Abstract:
A beach chair including a seat having rigid, yet collapsible, frame. The frame carries a flexible platform for supporting the buttocks of a person seated upon the seat and a flexible backrest with shoulder straps secured thereto for supporting the back of a person seated upon the seat and permitting the chair to be easily transported when not employed for seating purposes. The frame has a U-shaped forward support member with a pair of forward legs being connected together by a forward crosspiece for maintaining the front of the platform at a fixed height above the ground. The frame also has a U-shaped rearward support member with a pair of rearward legs being connected together by a rearward crosspiece for maintaining the rear of the platform at a fixed height above the ground. A swivel apparatus is attached to the seat and is provided with a load-distributing platform for positioning upon the ground. A saddle is pivotally secured atop the platform for supporting the seat above the ground. A pair of mounting clips is secured to the front of the saddle for firmly, yet releasably, grasping the forward crosspiece of the seat. A mounting bracket is secured to the rear of the saddle for holding the rearward crosspiece.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to chairs and seats and, more particularly, to an apparatus for moving the bottom and back of a chair as a unit about a vertical axis. 
   BACKGROUND OF THE INVENTION 
   In patents issued in the past, I described an apparatus that permits a beach chair of conventional construction to be swiveled about a vertical axis. A person seated in a chair carried by this apparatus can, with minimal effort, turn in any direction. Such a capability makes it easy to keep track of one&#39;s mobile children at a beach. Additionally, sunbathing opportunities are enhanced since a user can turn toward the sun as it tracks across the sky. Away from the beach, the apparatus can be used to follow the action at outdoor sporting events and barbecues. 
   Over time, I improved my apparatus. First, the apparatus was reinforced to make it stronger and more stable on sandy ground. Then, it was adapted for universal attachment to different makes and models of beach chairs. Unfortunately, some considered the improved apparatus to be bulky and difficult to transport even though it was supplied with handholds. I have, now, come to conclude that permanently combining my apparatus with a collapsible beach chair and, then, making the combination easy to tote would benefit users and enhance sales. 
   SUMMARY OF THE INVENTION 
   In light of the problems associated with the known chairs capable of swiveling, it is a principal object of the invention to provide a chair of the sort that can fold or collapse into a small volume and that can be transported from place to place upon the back of a user in the manner of a backpack. Collapsing can be accomplished without resort to tools or prolonged periods of training. My chair, it is believed, is intuitive to use. 
   It is another object of the invention to provide a chair of the type described that can lie atop beach sand with a minimum of penetration and with a minimum of sideways sliding while supporting a user. 
   It is an object of the invention to provide improved features and arrangements of features in a chair for the purposes described that is lightweight in construction, compact in size, easy to transport, inexpensive to manufacture, and fully dependable in use. 
   The foregoing and other object and advantages of the present invention will become readily apparent upon further review of the following detailed description of the chair embodiment illustrated in the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention may be more readily described with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view of an opened beach chair in accordance with the present invention. 
       FIG. 2  is a side view of the beach chair of  FIG. 1  in a collapsed state and being worn as a “backpack” for transport. 
       FIG. 3  is an exploded perspective view of the base portion of the beach chair. 
       FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 1 . 
       FIG. 5  is an exploded perspective view of the chair-retaining bracket of the base portion of the beach chair. 
       FIG. 6  is a perspective view of the chair-retaining bracket. 
   

   Similar reference characters denote corresponding features consistently throughout the accompanying drawings. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the FIGS., a beach chair in accordance with the present invention is shown at  10 . Chair  10  includes a collapsible seat  12  and a swivel apparatus  14  connected to the bottom of seat  12 . To transport chair  10  long distances, seat  12  is partially disconnected from swivel apparatus  14 , folded up, and secured to the shoulders  16  of a user  18  by means of a pair of shoulder straps  20 . 
   Seat  12  includes a forward support member  22  and a rearward support member  24  that, together, comprise the base of seat  12 . Member  24  has a pair of rearward legs  26  positioned side-by-side and connected together by a rearward crosspiece  28  in a U-shaped arrangement. Member  22 , however, has a pair of forward legs  30  positioned side-by-side between legs  26  and connected together by a forward crosspiece  32  in a U-shaped arrangement. The free end of each of legs  30  is positioned adjacent the free end of a respective one of legs  26 . One of a pair of pins  34  extends through the adjacent free ends so as to pivotally connect members  22  and  24  together. 
