U.S. patent number 3,837,704 [Application Number 05/371,968] was granted by the patent office on 1974-09-24 for seating furniture.
Invention is credited to Fritz Bauer.
United States Patent |
3,837,704 |
Bauer |
September 24, 1974 |
SEATING FURNITURE
Abstract
An article of seating furniture having means to continuously
adjust the seat height, back rest height and back rest tilt through
the operation of a single operating lever which can be operated
from a seated position. Motion of the lever in one direction
releases a gas spring controlling seat height, motion of the lever
in a second direction releases a gas spring controlling back rest
tilt, and rotation of the lever causes height adjustment of the
back rest.
Inventors: |
Bauer; Fritz (Schulzstr. 14,
DT) |
Family
ID: |
23466146 |
Appl.
No.: |
05/371,968 |
Filed: |
June 21, 1973 |
Current U.S.
Class: |
297/344.19;
297/353; 297/410; 297/354.12 |
Current CPC
Class: |
A47C
3/30 (20130101); A47C 7/402 (20130101); A47C
1/0244 (20130101) |
Current International
Class: |
A47C
7/40 (20060101); A47C 1/024 (20060101); A47C
3/30 (20060101); A47C 1/022 (20060101); A47C
3/20 (20060101); A47c 007/40 () |
Field of
Search: |
;297/353,355,345,354,300,306 ;248/400,161 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Zugel; Francis K.
Attorney, Agent or Firm: Browdy and Neimark
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is a continuation-in-part of application
Ser. No. 107,021 which is hereby incorporated by reference. The
present application is also related to my U.S. Pat. No. 3,656,593
and 3,711,054.
Claims
What is claimed is:
1. An article of seating furniture comprising a seat, a back rest,
a back rest support connected to said back rest and pivotably
connected to said seat, a base connected to said seat, and a single
adjusting lever, said article of seating furniture further
comprising:
seat adjust means connected to said seat and said base for
adjusting the height of said seat;
back seat tilt means connected to said back rest support for
tilting said back rest backward and forward; and
back rest height adjust means connected to said back rest for
adjusting the height thereof,
wherein said seat adjust means, said back rest tilt means and said
back rest height adjust means are all controlled by said single
lever.
2. An article of seating furniture in accordance with claim 1,
wherein said seat adjust means includes a first pneumatic spring
incorporated in said base and connected to said seat, said first
pneumatic spring having a locking device operable by a release pin
and wherein said release pin is in contact with said lever whereby
a swing of said lever in a first direction will depress said
release pin and release the locking device of said first pneumatic
spring;
wherein said back rest tilt means includes a second pneumatic
spring connected at one end to the bottom of the seat and at the
other end to said back rest support, said second pneumatic spring
having a locking device operable by a release pin, and wherein said
release pin is in contact with said lever whereby a swing of said
lever in a second direction will depress said release pin and
release the locking device of said second pneumatic spring; and
wherein said back rest height adjust means includes a rotatable
threaded rod vertically mounted in said back rest support, a
threaded nut non-rotatably mounted on said threaded rod and
connected to said back rest, and a cable fastened at one end to
said threaded rod and at the other end to said lever whereby
rotation of said lever about the longitudinal axis thereof causes
rotation of said threaded rod and therefor vertical translation of
said threaded nut and back rest therealong.
3. An article of seating furniture in accordance with claim 2
wherein each of said first and second pneumatic springs
comprises:
a tubular casing containing a fluid filling;
a piston axially movable in said tubular casing mounted on a piston
rod emerging at one end of said casing through a seal therein, said
piston rod being immovably anchored on said base or said back rest
support;
said locking device capable of locking said piston in an adjusted
position blocking an overflow opening for said filling and having
said release pin emerging from the end of said casing adjacent said
lever, said pin being capable of opening said overflow opening and
of connecting the casing space ahead of said piston to the casing
space behind said piston via a by-pass chamber.
4. An article of seating furniture in accordance with claim 1
wherein said lever includes a spherical bearing mounted thereon and
said seat includes a holder fastened therebeneath and a bearing
mount fastened to said holder, and wherein said spherical bearing
is mounted in said bearing mount.
5. An article of seating furniture in accordance with claim 4
wherein said holder includes recesses therein through which said
lever passes, said recesses forming guides for the motion of said
lever in said first and second directions.
6. An article of seating furniture in accordance with claim 2
wherein said lever includes a spherical bearing mounted thereon and
said seat includes a holder fastened therebeneath and a bearing
mount fastened to said holder, and wherein said spherical bearing
is mounted in said bearing mount.
