Adjustable furniture apparatus

An adjustable furniture device having at least one adjustable longitudinal support element including a female section and a male section in telescoping engagement, with positionally-adjustable devices interposed between the male and female members to permit longitudinal adjustment of the support element, and thereby adjustment, for example, of height.

FIELD OF THE INVENTION 
This invention is related generally to furniture (sometimes referred to 
herein as "furniture pieces") and, more specifically, to furniture which 
may be adjusted in height and certain other respects. 
BACKGROUND OF THE INVENTION 
The furniture pieces of the invention have at least one adjustable 
longitudinal support element (i.e., elongate element which is adjustable 
in length), with one female section and one or several adjustable male 
sections. This novel invention permits the length of engagement of the 
male and female members, and thereby the furniture height, to be adjusted 
in a simple and inexpensive manner. 
Such pieces of furniture are known, for example, as vertically adjustable 
tables or chairs, whereby the legs consist of two sections which can be 
adjusted and fastened to each other. (German Patent DE 32 45 280 
illustrates such a device.) However, the adjusting mechanisms of such 
devices of the prior art are often prohibitively expensive. 
A piece of furniture having an easily assembled and easily adjustable 
longitudinal adjusting mechanism which provides strong support would 
represent a significant advance. 
OBJECTS OF THE INVENTION 
It is an object of this invention to provide an improved furniture 
apparatus overcoming some of the problems and shortcomings of the prior 
art. 
A further object of the invention is to provide an improved furniture 
apparatus in which the height may be adjusted. 
A further object of this invention is to provide a piece of furniture with 
an improved adjustable longitudinal support element. 
It is also an objective of the invention to provide an improved furniture 
apparatus in which the height may be rapidly and easily adjusted to a 
variety of positions. 
Yet another object is to provide an improved furniture apparatus which is 
stackable. 
A further object is to provide an improved furniture apparatus which is 
easily transportable. 
It is also an object to provide an improved chair in which the seat height 
may be adjusted. 
An additional objective is to provide an improved furniture apparatus which 
is inexpensive to manufacture and sell. 
A still further object of this invention is to provide adjustable furniture 
apparatus with improved sturdiness. 
The purpose of the present invention is to provide, at a reasonable cost, a 
piece of furniture in which longitudinal adjustment of adjustable elongate 
members can be carried out easily. 
These and other important objects will be apparent from the following 
descriptions and from the drawings. 
SUMMARY OF THE INVENTION 
The invention accomplishes these and other objectives. 
The adjustable longitudinal support elements of this invention have male 
and female leg sections which can be inserted into each other. The male 
member has several substantially annular grooves that are at least partly 
circumferential and are equally spaced along the axis of the male member 
in predetermined dimensional increments. A positionally-adjustable 
abutment device is interposed between the male member and female member. 
In preferred embodiments, the abutment device is a rubber ring or flexible 
(elastic) plastic ring which is fit into at least one of the grooves. The 
inner diameter of the female section is expanded at its terminal area that 
faces the inserted section in order to receive the rubber ring or plastic 
ring in a clamping recess which is adjusted to the outer diameter of the 
rubber ring or plastic ring. The inner diameter of the female section of 
the area which is juxtaposed to the area stated above is adjusted to the 
outer diameter of the male section in order to produce a sliding seat. 
The support elements can thereby be taken apart in two male and female 
sections and can easily be assembled and adjusted to the desired length in 
a telescoping manner. This is done in such a manner that the rubber rings 
slide or roll into the respective grooves. The supporting force of the 
adjustable longitudinal support element is thereby surprisingly high. It 
is sufficient for the recess to act in a clamping manner at its supporting 
area. This type of adjustment also takes into consideration the fact that 
a certain adjustment, once selected, generally need not often be changed. 
In one preferred embodiment, the male section of the support element is the 
upper leg section and the female section preferably is the lower leg 
section of a chair or table. The chair or table can easily be taken apart 
and transported. Such a chair fits, for example, into a suitcase which is 
the size of a briefcase. 
The design of the preferred holding mechanism is advantageous because each 
of the grooves has a round cross-section and the rubber or plastic rings 
are O-rings. This allows in a simple and inexpensive manufacturing process 
and easy adjustment of the rubber rings.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a chair 1 which is one embodiment of the invention. FIG. 1 is 
a front view of chair 1 which is taken apart into its main components. A 
back rest 4 is attached to the top of the seat 3. One or several, 
preferably four, support elements 2, in the form of legs, are attached to 
the bottom of seat 3 by means of fastening elements 2.3. The legs 2 
consist of a male member 2.1 in telescoped engagement with a female member 
2.2. Male and female members 2.1 and 2.2 each have distal ends 2.1a and 
2.2a, respectively. One or the other distal end may be attached to the 
bottom side of the substantially flat support member such as seat 3 with a 
suitable fastener. This arrangement holds seat 3, or other support member, 
substantially parallel to a reference plane 3.1. 
A positionally-adjustable abutment device 2.5 is interposed between male 
and female members 2.1 and 2.2 to vary the length of support element 2 and 
to fix male member 2.1 and female member 2.2. Abutment device 2.5 may be 
rubber rings or elastic plastic rings. Rubber rings 2.5 are preferably 
designed as O-rings; and the cross-section of grooves 2.4 are 
correspondingly round. 
