Note: Descriptions are shown in the official language in which they were submitted.
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PROTECTIVE CAP FOR A BALL HITCH OF A TRAILER COUPLING
Specification
The invention relates to a protective cap for a ball
hitch of a trailer coupling of a motor vehicle. The
protective cap consists of a cup-like base member which can
be inverted over the ball hitch to cover the same and fixed
there.
A protective cap of the type mentioned above is
disclosed in the German Gebrauchsmuster 80 06 147. This
protective cap has a locking device which consists of a bolt
which is mounted in an enlargement of the base body for
rotation transverse to its longitudinal axis. The bolt is
associated with a forwardly projecting peripheral surface of
the ball hitch in its closed position and with a rearwardly
projecting peripheral surface of the ball hitch in its open
position. By rotating the bolt to an open position, the
ball hitch is freed so that the protective cap can be taken
off. When the bolt is ln its closed position, the
protective cap is attached to the ball hitch so as to be
unlosable. The locking device prevents automatic
disengagement of the protective cap from the ball hitch so
that the protective cap becomes lost. The invention
fundamentally addresses another problem which resides in
that the user removes the protective cap when the trailer
coupling is to be used and must keep it until the ball hitch
is again covered. Frequently, this keeping is not performed
with sufficient care so that the protective cap is lost.
It is accordingly an ob;ect of the invention to create
a protective cap of the type outlined above which can be
reliably kept without loss.
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According to the invention, this ob;ect is achieved in
that at least one section of the protective cap is
magnetically constructed such that, when the magnetic cap is
removed from the ball hitch and transferred to a
ferromagnetic portion of the motor vehicle, it is seated
there. To use the trailer coupling, the user thus simply
takes the protective cap off the ball hitch and assigns it
to a ferromagnetic portion of the motor vehicle such as, for
example, the chassis or the body panel. The protective cap
- due to its magnetic effects - is then automatically seated
there and remains in the seated position until renewed
covering of the ball hitch is desired. Fundamentally, it is
possible to make an arbitrary section of the protective cap
magnetic. This section of the protective cap is then placed
on the ferromagnetic portion of the motor vehicle. However,
it is also possible to make the entire protective cap
magnetic so that the protective cap need not assume any
particular position to be seated.
In accordance with a preferred exemplary embodiment of
the invention, however, the rim of the opening of the
cup-like base member is magnetic. To this extent, it
suffices for the base member to be magnetic axially only.
Since the rim of the opening of the base member forms a
flat, annular surface, particularly secure seating on the
ferromagnetic portion of the motor vehicle can be achieved
because the protective cap cannot perform any rolling
movements. Moreover, such seating assures that the
ferromagnetic portion covers the opening of the protective
- cap so that no dirt or the like can penetrate into the
interior of the base member. As a result, an abrasive
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effect which could arise due to infiltrated sand or dust
particles is avoided when the protective cap is again placed
on the ball hltch.
An annular, magnetic, radially outward projecting
flange is preferably arranged at the rim of the opening of
the base member. This annular flange enlarges the seating
area on the ferromagnetic portion of the motor vehicle so
that an especially secure seating can be achieved.
In particular, at least one magnet is disposed at the
underside of the annular flange. This can also be inserted
in a recess of the annular flange. It is possible here to
cast around the magnets when the base member is produced by
in;ection molding of plastic. Alternatively, however, the
magnet can be glued to the annular flange or held there by
snap action.
A preferred further development of the invention
provides for the annular flange to consist of plastic with
an embedded magnetic substance. This magnetic substance is
finely dlstrlbuted in the plastic so that no attachment of a
separate magnet must take place and the magnetic effect is
"unlosable".
An additional preferred possibility is to likewise make
the base member of plastic. Thls plastic is preferably
resistance to impacts. If no annular flange is provided,
then the plastic of the base member can also have magnetic
properties.
The annular flange can either be a separate part which
is secured to the base member or is integral with the base
member.
The drawings illustrate the invention with reference to
several exemplary embodiments and, in fact, there is shown:
Figure 1 a partly sectional side view of a protective
cap,
Figure 2 a further embodiment of a protective cap
with an axially outwardly projecting annular flznge,
Figure 3 the embodiment of Figure 2 with separate
magnets,
Figure 4 an embodiment with an integrated magnetic
substance, and
Figure 5 a bottom view of the protective cap with
separate magnetic structure.
Figure 1 shows a protective cap 1 having a cup-like
base member 2 with an opening 3. The base member 2 consists
of a cylindrical zone 4 having a circular cross section and
an adjoining frustoconical zone 5. To protect a ball hitch
of a (non-illustrated) trailer coupling of a motor vehicle,
the protective cap 1 can be inverted over the ball hitch to
cover the same. The ball hitch then lies in the interior of
the cup-shaped base member 2 and is thus protected from
dust, etc.
