U.S. patent number 3,724,897 [Application Number 05/111,429] was granted by the patent office on 1973-04-03 for wire rod chair.
This patent grant is currently assigned to Steelcase Inc.. Invention is credited to Randall P. Buhk, Frederick S. Faiks.
United States Patent |
3,724,897 |
Faiks , et al. |
April 3, 1973 |
WIRE ROD CHAIR
Abstract
The specification discloses a chair having a seat, back and wire
rod frame. The frame includes five wire rods and a stretcher welded
together to provide an integral seat support, leg assembly and back
support. Three of the five rods are welded together in endwise
abutment to provide the frame with a continuous, uninterrupted
appearance. The two wire rods at the rear extend upwardly forming
rear legs, then diverge inwardly along the rear of the seat. They
meet and extend upwardly together, rigidly joined to form an
upright portion. The rods then diverge outwardly and upwardly to
provide a U-shaped back support. The seat includes downwardly
depending tabs at either side which mate with flanges on the sides
of the seat support portion of the frame. The front of the seat
comprises a lip which curls over a front rod of the seat support.
The chair rests on four glides, all of which have fastening
intelligence such that the chairs of this invention can be ganged
together. The glides on one runner have facing fastening
intelligence while those on the other runner have fastening
intelligence facing away from one another, such that fore and aft
and lateral movements of joined chairs are eliminated.
Inventors: |
Faiks; Frederick S. (Comstock
Park, MI), Buhk; Randall P. (Wyoming, MI) |
Assignee: |
Steelcase Inc. (Grand Rapids,
MI)
|
Family
ID: |
22338496 |
Appl.
No.: |
05/111,429 |
Filed: |
February 1, 1971 |
Current U.S.
Class: |
297/447.3;
297/239; 297/448.2 |
Current CPC
Class: |
A47C
3/04 (20130101); A47C 1/124 (20130101); A47C
5/04 (20130101) |
Current International
Class: |
A47C
1/00 (20060101); A47C 3/04 (20060101); A47C
5/00 (20060101); A47C 1/124 (20060101); A47C
5/04 (20060101); A47C 3/00 (20060101); A47c
001/12 () |
Field of
Search: |
;297/239,248,445,446,447,450,451,460 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nunberg; Casmir A.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows.
1. A chair having a seat, back and wire rod frame comprising: a
pair of flexible wire rods forming an integral rear leg and back
support assembly; said rods extending upwardly and converging
inwardly; said rods meeting and being rigidly joined at a point
below said back and generally centrally thereof; said rods
diverging outwardly and upwardly from said juncture to form a back
support; said back being secured to said back support whereby it
can twist slightly about said juncture.
2. The chair of claim 1 in which said chair back comprises a groove
in its bottom edge and extending at least partially up its side
edges; the shape defined by said grooved edge portions
corresponding to that of the shape of said back support whereby
said groove embraces said back support for holding said back in
place.
3. The chair of claim 2 in which said groove terminates at each
side of said back at a downwardly opening hole in said back; said
holes being adapted to receive the ends of said wire rod back
support.
4. The chair of claim 1 in which said converging portions of said
rod means jut rearwardly away from said seat at the rear center
thereof such that said upright portion is recessed from the rear
edge of said seat.
5. A chair having a seat, back and comprising: a wire rod frame
having an integral seat support, leg assembly and back support;
said seat support comprising a continuous wire rod extending
laterally along the rear of said seat and being bent forwardly and
extending forwardly along each side of said seat; said leg assembly
comprising front legs extending downwardly from the front of each
of said forwardly extending portions of said seat support, runners
extending rearwardly from the bottom of each of said front legs,
and rear legs extending upwardly from the rear of each of said
runners; said rear legs converging inwardly at a point below said
back and then diverging outwardly and upwardly to define said back
support; and said rear legs being rigidly joined to said laterally
extending portion of said seat support.
6. The chair of claim 5 in which said wire rod frame comprises a
continuous wire rod, whereby said frame has a continuous, unbroken
appearance.
7. The chair of claim 5 in which said frame comprises a front
support rod rigidly joined at its ends to the front of said
forwardly extending portions of said seat support; said front
support rod extending around the front edge of said seat to provide
support for the front of said seat.
