Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE:UPHOLSTERY FOR A CH~IR
INVE~TORS: Fritz M. Fend
Hermann Meiller
FIELD OF THE I~VE~TION
The field of the invention relates to chair design.
BACKGROUND OF THE INVENTION
Over the years, numerous different chair designs have
been developed. Several such designs have employed a pre molded
seat, with an integral back, attached to a tubular frame. Various
ways of attaching the tubular frame to the seat were employed.
Some designs employed brackets which allowed the seat to be
secured to the bracket and at the same time allowel the frame to
be secured to the bracket using suitable fasteners such as screws
or bolts. Illustrative of such designs are U.S. Patent 3,904,243,
3,476,342; 3,166,030: and 2,999,662. Other designs have employed
a plurality of split sleeves formed on the undersurface of the
seat which were pressed onto a frame member. These split sleeves
generally had a U-shaped configuration and were open at their
lower end. The sleeve materials were resilient. When the seat
was pressed onto the frame member the clip members parted tempor-
arily followed by the clip members springing back to the original
position and gripping the frame member. Illustrative of such
designs are U.S. Patents 3,245,715 and 3,146,028. It is noted
that in U.S. Patent 3,146,028, the rear engagement between the
seat and the frame occurs behind the bacX of the seat as opposed
to the underside of the seat. However, the technique of using
flexible engaging elements is still employed. U.S. Patent
3,061,374 employs t:he identical technique revealed in U.S. Patent
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3,146,028. Another design has been to employ a frame involving
interlocked and inclined legs which engage a pair of opposed open
hooks in order to support a load. This design is shown in the
application oE a support for a portable barbecue grill as illus-
trated in U.S. Patent 3,556,076. The legs 50 and 44 are retained
in the hook member 66 and are retained in that position by an
interference fit with the other side of the grill 86. A combina-
tion of a hook element with a resilient U-shaped clamping element
to retain a seat to a frame is illustrated in U.S. Patent
3,393,941. The '941 patent illustrates a front hook shaped
support member combined with a rear U-shaped grippi!ng member which
resiliently flexes over the support bar lb and then engages the
support bar as the resilient members 2d resume their initial posi-
tion. Also relevant to the apparatus of the present invention is
U.S. Patent 400,296 illustrating a wire clamp wherein a wire 3 is
installed through a pair of opposed hook shaped members 2 in such
a manner that the installation of one wire over another wire
retains the two wires together.
One of the design shortcomings of using resilient U-
shaped clip members, to resiliently flex over a support member and
then spring back to their original shape, is that only a limited
amount of gripping force is available to retain the seat to the
frame. In the design of the '941 patent, which employs the hook
shaped member in the front of the seat and the inverted U-shaped
clip member in the hack of the seat, the entire back of the seat
can be dislodged from the frame if a sufficiently large load is
applied to the very front of the seat. Similarly, when such
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chairs of the design of the '941 patent are being handled in
normal use, a significant ]oad applied from the rear of the back
rest toward the front of the seat with the frame restrained will
also potentially dislodge the connection 2d at the rear of the
seat.
It is thus desirable to provide an a-ttachment system
that is economical to manufacture and has the desirable proper-ties
of maintaining a secure engagement between the frame and the seat.
Another desirable feature is to provide the above-recited features
in combination with an upholstered seat. In using an upholstered
seat, it is desirable to secure the edge of the upholstery fabric
out of sight of the person viewing the chair. In that manner, the
aesthetic features of the chair are accentuated without any dis-
traction from fasteners between the upholstery and the seat. Some
designs have applied a visible welt to the periphery of the uphol-
stery to secure the upholstery to the seat. Illustrative o~ such
designs are U.S. Patent 4,558,904; 2,151,628; and 3,273,178.
Other designs have employed a pronounced peripheral casing around
the seat which included a mechanism for attaching the edges of the
upholstery to the seat. Illustrative of such design is U.S.
Patent 2,551,084. Other designs have employed an elongated pro-
file strip which has its ends specifically designed to engage a
recess in the underside of the seat for the purposes of retaining
the cushion and upholstery covering to the seat. Illustrative of
such design is U.S. Patent 4,408,797. Yet another method of
securing the upholstery to the shell is to employ a retaining
element having a substantially circular cross-section with an
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extending finger therefrom. The fabric ends are rollecl around the
finger and then snapped into a peripheral C-shaped retaining
track. Illustrative of such designs are U.S. Patents ~,357,723
and 4,465,534. Other designs have employed a recessed groove wi-th
a welt cord disposed therein. The welt cord was attached into the
groove by means of a staple. Alternatively, an adhesive was u,sed
to hold the edge of the fabric to the welt before -the welt was
fitted into the mounting groove. Illustrative of such design is
U.S. Patent 4,370,002.
