Note: Descriptions are shown in the official language in which they were submitted.
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WEIGHT DISTRIBUTING HITCH AND
SLIDE BRACKET ASSEMBLY
Technical Field
The present invention relates generally to the
towing field and, more particularly, to a new and
improved weight distributing hitch assembly
incorporating a novel spring bar and slide block or
shoe arrangement for distributing weight and
controlling trailer sway.
Background of the Invention
Hitch assemblies for more evenly distributing the
tongue weight of a trailer over the front and rear
axles of a towing vehicle are well known in the art. A
particularly advanced design of weight distributing
hitch assembly is disclosed in the assignee's issued
U.S. Patent 5,375,872 to Kass et al. entitled "Weight
Distributing Hitch". This hitch assembly includes a
hitch bar for receipt in a receiver mounted to the
vehicle and a ball mount head for mounting on the hitch
bar at a selected tilt angle. A pair of spring bars
are mounted at their proximal end to the ball mount
head. The distal ends of these spring bars are
' connected by means of cooperating lift units and chains
to the frame of the trailer. Such state of the art
lift units are exemplified by Reese Products, Inc.
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product number 21160 incorporating a body that is mounted to
the trailer frame, a chain hook with pivoting locking lever
and a safety pin for securing the chain hook and lever in an
operative position. As is known in the art, the amount of
leveling or load transfer to the front axle of the vehicle
is adjusted by the selection of the tilt angle of the ball
mount head and the engagement of different links of the
chains with the chain hooks of the lift units.
While such an arrangement is effective for its
intended purpose, it should also be appreciated that the
state of the art lift unit connection between the spring
bars and trailer frame provides little or no effective means
of resisting or controlling trailer sway: that is,
undesirable lateral movement of the trailer relative to the
towing vehicle. In fact, such sway may arise as a result of
a number of factors often encountered during towing
operation including uneven, rough and/or winding road
conditions; gusty cross-wind weather conditions, uneven
trailer loading conditions; and/or result from inherently
incompatible trailer and towing vehicle suspension
characteristics. Accordingly, a need is also identified for
a weight distributing hitch assembly that provides some
inherent control of trailer sway to maximize driver
confidence, comfort and control during towing.
Summary of the Invention
According to a broad aspect of the invention,
there is provided a weight distributing and sway controlling
hitch assembly for towing a trailer behind a vehicle,
comprising: a hitch bar for mounting to the vehicle; a ball
mount head carried on the hitch bar; a hitch connector
carried on the ball mount head; a pair of friction pads
mounted on the trailer; a pair of shoes, each shoe of said
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pair of shoes being received on one of said friction pads
while allowing relative sliding movement thereto; and a pair
of spring bars for distributing trailer weight relative to
said vehicle, each of said spring bars including a proximal
end mounted to said ball mount head and a distal end for
engaging one of said shoes.
Accordingly, it is a primary aspect of the present
invention to provide a weight distributing hitch assembly of
an improved design overcoming the above-described
limitations and disadvantages of the prior art.
Another aspect of the present invention is to
provide an improved weight distributing hitch assembly
incorporating a spring bar and slide block or shoe
arrangement which effectively provides both weight
distribution and sway control so as to improve towing
performance and overall driver comfort.
Additional aspects, advantages and other novel
features of the invention will be set forth in part in the
description that follows and in part will become apparent to
those skilled in the art upon examination of the following
or may be learned with the practice of the invention.
To achieve the foregoing and other aspects, and in
accordance with the purposes of the present invention as
described herein, an improved weight distributing hitch
assembly is provided for towing a trailer behind a vehicle.
The weight distributing hitch assembly includes a hitch bar
of a type known in the art for mounting to the towing
vehicle. More specifically, the hitch bar includes a
mounting post that is received in the receiver box of a
hitch receiver that is secured to the frame of the towing
vehicle in a known manner.
