Abstract:
The present invention involves a four (4) wheel trolley used in a track and trolley system which allows the trolley to move smoothly along a track, bear and carrying heavy movable wall panels, and minimize the stacking depth of the movable wall panels when such panels are stored. The trolley includes trolley discs that define an outer circumferential groove. The outer circumferential grooves allow the trolley discs to maintain a lubricant reserve so that the trolley discs may move smoothly along the track. While the trolley may carry heavy loads, because of its relatively small size, the trolley minimizes the stacking depth of movable wall panels in their storage positions.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The field of the present invention pertains to movable wall panel systems that are used to partition large rooms into smaller rooms.  
           [0003]    2. Description of the Related Art  
           [0004]    Movable wall panel systems find useful application in a variety of venues, such as classrooms, offices, convention centers and hospitals. In these venues, the movable wall panels can be utilized to efficiently divide or compartmentalize an interior space into a multitude of separate, smaller rooms. These systems typically include an overhead track and trolley suspension system. The movable wall panels are connected to trolleys that roll within an overhead track. Travel of the trolleys within the track allows the panels to be moved between a stacked arrangement in a storage location, and a wall-forming, extended arrangement in alignment with the overhead track. Trolleys play an important role in movable wall panel systems because they transport the weight of the movable wall panel and provide movement through the track to take the movable wall panel from a first point to a second point.  
           [0005]    One type of movable wall panel system is a single panel system. In a single panel system, individual wall panels are stored in a stacked position in a remote pocket of the venue in which the system is being used. When the single panels are actually in use, they are extended from their stacked position and carried by a pair of trolleys to their wall-forming, extended position.  
           [0006]    Because single panel systems are often used in conference and convention facilities, the systems must be suited to accommodate tall, wide and heavy movable wall panels. The trolleys used in these single panel configurations must be capable of bearing and carrying heavy loads. For this reason, one type of trolley frequently used in single panel systems is an eight (8) wheel trolley. Eight (8) wheel trolleys normally have large bodies for suspending and carrying heavy movable wall panels.  
           [0007]    One problem with the use of eight (8) wheel trolleys or other trolleys with similarly large bodies is the amount of storage space needed to house the panels in a stacked arrangement. As described earlier, the single wall panels in a single panel system are stored in a stacked fashion in a remote pocket of the venue in which the panels are being used. In this way, the trolleys are stacked against one another. Due to the large trolley bodies necessary for bearing heavy loads, the stacking depth of the pockets in which the single panels are stored is quite limited. This shortage of stacking depth forces any venue using such single panel systems to either spend more money to increase the depth of its storage pockets or to use a smaller number of panels in the venue&#39;s single panel system.  
           [0008]    A problem is further created when smaller trolleys are used in single panel systems in an attempt to increase the stacking depth of the movable wall panels in storage. Because the trolleys are smaller in size, the trolleys can neither bear the load of heavy wall panels nor carry the heavy wall panels to their extended orientation. Even further, the use of smaller trolleys prove to be ineffective when carrying the heavy movable wall panels at higher heights. If an attempt is made to increase the heights in which the smaller trolleys may be used, the load-bearing capacity of the trolleys is compromised.  
           [0009]    Yet another problem exists when a trolley&#39;s discs are not adequately lubricated. A lack of lubrication to a trolley&#39;s discs places a larger burden on the track on which the trolley moves. Subsequently, the trolley not only moves roughly along the track, but in doing so, the trolley may also damage the track.  
           [0010]    The prior art includes an example of lubricating rollers, specifically those that form part of the roller chains of conveyors. In this example, the rollers include chambers with radial partitions extending inwardly across the chambers from the outer periphery of the rollers to the outer surface of bushings to which the rollers are attached. The radial partitions define lubricant passages, and the bushings have lubricant holes which are adapted to communicate with the rollers&#39; lubricant passages. When lubricant falls onto the radial partitions of the rollers, the lubricant is guided by the lubricant passages to the bushings, whereupon it lubricates the bushings and then passes through the bushing&#39;s lubricant holes to the pins to which the bushings are mounted. The pins are then lubricated as well. In this way, every part of the roller chain is lubricated. A shortcoming of this prior art is that it does not teach how to effectively lubricate the surface of the rollers.  
         SUMMARY OF THE INVENTION  
         [0011]    The trolley of the present invention reduces the stacking width and provides versatility in adapting to track structures. In an exemplary embodiment of the present invention, the track of the track and trolley system includes a pair of bottom flanges extending longitudinally inward from the track&#39;s walls, and the bottom flanges are horizontally displaced from each other to define a channel between them. Each of the bottom flanges defines a disc-supporting surface.  
           [0012]    In one embodiment of the present invention, the trolley includes a trolley body which has first and second axle members having opposite ends. The axle members are positioned within the trolley body in a rotational manner so that they may rotate within the trolley body. The trolley includes four (4) trolley discs which are rotationally attached to each end of the two axles, respectively. The trolley discs enable the trolley to move along a track. Each of the trolley discs define an outer circumferential groove. The outer circumferential groove enables the trolley discs to maintain trolley wheel lubricant so that the trolley moves smoothly along the track.  