SUMMARY OF THE INVENTION
The invention comprises a chair having a,-frame with a
forward and rear transverse supporting members. A seat is mounted
to the forward and rear transverse members and further comprises a
rear attachment between the seat and the rear transverse support-
ing member to secure the rear of the seat to the frame. A front
attachment member extends from the seat and is adapted to engage
the forward transverse supporting member when the rear attachment
member engages the rear transverse supporting member. A clip
adapted to engage the ~orward transverse support member secures
engagement between the front attachment member and the forward
transverse supporting member. The seat is constructed having a
peripheral groove which is disposed behind or underneath the seat
so as not to be visible when standing in front of the chair. A
combination cushion and upholstery covering is applied to the
chair with the edges of the upholstery extending to the lowermost
point of the peripheral groove whereupon a welt is inserted into
the groove to retain the edges of the fabric.
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DESCRIPTION OF THE DRAWINGS
Fig. 1 is an isometric view of the chair looking up at
the underside of the seat.
Fig. 2 is a sectional elevation taken along lines 2-2 of
Fig. 1.
Fig. 3 is a plan view of the underside of the chair as
illustrated in Fig. 1.
Fig. 4 is a rear elevational view of the backrest of the
chair illustrated in Fig. 1.
Fig. 5 is a detailed view of the method of attaching the
seat to the forward transverse supporting member. ,
Fig. 6 is an isometric view of the clip designed to
cooperate with the forward transverse supporting member to retain
the front end of the seat to the frame.
Fig. 7 is an isometric view of the rear of the seat
illustrating the peripheral groove therein and the welt adapted to
be inserted in such groove.
Fig. 8 is an enlarged view of the edge of the seat as
illustrated in Fig. 5 showing the application of the cushion and
the upholstery covering and the attachment of the upholstery in
the peripheral groove.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in the figures the chair C of the present inven-
tion includes a seat S and a frame F. Seat S is preferably a
molded unitary plastic member. Referring to Fig. 1, frame F has
four legs, 10, 12, 1~ and 16. These legs are generally vertical
and act to support the seat S. Legs 10, 1~, 14 and 16 are inter-
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connected by forward transverse supporting member 18 and rear
transverse supporting member 20. The frame is completed by
members 22 and 24 which are disposed parallel to each other.
forward transverse support member 18 and rear transverse support
member 20 are connected on one end to member 22 and on the
opposite end to member 24. In versions of the chair C which have
arms, as illustrated in Fig. 1, extensions 26 and 28 are provided
to members 22 and 24 respectively. As shown in Fig. 1, leg 16 is
extended to connect to extension 26 and also serve as a support
for arm rest 30. Similarly, as seen in Fig. 4, rear leg 10 is
connected to extension 28 and serves as a support member for arm
rest 32. Arm rests 30 and 32 can be produced as a premolded plas-
tic member, with or without upholstery, depending upon the desired
look and other cost factors.
The frame F is preferably constructed of a light weight
high strength metallic material and preferably 'nas a circular
cross-section. It is understood that other materials and cross-
sections can be used without departing from the spirit of the
invention.
The seat S is connected to the frame F by virtue o~ rear
attachment means R, front attachment member M and clip A (Fig.
3).
In the preferred embodiment, rear at-tachment means ~ is
illustrated in more detail in Fig. 2 and 3. As shown in Fig. 2.
rear attachment means ~ preferably comprises of matched pairs of
rigid crescent shaped extension members 34 on one side of the
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chair and identical crescent shaped extension members 36 on the
opposite side of the chair (Figs. 2 and 3). In the preferred
embodimen-t, members 34 and 36 are inc:Luded in the mold when the
seat S is formed. However, members 34 and 36 can be separately
made and subsequently at-tached to the underside of the seat S.
Although members 34 and 36 are shown disposed as matched pairs on
the underside of seat S, a sufficient:ly rigid unitary member,
preferably having the shape of members 34 or 36, can be employed
without departing from the spirit of the invention.
Referring to Fig. 2, members 34, as well as members 36
~hich are identical thereto, all have rearwardly f~cing arcuate
surfaces 38 w~ich are contoured for continuous engagement with the
outer periphery of rear transverse support member 20. Thus, in
securing the seat S to the frame F, the seat S is brought down to
bear on the frame with members 34 and 36 disposed between forward
transverse support member 18 and rear transverse support member
20. The seat is then pushed in a rearward direction (arrow 40,
Fig. 2) until arcuate surfaces 38 on members 34 and 36 are in firm
engagement with rear transverse support member 20.