   Seat  12  has a platform support member  36  that transmits the weight of a user to members  22  and  24 . Member  36  has a pair of platform braces  38  positioned side-by-side and connected together by a platform cross brace  40 . As shown, braces  38  are positioned between legs  26  and  30  with the free end of each brace  38  being pivotally connected to the midpoint of a respective one of legs  30  by one of a pair of pins  42 . 
   A pair of rollers  44  is affixed to platform support member  36  to support the rear end of member  36  above member  24 . A respective one of rollers  44  is affixed to each of braces  38  near its connection with cross brace  40 . Each of rollers  44  is hourglass shaped to receive one of rearward legs  26  between its wide ends and to roll freely along the top of a rearward leg  26 . 
   A flexible platform  46 , formed of durable fabric, is stretched between braces  38 . Platform  46  is rectangular in outline and has opposite sides that are folded over and seamed to form sleeves  48  within which braces  38  are positioned. Platform  46  is dimensioned so that a taut, horizontal supporting surface is provided for the buttocks of a person seated upon chair  10 . 
   A backrest support member  50  is pivotally connected to member  36  for retaining a person seated upon chair  10  in an upright position. Member  50  has a pair of backrest braces  52  positioned side-by-side and connected together by a backrest cross brace  54 . Braces  52  are located above braces  38  with the free end of each brace  52  being pivotally connected to the rear end of a respective one of braces  38  by one of a pair of hinges  56 . Each hinge  56  has a U-shaped bracket  58  affixed to the rear end of a brace  38  and a pivot pin  60  that passes through a brace  52  and bracket  58 . 
   A flexible backrest  62 , formed of durable fabric, is stretched between braces  52 . Like platform  46 , backrest  62  is rectangular in outline and has opposite sides that are folded over and seamed to form sleeves  64  within which braces  52  are positioned. Backrest  62  is dimensioned so that a taut, upright supporting surface is provided for the back of a person seated upon chair  10 . 
   A pair of shoulder straps  20  is affixed to backrest  62 . Each shoulder strap  20  includes a strip of webbing  66  that is sewn at one of its ends to the top of backrest  62 . Each shoulder strap  20  also includes an elongated pad  68  that is sewn at one of its ends to the bottom of backrest  62 . A clasp  70  is sewn onto the free end of each pad  68  by means of which the free end of a webbing strip  66  is adjustably fastened to a pad  68 . 
   The female portion  72  of a clip  74  is secured to the top of backrest  62  and can be selectively attached to the male portion  76  of clip  74  that is secured to swivel apparatus  14  to help retain seat  12  in a collapsed condition for easy transport. As shown, a loop of webbing  78  extends through female portion  72  and is sewn to backrest  62 . Webbing loop  78  is positioned midway between webbing strips  66  at the middle of backrest  62 . 
   A tubular, foam pad  80  is secured to backrest support member  50 . Pad  80  encircles cross brace  54  to isolate cross brace  54  from the upper body of a person sitting upon seat  12 . Furthermore, pad  80  prevents the back of the legs of user  18  from rubbing against seat  12  while seat  18  is being transported like a backpack. 
   Seat  12  has a pair of arms  82  for supporting those of a person seated therein. Each of arms  82  has a pair of abutting rails  84 . The back ends of each pair of rails  84  are pivotally connected to the bottom end of a respective one of backrest braces  52  by a pin  86 . The front ends of each pair of rails  84 , on the other hand, carry a bracket  88  therebetween for adjusting the inclination of backrest  62 . Each bracket  88  has a central opening  90  for loosely receiving a pin  34  between legs  26  and  30 . Each opening  90  is provided with an irregular top surface that includes a number of forwardly and upwardly trending slots  92  into which a pin  34  is selectively extended. When pin  34  is located in a forwardly positioned slot  92 , backrest  62  is reclined to a great degree. When, however, pin  34  is located in a rearwardly positioned slot  92 , backrest  62  is held in an upright orientation. 
