Note: Descriptions are shown in the official language in which they were submitted.
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DOORSTOP
Field of the Invention
This invention relates to a doorstop. Doorstops are used particularly in motor
vehicles. An
example of a doorstop for a motor vehicle is described in U.S. Patent No.
6,842, 943 to
Hoffmann et al.
Background of the Invention
Doorstops are commonly used in motor vehicles, and serve a number of purposes.
For
example, a doorstop augments the mechanism that facilitates capturing the door
in the closed
position. A doorstop further aids in guiding some of the travel of the door.
Additionally, a
doorstop may help cushion the impact of the door closing against the body of
the vehicle.
Further, when the cushion on the doorstop is compressed by a closed and
latched door, the
compressed cushion projects an outwardly directed resultant force on the door,
which aids in
maintaining the door rigidly secured against the body of the vehicle via the
latch, thus preventing
the door from rattling during travel.
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Summar~of the Invention
According to the invention, there is provided a doorstop having at least two
cushions on
an upper surface thereof. The footprints, or bases, of the cushions have the
approximate shapes
of the surfaces to which they are attached. Thus, they are shaped cushions.
The base of a shaped
cushion may generally resemble a perimeter of the surface to which it is
attached.
In one embodiment, the doorstop comprises two housing parts, each of
approximately
trapezium shape, and each having a shaped cushion on the upper surface
thereof. The doorstop
further comprises a central aperture therethrough, and the shaped cushions may
be positioned
around the aperture on the upper surface of the doorstop.
The doorstop may also have at least two male protrusions extending in a
direction away
from the cushions, the protrusions being spaced apart in a direction along a
longitudinal axis of
the doorstop. The protrusions may be threaded or unthreaded.
The two housing parts of the doorstop may fit together with an aligning
mechanism
comprising two cooperative elements, such as two male/female bushings.
Additionally, the two
housing parts may be formed using a sonic welding process.
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Brief Description of the Drawings
Embodiments of the invention will now be described, by way of example, with
reference
to the accompanying drawings in which:
FIG. 1 is a sectional side view of a doorstop from U.S. Patent No. 6,842,943;
FIG. 2 is a top plan view of two parts of a doorstop according to one
embodiment of the
present invention;
FIG. 3 is a side perspective view of the two disassembled parts forming the
doorstop of
FIG. 2.
FIG. 4 is an interior side elevational view of one part of the doorstop taken
along lines
4-4 in FIG. 3;
FIG. 5 is a perspective view of a doorstop of approximately rectangular cross-
section;
FIG. 6 and 7 illustrate other parts for use with the doorstop part of FIG. 5;
FIG. 8 is another embodiment of a doorstop;
FIG. 9 is a part for use with the doorstop of FIG. 8;
FIG. 10 is another embodiment of a doorstop;
FIG. 11 is a part for use with the doorstop of FIG. 10;
FIG. 12 is another embodiment of a doorstop;
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FIG. 13 is a side perspective view of the two disassembled parts forming the
doorstop of
FIG. 12;
FIG. 14 is an interior side elevational view of one part of the doorstop taken
along lines
14-14 in FIG. 13
Detailed Description of the Invention
FIG. 1 shows a sectional side view of a doorstop, as illustrated in U.S.
Patent No.
6,842,943, the plane of section running through the doorstop parallel to the
pivot axis and the
door retaining rod 1 passing through the retaining piece 2. At its bottom end
in the figure, the
door-retaining rod 1 has a bearing eye 6, and at the other end an abutment 9.
The door-retaining
rod 1 is constructed from a metal core 7, for example a flat steel section,
which is covered with
plastic. The plastic covering 8 is applied with different thicknesses over the
length and forms
bulges in the form of local thickenings, which form the brake ramps 4 and the
catch depressions
between the bulges. In the exemplary embodiment shown, the abutment 9, which
forms the
limit stop corresponding to the open position of the door, is of integral T-
shaped design. The
abutment 9 or the limit stop may also be alternatively formed by a pin, which
is arranged through
a corresponding opening in the door retaining rod 1 in the direction of the
pivot axis. The brake
ramps 4 and the catch depressions 5 are formed on the sides of the door-
retaining rod facing the
pivot axis. In the position shown, the brake and/or stop bodies 3 bear
bilaterally preloaded
against catch depressions. The door-retaining rod 1 is led through the opening
13 in the housing
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10. The brake and/or stop bodies 3 are guided in guide openings 25 arranged
perpendicular to the opening 13.
The brake and/or stop bodies 3 take the form of hollow cylinders which are
sealed at one
end by a semi-spherical cap 14. In their open end, they accommodate a pressure
spring 12 resting
on the closing cap 14, the spring being supported on a side wall of the
housing 10. The end faces
of the housing 10 are enclosed by U-shaped metal frames 11, which also
constitute the
supporting wall for the pressure springs. The brake and/or stop bodies 3 have
a central bore 16
accessible from their cylindrical cavity 15 and further bores 17 arranged in a
circle around this.
