and may be readily concealed and protected within the confines of 
the wheel lift device. 
Numerous other modifications and adaptations of the present invention will 
be apparent to those skilled in the art and thus, it is intended by the 
following claims to cover all such modifications and adaptions which fall 
within the true spirit and scope of the invention.