8. The chair of claim 7 in which said seat includes a downwardly
curling lip along its front edge which wraps around said front
support rod of said seat support.
9. A chair having a seat, back and comprising: a wire rod frame
having an integral seat support, leg assembly and back support;
said seat support comprising a wire rod extending laterally along
the rear of said seat and forwardly along each side of said seat;
said leg assembly comprising front legs extending downwardly from
the front of each of said forwardly extending portions of said seat
support, runners extending rearwardly from the bottom of each of
said front legs, and rear legs extending upwardly from the rear of
each of said runners; said rear legs converging inwardly at a point
below said back and then diverging outwardly and upwardly to define
said back support and said rear legs being rigidly joined to said
laterally extending portion of said seat support; a front support
rod rigidly joined at its ends to the front of said forwardly
extending portions of said seat support; said front support rod
extending around the front edge of said seat to provide support for
the front of said seat; said seat including a downwardly curling
lip along its front edge which wraps around said front support rod
of said seat support; the inner cross section of said lip being
generally V-shaped such that the "V" base of said lip does not
directly engage said front rod; said lip being slightly flexible
such that when force is applied to said seat, said lip is expanded
around said rod, allowing said "V" base to move towards said front
support rod, thereby providing said seat with shock absorbing give
when forces are applied thereto.
10. A chair having a seat, back and comprising: a wire rod frame
having an integral seat support, leg assembly and back support;
said seat support comprising a wire rod extending laterally along
the rear of said seat and forwardly along each side of said seat;
said leg assembly comprising front legs extending downwardly from
the front of each of said forwardly extending portions of said seat
support, runners extending rearwardly from the bottom of each of
said front legs, and rear legs extending upwardly from the rear of
each of said runners; said rear legs converging inwardly at a point
below said back and then diverging outwardly and upwardly to define
said back support; and said rear legs being rigidly joined to said
laterally extending portion of said seat support; a flange being
rigidly secured and extending inwardly from each of said forwardly
extending side portions of said seat support; said flange having a
slot therein; said seat having a downwardly depending tab at each
of its sides for mating engagement with said slots.
11. A chair having a seat, back and comprising: a wire rod frame
having an integral seat support, leg assembly and back support;
said seat support comprising a wire rod extending laterally along
the rear of said seat and forwardly along each side of said seat;
said leg assembly comprising front legs extending downwardly from
the front of each of said forwardly extending portions of said seat
support, runners extending rearwardly from the bottom of each of
said front legs, and rear legs extending upwardly from the rear of
each of said runners; said rear legs converging inwardly at a point
below said back and then diverging outwardly and upwardly to define
said back support; and said rear legs being rigidly joined to said
laterally extending portion of said seat support; front and rear
glides on each of said runners, each glide on a first runner having
fastening intelligence facing the other glide, and each glide on a
second runner having fastening intelligence pointed away from the
other glide; said runner glides being positioned closer to one
another than said first runner glides whereby when two chairs are
placed in closely adjacent fashion, said first runner glides on one
chair cooperate with said second runner glides on the other chair
to hold the chairs together and prevent their fore and aft movement
with respect to each other.
12. The chair of claim 11 in which the front glide on one runner
and the rear glide on one runner are male fasteners whose fastening
intelligence comprises a projection from one end thereof which is
inclined at an acute angle to said runner; said front glide on the
other runner and the rear glide on the other runner comprises a
female fastener whose fastening intelligence comprises a recess for
mating said projection, said recess being inclined at approximately
the same acute angle to said runner.
13. The chair of claim 12 in which said projection on said front
male glide includes a tab forming the leading edge of said
projection and said recess on said front female glide comprises a
mating slot at the base of said recess for receiving said tab.
14. The chair of claim 13 in which each of said male and female
glides comprises a bumper portion extending outwardly from said
projection and recess respectively, said bumper portion being
inclined at an obtuse angle to said runner; said bumper portions of
adjacent male and female glides on adjacently positioned chairs
being the first portions of said adjacent glides to abut when said
fasteners are forced together, and said abutting bumper portions
acting to guide the fasteners into mating engagement at said acute
angle portions.
