Abstract:
A chair particularly useful for an auditorium utilizes spherical bearings to mount the bottom of the chair to upright standards. The spherical bearing includes a base portion and a top portion that are secured to the chair bottom to hold the spherical bearing roller. An axle extends through each standard to engage the bearings to support adjacent chairs. The axles are threaded to receive a nut to secure the axles to the standards.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of International Application number PCT/US01/23135 with an international filing date of Jul. 23, 2001, which was published in the English language under Article 21(2) on Jan. 31, 2002, and now abandoned. This application also claims the benefit of U.S. Provisional Application serial No. 60/219,640, which was filed on Jul. 21, 2000. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to the art of chairs, particularly chairs installed in rows in auditoriums.  
         SUMMARY OF THE INVENTION  
         [0003]    In accordance with the invention, a chair for use in an auditorium comprises side standards onto which are mounted a pivotal seat portion and a bracket for support of a back portion. Axles, or shafts, extend from each standard to engage a spherical bearing on the seat portion to pivotally support the seat portion on the standards. This arrangement allows the axles to be unaligned or non-parallel, which also means that the standards themselves do not have to be parallel to each other. Thus, adjacent standards may be arranged at an angle, for example, when the row of chairs is curved. As well, the standards need not be at identical vertical positions, variations of two inches or so being easily accommodated. When utilizing a row of chairs, adjacent chairs share a standard and an axle.  
           [0004]    The spherical bearings may be any of several arrangements. One preferred arrangement is to provide a race as part of the bottom of the structural part of the seat portion that receives a spherical bearing member. That structural part may be plastic and the bearing race molded therein. An axle then extends from the standard into the bearing member. The race may be removable or an integral part of the seat portion and may be a single element or two or more parts. Preferably, part of the race is molded into the bottom of the seat and another part bolted to the bottom. Also, a short axle extends from the standard to the bearing, and a single axle element may extend through the standard to engage spherical bearings on adjacent seats on opposite sides of the standard.  
           [0005]    In one embodiment, retaining clips are secured to the axles to retain the seat bottom in the desired location, which is generally centrally located between the standards. The retaining clips may be of different sorts but a preferred clip is a coiled spring that normally assumes a condition where the helical coils grip the axle tightly in the normal position but which can be released from the axle by squeezing the ends of the spring to unwind the coils slightly. Other retaining clips that can be easily attached are known to those of skill in the art.  
           [0006]    In another embodiment, the seat bottom is maintained centered by placing a compression spring between each of the standards and a respective location on each side of the seat bottom, such as the bearing. The springs push against each other and, thus, maintain the seat in a centered position. Because the seat is centered, the additional use of retainer clips is optional. A spacer may also be used to reduce the required length of the springs.  
           [0007]    The axle shafts preferably have a threaded central portion whereby they can be attached to the standards by nuts that clamp the standard between them. Clearly other techniques for securing the axle to a standard may be used.  
           [0008]    The back portion of the chair is preferably mounted on a bracket that is pivotally mounted on a standard. The angular orientation of the bracket in a vertical plane may be adjusted with respect to the standard by aligning adjustment holes in the bracket with a mounting hole in the standard and securing the bracket to the standard through these holes by a bolt. Other securing arrangements, such as a detent mechanism or a frictional engagement, are contemplated.  
           [0009]    One end of the pivotal seat portion is provided with a stop portion that engages the bottom of the back portion when the chair is in the use position such that the orientation of the use position of the chair is determined by the position of the back portion. Thus, adjustment of the orientation of the back portion automatically adjusts the orientation of the seat portion, and the bracket and seat are arranged so that a rearward tilt of the back portion automatically results in a more upward tilt of the seat portion and vice-versa. This simplifies adjustment of the orientation of the chairs.  
           [0010]    A further feature of the invention is that the standards are cast metal and the top portions are recessed slightly. This allows a coating of soft material, such as a plastic to be-coated on the top to provide a cap for added comfort of users.  
           [0011]    Preferably, the coated is applied by dipping the standard in the material.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a side view of a chair in accordance with the invention.  
