Patent Publication Number: US-2011062754-A1

Title: Stackable chair with rack attachment members

Description:
FIELD OF THE INVENTION 
     This invention relates generally to lightweight chairs and, more specifically, to stackable lightweight chairs. 
     BACKGROUND OF THE INVENTION 
     Stackable lightweight chairs have become very popular. Increasingly popular are stackable lightweight chairs having a rack, such as a book rack, disposed below the seating surface of the chair. Such a stackable chair with a rack disposed below the seating surface is illustrated in  FIG. 13 . 
     A problem with such stackable chairs having a rack disposed below the seating surface is that, once the rack is attached to the chair, the chair becomes relatively “non-stackable.” This is because the racks prevent each chair from closely nesting with an identical chair. This problem is illustrated in  FIG. 14 . 
     The relatively “non-stackable” nature of stackable chairs having a rack disposed below the seating surface is especially important to those responsible for shipping large quantities of such stackable chairs in bulk. Because of the relative “non-stackability”of such chairs, the cost of shipping large quantities of such chairs in bulk is unduly large. 
     Attempts have been made to avoid the shipping difficulties caused by the aforementioned lack of stackability by shipping chairs separate from “slip-on” wire book racks—flexible wire book racks which can be flexed and installed into leg holes by the end user. However, such slip-on wire book racks are typically retained loosely within a chair, so that the book racks tend to rattle. Also, such slip-on wire book racks can be easily removed from chairs by mischievous students, thereby resulting in safety issues. 
     Accordingly, there is a need for a stackable lightweight chair designed for use with a rack disposed below the seating surface which avoids the above-mentioned problem with the prior art. 
     SUMMARY OF THE INVENTION 
     The invention satisfies this need. The invention is a stackable chair comprising (a) a seating surface, (b) at least three legs disposed generally vertically below the seating surface, the at least three legs being disposed at an angle slightly less than 90° with respect to the vertical, such that the chair is capable of stacking onto an identical chair, and (c) a rack attachment member attached to each of the at least three legs. Each rack attachment member comprises (i) a leg attachment portion attached to one of the at least three legs, and (ii) a rack attachment portion capable of reversibly securing a portion of a rack to one of the at least three legs below the seating surface. 
    
    
     
