Note: Descriptions are shown in the official language in which they were submitted.
= HEIGHT ADJUSTABLE HEADREST DEVICE
Field of the Invention
The invention relates to a height adjustable headrest device as well as a
wheel chair with such
a height adjustable headrest device.
Background of the Invention
Height adjustable headrest devices are known in the prior art. They are used,
among others,
with seats in the medical field as well as in the field of care, for example
also in wheel chairs.
A shower and toilet wheel chair with a height adjustable headrest is
distributed under the
product name OCEAN VIPTM by AQUATEC GmbH, Alemannenstr. 10, 88316 Isny,
Germany.
The height adjustable headrest device of this known shower and toilet wheel
chair will be
described below in connection with certain Figures included within this
specification. It is to
be understood that the representations in the figures of this application are
not drawn to scale.
For a better representation of certain details, the representation of some
components is
enlarged and simplified.
Summary of the Invention
One of the objects underlying the invention is to further improve the known
height adjustable
headrest device, in particular with respect to function and operating safety.
The invention provides a height adjustable headrest device with a crossbar
element and a
headrest supporting element as well as a clamp connection for the continuously
variable
mounting of the headrest supporting element at the crossbar element, wherein
the clamp
connection comprises a retaining clamp comprising two recesses as well as a
tapped bore, the
retaining clamp gripping around the crossbar element, a centering bushing
comprising an
external thread and an internal thread, the centering bushing being screwed
into the tapped
bore of the retaining clamp, and a screw element screwed into the centering
bushing, wherein
the headrest supporting element is inserted in the recesses of the retaining
clamp, the crossbar
element comprises a bore into which the centering bushing is inserted, and the
clamp
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connection is effected by screwing in the screw element into the centering
bushing and thus
bringing the headrest supporting element near the crossbar element.
The height adjustable headrest device according to the invention thus differs
from the known
height adjustable headrest device illustrated above in the design of the clamp
connection, that
is in that a centering bushing is provided which comprises an external thread
and an internal
thread. The centering bushing is screwed into the tapped bore of the retaining
clamp with its
external thread. With a cylindrical centering section, the centering bushing
is inserted in a
correspondingly designed bore of the crossbar element. The screw element is
screwed with
the clamp connection by means of the internal thread of the centering bushing.
By the provision of the centering bushing, a particularly exact holding and
fixing of the
components with respect to one another is ensured.
In a preferred embodiment of the invention, the sense of rotation of the
internal thread of the
centering bushing is opposed to that of the external thread of the centering
bushing. If, for
example, the internal thread is designed as left-handed thread, the external
thread is designed
as right-handed thread. This prevents tlie threaded bushing from being screwed
out of the
retaining clamp when the screw element is unintentionally actuated.
Preferably, a spacer is arranged between the headrest supporting element and
the crossbar
element and held via a groove and tongue connection in the retaining clamp in
a preferred
embodiment. The spacer is preferably made of plastics to ensure clamping as
wear-resistant
and backlash-free as possible.
The crossbar element preferably has a tubular design. In the crossbar element,
opposite the
bore for receiving the centering bushing, preferably a bulging which is
concave to the inside
is provided which acts as abutment for the screw element.
The headrest supporting element and the corresponding recesses of the
retaining clamp
preferably have a rectangular design. It is to be understood that other
shapes, for example
circular or other.rounded geometries, are also possible.
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A wheel chair according to the invention with a height adjustable headrest
device according
to the present invention is preferably designed such that the crossbar element
is designed as
push handle.
In the Drawings
The invention will be illustrated below with reference to a preferred
embodiment and the
enclosed drawings, wherein
Fig. 1 is a perspective representation of a height adjustable headrest device
according to the
invention,
Fig. 2 is a schematic representation of the clamp connection wherein the
crossbar element is
omitted for better representation,
Fig. 3 is an exploded drawing of a spacer, the centering bushing, the
retaining clamp and the
screw element,
Fig. 4 is a perspective representation of the centering bushing,
Fig. 5 is a sectional representation of the centering bushing,
Fig. 6 is an axial plan view of the fixing bushing,
Fig. 7 is a perspective representation of a known height adjustable headrest
device
corresponding to Fig. 1,
Fig. 8 is a partially sectional representation of a known embodiment of a
clamp connection,
Fig. 9 is an enlarged perspective representation of a known retaining clamp,
Fig. 10 is a partially sectional side view of a known embodiment of a clamp
connection, and
Fig. 11 is a perspective sectional representation of a crossbar element.
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Detailed Description
Having regard to the prior art, Fig. 7 shows a known height adjustable
headrest device 200 in
a perspective representation. The device comprises a headrest 201 which is
fixed to a
horizontal bar 202. The headrest can be shifted horizontally by releasing a
clamping device
203 whereby the horizontal bar 202 can be shifted along the shorter shank 204A
of a headrest
supporting element 204 designed in the shape of a J.
The headrest supporting element 204 is fixed to a crossbar element 210 by
means of a clamp
connection 300. The crossbar element 210 can, for example, be the central part
of a push
handle of a wheel chair.
The clamp connection 300 is shown in Fig. 8 in a perspective representation
and in Fig. 10 in
a side view, in each case partially cut open, where in each case only a part
of the headrest
supporting element 204 as well as the crossbar element 210 is shown.