         [0013]    [0013]FIG. 2 is an assembly view of the bottom of the chair shown in FIG. 1.  
         [0014]    [0014]FIG. 2 A is a side view, partially in cross section of a second embodiment of the bearing of FIG. 2.  
         [0015]    [0015]FIG. 3 is an assembly view of a second embodiment of the bottom of the chair shown in FIG. 1.  
         [0016]    [0016]FIG. 4 is a front view showing a preferred installation of two chairs in accordance with the invention.  
         [0017]    [0017]FIG. 5 is partial vertical cross section of a preferred axle and seat installation.  
         [0018]    [0018]FIG. 6 is a perspective of a preferred spherical bearing.  
         [0019]    [0019]FIG. 7 is an exploded perspective of the bearing shown in FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    With reference to FIG. 1 of the drawings, a chair in accordance with the invention comprises a seat portion  2 , a back portion  4 , and side standards  6  onto which the seat and back portions are mounted.  
         [0021]    The back portion is mounted on opposed brackets  8 , which are generally vertical plates. The lower parts of the brackets  8  are mounted on the standard at pivots  10  for pivotal movement in a vertical plane. The upper parts of the brackets are provided with a series of adjustment holes  12  that selectively align with a mounting hole on the standard to secure the bracket in a given orientation. Thus, the angle of the back portion with respect to the horizontal can be adjusted by pivoting the bracket to align a selected hole  12  with the mounting hole in the standard. In the preferred embodiment, the bracket is secured in that position by passing a bolt through the holes in the bracket and into a threaded portion of the hole in the standard.  
         [0022]    The lower part of the back portion extends rearward from the bracket  8  such that it moves in an arc as the angle of the bracket, and, hence, the angle of the back portion is adjusted. The seat portion  2  is pivotally mounted to the standards as well, and includes a rear portion  16  that engages the bottom portion  14  of the back portion when the chair is in the use position. Thus, the angle of the seat portion  2  in the use position is a function of the vertical position of the bottom portion  16  of the back portion  4 . The vertical position of the bottom portion  14  of the back portion  4  is, in turn, determined by the angular orientation of the brackets  8 . Thus, adjustment of the angular orientation of the back portion  4  automatically adjusts the angular orientation of the seat portion  2  when in use. The structure is arranged such that tilting the back portion  4  away from the vertical causes the orientation of the seat portion  2  to tilt toward the vertical.  
         [0023]    The rear portion  16  is preferably weighted to pivot the seat portion  2  vertical when not in use.  
         [0024]    [0024]FIG. 2 shows one construction of the seat portion  2 . The seat portion  2  includes a bottom part  18  onto which is mounted two spherical bearing sets, each comprising a lower race or cradle  20  for a spherical bearing roller  22 . An upper race or cap  24  is secured onto the lower race  20  to hold the bearing roller. The seat is supported on two axels  26  that pass through or from opposed standards  6  to engage respective spherical bearings. Because the bearings are spherical, the axles  26  need not be parallel or aligned.  
         [0025]    [0025]FIG. 2 a  illustrates one embodiment of the bearing. The cap  24  has legs  25  that extend outward from the bearing race and receive screws  27  for securing the cap to the bottom  18  of the seat.  
         [0026]    [0026]FIG. 3 shows another embodiment wherein the bearing race is continuous, eliminating the separate cap  24 .  
         [0027]    The standards are preferably of cast metal with the vertical and horizontal parts defining a boundary  28  that is recessed or stepped. This allows the tops to be dipped in a soft material to the thickness of the recess or step to provide the standards with an upholstery-like covering that is very durable and attractive, as well as a uniform-looking or smooth surface between the lower part of the standard and the top part.  
         [0028]    [0028]FIG. 4 shows a preferred installation in accordance with the invention, and FIG. 5 is an assembly view of the elements of the installation of FIG. 4. In accordance with this embodiment, the axles  26  comprise rods with centrally located threaded portions  30 . The axle is installed in a standard by placing the axle through a hole  32  and by securing the axle to the standard by tightening nuts  34 . Nuts  34  may both be removable, or one may be fixed to the axle. As well, the axle may have a fixed shoulder serving the function of the head of a bolt in place of one of the nuts  34 . In that case each axle would have a single removable nut  34 .  