15. The chair of claim 5 in which said inwardly converging rear
legs are rigidly joined at a point below said back and generally
centrally thereof; said rear legs diverging outwardly and upwardly
from said juncture to define said back support; and said back being
secured to said back support whereby it can twist slightly about
said juncture.
Description
BACKGROUND OF THE INVENTION
This invention relates to chairs, particularly chairs having wire
rod frames. In its more specific aspects, it relates to such chairs
which can be ganged together or stacked vertically.
Existing wire rod chairs have a number of unfortunate drawbacks,
not the least of which is their generally ugly appearance. The
unsightly assembly of a plurality of rods welded together gives
these chairs the appearance of skeletons from the "Twilight
Zone."
Additionally, prior art wire rod chairs support the chair back on a
pair of spaced rods extending vertically from behind the seat. This
renders the back inflexible and somewhat uncomfortable. Further, it
is somewhat difficult to secure both the chair back and the chair
seat to the wire rod frame since there is nothing substantial upon
which to secure these members.
The fastening means provided for ganging prior art wire rod chairs
together suffer from numerous drawbacks. For example, the chair
disclosed in U.S. Pat. No. 3,278,227 utilizes a fastening member
located near the front of a bottom runner and a second fastening
member located on the side of the rear leg. If the chair warps
slightly with age, considerable pressure is put on each of these
two fastening members, and it is very possible for one of them to
spring loose. Indeed, it is possible that only one of them may be
fastenable after the chair has warped. Furthermore, an independent
glide member is required near the rear of the runner on the
chair.
SUMMARY OF THE INVENTION
The chair of the present invention embraces a number of related
concepts which obviate the difficulties and drawbacks set forth
above. A pair of wire rods form an integral rear leg and back
support assembly. Each of the rods extends generally vertically to
form a rear leg, and both of the rods then diverge inwardly from
the tops of the rear legs along the rear edge of the seat. These
portions meet and then extend vertically upwardly together, rigidly
joined, to form an upright portion. The rods then diverge outwardly
and upwardly from this upright portion to form a back support
having a generally U-shaped configuration. This centrally located
upright portion, connecting the chair back to the chair seat,
provides for increased flexibility in the back, and accordingly
increased comfort.
In another of its aspects, the invention contemplates the use of a
wire rod frame having an integral seat support, leg assembly and
back support. The seat support comprises a wire rod extending
laterally along the rear edge of the seat and forwardly along each
side thereof. The leg assembly comprises downwardly depending front
and rear legs joined together by a bottom runner, the front legs
extending downwardly from the front edge of each forwardly
extending portion of the seat support. The back support comprises a
converging portion formed by wire rods converging inwardly from the
tops of the rear legs and extending along the rear edge of the
seat. These converging rod portions join to form the upright
portion and outwardly diverging U-shaped back support referred to
above. The converging portions are rigidly joined to the laterally
extending portion of the seat support. To enhance the beauty of the
chair, this integral frame can be formed out of a single continuous
wire rod, or a plurality of rods welded together in endwise
abutment to give the appearance of a continuous wire rod.
The chair back contemplated by this invention includes a groove in
its bottom edge and extending partially up its side edge. The shape
of the back outlined by these grooved edges conforms to that of the
generally U-shaped back support referred to above such that the
groove embraces the wire rod back support.
The chair seat includes a downwardly depending tab at either side
thereof which enters into mating engagement with a slot in a flange
which depends inwardly from the forwardly extending side rods of
the seat support referred to above. The front of the chair seat
comprises a lip which curls downwardly over a front rod which is
welded at its ends to the forwardly extending side portions of the
seat support. This front lip has a generally V-shaped cross section
such that the base of the "V" does not actually contact the wire
rod unless force is applied to the seat. This results in secure
fastening and a slight flexibility for absorbing shocks, such as
are frequently applied to chair seats.