The clamp connection 300 comprises a U-shaped retaining clamp 360 having two
rectangular
recesses 361A, 361B, through which the headrest supporting element 204, which
also has a
rectangular design, can be inserted. The internal radius of the retaining
clamp 360 having a
U-shaped design is dimensioned such that it is adapted to the outside diameter
of the crossbar
element 210. Between the crossbar element 210 and the headrest supporting
element 204, a
spacer 370 is arranged which is held in the retaining clamp 360 by means of a
groove and
tongue connection so as to be shifted. The corresponding grooves 362A and 362B
of the
retaining clamp 360 are shown in Fig. 9.
A tapped bore 380 is provided in the retaining clamp 360 in which a screw
element 390 is
screwed in.
The screw element 390 is provided with a star handle (391) which permits
manual release
and tightening of the clamp connection 300.
The function of the known clamp connection will be illustrated below. As is in
particular
represented in Figures 8 and 10, the retaining clamp 360 is placed around the
crossbar
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element 210 such that the tapped bore 380 is flush with a bore 211 provided in
the crossbar
element 210. Opposite the bore 211, a bulging 212 concave to the inner surface
is provided in
the crossbar element 210.
The spacer 370 is inserted into the retaining clamp 360 and the headrest
supporting element
204 is inserted through the recesses 361A, 361B of the retaining clamp 360.
The screw
element 390 is screwed into the tapped bore 380 and in the process inserted
through the bore
211 of the bar element 210 until it lies against the bulging 212. When the
screw element 390
is further screwed in, the retaining clamp 360 is moved to the right with
respect to the bar
element 210 in Fig. 10, which causes the headrest supporting element 204 to be
pressed
against the spacer 370 and the spacer 370 to be pressed against the crossbar
element 210.
Thereby, a clamp connection is formed which provides secure positioning of the
headrest
supporting element 204 with respect to the crossbar element 210.
If the screw element 390 is slightly screwed out of the retaining clamp 360,
the clamp
connection is released and the headrest supporting element 204 can be shifted
in the
longitudinal direction with respect to the retaining clamp 360 and thus with
respect to the
crossbar element 210. Thus, a continuously variable height adjustment of the
headrest 201 is
achieved.
A known prior art device has been described having regard to Figures 7 to 11
as outlined
above. As far as not described otherwise in the following, certain components
or features of
the known prior art device may be found in similar elements in the height
adjustable headrest
device according to the invention. Accordingly, in Figures 1 to 6, those
components which
correspond to the respective known components according to Figures 7 to 11 are
provided
with reference numerals which are lower by the amount of 200 with respect to
the respective
corresponding reference numerals in Figures 7 to 11. Thus, for example,
reference numeral 1
is assigned to the headrest in the embodiment of the invention according to
Fig. 1, while
reference numeral 201 is used for the headrest of the known embodiment
according to Fig. 7.
The crossbar element 10 according to the present invention basically
corresponds to that
according to the prior art described in the beginning. Only the bore 11 has a
different design
in the crossbar element according to the invention, as will be illustrated
below. In Fig. 11, for
the sake of simplicity, therefore both reference numerals 210 are used for the
crossbar
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element according to the prior art, and reference numeral 10 for the crossbar
element
according to the invention. The same goes for the reference numerals 211 and
11 for the bore
as well as reference numerals 212 and 12 for the bulging.
As described before, the clamp connection of the height adjustable headrest
device according
to the invention comprises a centering bushing 20. In this respect, reference
is made in
particular to Figures 2 to 5. The centering bushing 20 comprises an external
thread 22, with
which it can be screwed into the tapped bore 180 of the retaining clamp 160. A
collar 25
provided at the centering bushing 20 serves as contact face.
The centering bushing 20 moreover has a centering section 21 inserted in the
bore 11 of the
crossbar element 10. It is to be understood that with the crossbar element 10
of the clamp
connection of the height adjustable headrest device according to the
invention, the bore 11
has to be designed such that it is adapted to the outside diameter of the
centering section 21
of the centering bushing 20 as sliding fit. In the prior art illustrated in
the beginning, the bore
211 is in contrast dimensioned such that the threaded portion of the screw
element 390 can be
passed through.
The screwing of the centering bushing 20 into the tapped bore 180 of the
retaining clamp 160
is facilitated by a groove 26 in which a screwdriver can be set.
The centering bushing 20 moreover has an internal thread 23 the sense of
rotation of which is
opposed to that of the external thread 22. If the external thread 22 is
designed as right-handed
thread, the internal thread 23 is designed as left-handed thread.
Correspondingly, the internal
thread 23 is designed as left-handed thread if the external thread 22 is
designed as right-
handed thread.
After the screwing of the threaded bushing 20 into the tapped bore 180 of the
retaining clamp
160, the same can be put over the crossbar element 10 such that the centering
section 21 of
the centering bushing 20 penetrates the bore 11 of the crossbar element 10.
The spacer 170
can then be inserted into the retaining clamp 160, and subsequently the
headrest supporting
element 4 is passed through the recesses 161a, 161b. Finally, the screw
element 190 is
screwed into the centering bushing 20 by means of the star handle 191 until it
lies against the
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bulging 12 of the crossbar element 10. If the screw element 190 is further
screwed in, the
headrest supporting element 4 is clamped with the crossbar element 10 via the
spacer 170.
The foregoing are examples of certain aspects of the present invention. Many
other
embodiments, including modifications and variations thereof, are also possible
and will
become apparent to those skilled in the art upon a review of the invention as
described herein.
Accordingly, all suitable modifications, variations and equivalents may be
resorted to, and
such modifications, variations and equivalents are intended to fall within the
scope of the
invention as described herein and within the scope of the appended claims.
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