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The weight distributing hitch assembly also
includes a ball mount head for mounting on the distal or
head-receiving end of a hitch bar. Preferably, a hitch
ball, also of a type well known in the art, is carried on
the ball mount head. Such a hitch ball is adapted for
receipt in a cooperating trailer coupler socket of the
trailer to be towed behind the vehicle.
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The weight distributing hitch assembly also
includes a pair of friction pads. These friction pads
are mounted to opposing sides of the trailer such as
the outwardly directed faces of the two frame rails
that form an A-frame trailer.
The weight distributing hitch assembly also
includes a pair of spring bars for distributing trailer
weight relative to the vehicle. More specifically,
each of the spring bars include a mounting trunnion at
its proximal end that allows the spring bar to be
secured to the ball mount head. Each spring bar also
includes an inwardly projecting or transverse lug
adjacent a distal end.
Still further, the hitch assembly also includes a
pair of slide blocks or shoes. One shoe is received on
and mounted to the lug at the distal end of each spring
bar. In operation, the shoes engage and slide along
the friction pads carried on the trailer frame. Since
each friction pad is formed from a durable, high
friction material, frictional resistance to relative
sliding movement of the shoes is provided. As a
result, lateral movement of the trailer relative to the
towing vehicle is resisted and, therefore, an effective
anti-sway mechanism is advantageously provided. It
should be appreciated, however, that this frictional
resistance is readily overcome during operator
controlled vehicle maneuvering so that relative pivotal
movement about the hitch ball and coupler socket is
freely allowed during turning. Thus, trailer sway is
resisted without compromising any operator control. '
Preferably each shoe includes a retaining bracket
and cooperating fasteners that are utilized to secure '
the shoe to the lug of the associated spring bar. In
addition, each shoe includes a channel defining a load
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bearing face that engages one of the friction pads. The
channel further includes side walls that lap the engaged
friction pad and maintain proper alignment between the
engaged friction pad and the shoe during towing.
5 Still other aspects of the present invention will
become apparent to those skilled in this art from the
following description wherein there is shown and described a
preferred embodiment of this invention, simply by way of
illustration of one of the modes best suited to carry out
the invention. As it will be realized, the invention is
capable of other different embodiments and its several
details are capable of modification in various, obvious
aspects all without departing from the invention.
Accordingly, the drawings and descriptions will be regarded
as illustrative in nature and not as restrictive.
Brief Description of the Drawing
The accompanying drawing incorporated in and
forming a part of the specification, illustrates several
aspects of the present invention and together with the
description serves to explain the principles of the
invention. In the drawing:
Figure 1 is an exploded perspective view of the
weight distributing hitch assembly of the present invention;
Figure 2 is a detailed fragmentary and partially
sectional view showing the positioning of a spring bar with
associated shoe for sliding along a friction pad
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carried on the trailer frame; and
Figure 3 is a top plan view showing connection to
a trailer.
t
Reference will now be made in detail to the
present preferred embodiment of the invention, an
example of which is illustrated in the accompanying
drawing.
Detailed Description of the Invention
Reference is now made to Figure 1 showing the
weight distributing hitch assembly 10 of the present
invention. As should be appreciated, the hitch
assembly 10 includes a hitch bar 12 of a type known in
the art including a tubular mounting post 14 for
engagement in a receiver box R of a hitch receiver
mounted to a vehicle (not shown). A pin P and
cooperating clip C secure the hitch bar 12 in the
receiver box R. Such a hitch receiver is, for example,
a Class III 35 Series hitch receiver as manufactured by
Reese Products, Inc. of Elkhart, Tndiana, the assignee
of the present invention.
The distal end of the hitch bar 12 includes a
split end mounting rack 16 having a series of aperture
sets 18 allowing for height adjustment of the ball
mount head 20. The ball mount head 20 may be a one-
piece, integral construction cast from ductile iron.