   Swivel apparatus  14  includes a saddle  94  attached to a load-distributing platform  96  by a pivot pin  98  that permits saddle  94  to rotate about a vertical axis when platform  96  is positioned upon the ground. A mounting bracket  100  permanently secures rearward crosspiece  28  of seat  12  to the rear of saddle  94 . A pair of clips  102  releasably secure forward crosspiece  32  to the front of saddle  94 . Disengaging crosspiece  32  from clips  102  permits seat  12  to be easily collapsed for storage and transport. 
   Saddle  94  includes a rectangular plate  104  having a peripheral lip  106  for reinforcement purposes. At the center of plate  104  is a pivot pin receiver  108 . Located at each of the corners of plate  104  is a pair of recessed keyholes  110  like those described in U.S. patent application Ser. No. 11/403,124, filed by me on Apr. 13, 2006, which is incorporated for all purposes herein. Each keyhole  110  includes a circular bore as at  112  at its center. From opposite sides of bore  112  one of a pair of rectangular slots as at  114  radiates outwardly. 
   A pair of clips  102  is connected to saddle  94  with each being respectively located within one keyhole  110  at each front corner of platform  96 . Each clip  102  has a base  116  for connection to saddle  94  and a pair of arcuate jaws  118  affixed to base  116  for a “snap-fit” connection to crosspiece  32 . Base  116  includes a downwardly extending shaft  120 . At the free end of shaft  120  is affixed a key bit  122  being a rod oriented at right angles to shaft  120  and sized for passage through each keyhole  110 . After passage of key bit  122  through a keyhole  110 , the associated clip  102  is rotated 90° to lock the clip  102  snugly upon platform  96 . 
   Mounting bracket  100  is connected to the rear end of saddle  94 . Bracket  100  has a base portion  124  and a cover portion  126  that, together, grasp crosspiece  28  and connect such to saddle  94 . Base portion  124  includes a wedge  128  that extends from one side of saddle  94  to the other. Wedge  128  has a channel  130  in the top thereof that extends the length of wedge  128  and is semicircular in cross section so as to snugly engage the bottom of crosspiece  28 . A pair of pins  132  extends downwardly from the bottom of wedge  132  for snug positioning in opposed keyholes  110  in the rear of saddle  94 . Each pin  132  includes a cylindrical stem  134  at its center, for snug positioning in a circular bore  112 , from which two, rectangular wings  136 , for positioning in slots  114 , extend respectively forward and rearward. Adjacent the free end of each wing  136 , wedge  128  is provided with an aperture  138  for the passage of a threaded fastener  140  for joining base portion  124  and cover portion  126 . 
   Cover portion  126  includes a block  144  from the front of which a pair of feet  146  extend forwardly in a U-shaped configuration. As shown, block  144  has a cutout, defined by top wall  148  and front wall  150 , in its bottom and at its rear end to fully receive base portion  124 . A semicircular channel  152  is provided in top wall  148  that extends the length of block  144  for snugly engaging the top of crosspiece  28 . A pair of apertures  154  is provided at each end of block  144  for alignment with apertures  138  and for receiving threaded fasteners  140 . 
   Feet  146  evenly distribute loads from seat  12  to saddle  94 . Each foot  146  is provided with a vertical bore  156  for the downward passage of a bolt  158 . Bores  156  are axially aligned with the circular bores  112  of the forwardmost keyholes  110  at the rear end of saddle  94  when pins  132  are positioned in the rearwardmost keyholes  110  at the rear end of saddle  94 . The threaded stem of bolt  158  extends from the bottom of a foot  146  and through a bore  112  and is locked there by a nut  160  turned onto bolt  158  and engaged with the bottom of platform  96 . 
   Adjacent each of the opposite ends of bracket  100 , a flexible clasp  162  is secured to crosspiece  28  to assist in retaining seat  12  in a collapsed state for storage and transport. Each clasp  162  has a tubular sleeve  164  that fits snugly over crosspiece  28 . An elongated stem  166  is affixed to sleeve  164  and extends upwardly therefrom. A pair of arcuate jaws  168  is affixed to the free end of stem  166  and extends forwardly therefrom. Jaws  168  are adapted for a “snap-fit” connection to lower cross brace  40 . 