Each of the chair runners includes front and rear glides. Those on
one runner have facing fastening intelligence, while those on the
second runner have fastening intelligence facing away from one
another. The glides on the second runner are more closely spaced,
such that they can be mated with the glides on the first runner of
an adjacent chair to prevent fore and aft movement.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of this invention will be
understood and appreciated by reference to the appended
specification and drawings wherein:
FIG. 1 is an exploded perspective view of the chair back, seat and
wire rod frame;
FIG. 2 is a perspective view of the assembled chair;
FIG. 3 is a side view of the wire rod frame;
FIG. 4 is a front view of the wire rod frame;
FIG. 5 is a bottom plan view of the wire rod frame taken along
plane V--V of FIG. 4;
FIG. 6 is a front view of the chair back;
FIG. 7 is a side view of the chair back;
FIG. 8 is a view taken along line VIII--VIII of FIG. 6;
FIG. 9 is a plan view of the chair seat;
FIG. 10 is a side view of the chair seat;
FIG. 11 is a view taken along line XI--XI of FIG. 9;
FIG. 12 is a view taken along line XII--XII of FIG. 9;
FIG. 13 is a view taken along line XIII--XIII of FIG. 9;
FIG. 14 is a broken side view of a first one of the two runners on
the wire rod frame;
FIG. 15 is a broken side view of the second one of the two runners
on the wire rod frame; and
FIG. 16 is a broken plan view of adjacent runners on adjacent
chairs as they are being moved into mating engagement.
PREFERRED EMBODIMENT
In the preferred embodiment, the chair of this invention comprises
a frame 10, a chair seat 50, a chair back 60 and four ganging
glides 71, 75, 81 and 85 (FIG. 1). Frame 10 has been divided into
three sub-assemblies, including a seat support 20, a leg assembly
30, and a back support 40 (FIG. 3).
It has been found that frame 10 can be conveniently constructed of
five separate wire rods. However, the beauty of the frame is
greatly enhanced by welding three of these rods together in endwise
abutment to form, or at least give the appearance of a single
continuous wire rod. Two of these three rods form the right side
and left side of the chair respectively. Thus, each rod defines
side rod 22 of seat support 20, front leg 31, runner 32, rear leg
33 and half of back support 40. The third rod defines the rear
support 21 of seat support 20. One of the remaining two rods, a
front seat support rod 23 is hidden from view in the fully
assembled chair as can be seen by comparing FIGS. 1 and 2. Seat
stretcher 27 is also hidden from view. Thus, the fully assembled
chair appears to be constructed of one continuous wire rod and a
single brace rod 34 (FIG. 2).
Seat support 20 comprises a rear support rod 21 which extends
laterally across the back edge of the seat area (FIG. 5). Side
support rods 22 then extend forwardly from the ends of rear rod 21
along the side edges of the seat area. While side support rod 22 is
preferably only a portion of a rod, it is referred to as "a rod"
for purposes of convenience and because it could in fact be a
single rod welded to other rods. A front support rod 23 is welded
at its end edges to side rods 22 and extends laterally across the
front of seat 50 to provide support therefor. A flange 24 is
rigidly secured, as by welding, to each side rod 22 and extends
inwardly therefrom. Each flange 24 includes a pair of slots 25 and
holes 26 which facilitate the securance of seat 50 to seat support
20. Preferably, slot 25 is formed at that portion of flange 24
which is narrower such that when flange 24 is welded to side rod
22, a slot remains, defined by side rod 22 on one side and flange
24 on the other. Finally, stretcher 27 extends from one side
support 22 to the other, near the front thereof.
Seat 50 is molded of any suitable plastic such as polypropylene so
as to conform to the shape of the human buttocks. It includes a
pair of downwardly depending tabs 51 on either side thereof (FIGS.
9, 10 and 13). Tabs 51 are dimensioned and located such that they
fit into mating engagement with slots 25 when seat 50 is placed on
seat support 20.
Seat 50 also includes three bosses 52 on either side thereof and
between adjacent tabs 51 (FIG. 9). These correspond in position to
the holes 26 in flanges 24 such that when seat 50 is in position on
seat support 20, screws can be passed upwardly through holes 26 and
into bosses 52 to further facilitate the securance of seat 50 to
seat support 20.
Seat 50 also includes a front lip 53 which extends across the front
edge thereof (FIG. 9) and which curls down around front support rod
23 in the manner shown in FIG. 12. Lip 53 extends around the front
corners to form side lip portions 54 (FIG. 9) which also curl down
around front support rod 23, but in the manner indicated in FIG.