In the preferred embodiment, seat S has been construc-
ted of a premolded plastic material further including a front
attachment member M. As seen in Fig. 3. front attachment member M
is disposed along the fron-t of seat S such that when arcuate sur-
face 38 of rear attachment means R engages rear transverse support
member 20, front attachment member M engages forward transverse
support member 18 (Fig. 2). Attachment member M extends out oE
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the underside of seat S in a locatlon adjacent both ends of
forward transverse support member 18. Attachment member M may be
formed integrally with seat S or may be separately formed for
subsequent attachment without departing from -the spirit of the
invention.
As seen in Figs. 3 and 5, attachment member M comprises
pairs of rigid crescent shaped extensions 40 from the underside of
seat S. Crescent shaped extensions 40 each have a rearwardly
facing arcuate surface 42 which conforms to the outer periphery of
forward transverse support member 18 for continuous engagement
therebetween. As shown in Fig. 3, a pair of cresce'nt shaped
members 40 are disposed at either end of forward transverse
support member 18. It is understood to be within the purview of
the invention, as an alternative to two crescent shaped members 40
in a spaced relationship to each other, to employ one unitary
attachmen-t member M, at each end of forward -transverse supporting
member 18, having the width of the gap shown between the crescent
members 40 in Fig. 3. Alterna-tively, an attachment member M which
extends the length of front transverse support member 18 can be
used.
When assembling the seat S to the frame F, rearwardly
facing arcuate surfaces 42 of each member 40 engage forward
transverse support member 18 as rearwardly facing arcuate surfaces
38 engage rear transverse support member 20. It is understood to
be within the purview oE the invention to have arcuate surfaces 38
and 42 both forward facing (arrow 44, Fig. 2), however, it is
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preferred to have arcuate surfaces 38 and 42 both facing in the
same direction and rearwardly (arrow 40 Fiy. 2).
To compLete the attachment of seat to frame f, clip A is
inserted to interact with seat S and forward transverse support
member 18. It is understood that it is within the purview of -the
invention to apply clip A to interact with seat S adjacent rear
transverse support member 20 only, or both at the forward 18 and
rear 20 transverse members. Alternatively, the seats can be
secured to members 22 and 24 in the same variety of ways described
above. However, it is preferred to have the clip disposed solely
adjacent forward -transverse support member 180
The details of clip A are shown in Figs. 5 and 6. Clip
A is constructed preferably from a light weight high strength
material such as a rigid plastic. Other materials may be used
without departing from the spirit of the invention. Clip A
includes an arcuate surface 46 which as shown in Fig. 5 is forward
facing and adapted to the contour of forward transverse support
member 18 for continuous engagement therebetween. Arcuate surface
46 blends into a projection 48 extending from clip A. Projection
48 has an arcuate end surface which is designed to conform to the
arcuate depression 52 disposed adjacent crescent shaped projec-
tions 40. Arcuate surface 50 is disposed between substantially
straight surfaces 54 and 56. Surfaces 54 and 56 engage surfaces
58 and 60, respectively when the clip A is installed. Surface 60
is preferably disposed on crescent shaped member 40 while surface
58 preferably comprises the underside of a portion of the seat S.
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Another projection 62 contains a bearing surEace 64.
~en the clip A is installed, bearing surface 64 engages surface
66 premolded on the underside of seat S. Thus, when clip A is
installed there is preferably flush continuous contact between
surfaces 64 and 66. Surface 64, acting in part through edge 68 of
clip ~, transfers loads applied to seat S through edge 68 onto
forward transverse support member 18. Projection 62 extends
beyond surface 54 and comprises of surfaces 70, 64 and 72.
Surfaces 70 and 7~ are parallel to each other and surface 64 is
perpendicular to surfaces 70 and 72. Surface 70 extends
perpendicularly from surface 54 at one end thereof~ Edge 68
extends angularly from surface 72 toward lower end 90 of clip A.
Another projection 74 extends from surface 54 from a
point between projection 48 and projection 62.
Projection 74 is rearwardly inclined from surface 54 to
its free end 76 (Fig. 6). End 76 has a substantially planar
engagement surface 78 thereon. Thus, projec-tion 74 is defined by
top surface 80, engagement surface 78, and bottom surface 82. As
seen in Fig. 5, engagement surface 78 extends Eurther from surface
54 than bearing surface 64. Projection 74 is designed for inward
deflection toward surface 54 during the installation procedure for
clip A as will be described hereinbelow.
Seat S is formed having a depression 84 thereon.
"Depression" is used in the relative context to emphasize that
bottom surface 88 does not project from seat S as far as surface
66. To avoid an overly thin seat S, the entire area around
depression 88 and surface 66 can be built up as shown in Fig. 5.