The ball mount head 20 is secured to the mounting rack
16 of the hitch bar 12 by means of two cooperating
fasteners shown as bolts 22 and cooperating locking
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nuts 24. Washers 26 may be provided on the lower bolt
22 if desired.
More specifically the ball mount head 20 includes
J
a pair of spaced, parallel mounting flanges 30 so as to
form a yoke adapted to be received on the mounting rack
16. When properly mounted, the lower bolt 22 extends
through the aligned cooperating apertures 32 (only one
visible in Figure 1) in the mounting flanges 30, the
two washers 26 and the one aligned aperture set 18 in
the interdisposed mounting rack 16. Similarly, upper
bolt 22 extends through a pair of indexable, eccentric
washer 35, the aligned cooperating arcuate slots 34 in
the mounting flanges 30 and through a second aligned
aperture set 18 in the interdisposed mounting rack 16.
The arcuate slots 34 allow the ball mount head 20 to be
pivoted relative to the hitch bar 12 about the lower
bolt 22. The locking nuts 24 are then placed upon the
bolt 22 and tightened. This arrangement allows the
tilt angle of the ball mount head 20 to be selected by
manipulation of the indexable, eccentric washers 35 in
a manner described in detail in previously referenced
U.S. Patent 5,375,872 to Kass et al.
As also shown in Figure 1, the weight distributing
hitch assembly 10 includes a pair of spring bars 36.
Each spring bar 36 includes a trunnion 38 at its
proximal end for mounting in the ball mount head 20.
More specifically, each mounting trunnion 38 includes a
pair of oppositely disposed and outwardly projecting
pivot pins 40. As is known in the art, the pivot pins
40 are received in a first set of cooperating sockets
42 in the upper and lower legs or platforms 44, 46 of
the ball mount head 20. A more detailed presentation
of the trunnion connection of the spring bars 36 to the
ball mount head 20 is presented in the assignee's U.S.
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Patent 5,562,298, filed on October 7, 1994, entitled "Weight
Distributing Hitch Assembly". Each spring bar 36 also
includes a lug 54 adjacent the distal end thereof that
projects inwardly in a transverse direction. Thus, the lug
54 and main body of the spring bar 36 form a substantially
L-shape.
The upper platform 44 of the ball mount head 20
also includes an aperture for receiving a hitch connector
such as hitch ball 52. The hitch ball 52 is secured to the
upper platform 44 by a weld or other appropriate means known
in the art.
A slide block or shoe 56 is secured to each lug
54. More specifically, each shoe 56 includes a pair of
mounting posts 58 defining a lug receiving slot 60
therebetween. As shown best in Figure 2, the lug 54 is
positioned in the slot 60 and is held in position by an
overlying clamp 62 secured in place by a pair of fasteners
such as screws 64 that threadedly engage in the mounting
posts 58. Further, each lug 54 includes a slightly flared
or dimpled end 66 that prevents the lug from pulling free
from the shoe 56 when clamped in position. More
specifically, when the lug 54 is properly clamped in the
shoe 56, the flared or dimpled end 66 prevents the lug 54
from pulling out of the shoe 56 back through the slot 60.
As best shown in Figure 2, the shoe 56 on each
spring bar 36 is received by and rides upon a friction pad
68. The friction pad 68 is formed from a durable, high
friction material such as available from Friction Material
Company under products designation NA 104 which is bonded to
a supporting substantially L-shaped mounting bracket 70
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preferably formed from a sheet metal such as steel. Two
countersunk screws 72 engage
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the bracket 70 and thereby secure the friction pad 68
and bracket to the frame.- Fastener such as screws 74
r
or cooperating nuts and bolts (not shown) are utilized
to secure the mounting brackets 70 to the frame F of
the 'trailer when holes are not permitted in the top
flange of the frame.