Rings 2.5 are pulled over male member 2.1 and are held there in 
substantially annular grooves 2.4. Grooves 2.4 are spaced along male 
member 2.1 in predetermined dimensional increments for receiving rings 
2.5. This novel arrangement permits rings 2.5 to be 
positionally-adjustable along male member 2.1 in predetermined dimensional 
increments. 
In FIG. 2A a number of chairs 1 are shown stacked together. Chairs 1 are 
substantially upright. Chairs 1 can easily be stacked due to the shape of 
their seats 3 and the arrangement of legs 2. FIG. 2B shows another way of 
stacking chairs 3 whereby the back rests 4 are removed and before 
stacking. Chairs 1 alternately project towards the back and the front. 
FIG. 3A shows a fastening element 2.3 which is attached at the bottom of 
seat 3 and is equipped with a threaded pin 2.8. Male member 2.1 (or female 
member 2.2) can be removably attached to seat 3 by being screwed onto 
threaded pin 2.8. As an alternative, a different fastening or clamping 
mechanism, such as a bayonet fitting (not shown), can be selected. This 
bayonet fitting can be operated very rapidly. 
Grooves 2.4 are clearly visible in FIG. 3A and in FIG. 3B. FIG. 3B shows 
male and female members 2.1 and 2.2 (attached to each other) whereby 
female member 2.2 is the outer leg portion and male member 2.1 is inserted 
in female member 2.2. Female member 2.2 has an interior passage 2.11 with 
an expanded recess 2.11a and an abutment shoulder 2.12. Rubber ring 2.5 
contacts and fits into shoulder 2.12. Rubber ring 2.5, which is placed 
around male member 2.1, is fixed, for example, by a clamping effect in 
such a manner that male member 2.1 can only be inserted into female member 
2.2 up to the point where rubber ring 2.5 sits on shoulder 2.12 of recess 
2.11a, and is securely fixed in this position. To achieve a secure 
support, it is sufficient for there to be only one expanded recess 2.11a 
at the upper rim area of female member 2.2. The diameter of interior 
passage 2.11 is adjusted to the outer cross-section contour of male member 
2.1, so that male member 2.1 can be inserted easily into passage 2.11 
without play. 
FIGS. 4A, 4B and 5 show examples of different embodiments for attachment of 
back rest 4 to seat 3. The same holding mechanism is used as described 
above. A back rest support 4.7 has at least two ends 4.7a each of which is 
inserted into one of the paired openings 3.7 at the back section of seat 
3. As shown in FIG. 1, back rest support 4.7 can, for example, be designed 
as a loop with two ends 4.7a which can be inserted into openings 3.7 of 
seat 3 in a detachable manner. A tight fit of back rest 4.7 support in 
holes 3.7 is preferred. 
According to FIGS. 4A and 4B, ends 4.7a are positioned through openings 3.7 
and protrude from the bottom surface 3a of seat 3. A 
positionally-adjustable abutment device 4.9 is secured with respect to 
back rest 4.7 abutting seat top portion 3b. The stop for back rest 4.7 is 
formed by a holding ring 4.9 which rests on the seat top surface 3b when 
back rest support 4.7 is inserted. Several grooves (not shown) can be 
available in back rest 4.7 for the rings 4.9 in order to achieve 
adjustment of height. 
As shown in FIG. 4B, a respective rubber ring 4.9a can also be adjusted 
under seat 3 to hold back rest 4.7. In FIG. 4B, a rubber or plastic ring 
4.9a is arranged under seat 3 in order to prevent movement of back rest 
4.7. The ring 4.9a has a slightly smaller inner diameter than the back 
rest ends 4.7a, so that it is held securely. 
FIG. 5 shows a design with depth adjustment for back rest 4. For this 
purpose, several openings 3.7 in the form of borings are provided and are 
distributed in a vertical direction. Two rows of openings 3.7 are present 
for both ends 4.7a of back rest support 4 which can be inserted therein. 
The insertion of back rest support 4.7 and the adjustment options can also 
be seen in FIG. 5. 
For easy stacking, the back section 3c of seat 3 may be widened as compared 
to the front section 3d, as shown in FIGS. 2A, 2B and 5. In this 
embodiment, the support member is a seat 3 having a top and bottom surface 
3b and 3a and two pairs of opposed elongate support elements 2 attached to 
and projecting from bottom surface 3a. The distance between the first pair 
of support elements 2 is greater than the distance between the second pair 
of support elements 2 so that a plurality of chairs 1 may be stacked one 
on top of the other. 
A device for storing the disassembled parts (not shown), such as leg 
sections 2.1 and 2.2, back rest 4 and perhaps rubber rings 2.5 and 
fastening elements, may be provided at the bottom of seat 3. 
Rubber rings 2.5, 4.9 and 4.9a, referred to above, can also be plastic 
rings, as stated previously, in which the plastic has characteristics 
similar to the rubber material. 
The principle of the described adjustable longitudinal mechanism, with 
rubber or plastic rings which fit into grooves, can be used for many 
applications, including height adjustment of chairs, and adjustment of 
backrests, or for the height adjustment of tables, closets and stands such 
as music stands, light stands, wardrobes, desks or similar objects. The 
use of this principle is also possible for horizontal adjustable elongate 
supports. Finally, the described adjusting mechanism can be used with two 
or more leg sections 2.1 and 2.2. 
While the principles of this invention have been described in connection 
with specific embodiments, it should be understood clearly that these 
descriptions are made only by way of example and are not intended to limit 
the scope of the invention.