         [0029]    The seat bottom may be held in the desired location in various ways. In one embodiment, a spring retainer clip  36  is placed on the shaft to limit the movement of the bearing  22  along the axle. Preferably the retainer clip is a coiled spring that can be released by squeezing the ends to expand the coil to allow it to move onto the axle. When the coils are released, the clip is frictionally held to the axle. When used on opposite sides of the set bottom after centering the retainer clips maintain the seat bottom centered. Additionally or alternatively, a compression spring  37  may be placed between each standard and the seat bottom (e.g., the bearing). This spring urges the seat away from each standard and effectively centers the seat bottom by pushing against the spring on the opposite side of the seat bottom. A spacer  35  may be used to reduce the required length of the spring  37 .  
         [0030]    [0030]FIG. 6 shows a preferred embodiment of a spherical bearing assembly  38 . This assembly is a self-contained unit configured to be attached to the seat bottom in the manner shown in FIG. 2 a.  The assembly  38  includes a bearing top  40  that receives an bearing base  42  to form a spherical race to receive spherical bearing roller  44 . Bearing top  40  includes outwardly extending legs  46  for receiving mounting screws (not shown), and the cap provides a generally flat bottom surface  48  for engaging the bottom of the seat  18 . Preferably the seat bottom is molded plastic with ribbing for strength and provides a cavity for receiving the assembly  38  to facilitate assembly.  
         [0031]    The bearing base includes projections  50  that are received in recesses  52  in the bearing top. The projections are preferably T-shaped in vertical cross section to provide a vertical part  54  and a horizontal part  56 . The recesses  52  have corresponding portions receiving these parts. Cooperation between the several surfaces forming the bearing top and bearing base maintains the relative positions of the bearing top and the bearing base both before and after final attachment to the seat bottom.  
         [0032]    The mating surfaces of the bearing top  40  and the bearing base  42  are shaped such that the bearing base forms a generally spherical race with adequate clearance to provide smooth operation of the spherical bearing  44  therein. The spherical bearing may have a circumferential groove to eliminate molding problems to ensure smooth operation. The sides  58  of the bearing base  42  are tapered inward to facilitate molding and assembly. Further, the dimensions are such that the bottom surface  60  of the bearing base is coplanar with the bottom surface  48  of the bearing top after installation. This ensures that the load applied to the cooperating bottom surface of the seat bottom by a seated person is accepted by the bearing base and transferred to the bearing roller  44  and axle  26 .  
         [0033]    This is accomplished by making the dimensions of the bearing base, e.g., the distance between sides  58 , slightly greater than those of the of the receiving cavity in the bearing top, e.g., the distance between the sides  62  of the receiving cavity in the bearing top, whereby the bottom surface  60  of the bearing base protrudes slightly beyond the bottom surface  48  of the bearing top before installation. As the screws are tightened on the legs  46 , the bearing top is forced to deform slightly to ensure continuous contact between the bottom surface  60  of the bearing base and the cooperating seat base. Thus, the force on the seat base is always received by and transmitted through the bearing base without applying a force to the bearing top through the legs, which would tend to separate the bearing top from the bearing base and result in a poor fit between the parts.  
         [0034]    Installation is preferably accomplished as follows. First the standards are installed. Then the seat backs  4  are installed to stabilize the standards. The axles  26  are then installed by bolting them into the standards. In the embodiment of FIG. 2, the seat cushions may be installed onto the axles by sliding the spherical bearings onto the axles and securing the caps to the seats.  
         [0035]    In the embodiments of FIGS. 3 and 6, the bearing assemblies are first secured to the seats, preferably at the factory. During installation, one axle is attached to the standard on one side of the seat, and the bearing roller for that side of the seat is slid onto that axle. Then an axle is attached to the standard on the other side of the seat and slid into the bearing roller for that side as well. The bottom cushions are centered between the standards, and the retainer clips are then installed to retain the cushions centered. The process is continued from one end of the to the other end.  
         [0036]    Modifications within the scope of the appended claims will be apparent to those of skill in the art.