U.S. patent application number 09/790752 was filed with the patent office on 2002-08-22 for chair, in particular work chair.
Invention is credited to Knaus, Oskar.
Application Number | 20020113473 09/790752 |
Document ID | / |
Family ID | 26055030 |
Filed Date | 2002-08-22 |
United States Patent
Application |
20020113473 |
Kind Code |
A1 |
Knaus, Oskar |
August 22, 2002 |
CHAIR, IN PARTICULAR WORK CHAIR
Abstract
A chair has a seat shell, a cushion having a front edge which
extends outwardly beyond a front edge of the seat shell, a shaft
arranged under a seat surface, an actuating element connected with
the shaft and also connected with the front edge of the cushion, at
least one first toothed disc arranged on the shaft, an endless
element guided on the toothed disc and connected with the seat
shell, a second toothed disc which together with the first toothed
disc is displaceable parallel to the seat shell, so that by raising
or lowering of the actuating element the front edge of the cushion
is displaceable forwardly or rearwardly.
Inventors: |
Knaus, Oskar; (Messstetten,
DE) |
Correspondence
Address: |
STRIKER, STRIKER & STENBY
103 East Neck Road
Huntington
NY
11743
US
|
Family ID: |
26055030 |
Appl. No.: |
09/790752 |
Filed: |
February 22, 2001 |
Current U.S.
Class: |
297/284.11 |
Current CPC
Class: |
A47C 1/023 20130101;
A47C 31/02 20130101 |
Class at
Publication: |
297/284.11 |
International
Class: |
A47C 007/14 |
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended claims:
1. A chair, comprising a seat shell; a cushion having a front edge
which extends outwardly beyond a front edge of said seat shell; a
shaft arranged under a seat surface; an actuating element connected
with said shaft and also connected with said front edge of said
cushion; at least one first toothed disc arranged on said shaft; an
endless element guided on said toothed disc and connected with said
seat shell; a second toothed disc which together with said first
toothed disc is displaceable parallel to said seat shell, so that
by raising or lowering of said actuating element said front edge of
said cushion is displaceable forwardly or rearwardly.
2. A chair as defined in claim 1; and further comprising a joint
component on which said shaft with said at least one first toothed
disc and said at least second tooth disc are arranged, said
component being supported on said seat shell displaceably relative
to said seat shell.
3. A chair as defined in claim 2, wherein said component is a web
which has a front end supporting said shaft with said first toothed
disc and a rear end supporting said second toothed disc.
4. A chair as defined in claim 3; and further comprising a rod
connected with said seat shell; and a bush which is guided on said
rod, said web being mounted on said bush.
5. A chair as defined in claim 4, wherein said rod and said bush
are arrestable with one another.
6. A chair as defined in claim 1; and further comprising deviating
rollers which arrest said endless element.
7. A chair as defined in claim 1, wherein two said first toothed
discs are arranged on said shaft at a left side and at a right side
from a center of said seat shell, said endless element being guided
over said two first toothed discs.
8. A chair as defined in claim 1, wherein said shaft is formed as a
hexagonal shaft, said toothed discs mounted on said shaft having a
corresponding hexagonal opening.
9. A chair as defined in claim 1, wherein said endless element is
an endless toothed belt.
10. A chair as defined in claim 1, wherein said endless element is
an endless chain.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a chair, in
particular a work chair, which has a seat shell provided with a
cushion, wherein the front edge of the cushion extends outwardly
beyond the front edge of the seat shell.
[0002] Persons must sit on work chairs over a long time. Since the
long seats are not convenient for long time sitting, it is for
example important when the seat support ergonomically supports the
thighs. In other words, the seat surface must be dimensioned as to
its depth so that it supports the thighs over its whole length, but
does not press in the knee hollow when the pelvis abuts against the
back rest. Since the chairs as a rule are made in accordance with
predetermined standards, it is possible that for persons whose
thighs lengths do not correspond to the standards can sit on the
chair with less comfort. Moreover, frequently a chair is used by
several persons of different body sizes, for example during layer
exchange. Standard chairs are not identically convenient for
sitting of all users. In order to eliminate these problems, chairs,
in particular work chairs are equipped with a seat depth
adjustment. Seats with a seat depth adjustment have preferably a
telescopic extension formed so that moving the extension in or out
provides a corresponding individual adjustment of the supporting
surface for the thighs. A full surface support of the cushion and
thereby of the thighs is however possible in this construction only
with very high expenses.
SUMMARY OF THE INVENTION
[0003] Accordingly, it is an object of the present invention to
provide a chair of the above mentioned general type, which with a
simple construction, provides a seat depth adjustment which is also
easy to operate.
[0004] In keeping with these objects and with others which will
become apparent hereinafter, one feature of present invention
resides, briefly stated, in a chair, in which the front edge of the
cushion is mounted on an actuating element which is connected with
a shaft arranged under the seat surface, and at least one toothed
disc is arranged on the shaft over which an endless belt or an
endless chain is guided, the belt or the chain are fixedly
connected with the seat shell and a second toothed disc which is
displaceable together with the first toothed disc parallel to the
seat shell is guided so that, by raising or pressing down of the
actuating element, the front edge of the cushion is displaceable
forwardly or rearwardly.