7. An article of seating furniture in accordance with claim 6
wherein said back rest tilt means further includes a sliding block
mounted in said holder perpendicular to the direction of said
lever, said sliding block having a projection that contacts the
release pin of said second pneumatic spring, wherein one end of
said lever passes through said sliding block allowing displacement
of said block upon swinging said lever in said second direction
which in turn depresses said release pin and allows movement of
said back rest.
Description
BACKGROUND OF THE INVENTION
The invention relates to an article of seating furniture, more
particularly to a chair, with a seat and back rest adjustable to
the particular body dimensions of the user.
The construction of such chairs, used more particularly in offices,
factories or the like, is based on the recognition that the best
possible efficiency of a worker is only achievable if he can
suitably assume a comfortable and anatomically correct seated
position at his work-place. Also, such seating contributes
considerably to remaining in health. In order to be able to adapt
the seat, more particularly the working chair, to the body
dimensions of the user, not only is it necessary to construct the
seat so as to be adjustable in height, but also the back rest must
be constructed so as to be adjustable in its height and depth and
in the horizontal direction.
A chair constructed in this manner is understandably expensive to
manufacture since for each possibility of displacement, a separate
operating lever, hand grip or the like is provided. The number of
operating levers makes it necessary to distribute them and
correspondingly arrange them at different places on the chair frame
carrying the seat, most of these places being inaccessible by the
user in the seated position. Consequently, frequently the greatest
part of the adjustment possibility is not exploited at all. Apart
from this, the large number of these operating levers detracts from
the shape and the appearance of the chair so that in spite of the
existing requirement, mainly only one or two displacement
possibilities are provided with such chairs, in order to simplify
and accordingly make more economic the manufacture of adjustable
chairs.
In my U.S. Pat. application Ser. No. 107,021 a chair of this kind
has already been described, in which the raising and lowering of
the seat and the adjustment of the back rest can be accomplished by
means of a single operating lever. To adjust the height of the back
rest, a locking pin is released by means of the operating lever, so
that the back rest (including the supports holding it) can be moved
by hand. The horizontal adjustment of the back rest is accomplished
in such a way that the locking mechanism of a horizontal and
horizontally displaceable arm supporting the back rest is released
by means of the operating lever, so that the back rest can then be
moved with the other hand.
That invention, which formed the basis of my older application,
offered numerous advantages over the older known designs, but was
still relatively complicated in its design; in particular, the
operator was required to use both hands to adjust the height or the
horizontal adjustment of the back rest.
Hence, the purpose of the present invention is to design a chair of
this kind in such fashion that the height adjustment of the seat,
the height adjustment of the back rest and its horizontal
adjustment can not only be carried out by using a single operating
lever, but that the operator no longer needs to use his other hand
to accomplish these movements, thus making this mechanism
especially simple.
SUMMARY OF THE INVENTION
Consequently, the present invention relates to an article of
seating furniture with a gas spring incorporated in the base for
height adjustment of the seat, as well as a back rest that can be
moved forward and backward and can be adjusted for height, having a
two-armed operating lever mounted beneath the seat in a carrier
bracket, said lever being horizontally and vertically swivelable
and rotatable, wherein a vertical movement of the lever acts on the
release pin of a locking device on the gas spring which connects
the housing of the operating piston with a housing located behind
the operating piston of the gas spring, and wherein a horizontal
movement of the lever acts on the release pin of a second gas
spring similar to the first gas spring, said gas spring being
connected on the one hand with the lower surface of the seat and on
the other hand with the swivelable support of the back rest
opposite the seat, to move the back rest, and wherein the flexible
shaft of a Bowden cable is connected to the end of the operating
lever, the other end of said Bowden cable being connected to a
threaded rod mounted on the support of the back rest, said threaded
rod having mounted on it a threaded nut non-rotatable with respect
to the support, wherein the back rest is fastened to the threaded
nut.
BRIEF DESCRIPTION OF DRAWINGS
Further advantages and features of the invention follow from the
description below of an embodiment of the invention as shown in the
drawing:
FIG. 1: Upper part of a chair according to the invention, primarily
in lengthwise cross-section;
FIG. 2: A horizontal cross section through the chair along line
II--II in FIG. 1;
FIG. 3: Vertical section along line III--III in FIG. 2;
FIG 4: A partial cutaway view of the top end of the support of the
back rest as indicated by arrows IV--IV in FIG. 1;
FIG. 5: The bottom part of the chair according to FIG. 1, and
FIG. 6: A gas spring used in a chair according to the invention, in
lengthwise section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In an article of seating furniture, in particular an office chair
according to the invention, a plate 1, screwed by means of holes 2
to a seat 3, has fastened to its lower surface an arm 4 in the
shape of the letter U extending backwards and open toward the
bottom, by means screws 5. The rearmost free end of this arm 4 has
mounted on it a support 6 extending upward, which has a roughly
rectangular hollow, box-shaped cross section. This support 6 is
mounted on the projecting side flanges 7 of arm 4 and is free to
swivel around a horizontal pin 8 in such fashion that this support
can be swiveled forward or backward as seen from the viewpoint of
an individual using the chair. The U-shaped arm 4, open toward the
floor, has mounted in it by means of a fastening pin 10 a gas
spring 9, which will be described in greater detail below, said pin
passing through appropriate holes in the side flanges 7 and a
corresponding hole in the gas spring 9.