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~epression 84 has a longltudinal axis substan-tially parallel to
forward transverse suppor-t member 18 and is preferably disposed
rearwardly thereof. As seen in Fig. 5, when clip A is assembled
to seat S and forward transverse support member 18, projection 74
extends into depression 84. Depression 84 further includes
contact surface 86 and a substantially planar bottom surface 88
disposed adjacent and perpendicularly thereto. As seen in Fig. 5,
when clip A is installed, the final position of projection 74 has
engagement surface 78 butted flush up against contact surface 86
and top surface 80 in contact with bottom surface 88 of depression
84.
The installation process of clip A requires the initial
placement of clip A adjacent forward transverse support member 18.
Initially, projec-tion 74 will be somewhat deflected toward surface
54 from its neutral position. Simultaneously, arcuate end surface
50 will be oriented in the direction of depression 52 on crescent
shaped members 40. Subsequently, suitable pressure or blows
applied to surface 72 result in advancement of clip A, whereupon
projection 74 clears surface 66 and springs into deprsssion 84.
The spring forces built up as a result of the initial deflection
of projection 74 toward surface 54 are employed in forcing projec-
tion 74 into depression 84. There results a preferably force fit
between contact surface 86 and engagement surface 78 thus retain-
ing projection 74 within depression 84. Simultaneous with the
engagement of contact surface 86 with engagement surface 78,
arcuate end surface 50 of clip A engages the base of the arcuate
depression 52 within crescent members 40. The interference fit
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between surfaces 78 and 86 forces arcuate end surface 50 into
tight contact with arcuate depression 52 and forces a tight
contact between arcuate surface 46 ancl forward transverse support
member 18. It should be noted that during the installation
process, bearing surface 64 has been translating with respect to
its mating surface 66 on seat S. The final position of clip A is
illustrated in dashed lines in Fig. 5.
As shown in Fig. 3, a pair of clips A are installed
adjacent either end of forward transverse support member 18
between a pair of crescent shaped members 40. Fig. 3 also shows
that clips A are disposed at either end of forward~transverse
member 18 opposite a pair of crescent shaped extensions 40 on the
underside of sea-t S. In the preferred embodiment, the interfer-
ence fit between contact surface 86 and engagement surface 78
serves to prevent axiaL translation of clips A with respect to the
longitudinal axis of forward transverse support member 18. Alter-
native means can also be employed to restrain axial movement of
clip A relative to the longitudinal axis of forward transverse
support member 18. For example, the width of clip A can be
slightly less than the spacing between crescent shaped members 40.
Arcuate depression 52 (Fig. 5), rather than going completely
through each crescent shaped member 40 can extend only partway
through whereupon the wall structure of crescent shaped members 40
adjacent the arcuate depressions 52 can act as a lateral travel
stop ~o clip A. Alternatively, some interaction can be provided
between the lower end 90 of clip A and the lower extension 92 of
arcua-te surface 42 disposed on crescent shaped extension 40.
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Finally, surface 6~ can be provided with a pair of perpendicular
wing walls at ei-ther end (not shown) to restrain cllp A.
Another aspect oE the present invention is the method of
attaching the upholstery 100 (Fig. 8) to the seat S. The under-
side of seat S has a con-tinuous groove 102 as illustrated in
Fig. 7. Upholstery 100, preferably having a flame bonded backing,
is stretched onto a mold (not shown). A cushion 104 of poly-
urethane foam is foamed directly onto the back surEace 106 of the
upholstery 100. Preferably, the upholstery 100 and cushion 104
combination is positioned on the upper surface of the seat S. The
upholstery-cushion combination is pressed onto the!seat S thereby
providing extra amount of fabric 108 which projects beyond the
edges of the seat S. The fabric is pulled around and into contin-
uous groove 102. As shown in Fig. 8, the fabric terminates at the
lowermost point 110 within continuous groove 102. A continuous
resilient member 112, preferably rubber having a round cross-
section, is inserted into groove 102 and retains the end 108 o~
upholstery 100 to the lowermost point oE groove 102. The mounting
force previously applied to the cushion and upholstery is with-
drawn, as a result a taut, smooth fabric 100 wraps around the
seat S. Groove 102 is rearwardly facing near the front of the
chair so as to hide its existence to one viewing the upholstered
seat while standing next to the chair. The groove 102 is downward-
ly facing along sections 114 and 116 and rearwardly facing along
sections 118, 120 and 122.
The foregoing disclosure and description of the invention
are illustrative and explanatory -thereof, and various changes in
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the size, shape and materials, as well as in the details of the
illustrated construction may be made without departing from the
spirit of the invention.
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