U.S. patent number 3,594,041 [Application Number 04/848,824] was granted by the patent office on 1971-07-20 for reverse cantilevered tubular chair.
Invention is credited to Ralph K. Rye.
United States Patent |
3,594,041 |
Rye |
July 20, 1971 |
REVERSE CANTILEVERED TUBULAR CHAIR
Abstract
A two-part, tubular chair having a cantilevered seat that is
supported at the rear of the chair. The chair base frame is formed
from two tubular members, one positioned within the other, which
are bent together to provide sufficient structural strength to
prevent deflection of the reverse cantilevered seat section A
tubular back frame having a back rest member is removably secured
to the base frame to complete the chair structure.
Inventors: |
Rye; Ralph K. (Swampscott,
MA) |
Family
ID: |
25304375 |
Appl.
No.: |
04/848,824 |
Filed: |
August 11, 1969 |
Current U.S.
Class: |
297/451.3;
D6/372; 297/295 |
Current CPC
Class: |
A47C
3/023 (20130101); A47C 5/10 (20130101); A47C
5/04 (20130101) |
Current International
Class: |
A47C
5/04 (20060101); A47C 5/00 (20060101); A47c
007/00 (); A47c 007/14 () |
Field of
Search: |
;297/239,445--451,417,418 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nunberg; Casmir A.
Claims
Having described in detail the preferred embodiment of my
invention, what I claim and desire to secure by Letters Patent of
the United States is:
1. A reverse cantilevered, tubular chair comprising:
a chair frame formed from two tubular elements, each tubular
element comprising two tubular members, one positioned within the
other, said chair frame tubular elements each being bent into a
forwardly extending horizontal leg section which turns upwardly at
the rear to form a vertically extending back leg section which
turns forwardly at the upper end thereof to form a substantially
horizontal arm section which, at the forward end thereof, curves
downwardly and then backwardly to form a substantially horizontal
seat support section and finally turns upwardly to form a
substantially vertical side section;
means for maintaining said chair frame forwardly extending,
horizontal legs sections in spaced, coplanar relation;
means for maintaining said upwardly extending, substantially
vertical side sections in spaced, fixed relation; and,
a seat member mounted between said seat support sections
2. A reverse cantilevered, tubular chair comprising:
a base frame formed from two tubular elements, each tubular element
comprising two tubular members, one positioned within the other,
with the inner tubular member being longer than and extending
beyond one end of the other tubular member, said base frame tubular
elements each being bent into a forwardly extending horizontal leg
section which turns upwardly at the rear to form a vertically
extending back leg section which turns forwardly at the upper end
thereof to form a substantially horizontal arm section which, at
the forward end thereof, curves downwardly and then backwardly to
form a substantially horizontal seat support section which
terminates in the extended portion of the inner tubular member;
means for maintaining said base frame forwardly extending,
horizontal legs sections in spaced, coplanar relation;
a back frame comprising: two tubular side members fitted over the
extended portions of said base frame inner tubular members, said
side members extending backwardly and upwardly, and means for
maintaining the upwardly extending portions of said side members in
fixed, spaced relation; and,
a seat member mounted between and removably secured to said seat
support sections.
3. The chair of claim 2 further characterized by said means for
maintaining the upwardly extending portions of said side members in
fixed, spaced relation including a backrest member.
4. A reverse cantilevered, tubular chair comprising:
a base frame formed from two tubular elements, each tubular element
comprising two tubular members, one positioned within the other,
with the inner tubular member being longer than and extending
beyond one end of the other tubular member, said base frame tubular
elements each being bent into a forwardly extending horizontal leg
section which turns upwardly at the rear to form a vertically
extending back leg section which turns forwardly at the upper end
thereof to form a substantially horizontal arm section which, at
the forward end thereof, curves downwardly and then backwardly to
form a substantially horizontal arm section which, at the forward
end thereof, curves downwardly and then backwardly to form a
substantially horizontal seat support section which terminates in
the extended portion of the inner tubular member;
means for maintaining said base frame forwardly extending,
horizontal legs sections in spaced, coplanar relation;
a tubular back frame having a substantially horizontal transverse
back section and two downwardly and forwardly depending side
sections, said side sections being fitted over the extended
portions of said base frame inner tubular members;
a seat member mounted between and removably secured to said seat
support sections; and,
a backrest member mounted between and removably secured to said
back frame side sections.