The piston rod 11 of this gas spring 9 has on its free end a boss
12, said boss being connected below pin 8 by means of a fastening
bolt 13 to part 14 of support 6 projecting downward. At the end
opposite the outlet of the piston rod 11, gas spring 9 has a
release pin 15, which when activated in a manner to be described
below eliminates blockage of this gas spring and the piston rod 11
either emerges from said gas spring under the pressure of the gas
in the latter and moves support 6 clockwise about pin 8 or the
exertion of an appropriately large force on the support in a
counterclockwise direction displaces the support in the
counterclockwise direction, pressing the piston rod 11 back into
the gas spring 9.
A rod 16 with a trapezoidal thread is mounted axially
non-displaceably in the upper part of the support. This rod 16 is
mounted at the top in an end plate 17, said plate being clamped on
the support, while rod 16 is mounted at the bottom in a bushing 18,
which is also clamped to the support. The end plate 17 and the
bushing 18 are made of an elastic plastic. A threaded nut 19 is
mounted on rod 16, said nut having a flange 21 projecting forward
out of a slot 20 on support 6, said flange having fastened to it a
diagonally extending plate 22 with two holes 23. In order to allow
flange 21 to extend outward through slot 20, threaded nut 19 is
prevented from turning with respect to support 6, so that when rod
16 is turned the nut 19 and with it plate 22 are displaced upward
or downward. A back rest 23a can be screwed to plate 22 by means of
screws through holes 23, said back rest being displaced upward or
downward through vertical displacement of threaded nut 19 for
adjustment to the seated height and shape of the user.
The rod is turned by means of a so-called Bowden cable, which is
formed in known fashion of a flexible shaft 24 housed in a flexible
although stiff and non-rotatable tube 25. The tube 25 is fastened
to bushing 18, while the flexible shaft 24 is attached to rod
16.
A roughly tubular holder 26 is welded to the bottom of plate 1,
approximately in the center of the latter, said holder having on
its lower end two laterally extending flanges 27, forming a slot 28
between them. The upper end of a gas spring 29 is inserted in this
lower end of holder 26, said gas spring being held in holder 26 in
such fashion that the two flanges 27 can be squeezed together by
means of a screw 30.
A double-armed lever 31, preferably consisting of a rod with
circular cross section, is mounted on holder 26 in such fashion
that it can be swiveled and rotated in all directions but is
axially non-displaceable. Lever 31 has mounted on it a plastic
bearing in the shape of a segment of a sphere, said bearing being
mounted in a corresponding bearing housing 33, said bearing housing
being fastened in turn externally by means of screws 34 to holder
26. One arm 35 of the lever extends from bearing 32 through two
corresponding openings in the tubular holder 26 located opposite
each other. An operating handle 37 is mounted on the other,
outwardly directed arm 36 of the lever, said handle serving to
effect displacement or rotation of the lever.
The flexible shaft 24 of the Bowden cable is fastened to the free
end of arm 35 of lever 31 so that when lever 31 is rotated the back
rest 23a is displaced upward or downward.
Arm 35 of lever 31 is mounted above a release pin 38 on gas spring
29, so that when hand grip 37 is raised arm 35 is pressed downward,
activating the release pin. The design and function of this gas
spring 29 are completely identical to those of gas spring 9 and
will be described in greater detail below.
A horizontally displaceable sliding block 39 is mounted
perpendicular to the axial direction of lever 31 in the slots 40
and 41 of holder 26 located opposite each other, said holder being
roughly plate-shaped and bent into the form of a hook at one end
projecting from holder 26, so that a projection 42 is formed which
rests against the release pin 15 on gas spring 9. In the part of
the sliding block 39 which is located inside the tubular holder 26,
there is a recess 43 open toward the floor, through which arm 35 of
lever 31 passes. When hand grip 37 is swiveled clockwise (see FIG.
2) the sliding block (see FIG. 2) is displaced toward the left and
presses the release pin 15 into gas spring 9, releasing the latter.
