Chair Backrest

Abstract

A chair backrest comprises a closed loop frame, a net, a frame cover, and the subsidiary supporting-arms. The frame includes a protruding loop edge, defining a global frame-net interface with frame fixing holes therein. A loop-like net fixing piece is used for nailing the border of the net onto the frame-net interface. The subsidiary supporting-arms consists of a pair of branching poles; the ends of the branching poles are connected to a common base with the upper portion of the poles fixed to the frame by frame-arm fixing devices and frame-arm fixing pieces. A back reinforcement board traversing between the right side and the left side of the frame can be added to the rear side of the frame to further support the frame against forces applied.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective front view of a chair backrest in accordance with the present invention.

FIG. 2 is an exploded perspective rear view of a chair backrest in accordance with the present invention.

FIG. 3 is a perspective front view of the frame and the latticed net in assembly, with a net fixing loop (shown in darkened dashed line) mounting on top of the net.

FIG. 4 is a perspective assembly front view of a chair backrest in accordance with the present invention.

FIG. 5 is a perspective assembly rear view of a chair backrest in accordance with the present invention.

FIG. 6 is a side cross-sectional assembly view of a chair backrest in accordance with the present invention, with two partially enlarged views.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1-2, a backrest in accordance with the present invention generally comprises a frame 1, a latticed net 2, a frame cover 3, and supporting arms 4.

The frame 1 is made from hard plastics in the shape of a loop tilting outwardly in the lower back portion thereof. At the rear side of the frame 1 (facing away from a chair occupant) is equipped with a back-reinforcement board 11, traversing between the left and the right side of the frame 1. The back-reinforcement board curves toward the rear of the frame and comprises ventilating bores 111. The frame 1 is further intensified by the back reinforcement board 11. As a result, the elastic tension of the net 2 installed over the frame 1 is also enhanced.

The loop-like front edge 12 of the frame 1 protrudes outwards (facing a chair occupant) and defines a frame-net interface 13, the shape of which at any point of the frame has a sharp angle like a mirror image of L (such as “┘”), an upside-down L (such as “Γ”), or an upside-down and mirrored image of L (such as “┐”), depending on different sections of the frame concerned. The loop-like front edge 12 curves smoothly at the two upper corners. The frame-net interface 13 is further perforated with a couple of frame-net fixing holes 14, through which fasteners extend.

The frame-arm fixing section 15 is each positioned on the right and left side of the rear of the frame 1, declining slightly inwardly toward the lower center of the frame 1. Through the frame-arm fixing device 15 on each of the left and right side of the frame 1, the supporting arms 4 is assembled to the frame 1. Each of the frame-arm fixing section 15 includes a frame-pole fixing groove 151 for engaging with each of the two supporting poles; the frame-pole fixing groove 151 is formed with frame-pole fixing bores 152 for locking the supporting pole 41 with the frame-arm fixing device 15, and hence the frame 1.

The latticed net is made from soft materials with its border contacting the frame-net interface 13 secured by a net fixing loop 5. Alternatively, the net fixing loop 5 can be replaced by any equivalent device for nailing the net 2 onto the frame 1.

The frame cover 3 is configured in a loop for mounting onto the frame 1, with both the border of the lattice net 2 and the net fixing loop 5 enclosed under the inner side thereof. Furthermore, a suppressing lock 31 juts out along the inner surface of the frame cover 3 to suppress in position both the border of the net 2 and the net fixing loop 5. Frame cover fixing bores 32 are configured on the frame cover 3 at locations corresponding to where the frame-net fixing holes 14 of the frame 1 are formed.

Supporting arms 4 comprises two supporting poles 41, an arm base plate 42, and frame-arm fixing pieces 43. The pair of supporting poles 41 is made of metal, shaped like a curved-V. The metal arm base plate 42 at the lower ends of the supporting poles 41 connects to a chair seat (not shown in the figures). On the upper portion of the supporting poles 41 are formed frame-arm fixing bores 411. The frame-arm fixing piece 43 defines a pole-fixing grooves 431 and are formed with pole fixing holes 432 in it for engaging supporting arms 4 to the frame 1.

Referring to FIG. 3, in assembly, a latticed net 2 first mounts over the frame-net interface 13 of the frame 1, secured to the frame 1 by a fixing loop 5. Since a net 2 is supported by a projecting loop-like front edge 12, it is empowered with quite durable elasticity. Likewise, by having a sharp angle inside the frame-net interface 13, the net fixing loop 5 functions as a even stronger fastener in engaging the net 2 to the frame-net interface 13.

Referring to FIG. 1 to FIG. 6, a frame cover 3 mounts on top of the frame 1, covering the frame-net interface 3 completely. Fasteners (such as screws) extends through the frame-net fixing holes 14 of the frame 1, and the cover fixing holes 14 of the cover 3 such that the cover 3 encompasses the border of the net 2 and the fixing loop 5 underneath. On the whole, the backrest after complete assembly gives a single-piece elegant look. Furthermore, a suppressing loop 31 of a frame cover 3 provides an extra force to stabilize the net 2 and the fixing loop 5, and thereby to better secure them onto the frame-net interface 13.

Referring to FIG. 2 and FIG. 5, the upper ends of the pair of supporting poles 41 of supporting arms 4 are each assembled inside the frame-pole fixing groove 151. By having a fastener (such as a screw) extend through the pole fixing holes 432 of the frame-arm fixing piece 43, the frame-arm fixing bores 411 of the supporting poles 41, and the frame-pole fixing bore 152 of the frame 1, the frame 1 is armored by the supporting arms 4 against deformation or rupture (due to heavy weights or temperature changes), which in turns upholds the elastic tension of the net 2.

Although a preferred embodiment in accordance with the present invention has been provided in this application, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention hereafter claimed.

Claims

1. A chair backrest comprising: a frame made of hard plastics shaped like a closed loop with frame fixing holes, wherein the outer front loop-like edge of said frame protrudes outwards facing a chair occupant's back, defining a loop-like frame-net interface with a sharp angle, wherein said frame-net interface being confined by said front loop-like edge and the opposing rear periphery of said frame; said frame-net interface is formed with frame-net fixing holes;on each the right and left side of the rear of said frame is formed a frame-arms fixing section, defining an inner groove and frame-arms connection holes for engagement;a net fixing piece;a net made from soft materials with the border of said net secured onto said frame-net interface by said net fixing piece;a frame cover shaped like a closed loop for mounting over said frame-net interface; said frame cover is configured with cover-fixing bores at locations corresponding to said frame-net fixing holes;along the inner surface of said frame cover is formed a loop-like suppressing lock for stabilizing in position the border of said net and said net fixing piece underneath; anda supporting-arms assembly with branching V-like supporting poles; the upper portion of each said supporting poles connects to said frame-arms fixing section of said frame.

2. The chair backrest as claimed in claim 1 wherein said net fixing piece is a nailing loop.

3. The chair backrest as claimed in claim 1 wherein said supporting-arms assembly comprises: two supporting poles, shaped in a V-like branch from bottom to top, with frame-arm fixing bores at the upper portion of said supporting poles;a base plate to which the bottom ends of said two poles connect; andframe-arm fixing pieces for engaging the upper portion of each said supporting pole to said frame-arms fixing section of said frame; each said frame-arms fixing piece defines an inner pole-fixing groove and a pole-fixing bore for fasteners to go through.

4. The chair backrest as claimed in claim 1 wherein said frame is made from hard plastics, while said supporting poles and said base plate are made of metals.

5. The chair backrest as claimed in claim 1 wherein said frame is reinforced with a frame supporting board, traversing between the right and left side of said frame in a curve way toward the rear of said frame.