11. Front lip 53 and side lips 54 not only act to hide front
support rod 23 from view, but also cooperate with front support rod
23 to hold seat 50 securely in place.
As can be seen by reference to FIG. 12, front lip 53 has a
generally V-shaped cross section such that the base of the "V" does
not actually abut rod 23. Rather, only the sides of the "V" embrace
rod 23. However, when force is applied to seat 50, as when a person
sits or bounces thereon, lip 53 expands slightly and slides
rearwardly on rod 23, the base of the "V" moving toward abutment
with rod 23. Thus, this generally V-shaped cross section for front
lip 53 provides seat 50 with a slight shock absorbing
resiliency.
Leg assembly 30 includes a pair of front legs 31 which extend
downwardly from the front of side rods 22 of seat support 20 (FIG.
3). Runner 32 then extends rearwardly from the bottom of front leg
31 and rear leg 33 extends upwardly from the rear of runner 32. The
junction between the base of front leg 31 and the front of runner
32 is made through an outwardly bent portion 35. Bent portion 35
sets runners 32 to the outside of the outer dimensions of seat
support 20 and thereby facilitates the stacking of the chairs of
this invention, one on top of the other. Leg assembly 30 is
completed by a brace rod 34 extending laterally between the front
legs 31 in order to give the entire frame 10 additional strength
and rigidity.
Back support 40 begins with a converging portion 41 (FIG. 5). The
rods which form rear legs 33, as well as the right and left sides
of the chair generally, are bent at the top of rear legs 33 so as
to converge inwardly along the rear edge of seat 50, closely
adjacent to rear seat supporting rod 21 (FIG. 5). The converging
portions 41 meet near the rear center of the chair and are bent
upwardly in abutting fashion to form an upright portion 42 (FIG.
4). The abutting rods are rigidly secured together as by welding at
this point. The converging portions 41 bend outwardly slightly at
41a before actually being joined together to form upright portion
42 (FIGS. 5 and 3). This keeps upright portion 42 from engaging a
person's buttocks or lower back. The rod portions 43 then diverge
outwardly and upwardly from the top of upright 42 to thereby form a
generally U-shaped back frame to which back 60 may be secured.
Outwardly and upwardly diverging rod portions 43 are adapted to
receive and secure back 60. Back 60 is molded of a suitable plastic
material such as polypropylene. The mold is designed to provide
back 60 with a gradually curving contour to support the human back
(FIG. 7). Additionally, back 60 includes a groove 61 extending
across its bottom edge and up its side edges (FIGS. 6 and 7).
Groove 61 terminates at either side edge in a downwardly opening
hole 62 (FIGS. 6, 7 and 8). Back 60 is then slipped down onto
diverging and upwardly extending rod portions 43 with grooves 61
embracing these rods and with the ends of rods 43 extending
upwardly into holes 62. Groove 61 is reinforced by ribs 63, at
least some of which have arced bottom edges to receive rods 43.
Preferably, a small amount of epoxy or other suitable adhesive is
placed in holes 62 prior to assembly such that the ends of rods 43
remain firmly embedded therein. A mechanical fastening would also
be acceptable at this point.
The chair is provided with unique fastener glides 71, 75, 81 and 85
which are fastened to runners 32 by means of screws (FIGS. 14, 15
and 16). Glides 71 and 81 have male fastening intelligence and are
referred to as front male glide and rear male glide respectively.
Glides 75 and 85 have corresponding female fastening intelligence
and are referred to as the front female glide and rear female glide
respectively. Front male glide 71 and rear male glide 81 are
fastened on one of the runners 32 with their fastening intelligence
facing each other. Front female glide 75 and rear female glide 85
are fastened on the other runner 32, more closely together than are
glides 71 and 81, and with their fastening intelligence facing away
from each other. In this manner a pair of female fastener glides 75
and 85 on the rail of one chair fit snuggly to the insides of male
glides 71 and 81 on the rail of an adjacent chair to thereby hold
both chairs together, and prevent their fore and aft movement with
respect to each other. It should be noted that since FIGS. 14 and
15 are both side views, the front of runner 32 in FIG. 14 appears
on the right while the front of runner 32 in FIG. 15 appears on the
left.
