Abstract:
A chair with a chair back pivotally mounted to a pair of armrests which are fixedly secured to a seat. The chair back can be moved from a collapsed position located directly adjacent the seat to an upright position which is substantially transverse to the seat. When in the upright position, a pair of spring biased pins engaged with the chair back in the upright position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The field of this invention relates to furniture and more specifically to a chair where the back of the chair can be pivoted from a collapsed position, for shipping, located directly against the seat of the chair to an upright position, which is the normal position of usage. 
     2. Description of the Related Art 
     A typical chair has a seat and a back extending transversely or upright from the seat. This configuration of a chair is not readily adaptable to shipping after being manufactured for the reason that a chair inherently occupies a substantial amount of space. It is common for chairs to be manufactured in overseas manufacturing facilities which means that the chairs are required to be put into cartons and then shipped by shipping containers to the continental United States. The size of the shipping carton for a chair, which contains a back attached to a seat in the normal manner, is of a significant size and therefore limits the number of shipping cartons that can be placed within a shipping container. The shipping of assembled chairs means that the chairs incur a substantially increased shipping cost as opposed to any chair that is shipped in a disassembled state because a much fewer number of assembled chairs are locatable in a shipping container. 
     In the past, in order to minimize the shipping expense of chairs, it has been common to detach the chair back from the seat. The back can then be placed against the seat with the result that a significantly more compact unit is achieved for purposes of shipping. Once the disassembled chair reaches the retailer, either the retailer or the consumer is required to then assemble the chair. Assembly usually requires several bolt type fasteners to be installed in place and tightened. Many consumers find not only to assemble a chair to be an annoyance, but it also can be rather time consuming and difficult for certain individuals that have a minimal amount of mechanical skill. 
     It would be desirable to design a chair that did not require any tools for assemblage but yet the chair can assume a collapsed configuration. The retailer or consumer will only need to move the chair back to an upright position at which time the chair back will be locked in conjunction with the seat and the chair is now ready for usage. Such a quick and easy locating of the chair for usage is highly desired. 
     SUMMARY OF THE INVENTION 
     One of the primary objectives of the present invention is to construct a chair that is collapsible for purposes of shipping, but upon reaching the selling or consuming destination, the chair can be moved from its collapsed position to a normal usage position without requiring the using of any fasteners or the use of any tools. 
     The basic embodiment of chair with pivotable back of this invention comprises a seat which is adapted to support the buttocks of a human user. A first armrest is secured to one side edge of the seat and a second armrest is secured to the opposite side edge of the seat. A chair back is to be pivotally mounted in conjunction with both armrests with the chair back to be able to assume a collapsed position located directly against the seat. Upon the chair back being moved from the collapsed position to an upright position, a pin lock assembly interengages between each armrest and the chair back to lock the chair back in position. 
     A further embodiment of the present invention is where the basic embodiment is modified by there being formed a pair of holes in the chair back. 
     A further embodiment of the present invention is where the just previous embodiment is modified by there also being included in the chair back cam surfaces that cause the pin lock assemblies to be moved to a retracted position prior to engagement with their respective hole. 
     A further embodiment of the present invention is where the just previous embodiment is modified by each of the pin lock assemblies being spring biased tending to located the pin lock assemblies in an extended position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is to be made to the accompanying drawings. It is to be understood that the present invention is not limited to the precise arrangement shown in the drawings. 
     FIG. 1 is an isometric view showing the chair with pivotable back of the present invention in the collapsed position; 
     FIG. 2 is an isometric view similar to FIG. 1 but with the chair with pivotable back of this invention in the upright position; 
     FIG. 3 is a cross-sectional view taken generally along line  3 — 3  of FIG. 2 which depicts the initial positioning of a pin lock assembly in conjunction with the armrest as the chair back is being moved from the collapsed position to the upright position; 
     FIG. 4 is a cross-sectional view similar to FIG. 3 showing the pin lock assembly engaged with a cam surface of the armrest as it is being moved toward the upright position; 
     FIG. 5 is a cross-sectional view similar to FIG. 4 showing the position of the pin lock assembly when the chair back is locked in the upright position; 
     FIG. 6 is a cross-sectional view taken along line  6 — 6  of FIG. 2 showing the position of the chair back in the collapsed position; and 
     FIG. 7 is a cross-sectional view similar to FIG. 6 but showing the chair back in the upright position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring particularly to the drawings, there is shown the chair  10  of this invention. The chair  10  includes a substantially planar seat  12 . A person&#39;s buttocks (not shown) is adapted to be located on the upper surface of the seat  12 . The seat  12  has side edges  14  and  16 . Fixedly mounted to the side edge  14  is a first armrest  18 . A second armrest  20  is fixedly mounted to the side edge  16 . Armrest  18  includes a cushioned pad  22 . Armrest  20  includes a similar cushioned pad  24 . Normally, the cushioned pads  22  and  24  will be constructed of a rigid material covered with a cushioning material made of leather and plastic combined with foam or some other similar cushioning material. 
