TϊTLE OF THE TNVENTTON: ROCKTNG CHATR WTTH REMOVABLE ARMREST

FIELD OF THE INVENTION

The present invention relates to rocking chairs and more particularly to a rocking chair having a removable armrest.

BACKGROUND OF THE INVENTION

Regular lounger or sofa chairs commonly have a number of fixedly interconnected components, such as a ground-resting base, a seat, a backrest and a pair of lateral armrests. Some if not all of these chair components are padded and upholstered.

These chairs are known to be very comfortable to sit on, but involve a number of drawbacks, some of which are listed below: since they cannot be disassembled and piled up neatly and efficiently during transport, shipping and handling of these chairs is not cost-efficient; if the chair ever becomes damaged and needs replacement, the replacement procedure is complicated and requires the intervention of a professional, since it often involves detaching the upholstery, removing nails and screws, etc. changing the appearance of the chair is difficult and the intervention of a professional is usually required. The upholstery of the chair needs to be taken off its padded components of the chair, new upholstery must then be properly applied and secured to the chair, etc. A need exists for chairs whose parts can be easily interchanged, to facilitate delivery, replacement of damaged parts, customizing of the chair's appearance, etc.

SUMMARY OF THE INVENTION

The present invention relates to a modular chair comprising:

- a frame having a base and a seat attached to said base; - at least one armrest releasably attached to said frame;

- first releasable attachment means having a first connector carried by said armrest, and a second connector carried by said frame;

second releasable attachment means having a key carried by a selected one of said frame and said armrest, and a keyhole on the other one of said frame and said armrest, wherein said key and said keyhole can be interlocked by: o moving said armrest towards said frame along an engagement axis, to engage said key in said keyhole, and o pivoting said armrest relative to said frame about said engagement axis from:

^■ a first position where said key can be freely engaged in, and disengaged from said keyhole by moving said key away from said keyhole along said engagement axis, and where said first connector and said second connector of said first releasable attachment means are moved away from each other; towards

^■ a second position where said key is interlocked with said keyhole, and where said first connector and said second connector of said first releasable attachment means are moved towards each other and are interconnected; wherein to attach said armrest to said frame, said armrest is moved towards said frame to engage said key in said keyhole, and said armrest is pivoted from said first position to said second position.

In one embodiment, said key of said second attachment means is carried by said armrest, and said keyhole is made in said base of said frame. In one embodiment, said key defines an elongated stem affixed to said armrest, and an oblong tightening head carried transversally by said stem;

In one embodiment, said keyhole has an oblong shape similar to that of said tightening head; and said tightening head has smaller dimensions than said keyhole, to allow passage and insertion of said key through said keyhole. In one embodiment, said tightening head and said keyhole each define a distinct longitudinal axis, and in said first position, said tightening head longitudinal axis is parallel to said keyhole longitudinal axis, and in said second position, said longitudinal axis is transversal to said keyhole longitudinal axis.

In one embodiment, said keyhole comprises an inner end and an outer end, both of said inner end and outer end being open. Before moving said armrest from said first position to said second position, said key is inserted through said keyhole outer end until its said tightening head extends beyond said keyhole inner end.

In one embodiment, a cam plate is installed around said keyhole inner end, and when said key is inserted in said keyhole, said tightening head and said cam plate cooperate to move said armrest axially about said engagement axis, and bring said armrest closer to said base. In one embodiment, said cam plate is of variable thickness, and comprises a central ridge at which level said cam plate thickness is maximal. When said tightening head is in its said second position, said tightening head bears entirely against said cam plate.

In one embodiment, said first attachment means comprises a groove made in said armrest, and a catch secured to said base, said catch being interlocked with said groove when said armrest is in said second position. In one embodiment, said armrest is U-shaped and comprises an arm-supporting portion defining opposite end portions, a front strut attached transversally to said arm-supporting at a first one of said opposite end portions, and a rear strut attached transversally to said arm- supporting portion at a second one of said opposite end portions.

In one embodiment, said seat is removably attached to said base, said base comprises two lateral sides, wherein said at least one armrest is removably attached to one of said base lateral sides, and said chair further comprises a second armrest removably attached to another one of said base lateral sides, said second armrest also comprising an arm-supporting portion, a front and a rear strut.

In one embodiment, a backrest attachment means seat is provided on said rear strut of said at least one armrest and on said rear strut of said second armrest, said chair further comprising a backrest secured between both said armrests and attached to said backrest attachment means thereof.

In one embodiment, said base is a rocking base, and comprises a ground-bearing stationary portion and a rocking portion, said rocking portion being rockably mounted to said stationary portion.

