Protective cover for a trailer hitch

A cover for a trailer hitch, to prevent inadvertent injury to personnel when the hitch is not being used. An upstanding dome is provided for use with hitches of the type having a ball. The dome encircles the ball, and in addition provides a clearance space above the top of the ball, such that the cover can yield when jarred by the knee or leg of a person, thereby preventing injury. The cover has a base which is preferably oversize with respect to the dimensions of the hitch bar, and is provided with internal ribs or other cushioning structures that are yieldable. The ribs engage the surface of the bar such that when the cover is inadvertently bumped, the ribs yield, again preventing injury to the leg of a person. The cover also serves to protect parts of the hitch from corrosion.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED 
RESEARCH AND DEVELOPMENT 
Research and development of the present invention and application have not 
been Federally-sponsored, and no rights are given under any Federal 
program. 
BACKGROUND OF THE INVENTION 
FIELD OF THE INVENTION 
This invention relates generally to covers for trailer hitches, and more 
particularly to devices of the type intended to prevent injury to 
personnel working in the vicinity of a hitch, especially that resulting 
from inadvertent bumping of the hitch by a person's leg or knee. 
DESCRIPTION OF THE RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR 
.sctn..sctn.1.97-1.99 
The hazards associated with existing trailer hitches are generally well 
known to anyone who has worked with them; all too often, the hitches are 
susceptible of being inadvertently bumped by one's kneecap or leg. The 
injury, while not necessarily serious, is usually most annoying and 
painful. 
In an effort to avoid this, plastic or rubber covers have been designed, 
which go over the ball of the hitch when it is not being used. These 
covers consist essentially of a cup-like structure having a size which 
fits snugly over the ball. The material is generally rubber or plastic. 
Although these covers provide some degree of protection, the thickness of 
the material of which the cover is made is usually insufficient to absorb 
much of the shock of the bump. Also, in some cases the covers are 
difficult to install. Accordingly there has existed a need for improvement 
over the concept of employing a simple cup-like cover piece. 
SUMMARY OF THE INVENTION 
The above disadvantages and drawbacks of prior trailer hitch covers are 
obviated by the present invention, which has for one object the provision 
of a novel and improved cover which is extremely simple in its 
construction, and which provides significantly improved protection against 
inadvertent injury to personnel when a trailer is not connected to the 
hitch. 
A related object of the invention is to provide an improved trailer hitch 
cover as above set forth, which can be readily applied and removed without 
the use of special tools or equipment. 
Still another object of the invention is to provide an improved trailer 
hitch cover as above characterized, which is rugged, and which can be 
readily molded of plastic or rubber as a single piece, thereby keeping the 
manufacturing cost as low as possible. 
Yet another object of the invention is to provide an improved trailer hitch 
cover of the kind indicated, which requires no assembly or skilled labor 
in its fabrication or use. 
A still further object of the invention is to provide an improved trailer 
hitch cover as outlined above, which is adaptable, essentially without 
modification, to hitches of the box-end type as well as hitches of the 
kind incorporating a ball. 
The above objects are accomplished, in one embodiment, by a cover for a 
trailer hitch comprising a base portion adapted to at least partially 
surround the hitch bar, an upstanding dome portion connected with the base 
portion and encircling the ball of the hitch, and wherein the dome portion 
has a side wall with a cross-sectional configuration that enables it to 
readily expand, if necessary, upon being press-fitted over the ball. A 
head-space is provided in the dome portion, above the area occupied by the 
ball, such that upon impact, the dome portion's upper wall can, with some 
resistance, yield inwardly prior to coming into contact with the ball, 
thereby minimizing injury to a person's knee, leg, arm, etc. 
Preferably a single cover configuration can be employed with either 
ball-type or box-end type hitches, thus making the unit universal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
By way of example, referring to FIGS. 1-4 and in accordance with the 
present invention there is provided a novel and improved cover for a 
trailer hitch, designated generally by the numeral 10. Shown dotted in 
FIG. 3 is a trailer hitch 11 of the type having a ball 12 and comprising a 
hitch bar 13 and connecting stem 14 which latter can take the form of a 
bolt or stud that is secured to the bar 13. 
The cover 10 comprises a base portion 18 having a top wall 20 with an upper 
surface 22, side walls 24, 26 and 28, and a bottom wall 30, the base 
portion 18 being open at one side location to thereby define a cavity 32 
of generally box-like configuration. Side walls 24 and 28 have re-entrant 
terminal portions 25 and 29, respectively. 