Accordlng to the invention, at least one section 6 of
the protective cap 1 is magnetically constructed such that,
when the protective cap 1 is removed from the ball hitch and
is assigned to a ferromagnetic portion of the motor vehicle,
it is seated there, that is, it holds itself due to its
magnetic effects. This magnetic section 6 can be formed at
any arbitrary location of the protective cap 1. In the
exemplary embodiment of Figure 1, this section 6 is located
at the rim 7 of the openlng 3. Either a separate magnet is
arranged there or a magnetic substance 8 is embedded or
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incorporated ln the materlal of the base member 2 in the
region of the rim 7 of the opening 3. This is illustrated
by points in Figure 1. The base member 2 preferably
consists of plastic which is resistant to impacts. In
particular, manufacture can take place by injection molding.
The design of the invention has the advantage that the
protective cap 1 which has been taken off the ball hitch of
the trailer coupling can be kept on the motor vehicle so as
to be unlosable and is thus again available to cover the
ball hitch after the trailer coupling has been used.
Accordingly, lt does not get lost. The user simply finds a
ferromagnetic portion of the motor vehicle and assigns the
protective cap 1 thereto. It holds itself - due to its
magnetic effect - seated there.
Figure 2 shows a further exemplary embodiment of a
protective cap 1 which differs from the exemplary embodiment
of Figure 1 in that a radially outward projecting, annular
flange g having magnetic effects is formed at the rim 7 of
the opening 3.
According to Figure 3, at least one magnet 11 can be
arranged at the underside 1~ of the annular flange 9. This
is preferably located in a recess of the annular flange (not
illustrated) or it is surrounded by the plastic of the base
member 2 during an in~ection molding process (see Figure 3).
The exemplary embodiment of Figure 4 differs from that
of Figure 3 in that, instead of the magnet 11, a finely
divided magnetic substance 8 is there embedded in the
annular flange 9.
Figure S again illustrates an exemplary embodiment of a
protective cap 1 having an annular flange 9. A bottom view
with a line of sight towards the opening 3 is shown. In
this exemplary embodiment, four magnets 11 which are
uniformly distributed over the circumference are secured to
the underside 10 of the annular flange 9. This can be
accomplished, for example, by gluing or by snapping into
recesses. The outer surface of the magnet 11 is preferably
flush with the underside 10. This has the advantage that,
upon deposition of the protective cap 1 on the ferromagnetic
portion of the motor vehicle, the opening 3 is covered so
that the penetration of dirt and moisture, etc. is
prevented. In a corresponding manner, the same applies to
the exemplary embodiments of the remaining Figures.
It is also conceivable to use magnetic foils which can
be mounted at any arbitrary location of the base member 2,
particularly in the region of the rim of the opening 3. The
design of the invention provides the possibility of having
the protective cap 1 for covering the ball hitch available
for reuse immediately after employment of the trailer
coupling (that :Ls, after trailer operation). During its
deposition on the ferromagnetic portion (for example, a
panel)~ this ls held there in a sealed condition so that no
dire or dust, which could lead to an abraslve effect upon
reuse, can penetrate into the interior. Depending upon the
arrangement of the magnetic section 6 on the protective cap
1, the connection to the ball hitch of the trailer coupling
is also improved since, due to its magnetic effect, the
protective cap is held on the ferromagnetic trailer coupling
particularly securely. To the extent that the entire
protective cap is magn~tic, this holding action is naturally
especially large; however, even a magnetic rim 7 for the
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opening 3 can, under certain circumstances, - depending upon
the shape of the ball hitch and the protective cap - can
give rise to an improved hold on the trailer coupling. In
particular, the protective cap 1 consists of an elastic,
expandable plastic which is insensitive to heat and cold.
The magnets are designed as permanent magnets and are
preferably mounted so as to be protected against corrosion.
In daily use, the protective cap can also be employed
for totally different activities. Thus, particularly during
the delivery of goods, it is a known problem that the
delivery person holds bills of lading, invoices, etc. in the
hands when he opens his motor vehicle (rear doors) to remove
the goods, for instance. To be able to reliably deposit the
mentioned papers, he can take the magnetic protective cap 1
off the trailer coupling and secure it to the mentioned
ferromagnetic portion of the motor vehicle. The papers are
placed between the protective cap 1 and the ferromagnetic
portion. These are then held as well and cannot be lost,
especially not blown away by the wind.
The protective cap 1 is further suitable for checking
magnetic and antimagnetic substances; it can therefore also
be used as a testing device for damage caused by accidents,
e.g., when buying a motor vehicle, since a repair of a used
vehicle by means of fillers can, due to the missing
ferromagnetic effect, be detected therewith.
In particular, the outer peripheral surface of the
protective cap 1 is to be used as an ideal ad carrier.
Printing, etc. can be applied here to thereby produce
advertising slogans.