5. The chair of claim 4 further characterized by means for
fastening the downwardly depending side sections of said back frame
to arm sections.
6. A reverse cantilevered, tubular chair comprising:
a base frame formed from two tubular members, one positioned within
the other, with the inner tubular member being longer than and
extending at each end beyond the outer tubular member, said base
frame having a rearwardly opening, U-shaped support section with
vertically extending back leg sections which turn forwardly to form
substantially horizontal arm sections which, at the forward ends
thereof, curve downwardly and then backwardly to form substantially
horizontal seat support sections which terminate in the extended
portions of said inner tubular member;
a tubular back frame having a substantially horizontal transverse
back section and two downwardly and forwardly depending side
sections, said side sections being fitted over the extended
portions of said base frame inner tubular member;
a seat member mounted between and removably secured to said seat
support sections; and,
a backrest member mounted between and removably secured to said
back frame side sections.
7. The chair of claim 6 further characterized by means for
fastening said downwardly depending side sections of said back
frame to said arm sections.
8. The chair of claim 7 further characterized by said back frame
side sections being located inwardly from said base frame arm
sections.
Description
BACKGROUND OF THE INVENTION
This invention relates to the design and manufacture of chairs in
general and, more particularly, to a reverse cantilevered, tubular
chair in which the seat cantilevers forward from the rear legs of
the chair.
In the manufacture of tubular chairs, it is important to provide a
chair construction that maintains the structural relationships of
the chair components when the chair is subjected to the loading
imposed by the weight of the occupant of the chair. If the tubular
frame bends or gives too much, the resulting change in structural
relationships will severely impair the designed comfort of the
chair. The problem of structural deflection in a tubular chair
construction is even more critical in the case of chairs having a
cantilevered seat.
It is accordingly, a general object of the present invention to
provide a cantilevered tubular chair construction having sufficient
strength to maintain its designed configuration under loading.
It is a specific object of the present invention to provide a
two-part, reverse cantilevered tubular chair construction.
It is another object of the present invention to provide a reverse
cantilevered, tubular chair construction in which the chair base
frame is formed from two tubular members, one positioned within the
other, which are bent together to produce a continuous chair base
frame.
It is still another object of the present invention to provide a
two-part, reverse cantilevered tubular chair construction that can
be easily fabricated and, thereafter, assembled without requiring
special tools, adhesives or other fastening devices to maintain the
two chair components in fixed relation.
These objects and other objects and features of the invention will
best be understood from the following detailed description of a
preferred embodiment, selected for purposes of illustration, and
shown in the accompanying drawings in which:
FIG. 1 is a view in front elevation of a reverse cantilevered chair
constructed in accordance with the present invention;
FIG. 2 is a view in side elevation of the chair;
FIG. 3 is a plan view of the chair;
FIG. 4 is a view in cross section taken along line 4-4 in FIG. 1
showing the U-shaped configuration of the chair base frame;
FIG. 5 is a view in cross section taken along line 5-5 in FIG. 3,
with the seat and backrest members removed, showing the assembled
relationship of the chair base frame and the chair back frame;
FIG. 6 is a view in cross section taken along line 6-6 in FIG. 2
showing the fastening of the base frame arm section to the back
frame; and,
FIG. 7 is a front elevation of an alternative back frame
construction.
Turning now to the drawings and particularly to FIGS. 1 through 5
thereof, there is shown in varying views a two-part, tubular,
reverse cantilevered chair constructed in accordance with the
present invention and indicated generally by the reference numeral
10. The reverse cantilevered chair 10 has two major structural
elements: a base frame and a back frame indicated generally by the
reference numerals 12 and 14, respectively, in FIG. 1. These two
frames, when assembled as shown in FIGS. 1 through 4, support a
seat member 16 and backrest member 18. Specific details concerning
the materials and assembly of the seat and backrest members will be
described below after first discussing the construction and
configuration of the base frame 12 and the back frame 14.