Extending upwardly from the base portion 18 is a rounded dome portion 34, 
having an expandible side wall 36 and a top wall 38 which latter, in the 
illustrated example, is semi-spherical. According to the invention, the 
side wall 36 can have a polygonal cross-section; in the illustrated 
example this wall has eight sides, thereby enabling a limited expansion in 
radially outward directions when press-fitting the cover 10 over the ball 
12 of the hitch 11. 
An important feature of the invention is the provision of a well-defined 
enclosed, sealing head-space 40 between the lower surface 42 of the dome's 
top wall 38 and the upper surface 44 of the ball 12. Preferably the cover 
10 is fabricated of resilient material such as polypropylene, and with the 
thickness shown, the wall 38 will be reasonably stiff but not rigid. 
Impact forces applied to the wall 38, as by bumping from a person's knee 
or leg, will cause limited inward movement of the wall 38 against its 
resilience and in many cases against the pressure of air trapped and 
sealed in the head space 40. In effect, the provision of the head-space 40 
thus causes impacts of the type noted to be cushioned, thereby minimizing 
the chance of injury to personnel. 
This action relates to another feature of the invention involving the 
provision of an annular sealing seat 46 at the junction of the 
semi-spherical wall 38 and the side wall 36, whereby the head space 40 
constitutes an essentially air-tight chamber with the upper surface 44 of 
the ball 12. Air trapped in the chamber 40 will inhibit complete yielding 
or collapse of the wall 38; instead, there will result a desirable 
cushioning effect, as noted above, and which is similar to the effect of 
depressing a localized area on an air-filled ball, such as a basketball or 
tennis ball. 
Even if the seal between the seat 46 and ball 12 is not completely 
air-tight, the seat 46 nevertheless constitutes a stop or positioning seat 
or shoulder to prevent the top wall 18 from readily collapsing and coming 
into contact with the upper surface 44 of the ball 12. 
Other forms of stop shoulders could be provided, such as a series of nibs 
(not shown) spaced circumferentially around the inner surface of the side 
wall, etc. 
A further important aspect of the invention is the raised positioning of 
the wall 38, as defined by the distance between it and the top wall 20 of 
the base portion 18. The side wall 36 of the dome portion 34 maintains the 
head-space 40, since in order for the wall 38 to contact the upper surface 
44 of the ball 12, at least part of the side wall 36 would have to buckle 
or collapse, which has been found to be unlikely. 
As illustrated, the base portion 18 is open at one side, forming the cavity 
32, in order to accept the hitch bar 13. By the present invention, the 
base portion 18 is made oversize with respect to the dimensions of the bar 
13, and a series of projections or fins 48, 50 is provided on the inner 
surfaces of the top wall 20 and side walls 24, 26 and 28 respectively. The 
fins 48, 50 have the approximate dimensions illustrated, and define 
between them a series of spaces; the fins thus maintain both the top wall 
20 and side walls 24, 26 and 28 in spaced relation with respect to the 
hitch bar 13. 
The fins 48, 50 are preferably integral with the respective walls 20, 24, 
26 and 28, and the spaces so formed provide a desirable cushioning if the 
walls are inadvertently bumped by personnel. Stated differently, the fins 
48, 50 impart a controlled yieldability to the top wall 20 and side walls 
24, 26 and 28, thereby minimizing possible injury from outside contact 
with these areas of the cover. 
The fins 48, 50 extend inwardly as shown. Fins 50 on the side walls 24, 26 
and 28 are vertical, and the fins 48 on the top wall 20 are horizontal; 
refer to FIGS. 2-4. 
The friction of the fins 48, 50 on the bar 13 is effective in retaining the 
cover 10 in position, thereby minimizing the possibility of its becoming 
lost or misplaced. 
Another embodiment of the invention is shown in FIGS. 5-8, wherein like 
reference numerals having the suffix "a" have been assigned to similar 
components. A modified cover 10a is provided, comprising a base portion 
18a having a top wall 20a and side walls 24a, 26a, and 28a. The base 
portion 18a is open at one side location to thereby define the cavity 32a. 
Extending upwardly from the base portion 18a is a rounded dome portion 34a 
having a generally cylindrical side wall 36a with a series of internal, 
vertical stiffening ribs 52, and a top wall 38a. 
There is provided a well-defined enclosed, sealing head-space 40a between 
the lower surface of the top wall 38a and the upper surface of the ball 12 
(not shown in FIGS. 5-8). Impact forces applied to the wall 38a as by 
bumping from a person's knee or leg, will cause limited inward movement of 
the wall against its resilience. The provision of the head-space thus 
causes such impacts to be cushioned, thereby minimizing the chance of 
injury to personnel. 
As in the previous embodiment, the raised positioning of the wall 38a as 
defined by the distance between it and the top wall 20a of the base 
portion 18a maintains the head-space 40a. 