In order for arm 35 of lever 31 passing through holder 26 to
execute this horizontal swiveling movement, recess 44 which faces
the end of the arm 35 is widened in holder 26 correspondingly in
the direction of the projection 42 of the sliding block 39. It is
also widened toward the bottom (FIG. 3) so that lever 31 can
perform the swiveling movements to activate release pin 38 on gas
spring 29.
In the illustrated embodiment (FIG. 5) the pneumatic spring 29 is
received in a chair base 45. Such a chair base is formed by a guide
tube 46 onto which radically extending support arms 47 are fixed,
as by welding at the lower region of its exterior, the guide tube
extending perpendicularly to the floor 48 and axially slidably
carrying the pneumatic spring 29. A roller 49 may be provided at
the free end of each support arm 47, for example, a caster roller
which can swing in a circular path about a vertical axis.
Alternatively, of course, devices may be provided for equalizing
possible unevennesses in the floor. The lower end of the guide tube
46 is provided with a base 50 in which the free end of the piston
rod 51 is fixed axially non-displaceable but rotatable.
The manner of fixing the lower end of the piston rod 51 can be
accomplished in various ways. In this embodiment of the invention,
the base 50 of the guide tube 46 is formed by a welded-in thick
annular disk 52, the diameter of whose central opening is
considerably greater than the diameter of the studlike end 53 of
the piston rod 51. A thrust bearing 54 is arranged on the stud 53,
its upper face 55 being press-fitted onto the stud so as to bear
against the step formed between the stud and the main body of the
piston rod. The lower face 56, on the other hand, bears against the
inner side of the base 50 constituted by the annular disk 52. For
axially non-displaceably mounting the stud 53 in the base 50, the
opening 57 of the annular disk 52 is covered from the outside of
the base by an annular disk 58 which is seated on the stud 53
practically without play, and is secured by means of a spring ring
59. The spring ring 59 engages in an annular groove of the stud,
which is provided at such a spacing from the main body of the
piston rod, which corresponds to the total thickness of the thrust
bearing 54, the base 50 and the outer annular disk 58. Thus, the
stud 53 of the piston rod 51 is axially non-displaceably but
nevertheless rotatably movably anchored in the base 50 of the guide
tube 46 and can readily participate in the swivelling movement of
the chair seat. The housing 60 of the pneumatic spring 3 can slide
up and down axially directly in the guide tube 46 with little play.
Preferably, however, a bushing 61 (for example, of plastic) is
provided between the guide tube of the chair base, stool base or
the like and the housing of the pneumatic spring, the upper end of
the bushing being provided with a collar which closes off or masks
the upper wall edge of the guide tube, if desired. This lifting
device for the seat 1 of a chair is part of my U.S. Pat. No.
3,711,054, which is hereby incorporated by reference.
Each pneumatic or hydro-pneumatic lifting device or spring 9, 29
comprises a housing 60 which essentially consists of two
concentrically disposed steel tubes 62 and 63 of different
diameters. At one end the housing is gas or liquid tightly closed
by a double base 64, and at the other end by a plug 65. In the
inner steel tube 62, a piston 66 is axially displaceably guided,
and the piston is fixed by means of a hollow stud 67 onto the
piston rod 11, 51, a plunger or the like which extends in a gas or
liquid-tight manner through the plug. The double base comprises two
individual base portions 68, 69, which enclose between them a
by-pass or deflection region 70, the greater part of the deflection
region being disposed in the outer base portion 68 and only a small
part of the deflection region 70 extends into the inner base
portion 69. A releasing pin 15, 38 is axially displaceably guided
in a sealed manner, coaxially in the two base portions, its inner
end having a head 71 serving as an abutment.
Both base portions 68, 69 have cylindrical pot-shaped recesses 72
or 73 in their sides which face each other, the margins 73 of the
openings which face each other being widened towards the inside, in
a somewhat frusto-conical manner. The cylindrically extending part
has a depth which corresponds to the height extending parallel to
the longitudinal axis of a sealing ring 74 with an ideal
rectangular cross-section. The ring surface facing the deflection
region 70 of each sealing ring is notched substantially V-shaped in
cross-section so that the inner ring wall which surrounds and
guides the release pin 11, 51 is considerably smaller in height
than the outer ring wall of each sealing ring. The pressure of the
housing contents presses on each sealing ring in dependence on the
V-shaped notching so that the considerably higher ring wall is
pressed with essentially greater force into the cylindrically
pot-shaped recess than is the significantly lower ring wall pressed
on the shank of the release pin 15, 38 so that with axial
displacement of this relase pin the two sealing rings 74 can not be
moved out of their seats. In both base portions, the sealing rings
serve not only for sealing, but also additionally for guiding the
release pin, the bore receiving the release pin in the outer base
portion having a diameter which ensures a sliding or displacing of
the release pin.