[0005] When the chair is designed in accordance with the present
invention, then a seat depth adjustment is implemented in a simple
structural way and simultaneously can be easily operated by the
user.
[0006] Preferably, the shaft with the at least one first toothed
disc and with the at least one second tooth disc is arranged on a
common component, which is displaceable relative to the seat shell
and is supported on it.
[0007] The component can be for example a web with a front edge
which supports the shaft with the first toothed disc, and with a
rear edge which supports the second toothed disc.
[0008] The web can be mounted on a bushing which is guided on a rod
connected with the seat shell. This provides for a simple
construction.
[0009] The endless toothed belt or the endless chain can be
arrestable by deviating rollers. Thereby a person who sits on the
chair can not displace inadvertently with the legs the supporting
surface for the thighs.
[0010] For the same purpose or when desired as an additional
feature, the rod and the bushing can be arrestable with one another
by the endless toothed belt or the endless chain arrestable by the
deviating rollers.
[0011] For an improved guidance of the seat depth adjustment,
correspondingly left and right from the center of the seat shell,
two first toothed discs can be arranged on the shaft. An endless
toothed belt or an endless chain can be guided in this manner.
[0012] The shaft can be formed as a hexagonal edge shaft, and a
hexagonal opening can be provided on the toothed discs mounted on
it. Thereby the force transmission from the actuating element to
the toothed discs is ensured in a reliable manner by a form-locking
connection.
[0013] The novel features which are considered as characteristic
for the present invention are set forth in particular in the
appended claims. The invention itself, however, both as to its
construction and its method of operation, together with additional
objects and advantages thereof, will be best understood from the
following description of specific embodiments when read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a partially sectioned plan view of a seat depth
adjusting device of a chair in accordance with the present
invention;
[0015] FIGS. 2a and 2b are views showing a central longitudinal
section through a seat surface of a chair with a seat adjustment
device of FIG. 1, with two different seat depths; and
[0016] FIG. 3 is a partially sectioned part-side view of the seat
adjusting device of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] An actuarting element 10 of a chair in accordance with the
present invention is shown in FIG. 1 and formed as a rib. It is
connected with a shaft 11 in a way which is not described in
detail. Two first toothed discs 12 are mounted on the shaft 11.
They are connected with a second tooth disc 14 by endless tooth
belts 13. Endless tooth belts 13 are firmly connected by a mounting
element 15 with a seat plate 21 shown in FIG. 2. The second tooth
disc 14 as well as the shaft 11 with the first tooth discs 12 are
connected each with a web 16. The web 16 for this purpose is
provided with an opening 32, for receiving the shaft 11. The web 16
is screwed on a bushing 19 by screws 17 and 18. The bushings 19 are
displaceably guided on rods 20.
[0018] FIG. 2 shows a seat plate 21 of a work chair, which is
provided with a cushion 22. It can be seen that the web 16 is
arranged at the lower side of the seat plate 21, and one of the
second toothed discs 14 and the shaft 11 are supported on the web
16. Deviating rollers 24 arrest the endless toothed belt 13 which
is guided over the toothed discs 12 and 14. Thereby a person who
fits on the chair can not inadvertently displace rearwardly the
front edge 23 of the cushion 22 with its thighs. The rod-shaped
actuating element 10 is mounted on the shaft 11. It is also
connected with the front edge 23 of the cushion 22.
[0019] FIG. 2a shows the actuating element 10 in its position which
is turned forwardly and upwardly to a maximum. Thereby a maximum
seat depth for the chair can be adjusted.
[0020] FIG. 2b shows the front edge 23 of the cushion 22 which is
rolled rearwardly and downwardly by turning of the actuating
element 10. Thereby a smaller seat depth than in FIG. 2a is
provided.
[0021] When the actuating element 10 is turned, the shaft 10 and
the toothed disc 12 mounted on it are also turned together with the
actuating element. Since the endless toothed belts 13 are fixed by
clamping elements 15 on the seat plate 21, the turning of the
toothed discs 12 leads to a displacement of the web 16 on the rods
20. Because of this and because of the rolling of the cushion front
edge 23 in and out, the sitting depth can be adjusted steplessly in
accordance with the corresponding requirements of the user of the
chair.
[0022] FIG. 3 shows a detailed view of the seat plate 21. The rod
20 is mounted by screws 30 and 31 on the seat plate 21. The web 16
is connected with the bushing 19 in a way shown in FIG. 1. The
bushing 19 is displaceable on the rod 20 in the longitudinal
direction of the rod 20. Thereby also the web 16, which in its
front region has an opening 33 for receiving the shaft 11, can be
displaced in a longitudinal direction of the rod 20.
[0023] It will be understood that each of the elements described
above, or two or more together, may also find a useful application
in other types of constructions differing from the types described
above.
[0024] While the invention has been illustrated and described as
embodied in chair, in particular work chair, it is not intended to
be limited to the details shown, since various modifications and
structural changes may be made without departing in any way from
the spirit of the present invention.
[0025] Without further analysis, the foregoing will so fully reveal
the gist of the present invention that others can, by applying
current knowledge, readily adapt it for various applications
without omitting features that, from the standpoint of prior art,
fairly constitute essential characteristics of the generic or
specific aspects of this invention.
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