The present invention also relates to a method for attaching a removable armrest to a modular chair, said chair of the type comprising: a frame having a base and a seat attached to said base; - at least one armrest releasably attached to said frame; - first releasable attachment means having a first connector carried by said armrest, and a second connector carried by said frame; second releasable attachment means having a key carried by a selected one of said frame and said armrest, and a keyhole on another one of said frame and said armrest;

said method comprising the steps of: a) moving said armrest towards said frame along an engagement axis, to engage said key in said keyhole; b) pivoting said armrest relative to said frame about said engagement axis from: • a first position where said key can be freely engaged in, and disengaged from said keyhole by moving said key away from said keyhole along said engagement axis, and where said first connector and said second connector of said first releasable attachment means are moved away from each other, towards a second position where said key is interlocked with said keyhole, and where said first connector and said second connector of said first releasable attachment means are moved towards each other; and c) interconnecting said first connector and said second connector.

The present invention also relates to a modular chair comprising : - a frame having a base for receiving a seat;

- at least one armrest;

- releasable interlock means for releasably interlocking a first portion of said armrest with a first portion of said base;

- releasable male-female joint means for releasably interconnecting a second portion of said armrest with a second portion of said base, wherein said interlock means and said male- female joint means cooperate with one another upon relative movement of said armrest relative to said base to provide concurrent interlock of said armrest with said base.

In one embodiment, said male-female joint means includes a male means carried by said armrest, and a female means carried by said base and complementary to said male means.

In one embodiment, said male-female joint means includes integral cam means.

In one embodiment, the modular chair further includes resilient means, to release said releasable interlock means after said concurrent interlock of said armrest with said base. In one embodiment, the modular chair further includes a second armrest, with associated second said releasable interlock means and second said releasable male-female joint means.

In one embodiment, the modular chair further includes a seating member, a backrest member, seat attachment means for connecting said seating member to said base, and backrest attachment means for connecting said backrest member to each of said armrests and to said base.

DESCRIPTION OF THE DRAWINGS

In the annexed drawings :

Figure 1 is a front perspective view of the rocking chair according to one embodiment of the present invention, with the chair moved frontwardly to better show the pivotal links of the chair's rocking base; Figure 2 is a partially exploded front perspective view of the chair of figure 1, showing both armrests, backrest and seat detached from each other. In this figure, the front crossbar of the base rocking portion is partly broken to show the keyhole and the cam plate therearound;

Figure 3 is an enlarged of the left hand side armrest of the chair shown in figure 2; Figure 4 is a front perspective view of the base of the chair with both armrests detached from the base. In this figure, the front crossbar of the base rocking portion is partly broken to show the keyhole and the cam plate therearound;

Figure 5A is a front perspective view of the chair base, showing one armrest attached thereto and another armrest at the first step of its installation procedure. In this figure, the front crossbar of the base rocking portion is partly broken to show the keyhole and the cam plate therearound;

Figure 5B is an enlarged view of the area encircled by double-sided arrow 5B-5B in figure 5A;

Figure 5C is an enlarged perspective view of the cam plate; Figures 6A-6B are views similar to figures 5A-5B, but showing the armrest key inserted in the keyhole of the chair base;

Figure 7A is a rear perspective view of the content of figure 5A and 6A, but showing the armrest tilted towards is operative position where its rear strut is moved towards the base; Figure 7B is an enlarged view of the area encircled by double-sided arrow 7B-7B in figure 7A;

Figure 8 is an enlarged partial perspective view showing the position of the key of the armrest relative to the cam plate of the base, when the armrest is secured to the base; and

Figures 9-10 are rear, cross-sectional, partial elevations of the rear end of the base, showing sequentially how the catch on the chair base is interlocked with the groove in the armrest.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Figure 1 shows a rocking chair according to one embodiment of the present invention.

Rocking chair 20 is modular. It comprises a ground-resting base, which can be a fixed base, a reclining base, a rocking base, a reclining/rocking combination base, etc.

Furthermore, it comprises a removable seat, a removable backrest, and a pair of removable lateral armrests.

The drawings show an embodiment of the invention where base 22 is of the rocking type. Base 22 comprises a stationary base portion 24, and a rocking base portion 30. Stationary base portion 24 is made of a pair of inversely U-shaped ground-bearing braces 26, 26', connected together at the front by a front crossbar 28, and the rear by a rear crossbar 29. Rocking portion 30 is rockably mounted to the stationary base portion 24. Rocking portion 30 comprises a pair of U-shaped seat support members 32, 32' located on the sides of the pair of ground-bearing braces 26, 26' outwardly thereof. Each of seat support members 32, 32' is made of a single piece, and defines a lower horizontal section 32c, and two upright sections 32a, 32b extending upwardly from opposite ends of horizontal section 32c.