By the invention, the base portion 18a is made oversize with respect to the 
dimensions of the bar 13, and a series of projections or fins 48a, 50a is 
provided on the inner surfaces of the top wall 20a and side walls 24a, 26a 
and 28a respectively. The fins have the approximate dimensions 
illustrated, and define between them a series of spaces; the fins thus 
maintain both the top wall 20a and side walls 24a, 26a and 30a in spaced 
relation with respect to the hitch bar 13. 
The fins 48a and 50a extend inwardly as shown. Fins 50a on the side walls 
are vertical, and the fins 48a on the top wall are horizontal. 
On the inner surface of the top wall 38a of the dome portion are two 
stiffening ribs 54 and 56, forming an "X". These provide the desired 
rigidity to this area. 
The construction shown in FIGS. 5-8 has the distinct advantage of ease of 
molding, since there has been eliminated the bottom wall which existed in 
the first embodiment. Stripping of the cured article from the mold is thus 
facilitated. 
Still another embodiment of the invention is illustrated in FIG. 9, wherein 
like reference numerals having the suffix "b" have been assigned to 
similar components. In this embodiment, there is provided a modified dome 
portion 34b, which may or may not be adapted for use with an integral base 
similar to that of FIGS. 5-8. In addition to the dome portion's top wall 
38b, there is a generally cylindrical side wall 36b. By the invention, the 
inner surface of this side wall is provided with a series of vertically 
spaced annular ribs 58, any one of which is intended to form a seat or 
seal with the large diameter portion of the trailer hitch ball (12, FIG. 
3). Regardless of the location of the ball 12 with respect to the hitch 
base, one or two of the ribs 58 will fit tightly against the ball, 
creating an air-lock in the chamber 40b, as in the first embodiment. The 
air-lock provides a cushioning effect to the dome portion 34b, by limiting 
the tendency for the top wall 38b thereof to collapse when impacted by 
forces external of the cover. 
In other respects the embodiment of FIG. 9 can be similar to that of FIGS. 
5-8. 
Alternately, the construction of FIG. 9 could be employed without a base; 
instead, the construction would resemble an inverted cup with a lip which 
might or might not extend to and engage the hitch bar 13. 
Still another embodiment of the invention is shown in FIGS. 10 and 11, 
illustrating a greatly simplified cover. Essentially the cover comprises 
an inverted cup 60 having a top wall 62 and a side wall 64. Preferably the 
cup 60 is constituted of foam rubber or foam rubber-like substance, and 
the side wall 64 of the cup is sufficiently thick to provide a cushion 
between the ball of the hitch and an object (i.e. a person's knee) which 
might impact on the cover 60 from its exterior. The inner diameter of the 
cup 60 is preferably made to fit snugly around the ball. The area of the 
side wall adjacent the lip of the cup can be thickened slightly, as shown 
in FIG. 11, to improve the retention. 
Still another embodiment of the invention is shown in FIGS. 12 and 13, 
wherein like reference numerals having the suffix "c" have been assigned 
to similar components. 
By the invention, there is applied to the inner surface of the top wall 20c 
and side walls 24c, 26c and 28c of the base portion 18c strips 66 and a 
cutout 68 of thin foam material in order to provide the desired 
cushioning. A single strip 66 can be wrapped along the inside of the three 
side walls 24c, 26c, and 28c, with a fourth piece 68 of foam material 
secured to the inside of the top wall 20c. Attachment can be made by means 
of suitable cement or glue, or alternately by employing adhesive-backed 
foam strips similar to those used for weatherstripping windows and doors 
in buildings or residences. 
The dome structure associated with this base would typically be similar to 
that of FIGS. 1-4 or 5-8; accordingly details of these structures need not 
be repeated. 
From the above it can be seen that I have provided novel and improved cover 
constructions which have important features that minimize injury from 
inadvertent contact with an exposed trailer hitch. The cover can be molded 
as a single piece, including the fins illustrated in the first two 
embodiments. It is adaptable for use with trailer hitches of the 
ball-type, or else it can be employed with a box-end type hitch in which 
the area inside the dome portion 34 (FIGS. 1-4) would be unoccupied. 
Accordingly the unit can be universal for a given hitch size. 
The device is thus seen to represent a distinct advance and improvement 
over previously known covers of this kind. 
Variations and modifications are possible without departing from the spirit 
of the invention. 
Each and every one of the appended claims defines an aspect of the 
invention which is separate and distinct from all others, and accordingly 
it is intended that each claim be treated as such when examined in the 
light of the prior art devices in any determination of novelty or 
validity.