More specifically, as shown in Figure 3, one
friction pad 68 is mounted to each frame rail F behind
the trailer coupler socket S. In this position, each
friction pad 68 is oriented to receive a shoe 56 or one
of the spring bars 36. Spaced, parallel guide rails 76
(see Figure 2} at the inner and outer margins of each
shoe 56 form the sidewalls of a channel 78 that insures
that the shoes slide smoothly along and over the
friction pads 68 without binding. Each friction pad 68
resists free sliding movement of the shoe 56 riding
thereon. Such sliding movement is, of course,
generated whenever the trailer begins to sway in
response to, for example, rough, uneven and/or winding
road conditions, gusts and crosswinds and uneven
trailer loading. At these and certain other times the
frictional forces generated between the pads 68 and
shoes 56 oppose or resist the lateral movement of the
towed trailer relative to the towing vehicle. Trailer
sway is consequently reduced or virtually eliminated
under substantially any anticipatable operating
conditions.
It should be appreciated, however, that the degree
of resistance to transverse movement is not great
' 30 enough to interfere with the relative pivotal motion of
the trailer about the hitch ball 52 and coupler sockets
that occurs as a result of driver input during normal
vehicle operation. Thus, the trailer still properly
tracks behind the vehicle during towing. Thus, it
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should be appreciated that sway control is
advantageously provided without any compromise of other
important operating characteristics.
In use, the forward end of the trailer including
5 the coupler sockets is initially raised using the
tongue jack J. The vehicle and trailer a.s then
positioned so that the hitch ball 52 underlies the
coupler-socket S. Using the tongue jack J, next the
front end of the trailer is lowered so that the coupler
10 socket S nests over the hitch ball 52. The coupler
latch is then closed to secure the trailer to the
towing vehicle through the hitch assembly 10.
Next the front of the trailer and the rear of the
tow vehicle are raised about 2-3 inches by operation of
the tongue jack J. From this position, an individual
may grasp an intermediate portion of the spring bar 36
adjacent to the distal end thereof and flex the spring
bar upwardly. By shifting the spring bar 36 laterally
once it clears the trailer frame rails F, the spring
bar may be released and the shoe 56 or channel 78
dropped onto a friction pad 68. This is done so that
the guide rails 76 overlap the side edges of the
friction pad 68 and the weight bearing surface of the
shoe 56 defined between the guide rails engages the
friction pad. As noted above, the guide rails 76
insure that the shoe 56 remains in proper alignment as
it slides relative to the pad &8.
The individual operator then positions the second
spring bar 36 in the same manner. The trailer tongue
jack J is then retracted so that the hitch assembly ~.0 '
is distributing the full trailer tongue weight over the
front and rear axles of the towing vehicle in the
desired manner. This is a simple and efficient
operation that may be completed at the utmost
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convenience, confidence and satisfaction of the
individual. There is no need to select a proper chain
link or secure a lift bracket with a safety clip as
required by the state of the art lift units commonly
utilized in this field.
Additionally, the present weight distributing
hitch assembly 10 goes a step further than prior art
weight distributing hitch assemblies by providing
control of trailer sway. Specifically, the friction
pads 68 provide sufficient resistance to the relative
sliding movement of the shoes 56 to dampen swaying
motion without actually interfering with proper pivotal
movements of the trailer initiated by vehicle operator
inputs when turning during the towing operation.
Accordingly, it should be appreciated that the present
invention represents a significant advance in design
that achieves more than the prior art weight
distributing hitch designs.
The foregoing description of a preferred
embodiment of the invention has been presented for
purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to
the precise form disclosed. Obvious modifications or
variations are possible in light of the above
teachings. The embodiment was chosen and described to
provide the best illustration of the principles of the
invention and its practical application to thereby
enable one of ordinary skill in the art to utilize the
invention in various embodiments and with various
modifications as are suited to the particular use
contemplated. All such modifications and variations
' are within the scope of the invention as determined by
the appended claims when interpreted in accordance with
the breadth to which they are fairly, legally and
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equitably entitled.