       DRAWINGS 
       These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where: 
         FIG. 1  is a perspective view of a stackable chair having features of the invention; 
         FIG. 2  is a side view of the stackable chair illustrated in  FIG. 1 ; 
         FIG. 3  is a front view of the stackable chair illustrated in  FIG. 1 ; 
         FIG. 4  is a bottom view of the stackable chair illustrated in  FIG. 1 ; 
         FIG. 5  is a perspective view of a rack attachment member useable in the invention; 
         FIG. 6  is a top view of the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 7  is a second perspective view of the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 8  is a side view of the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 9  is a rear view of the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 10  is a bottom view of the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 11  is a detail view illustrating the attachment of a rack to a chair leg using the rack attachment member illustrated in  FIG. 5 ; 
         FIG. 12  is a side view of a plurality of stackable chairs having features of the invention; 
         FIG. 13  is a perspective view of a stackable chair of the prior art; 
         FIG. 14  is a side view of a stack of stackable chairs illustrated in  FIG. 13 ; and 
         FIG. 15  is a perspective view of a kit having features of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. 
     In one aspect of the invention, the invention is a stackable chair  10  comprising a seating surface  12 , at least three legs  14  and a rack attachment member  16  attached to each of the legs  14 . This aspect of the invention is illustrated in  FIGS. 1-4 . 
     The seating surface  12  is typically disposed in an approximately horizontal orientation. In the embodiment illustrated in the drawings, the seating surface  12  is integral with a back member  18 . In such an embodiment, it is typical that the seating surface  12  and the back member  18  are made from a plastic material. 
     The at least three legs  14  are disposed generally vertically below the seating surface  12 . However, each of the legs  14  is disposed at an angle slightly less than 90° with respect to the vertical, such that the chair is capable of stacking onto an identical chair. Typically, the at least three legs  14  comprise four legs  14 , as shown in the embodiment illustrated in the drawings. Also typically, each of the legs  14  is made from a tubular metal material such as steel. 
     Each rack attachment member  16  comprises a leg attachment portion  20  and a rack attachment portion  22  as illustrated in  FIGS. 5-10 . The leg attachment portion  20  of each attachment member is attached to one of the legs  14  of the chair. The rack attachment portion  22  is capable of reversibly securing a portion of a rack  23  to one of the chair legs  14  below the seating surface  12 . 
     As illustrated in the embodiment shown in the drawings, the rack attachment portion  22  of each rack attachment member  16  can define a continuous hollow cylinder. Such continuous hollow cylinder is sized and dimensioned to snugly attach around a portion of the rack  23  and to thereby firmly be retained to the rack  23 . 
     Also, as illustrated in the embodiment shown in the drawings, the leg attachment portion  20  is adapted to attach to one of the legs  14 . As seen in the drawings, the leg attachment portion  20  can define a clamp having a first clamp member  24  and a spaced apart second clamp member  26 . The first clamp member  24  and the second clamp member  26  are attachable to one another by one or more fasteners  28 , such as nuts and bolts. Preferably, the first clamp member  24  and the second clamp member  26  are attachable to one another by a single fastener. 
     As best seen in  FIGS. 5 and 7 , the proximal end  30  of each rack attachment portion  22  has an exterior surface  32 . Preferably, the first clamp of the leg attachment portion  20  of each rack attachment member  16  has an edge  34  which is sized and dimensioned to match the exterior surface  32  of the proximal end  22  of the rack attachment portion  22  in such a way that each first clamp member  24  supports a rack attachment portion  22  when the first clamp member  24  is attached to the second clamp member  26 . 
     Typically, the stackable chair  10  further comprises a rack  23 , such as a horizontally disposed book rack, attached to each of the rack attachment members  16  as illustrated in  FIG. 11 . As illustrated in the embodiment shown in the drawings, the rack  23  can have a center portion  36  and a plurality of radiating prongs  38 . Typically, each of the continuous hollow cylinders defined by each rack attachment portion  22  is sized and dimensioned to accept and retain one of the radiating prongs  38 . 
     Contrary to the user of “slip-on” wire book racks, the racks  23  are securely attached to each chair  10  such that the racks  23  do not rattle and are not easily removed from the chair  10  by mischievous students. 
     As illustrated in  FIG. 12 , stackable chairs  10  of the invention can be conveniently and efficiently shipped in bulk because the chairs  10  can be shipped prior to the rack  23  being attached to the chairs  10 . When identical chairs  10  of the invention are stacked upon one another, they nest in close relationship with one another as illustrated in  FIG. 12 . Because of the use in the invention of the rack attachment members  16 , a rack  23  can be quickly and conveniently attached to the chair  10  by the end user after a quantity of the chairs  10  have been shipped in bulk. 
     The stackable chairs  10  illustrated in  FIG. 12  are each shown having rack attachment members  16  attached to each of the chair legs  14 . Alternatively, the chairs  10  can be stacked and shipped without having rack attachment members  16  attached to each leg  14 . Instead, a kit  40  (described in more detail below) having one or more racks  23  and typically four attachment members  16  for each rack  23  can be shipped separately from the stack of chairs  10 . In this embodiment, the end user can quickly and easily attach rack attachment members  16  to each of the legs  14  of each chair  10 , and can thereafter quickly and easily attach a rack  23  to each of the chairs  10  using the rack attachment members  16 , as described above. 
     The stackable chair  10  of the invention is contrasted with stackable chairs of the prior art  110 .  FIG. 13  illustrates such a stackable chair of the prior art  110 . In this prior art stackable chair  110 , a rack  123  is attached to each of the four legs  114  by inserting one of the four rack attachment prongs  138  into a hole in one of the chair legs  114 . Alternatively, each of the four book rack attachment prongs  138  can be welded to one of the chair legs  114 . By these methods, the rack  123  is permanently and non-reversibly attached to the chair  110 . As discussed in the Background section above, the problem with such chairs  110  of the prior art is that they are very expensive to ship in bulk. Once the rack  123  is permanently attached to each chair  110 , the chair  110  no longer nests closely with identical chairs  110 . As illustrated in  FIG. 14 , identical chairs  110  of the prior art stack extremely inefficiently. 
     In a second aspect, the invention is a kit  40  comprising one or more racks  23  and at least three rack attachment members  16  for each rack  23 . One embodiment of such a kit  40  is illustrated in  FIG. 15 . In this aspect of the invention, the rack  23  comprises a center portion  36  and at least three radiating prongs  38 . Each rack attachment member  16  comprises (i) a rack attachment portion  22  defining a rack attachment portion  22  defining a hollow continuous cylinder with a proximal end  30  and a distal end  31 , the proximal end  30  having an exterior surface  32 , the hollow continuous cylinder being sized and dimensioned to accept one of the radiating prongs  38 , and (ii) a leg attachment portion  20  defining a clamp, the clamp having a first clamp member  24  and a second clamp member  26  spaced apart from one another. The first and second clamp members  26  are attachable to one another by one or more fasteners  28 . Preferably, the first clamp member  24  has an edge  34  sized and dimensioned to match the exterior surface  32  of the proximal end  30  of the rack attachment portion  22  in such a way that the first clamp member  24  supports the rack attachment portion  22  when the first clamp member  24  is attached to the second clamp member  26 . 
     In an alternative embodiment (not shown), the kit  40  can further comprise a plurality of fasteners  28 , such as nuts and bolts or rivots. 
     Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.