In the preferred embodiment of the invention, the chair base frame
12 is formed from two tubular members with one member positioned
within the other. The two tubular members are then bent together as
a unit to produce a continuous structural element which defines the
chair base frame 12. Looking at FIG. 5, it can be seen that the
base frame 12 comprises two tubular members, an outer tubular
member or tube 20 and an inner tubular member or tube 22 which
extends beyond the end of the outer tube 20. A corresponding
portion of the inner tube 22 also projects beyond the end of the
outer tube 20 at the left-hand side of the chair base frame 12 as
viewed in FIG. 3. The extended portion 22a of the inner tube 22
mates with and frictionally engages the inner wall of the tubular
back frame 14.
The two coaxial tubes 20 and 22 are bent together as a single unit
to form the chair base frame 12. For purposes of identification,
the continuous chair base frame 12 can be divided into the
following sections: a rearwardly opening, U-shaped support section
24 (FIG. 4) with vertically extending back legs sections 26 and 28
(FIGS. 1, 2 and 5) which turn forwardly to form substantially
horizontal arm sections 30 and 32 (FIGS. 2, 3 and 5) which, at the
forward ends, curve downwardly and then backwardly to form
substantially horizontal seat supports sections 34 and 36 (FIGS. 2
and 5) which terminate in the extended end portions 22a of the
inner tube 22. The U-shaped support section 24 can also be
subdivided sectionally into two horizontal forwardly extended leg
sections 24a and 24b which are held in spaced, coplanar relation by
the transverse bar 24c of the U-shaped section.
It will be appreciated that the transverse bar 24c can perform its
function of maintaining the chair base frame legs 24a and 24 b in
spaced, coplanar relation in positions other than at the front of
the chair. For example, if the chair base frame 12 is formed from
two sets of coaxial tubes with each set having a forwardly
extending leg section, a vertically extending back leg section, a
horizontal arm section and a substantially horizontal seat support
section, the transverse brace or bar 24c can be positioned at the
back of the horizontal leg section so that the U-shaped base
support section 24 opens in a forward direction. Other
configurations for the transverse bracing such as "H" and "X"
members can be used if the chair base frame is formed from two sets
of the coaxial tubular members. However, in the preferred
embodiment of the invention, the single, continuous coaxial tubular
element is used to form the backwardly opening U-shaped support
section and corresponding vertical leg sections, horizontal arm
sections and seat sections.
The coaxial, double-tube construction of the chair base frame 12 is
required for the reverse cantilevered chair of the present
invention in order to prevent undesirable deflection of the chair
frame under the weight of the occupant. It has been found by
experimentation that a single-tube base frame having the same
configuration as shown in FIGS. 1 through 5 does not have
sufficient strength to prevent the frame from bending forwardly.
The deflection occurs in the single tube construction because the
bending and pulling of the frame takes place in the straight
portions of the frame as well as in the curves, thus allowing the
seat to dip forwardly beyond the point of comfort for the occupant.
Using a standard size single steel tubing, such as, a low-carbon
steel tube, either welded or seamless, having an outer diameter of
1 inch, the deflection could not be overcome by employing a thicker
walled tube.
The problem of frame deflection in the reverse cantilevered chair
construction was solved by reinforcing the conventional steel
tubing with an inner steel tube of much lighter weight and smaller
diameter. A reverse cantilevered chair base frame 12 was
constructed from standard, low-carbon steel tubing using an outer
tube of 14 gage, 1 -inch outside diameter and 22 gage inner tube
having a 13/16 -inch outer diameter. The inner tube 22 was
positioned within the outer tube 20 with a snug fit prior to
bending. The two tubes, after being assembled in coaxial relation
to form a single continuous element, were then bent together as a
unit into the configuration shown in FIGS. 1 through 5. As the two
tubes were bent together, the inner steel tube 22 stretched thereby
tensioning the outer steel tube 20. Since the inner steel tube was
bent inside of the outside steel tube, crushing and distortion at
the bends on the exterior surface was reduced while the inside tube
distorted and wrinkled to give added internal strength. The
resulting double-tube base frame 12 was stiff and had very little
deflection and it provided more than enough added strength to
overcome the unwanted deflection encountered with the single
construction. However, it should be understood at this point that
the type of material, the diameters and gages of the tubing used in
the above example are by way of illustration only and should not be
construed as limiting with respect to the reverse cantilevered
chair construction of the present invention.