     The first armrest  18  includes a sleeve (not shown) with the second armrest  20  including a similar sleeve  29 . Pivot pins  26  and  28  are mounted within their respective side edges  30  and  32  of a chair back  34 . Pivot pin  26  is to engage within the sleeve (not shown) mounted in side edge  30 . Pivot pin  28  is to engage within sleeve  29  mounted in side edge  32 . The pivot pins  26  and  28  permit the chair back  34  to pivot between a collapsed position, which is shown in FIG. 1, to an upright position, which is shown in FIG.  2 . The upright position in FIG. 2 locates the chair back  34  substantially transverse relative to the seat  12 . Generally, the chair back  34  will be constructed of a rigid material upon which is placed a cushioning material and construction of the chair back  34  is deemed to be conventional. 
     Mounted within the chair back  34  and connecting with the side edge  30  is a pin lock assembly  36 . Also mounted within the chair back  34  and connecting with the side edge  32  is a pin lock assembly  38 . Each pin lock assembly  36  and  38  is constructed in precisely the same manner. The pin lock assemblies  36  and  38  include a housing  40 . Formed within the housing  40  is an internal chamber  42 . Mounted within the internal chamber  42  is a coil spring  44 . The housing  40  has a front portion  46  which is to extend exteriorly of the side edge  30  and also the side edge  32 . The remaining portion of the housing  40  is imbedded within the chair back  34 . Formed within the front portion  46  is a through hole  48 . Mounted within the through hole  48  is a pin  50 . The back end of the pin  50  is enlarged forming a flange  52 . The flange  52  is captured within the internal chamber  42  and abuts against the coil spring  44 . The pin  50  can be moved relative to the housing  40  between a retracted position, shown in FIG. 4, and an extended position, shown in FIGS. 3 and 5. 
     Armrest  20  has an inclined cam surface  54 . Armrest  20  also includes a flat cam surface  56 . Armrest  20  also includes a cam channel  58  which has a wall surface  68 . It is to be understood that the armrest  18  will have a similar inclined cam surface  54  and a flat cam surface  56 , which is not shown. Armrest  18  also has a cam channel  60  which is located in a facing relationship relative to the cam channel  58 . Cam channel  60  also has a wall surface  68 . It is to be understood that the cam channel  60  is to connect with pin lock assembly  36  while the cam channel  58  connects with pin lock assembly  38 . 
     As the chair back is moved from the collapsed position, shown in FIG. 1 to the upright position shown in FIG. 2, when the chair back  34  has been moved about sixty degrees in the direction of arrow  62 , pin  50  will come into contact with inclined cam surface  54 . As the chair back  34  continues to move toward the upright position, the pin  50  will slide along the surface of the inclined cam surface  54  causing the pin  50  to move from an extended position to a retracted position, which is shown in FIG.  4 . This compresses spring  44 . It is to be noted that spring  44  exerts a constant bias tending to locate pin  50  in the extended position. Pin  50  will then continue to ride along the flat cam surface  56  until the front portion of housing  40  comes into contact with cam channel  58 . Pin  50  will continue to ride within the surface of cam channel  58  until finally coming into connection with hole  64  formed in armrest  20 . At that particular time, pin  50  then will be moved to the extended position. This same type of engagement with hole  64  is also to occur simultaneously in conjunction with armrest  18 . The result is that chair back  34  is now fixedly locked in position relative to armrests  18  and  20  and seat  12 . 
     Normally, once chair back  34  is connected in the upright position, as shown in FIG. 2, there will never be a need to have the chair back  34  move again to the collapsed position. The collapsed position is only for the purpose of shipping of chair  10  to the retailer and to be used by the consumer. It can be seen that by pivoting chair back  34  to the upright position, as shown in FIG. 2, there are no tools that are required. However, at some time if it is deemed by the user desirable to have chair back  34  to be again moved to the collapsed position, which would again probably be for the reason of further transportability, there is provided a release hole  66  into which is to be inserted a small elongated tool which is designed to come into contact with pin  50  and permit such to be pushed sufficiently in order to disengage pin  50  from hole  64 . If the release hole of both armrests  18  and  20  is utilized, then chair back  34  will be permitted to move back to the collapsed position. 
     When chair back  34  is in the upright position, it is to be noted that the front portion  46  of each pin lock assembly  36  and  38  will be in tight connection with the wall surface  68  of cam channels  58  and  60 . This prevents any further movement of chair back  34  in the direction of arrow  62  so that chair back  34  is maintained in a precisely transverse position relative to seat  12 . The sitting force that is incurred from the user is transferred through the front portions  46  through their respective cam channels  58  and  60  and therefore hence to armrests  20  and  18  and then to seat  12 .