Each support 32, 32' comprises a front and a rear upper end, corresponding respectively to the upper end of front upright section 32a, and the free upper end of rear upright section 32b. The free upper ends of front upright sections 32a, 32a of both U-shaped seat support members 32, 32' are interconnected by a front crossbar 34, using a conventional tenon-and- mortise joint. Similarly, the free upper ends of rear upright sections 32b, 32b of both U-shaped support members 32, 32' are connected by a rear crossbar 36.

The upper free end portion of front upright section 32b is pierced and defines a keyhole 50 extending therethrough, keyhole 50 opening at both ends. Around keyhole 50, on the inner surface of front upright section 32b (the surface facing base 22), a cam member in the form of a cam plate 52 is provided (shown in isolation in figure 5C). Cam plate 52 comprises an oblong opening 53 defining a longitudinal axis 57, which coincides with the longitudinal axis of

keyhole 50. The peripheral edge of opening 53 is sized and shaped (i.e. in this embodiment has the same oblong shape as, and registers perfectly with), to match the peripheral edge of keyhole 50 around which cam plate 52 it is installed. Cam plate 52 defines an arrowed leading edge 54a and an opposite rectilinear edge 54b, which are transversal to longitudinal axis 57. Cam plate 52 also defines two other rectilinear edges 54c and 54d, parallel and positioned on either side of cam plate longitudinal axis 57. Cam plate 52 also defines a two-tiered inner surface 55, facing away from the seat support member 32 to which is it secured. Inner surface 55 comprises two slightly slanted planes 55a and 55b intersecting at a ridge 55c. Ridge 55c is substantially perpendicular to the longitudinal direction of oblong opening 53. The thickness of cam plate 52 is variable: it is thickest at the level of ridge 55c, and thins out progressively when moving away from ridge 55c and towards edges 54a and 55b.

Furthermore, a crooked alignment rod 46 is attached to the rocking base portion 32. It defines a main elongated portion 46a attached at its front end to front crossbar 34. Main portion 46a extends towards the hind of chair 20, and at the level of rear upright section 32b of seat support member 32, alignment rod 46 merges with a finger 46b, which extends transversally to main portion 32b and towards the outside of chair 20.

The rocking base portion 30 further comprises a pair of elongated catches 48, 48 (figure 4), each catch 48 screwed to the top end portion of the rear upright section 32b of a corresponding U-shaped support 32. These catches 48 are best seen in figure 7B. Each catch 48 comprises a cross-sectionally T-shaped attachment portion 48a, from which downwardly depends a resilient finger 48b provided with a projecting barb 48c at the free end portion thereof. A hemi-cylindrical trough 33 is made at the upper extremity of rear upright section 32b.

As mentioned above, rocking base portion 30 is "rockably" mounted to the stationary base portion 24. More particularly, stationary and rocking base portions 24, 30 are conventionally interconnected by two front pivotable links 38, 38 and by rear pivotable links 40, 40. This is best shown in figure 1. The front and rear pivot links 38, 38 and 40, 40 are elongated and are each connected to a corresponding brace 26 of stationary base portion 22 at one end, and to horizontal section 32c of the adjacent seat support member 32 at the other end. To stabilize the rocking motion of the rocking base portion 30 relative to the stationary portion 24, a front shaft 42 is fixed between the two front pivot links 38, 38, and a rear shaft 44 is fixed between the two rear pivot links 40, 40 (see figure 7A).

Back to figure 2, chair 20 further comprises a seat 60 detachably secured to rocking base portion 30 by suitable releasable attachment means. These releasable attachment means could for example consist of a number of studs (not shown) extending from the undersurface of seat 110, and firmly yet releasably snap-fitted in corresponding holes (not shown) made on front and rear crossbars 34, 36 of the rocking base assembly 30.

Two lateral armrests 70, 70' are releasably secured to the opposite sides of chair 20. One of these armrests 70 is shown in close up view in figure 3. Armrests 70, 70' are symmetrical; a description of one will suffice for both.

Armrest 70 comprises an elongated arm-supporting portion 72, with a front strut 74 and a rear strut 76 extending downwardly from opposite end portions of the arm supporting portions 72.