The second major structural element of the reverse cantilevered
chair, i.e., the back frame 14, is illustrated in FIGS. 1, 2, 3,
and partially shown in FIGS. 5 and 6. In the preferred embodiment,
the back frame 14 comprises a single tube which is bent to form two
downwardly and forwardly depending side sections 38 and 40 which
are held in spaced and fixed relation by a transverse back section
42. Looking at FIG. 5, it can be seen that the forwardly extending
portions of the side sections 38 and 40 slide over and are held in
frictional engagement with the extended portions 22a of the chair
base frame inner tube 22. The entire back frame, including the
downwardly depending and forwardly extending side sections 38 and
40, is located inwardly of the chair base frame arm sections 30 and
32 and can best be seen in FIGS. 1, 2, 3 and 5. Although this
location is preferred, the side sections of the back frame can be
located on the outside of the chair base frame arm sections without
departing from the scope of the invention.
The seat and backrest members 16 and 18, respectively, can be
formed from any suitable material, such as, for example, fabric,
leather or plastic. The use of a flexible material for the seat and
backrest members is preferred because it allows these members to be
slid over the seat support sections 34 and 36 and the back frames
side sections 38 and 40, respectively. However, it should be
understood that the seat and backrest members 16 and 18 can be
formed from a relatively rigid material, such as, wood, plastic or
metal and then hung from or otherwise secured to the appropriate
seat support and back frame side sections.
Turning now to FIGS. 5 and 6, the preferred embodiment of the
invention utilizes a fastening means between the substantially
horizontal arm sections of the base frame and the downwardly
depending side sections of the back frame. As shown in FIG. 6, the
fastening means comprises a pin 44 which is threadably secured to
the arm section of the outer and inner tubes 20 and 22. Each back
frame side section has an aperture 46 to receive the pin 44 in
frictional engatement. A corresponding aperture 48 is provided in
both sides of the back rest member 18 at a point that will line up
with the pin 44 and back frame aperture 46 when the backrest member
is positioned on the back frame as shown in FIGS. 1, 2 and 3.
The pins 44 keep the material of the backrest member 18 in place
and in doing so eliminate the chance of the back frame and arm
rattling where they cross. The pins also serve to exactly position
the two chair frame parts and, when weight is applied to the seat,
the pins transfer the pressure to the back legs. The pressure
transfer keeps the seat from sagging and changing the comfort
angles of the seat and back. This construction eliminates the
chance that over a long period of use the bend at the front where
the arm and seat support sections flow together will not stretch
out causing permanent changes in the angles of seating for
comfort.
FIG. 7 illustrates an alternative construction in which the
backrest member 18 is secured to the back frame side sections 38
and 40 by means of a plurality of braces 50 and corresponding
suitable fasteners 52. In this configuration, the combination of
the back rest and braces serves the dual purpose of holding the
side sections 38 and 40 in the desired position and at the same
time, provides a support for the chair occupant's back.
The combined back frame-backrest construction shown in FIG. 7 can
also be employed in another embodiment of the invention. It has
already been mentioned that the chair base frame 12 can be formed
from two sets of coaxial tubes and a transverse brace to maintain
the horizontal leg sections in spaced, coplanar relation. Since the
combined back frame-backrest construction shown in FIG. 7 performs
the same function as the back frame transverse bar 42, i.e., holds
the side sections 38 and 40 in spaced, fixed relation, it will be
appreciated that if the base frame is formed from two sets of
coaxial tubes, the sets can be extended in length enough to form
the upstanding side sections 38 and 40 as a continuous structural
element. In this embodiment, the reverse cantilevered chair 10 has
a chair frame comprising two sets of coaxial tubes with each set
having a forwardly extending leg section, a vertically extending
back leg section, a substantially horizontal arm section, a
substantially horizontal seat support section and a vertically
extending side section. The two sets of bent coaxial tubes are held
in spaced relation by suitable means, such as, the transverse brace
24c between the two forwardly extending leg sections and by means
positioned between and secured to the two vertically extending side
sections 38 and 40, such as, the transverse bar 42 or the combined
back frame-backrest construction shown in FIG. 7.
* * * * *