The rlease pin 15, 38, which essentially forms the blocking device
for the housing chamber 75 lying in front of the piston 66, has an
annular groove 76 disposed between the regions engaged by the two
sealing rings 74. The groove 76 has frusto-conically shaped
outwardly extending side walls 77. The annular groove 76 cooperates
with an axial bore 78 provided in the inner base portion 69 next to
the respective seal of the release pin, and opens into the housing
chamber 75. This bore 78 has a somewhat larger diameter than the
shank diameter of the release pin which passes coaxially through
this bore. If for the height adjustment of the spring, the release
pin is pushed into the housing, then the housing contents, i.e.,
gas under pressure, under the action of the piston movement, flow
through this bore 78 into the deflection chamber 70 through the
open annular groove 76 which is now adjoining.
The inner steel tube 62 carrying the piston 66 is arranged with its
end facing the blocking device gas and liquid tightly disposed on a
reduced diameter peripheral portion 79 of the inner base portion
69, if desired with the use of a sealing ring 80. The outer steel
tube 63, which surrounds the inner steel tube leaving an annular
gap-shaped surrounding chamber 81, extends over the outer periphery
of the inner base portion 69 and receives a centralizing rim 82 of
the abutting outer base portion 68, with which it is gas and liquid
tightly connected. By the dimensional diffference of the inner
diameter of the outer steel tube and the outer diameter of the
inner steel tube, the radial width of the by-pass chamber 81 is
determined. The by-pass chamber 81 is connected by at least one
axial flow opening 83 in the inner base portion 69 of the double
base 64, with the part of the deflection chamber 70 which extends
somewhat into this, through which any of the contents of the
housing present in the deflection chamber and standing under
pressure, passes into the by-pass chamber. For introducing the
container contents, e.g., compressed gas or gas and oil, the outer
base portion 68 may, for example, be provided with a threaded
closure 84.
At the other end of the housing 60, the plug 65 is stepped to the
inner diameter of the inner steel tube 62 so that a centralizing
region 85 results, which extends into the inner steel tube. The
outer steel tube 63 is extended over the outer periphery of the
plug which is common to both steel tubes, and is secured to this in
a gas and liquid tight manner. The bore in the plug carrying the
piston rod 11, 51, the plunger or the like, is provided with a seal
86 in which the piston rod 11, 51 is slidingly sealed. The bore 87
which extends towards the inside of the housing at the inner end of
the plug has a larger diameter than the piston rod, plunger or the
like, so that the pressure medium can flow out of the expansion
chamber formed as an annular groove 88 in the plug, into the
housing chamber 89 disposed behind the piston 66. The by-pass
chamber 81 is extending beyond the fixing point of the inner steel
tube 62 formed by the centralizing portion 85, so that the by-pass
chamber 81 can be connected with the annular chamber 88
constituting the expansion chamber in the plug, by at least one
radial bore 90.
If, for example, the lifting device, which is illustrated in the
drawing in substantially its fully drawn out position, is required
to be shortened, that is to say, the height of the seat is required
to be steplessly reduced, then the blocking device is opened by
pushing the release pin 38 into the housing 60. By pushing down the
chair seat, by hand, the piston 66 drives the housing contents
disposed in front of the piston through the deflection chamber 70
and through the flow opening 83 into the by-pass chamber 87 and
from there through the radial bores 90 into the annular chamber 88
of the plug 65, from where it can pass through the axial bore 87
into the housing chamber 89 behind the piston 66. On steplessly
reaching the desired height of the chair seat 1, the blocking
device is again closed; whereupon due to the loading of the housing
contents, for example compressed gas, the table top or the chair
seat is locked in the new position.
As a person skilled in the art can easily recognize, the gas spring
9, 29 can still flex or resiliently bounce after closing of the
release pin 15, 38 whenever there is a gas filling the spaces 75
and 89 on both sides of the piston 66. The piston 66 is then set
with the piston rod 11, 51 at a certain level, but it is not firmly
locked, i.e., it is not entirely unshiftable, but it can still flex
or resiliently bounce against the gas pressure. This pneumatic or
hydropneumatic spring is part of my U.S. Pat. No. 3,656,593, which
is hereby incorporated by reference.
It will be obvious to those skilled in the art that various changes
may be made without departing from the scope of the invention and
the invention is not to be considered limited to what is shown in
the drawings and described in the specification.
* * * * *