Near the bottom end of front strut 74, armrest comprises an I-shaped key 80, for engagement in keyhole 50, and for wedging engagement against cam plate 52. Key 80 is composed of a T-shaped base 82, in turn defining a flange 82a and a stem 82b. Flange 82a is received in an oblong indentation 75 made on the inner surface of strut 74 (the surface of strut 74 facing base 22 when armrest 70 is secured thereto), and is screwed in place. Stem 82b extends away from flange 82a, and its free end receives an oblong tightening head 84, pierced centrally and penetrated by a bolt 86 which secures it to the T-shaped key base 82. Tightening head 84 is oblong and also defines a longitudinal axis 85. Tightening head 84 has the same peripheral shape as keyhole 50. Tightening head 84 has slightly smaller dimensions than keyhole 50, to allow easy passage of key 80 in and out of keyhole 50.

An elongated groove 90 is made on rear strut 76, and runs upwardly from its lower end. Groove 90 defines an elongated portion 90a (having a T-shaped cross-section as shown in figure 7B), and a circular indention 90b. As can be seen in figures 9-10, circular indentation 90b is recessed deeper in the width of rear strut 76 than elongated groove portion 90a. The groove 90 of each armrest 70 will be for interlocking engagement with catch 48 attached to the upright section 32b of the corresponding U-shaped seat support member 32, as described hereinafter.

Back to figure 3, a dowel 92 is friction fitted in a corresponding hole 93 bored into — but not completely across — the rear strut 76. When in place (see figures 9-10), the dowel 92 extends beyond the inner surface of rear strut 76. When armrest 70 is attached to the base rocking portion 30, dowel 92 abuts snugly in trough 33 made at the upper extremity of rear upright section 32b.

Armrest 70 further comprises an elongated backrest retainer 100, defining a sliding track 102 therein. Near its upper end, backrest retainer 100 is penetrated by a mounting screw 104, which then penetrates centrally and loosely through a bushing 105, and is then screwed in a hole made in the vicinity of the upper end of rear armrest strut 76. Backrest retainer 100 is thereby pivotally mounted to armrest 70.

As can be seen in figure 1, chair 20 comprises a removable backrest 110. Backrest 110 comprises a pair of elongated gibs 112 (only one gib 112 is shown in figure 2), attached on the lower end of the lateral sides of backrest 110. When the armrests 70, 70' are secured to base rocking portion 30, backrest 110 can be secured between the armrests by sliding the gibs 112 inside track 102 of backrest retaining member 100. Releasable connection means are also provided on gibs 112 (not shown), which allow releasable fastening of gibs 112 in retaining member track 102. These releasable connection means can be, but are not limited to, a pair of resilient fingers (not shown) at the lowermost end of gibs 112, which come into holding engagement in a complementarily sized and shaped orifice (not shown) provided on retaining member 100 in its track 102. To releasably connect backrest 110 to the rocking base portion 30, both gibs 112 on the sides of the backrest 110 are engaged in track 102 of the corresponding retaining member 100, and backrest 110 is pushed downwardly until the resilient fingers (not shown) "click" inside the orifices (not shown) provided in track 102. To detach the backrest from base rocking portion 30, the resilient fingers can be pried manually away from the orifices until they are disengaged therefrom, and backrest 110 is then pulled upwardly to slide the gibs 112, 112 out of the retaining member tracks 102, 102.

The attachment procedure of armrest 70 to base 22 will now be described. First, as shown in figure 5A and 5B, armrest 70 is brought close to the side of base 22 where it is to be attached, and is tilted frontwardly as shown in figure 5A, such that its tightening head 84 be aligned with the keyhole 50, that is, such that the longitudinal axis 85 of oblong tightening head

84 be parallel to the longitudinal axis 57 of keyhole 50.

While in this frontwardly tilted position, armrest 70 is moved towards base 22 along an engagement axis 71 (figures 5A-5B) and key 80 is inserted inside keyhole 50 until key tightening head 84 extends on the other side of keyhole 50, i.e. until tightening head 84 emerges beyond inner surface 55 of cam plate 52, as shown in figure 6A and 6B. In this frontwardly tilted position of armrest 70, the longitudinal axis 57 of keyhole 50 is parallel to the longitudinal axis

85 of key tightening head 84, and key 80 can be freely slid in and out of keyhole 50.

Armrest 70 is thereafter tilted towards its operative position (arrow A ₂ in figure 7A), where the lower end of armrest rear strut 76 is moved towards base 22.