The male fastening intelligence of front male glides 71 comprises a
projection 72 of "V" shaped cross section and having a tab 73
forming the leading edge thereof (FIG. 14). Projection 72 and tab
73 extend away from runner 32 at an acute angle thereto (FIG. 16).
However, the projection 72 and tab 73 eventually reach a turning
point and turn sharply away to form a bumper portion 74 which is
inclined at an obtuse angle to rod 32. Bumper portion 74 also has a
generally "V" shaped cross section. Rear male glide 81 similarly
includes a projection 72 and bumper portion 74 inclined at an acute
angle and obtuse angle respectively with respect to runner 32.
Because of the similarity in parts, the numbers used for these
parts are the same for both front male glide 71 and rear male glide
81. However, rear male glide 81 does not include a projecting tab
73.
Front female fastening glide 75 includes a recess 76 of a generally
V-shaped cross section for mating with projection 72 of glide 71 on
the runner 32 of an adjacent chair (FIG. 15). Additionally, it
includes a slot 77 at the base of recess 76 for receiving tab 73.
Recess 76 and slot 77 are disposed an an acute angle to their
runner 32 in the same manner as are projection 72 and tab 73 (FIG.
16). Finally, front female glide 75 includes a recessed bumper
portion 78 which is inclined at an obtuse angle to runner 32. Rear
female glide 85 includes a similar recess 76 and bumper portion 78,
but does not include a slot 77.
FIG. 16 shows the adjacent runners 32 of a pair of adjacent chairs,
made in accordance with the preferred embodiment of this invention,
being moved toward each other in an abutting manner. The bumper
portions 74 and 78 of the adjacent glides are the first portions to
abut. These have V-shaped cross sections corresponding to the
generally V-shaped cross sections of projections 72 and recesses 76
and thereby act to guide the adjacent fastening glides into proper
mating engagement. When engagement is completed, tab 73 of front
male glide 71 will reside in slot 77 of front female glide 75.
Similarly, projection 72 will reside within recess 76. Engagement
of rear male glides 81 and rear female glides 85 is comparable.
Because of the fact that both female fastening glides 75 and 85
have intelligence facing outwardly while both male fastening glides
71 and 81 have intelligence facing inwardly, the adjacent chairs
are firmly held together and are prevented from moving fore and
aft. Lateral movement is prevented by the fact that the mating
portions 72 and 76 of mating glides are inclined at an acute angle
to their respective runners. The tab 73 on front male glide 71 acts
to provide added, positive engagement. It should be noted that
various ones of the glides could be relocated, so long as both of
the glides on a given runner 32 either faced away from each other
or toward each other.
Thus, in accordance with this invention, a wire rod chair is
provided having a number of unique features, including the wire rod
frame itself. The beauty of the frame is greatly enhanced by the
fact that it appears, when the chair is assembled, that the frame
is made of only two continuous wire rods, one being brace rod 34.
The chair seat can be readily secured to the frame with the unique
seat fastening means. Similarly, the back can readily be fastened
to the back support portion of the frame. The back includes a
unique groove which not only facilitates this fastening operation,
but which also lends a decorative, half-hidden appearance to the
wire rod frame. Furthermore, the unique back support construction
of the frame gives the back more flexibility than exists in current
wire rod chairs in that the back is supported on a central,
upwardly extending upright portion about which the back can twist
slightly. The chairs can be stacked, since runners 32 are disposed
to the outside of the side seat supports 22 due to the bend 35 at
the bottom of front legs 33.
Finally, the unique combination fastening and glide means outlined
above is yet another significant contribution of this invention. By
providing two fasteners on a straight rod portion of the wire rod
frame, the continued workability of the fasteners is insured,
regardless of whether or not the wire rod frame warps slightly with
old age. Warpage will take place mainly at bent portions, not along
straight rod portions. Furthermore, positive fastening is provided
even though each of the combination glide-fasteners includes
fastening intelligence on only one side thereof. Finally, by
providing two combination glide-fasteners on each runner, applicant
has eliminated the necessity of any additional glides or
fasteners.
It will be understood that the above is merely a preferred
embodiment of the invention and that many changes and alterations
can be made thereof without departing from its spirit and broader
aspects.
* * * * *