The shape and arrangement of the bores 16 and 17 permit approximately equal
wall thicknesses
in the semi-spherical cap 14. The semi-spherical cap 14 is truncated at its
front end. The
approximately equal wall thicknesses provide an advantageous prerequisite for
manufacturing
the brake and/or stop bodies from plastic by the injection molding process. In
its cylindrical part
19, the outer wall of the brake and/or stop bodies 3 is fluted in the
direction of movement,
thereby on the one hand ensuring a favorable distribution and transmission of
slide lubricants,
and on the other reducing the bearing surface of the cylindrical part 19 on
the inner surface of the
guide opening 25 and hence frictional forces occurring when the brake and/or
stop bodies 3 slide
in the guide opening 25.
Cushions 22 of an elastic material are integrated into the upper end surface
20 of the housing 10,
against which cushions the abutment 9 resiliently strikes when the door is in
the open position.
Fixing apertures 21 are arranged in the bottom end
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surfaces of the metal frames 11. In the exemplary embodiment shown, these have
an internal
thread for fixing the retainer piece to a door assembly piece by means of
threaded screws. Press-
on screws, not shown here, can also be used for fixing, however. It will be
obvious that in the
embodiment of the housing 10 and metal frame 11 shown, there is a high degree
of flexibility in
the choice of hole spacing and hence in the hole piercing variants.
Referring to FIGS. 2, 3 and 4, the doorstop is made of two similar housing
parts 30 and
32 of approximately trapezium shape in cross-section. A total of six stop
cushions 34 of elastic
material are integrated into the upper surfaces of the housing parts 30 and
32, three on each
plastic housing part. This number of cushions 34 is a substantial non-obvious
improvement over
previous arrangements and permits the accommodation of more "head"
configurations than
previously accomplished. Even a total of four cushions 34 were found to be
advantageous,
although six were better. It is a cost saving as well, over putting the
cushions on a link arm.
The two housing parts fit together with an aligning or "locking" mechanism
comprising
two round male/female bushings 36 and 38. It has been found that this tends to
overcome a
matching and stacking problem.
A male threaded stud 40 is provided on each housing part 30 and 32 to
facilitate assembly to a
vehicle by a customer.
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The parts of the housing can conveniently be produced by using a sonic welding
procedure. This would appear to result in a saving of costs for two rivets and
should save
integrity and time.
It will be understood that the frame in the housing according to the present
invention is
all plastic, whereas in U. S. Patent No. 6,842,943 to Hoffinann et al., the
frame 11 is a U-shaped
metal frame.
In some arrangements the housing parts may be offset.
It will be understood that injection molding may be utilized, and the parts
may be run on
vertical or horizontal machines. It is also anticipated that multi-cavity
molds may be used. Shrink
and warp behavior in insert molding, due to the size of the product, is
expected. Control of the
process characteristics, such as mold temperatures, injection speeds and
pressure, is required.
Proper drying of the material is required. Co-injection and/or over molding
can also be used to
manufacture the product.
It will also be understood that the fabrication technology that is used, may
be suitable for
the formation of large, long-fiber-reinforced structural thermoplastic parts.
Another embodiment of the present invention is shown in FIGS. 5-7. In FIG. 5
it will be
seen that the doorstop 50 is of rectangular shape in cross-section and has two
studs 52 and 54 in
an appropriate location. As will be appreciated, studs 52 and 54 may be
threaded or un-threaded.
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These studs are molded in the base of doorstop 50 which has a central aperture
56 whereby a link
arm assembly can be inserted.
To close the top of doorstop 50 two panels 66 and 68 (FIGS. 6 and 7) are used.
These are
each of a dimension to cover half the top of doorstop 50 and close the top
apart from rectangular
apertures 62 and 64. The two half panels 66 and 68, are molded with cushions,
i.e. bumpers, and
when completed by either heat or electrosonic "staking", will form an enclosed
top as in FIG. 5.
FIG. 8 illustrates a further embodiment in which the side 70 of the
rectangular doorstop
72 is open. Again, two studs are molded into place.
The side is closed by a right-angle shaped melded plastic part, as in FIG. 9,
with over-
molded soft rubber "bumpers" on the sides of the angle-shaped plastic parts.
It is assembled by
means of either heat staking or ultra-sonic welding to the rectanguloid part
72.
In a yet further embodiment, the rectanguloid plastic part 76 in FIG. 10 is
molded with a
rectangular cushion or bumper made of a rubber-like material. The bottom, or
base, is open, and
a molded plastic plate 78 (FIG. 11) with two studs is joined to part 76 by
means of either heat
staking or ultrasonic welding.
FIGS. 12-14 illustrate another embodiment of the invention. In contrast with
the
embodiment in FIGS. 2-4, here, the housing parts 30, 32 each have one
continuous shaped stop
cushion 35 rather than three separate cushions as shown in FIG. 2 and
identified by reference
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numeral 34. Accordingly, the cushions 35 extend along the perimeter of the
surface of the
housing and around the central aperture, thereby circumscribing it. The
footprints, or bases, of
cushions 35 can generally resemble the perimeters of the surfaces to which
they are attached.
Thus, cushions 35 provide added cushioning surface area versus cushions 34,
thereby increasing
the shock absorbing capability of each housing part 30, 32, and consequently
the doorstop as a
whole.
Similar to cushions 34, cushions 35 are comprised of elastic material, and
joined with the
upper surfaces of the housing parts 30 and 32. Of course, other shapes of
cushions 35, as well as
34, are readily envisioned.
Having thus described the invention in detail, it is to be understood that the
foregoing
description is not intended to limit the spirit and scope thereof. What is
desired to be protected by
Letters Patent is set forth in the appended claims.
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