As the armrest 70 is tilted towards its operative position, tightening head 84 is rotated with respect to keyhole 50 from: an "unlocked" position where the longitudinal axis 85 of oblong tightening head

84 is parallel to the longitudinal axis 57 of keyhole 50 and of oblong cam plate opening 53, and where the key 80 can be slid freely in or out of keyhole 50; towards a "locked" position where the longitudinal axis 85 of tightening head 84 is transversal to the longitudinal axis 57 of keyhole 50 and cam plate opening 53 (see figure 8), and where key 80 is "locked" in keyhole 50. Indeed, in this position, any attempt at pulling the key 80 out of keyhole 50 will result in the key tightening head 84 blocking against cam plate 52.

In addition, as armrest 70 is pivoted towards its operative position, tightening head 84 cooperates with cam plate 52 to solidify the attachment of the front strut 76 to rocking base portion 30, and make the attachment "non-wiggly". Indeed, as armrest 70 is pivoted from its frontwardly tilted position to its operative position (as suggested by arrow A ₂ in figure 7A), the rear surface of tightening head 84 slides against the two slanted planes 55a and 55b of cam plate 52 until it becomes perpendicular to cam plate opening longitudinal axis 57 (see figure 8).

As described above, the thickness of cam plate 52 is maximal at the level of ridge 55c. Therefore, as key 80 is pivoted towards its "locked" position (arrow A ₃ in figure 8), tightening head 84 slides against slanted planes 55a and 55b until it becomes parallel to and bears entirely against ridge 55c, and an axial displacement is imparted to key 80 as suggested by arrow A ₄ in figure 8. This axial displacement is also imparted to armrest front strut 74, and tends to move the latter inwardly towards base 22.

As such, the tilting of armrest 70 towards its operative position causes key 80 to become wedged in keyhole 50, which prevents the lower end of front strut 72 to wiggle when the chair is in use.

Concomitantly, as the armrest 70 is moved towards its operative position, the lower end of rear strut 76, grooved at 90, is moved towards catch 48. As shown in figure 7A-7B and 9-10, cross-sectionally T-shaped catch attachment portion 48a progressively slides in groove elongated portion 90a (which also has a T-shaped cross-section) until the bottom end of armrest rear strut 76 hits the projecting barb 48c on resilient finger 48b. Further pressure must then be applied on armrest 70 to force the bottom end of armrest rear strut 76 to forcibly push on the barb 48c and thus bend resilient finger portion 48b away from rear strut 76, to allow finger

portion 48 to slide inside groove 90. Catch 48 continues to slide inside groove 90 until the barb 48c reaches and is admitted in the indentation 90b made inside groove 90. At this point, finger 48b is allowed to recoil to its initial unbent position and "clicks" in place, and latch 48 becomes interlocked with groove 90. Concomitantly, dowel 92 is brought to rest snugly in trough 33. At this point, armrest 70 is attached to base 22, and more particularly to its rocking portion 30.

As armrest 70 nears its operative position, finger 46b of crooked alignment rod 46 is admitted in track 102 of the backrest retaining member 100, as shown in figure 10. This will prevent retaining member 100 to pivot relative to mounting screw 104. In an alternate embodiment where the chair base is provided with reclining capabilities, the crooked alignment rod be set in motion axially while reclining the chair to pivot backrest retaining member 100, and thus induce the reclining of backrest 110 accordingly to the motion of rod 46.

When armrest 70 is in its operative position as shown in figure 10, the lower end of latch finger portion 48b extends beyond the lower end of rear strut 76. To detach the armrest 70 from the base, one must first apply pressure on this exposed portion of resilient finger 48b as suggested by arrow A ₅ in figure 10, to bend it away from rear strut 76, such that barb 48c clears indentation 90b. Catch 48 having thereby released its grip on armrest rear strut 76, armrest rear strut 76 can now be slid away from catch 48, and the whole armrest pivoted towards the frontwardly tilted position shown in figure 6A. It this position, tightening head 84 of key 80 is parallel to keyhole 50, and key 80 can be pulled out of keyhole 50 to completely release armrest 70 from base rocking portion 30.

It is understood that a number of modifications could be made to the above described embodiment without departing from the scope of the present invention.

The releasable attachment means enabling the attachment of the armrest to the base could differ from those illustrated in the figures and described above. Attachment of the front end of the armrest could be accomplished by a pair releasable attachment means: a first releasable attachment means of the "twist-and-lock" variety, comprising a key that can be inserted and interlocked in a keyhole, the key and keyhole carried on respective ones of the armrest and base. The second attachment means could comprise first and second connectors which can be selectively and releasably interconnected, the first and second connectors being carried respectively by the armrest and the base.

In an alternate embodiment, the seat and backrest could be fixedly attached to said base.