   Load-distributing platform  96  is an inverted bowl with a downwardly extending rim  170  at the periphery thereof and an upwardly extending sealing ring  172  that is spaced inwardly from rim  170 . At the center of platform  96  is located a pivot pin anchor receiver  174 . At spaced intervals around receiver  174  and within ring  172 , platform  96  has dimples  176  sized to receive and hold ball bearings  178 . 
   Platform  96  has a pair of integral handles  180  for ease in carrying chair  10 . Handles  180  are formed by making a pair of slots  182  in platform  96  between ring  172  and rim  170  180° apart. 
   A loop of webbing  184  secures male portion  76  of a clip  74  to one of handles  180 . In use, male portion  76  is selectively attached to female portion  72  on backrest  62  to retain seat  12  in a collapsed condition for easy storage and transport. 
   A friction reducing mechanism  186  facilitates the rotation of saddle  94  on pivot pin  98 . Mechanism  186  includes ball bearings  178  set in dimples  176  in platform  96 . Mechanism  186  also includes a circular bearing race  188  joined by screws  190  to the bottom of saddle  94 . Race  188  has a circumferential channel  192  for engaging ball bearings  178 . Dirt is prevented from fouling bearings  178  by an annular seal  194 . 
   Pivot pin  98  secures saddle  94  to platform  96 . Pivot pin  98  comprises a bolt extending downwardly through pivot pin receiver  108  and into pivot pin anchor receiver  174  wherein pivot pin  98  threadably engages a nut  196 . To distribute loads, one washer  198  is provided directly beneath the head of pin  98  and another washer  200  is provided atop platform  96 . A sleeve  202  is also fitted around the threaded portion of pin  98  within receiver  108  to minimize friction as saddle  94  is rotated relative to platform  96 . A cover  204  is fitted over pivot pin  98  to prevent pin  98  from becoming fouled. 
   Use of chair  10  is straightforward and is initiated by unfolding it. First, with chair  10  in a collapsed state as shown in  FIG. 2 , chair  10  is removed from the back of user and placed on the ground. Then, jaws  168  of flexible clasps  162  are manually detached from lower cross brace  40  by lightly pushing the two features apart. Next, male portion  76  and female portion  72  of clip  74  are disengaged from one another by squeezing the sides of male portion  76  while simultaneously pulling male portion  76  from female portion  72 . Seat  12  is now telescoped by lifting upper cross brace  54  with support members  22  and  24  and platform brace  36  cascading downwardly from backrest support member  50 . 
   Once seat  12  is unfolded, it will be seen that cross brace  32  automatically aligns itself with the forwardmost pair of keyholes  110  at the front of saddle  94 . Into these keyholes  110 , clips  102  are installed by passing key bits  122  through keyholes  110  and, then, pivoting clips  102  90° to align jaws  118  with cross brace  32 . Next, cross brace  32  is pushed between jaws  118 . A user can now position himself upon seat  12  and swivel in any direction desired. If the user finds that platform  46  is originally set too low, he can raise the platform  46  by moving clips  102  to the rearward pair of keyholes  110  at the front of saddle  94 . Of course, the tilt of backrest  62  can be adjusted to the tastes of a user by the selective engagement of pins  34  with bracket slots  92 . 
   After use, chair  10  is collapsed by reversing the steps delineated above. Chair  10 , in a folded state, is easily transported and stored. Moving chair  10  relatively long distances is accomplished by positioning shoulder straps  20  over the shoulders  16  of a user  18 . Pads  68  prevent chair  10  from chafing the shoulders and clasps  70  permit the lengths of shoulder straps  20  to be adjusted to accommodate users of different statures. Being compact in size, chair  10  is easily stored in an automobile trunk or closet for immediate reuse. 
   While chair  10  has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications can be made to it. For example, seat  12  can be provided with a rigid framework of practically any sort provided that cross pieces  28  and  32  are provided for attachment to swivel apparatus  14 . Thus, it is to be understood that the present invention is not limited to chair  10  described above, but encompasses any and all chair embodiments within the scope of the following claims.