           [0013]    In another embodiment of the present invention, the trolley is used in conjunction with a track having a limited disc-supporting bottom surface. This track includes a pair of longitudinally extending bottom flanges that are horizontally displaced from each other to define a channel. Each of the bottom flanges project inward from the track&#39;s wall and define a bottom disc-supporting surface. Each of the bottom flanges further define a vertically contoured lip member, and each of the lip members define a second disc-supporting surface.  
           [0014]    The trolley used with the limited disc-supporting bottom surface includes four (4) discs, each of which define a first region and a second region. The radius of the second region is greater than the radius of the first region by about the height of the lip member. In this way, the trolley has greater support along the track having vertically contoured lip members. The first region of the trolley discs defines an outer circumferential groove. The outer circumferential groove enables the trolley discs to maintain trolley wheel lubricant so that the trolley moves smoothly along the track.  
           [0015]    Other objects of the invention will become apparent upon consideration of the following written description and accompanying figures. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0017]    [0017]FIG. 1 is frontal view of a movable wall panel system using the trolley of the present invention.  
         [0018]    [0018]FIG. 2 is a cross-sectional view of a track and trolley of the present invention taken along view line  2 - 2  of FIG. 1.  
         [0019]    [0019]FIG. 3 is a side view of the trolley of the present invention.  
         [0020]    [0020]FIG. 4 is a top-view of a track and trolley system stacking location.  
         [0021]    [0021]FIG. 4A is an exploded view of the circled section of FIG. 4.  
         [0022]    [0022]FIG. 5 is a side-view of the trolley of the present invention exhibiting the length of the trolley.  
         [0023]    [0023]FIG. 6 is a side-view of a pair of prior art four (4) wheel trolleys exhibiting the combined length of the trolleys.  
         [0024]    [0024]FIG. 7 is a cross-sectional view of an alternative embodiment of the track and trolley of the present invention.  
         [0025]    [0025]FIG. 8 is a side view of an alternative embodiment of the trolley of the present invention. 
     
    
       [0026]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the invention, the drawings are not necessarily to scale and certain features may be exaggerated or omitted in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention, in several forms, and such exemplifications are not intended to be construed as limiting the scope of the invention in any manner.  
       DESCRIPTION OF THE INVENTION  
       [0027]    The embodiment disclosed below is not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiment is chosen and described so that others skilled in the art may utilize its teachings.  
         [0028]    Movable wall panel system  1  includes movable wall panels  10 , track  20  and trolleys  30  depicted in FIG. 1. Trolleys  30  move on track  20  and movable wall panels  10  are suspended from and carried by trolleys  30 .  
         [0029]    As shown in FIGS. 2 and 3, in one embodiment of the present invention, track  20  forms a continuous housing about trolley  30 . Track  20  includes track walls  21  and bottom flanges  22 ,  23  projecting longitudinally inward from track walls  21 . Bottom flanges  22 ,  23  define disc-supporting surfaces  24 ,  25  on which trolley discs  32 ,  33  move. Bottom flanges  22 ,  23  are horizontally separated to form channel  26 .  
         [0030]    Trolley  30  consists of trolley body  31 , through which two rotational axle members  35 ,  36  are horizontally positioned. Attached to each end of rotational axle members  35 ,  36  is one disc of trolley discs  32 ,  33 . Trolley discs  32 ,  33  each define outer circumferential groove  34 . Outer circumferential groove  34  is used to accept and to maintain lubricant (not shown) applied to trolley discs  32 ,  33 .  
         [0031]    Trolley discs  32 ,  33  move on disc-supporting surfaces  24 ,  25  of bottom flanges  22 ,  23 . Because trolley discs  32 ,  33  are capable of maintaining a lubricant reserve within outer circumferential groove  34 , trolley discs  32 ,  33  move smoother on track  20  than trolley discs that are not capable of maintaining such a lubricant reserve. Extending down from trolley body  31  though channel  26  is trolley carrier  37 . Trolley carrier  37  is attached to movable wall panels  10  (FIG. 1) and allows trolley  30  to carry movable wall panels  10  along track  20 .  
         [0032]    Trolleys  30  and movable wall panels  10  are shown in FIG. 4 in the stacked position in which trolleys  30  and movable wall panels  10  are stored. A top view of the orientation of trolleys  30  in their stacked position is shown in FIG. 4A. Trolley  30  has a length L 1 . As can be seen, when movable wall panels  10  are in their stacked position, trolleys  30  are aligned in a linear fashion. Movable wall panels  10 , in a stored position, have stacking depth D. In this way, stacking depth D is in part determined by length L 1  of trolleys  30 .  
         [0033]    Trolleys  30  of the present invention may be more effectively stored, as trolley  30  has a length L1 (FIG. 5) and eight (8) wheel trolley  40  has a length L2 (FIG. 6) (eight [8] wheel trolley  40  is two four [4] wheel trolleys used in combination). L1 of trolley  30  is smaller than L2 of eight (8) wheel trolley  40 . For this reason, stacking depth D of multiple trolleys  30  in a storage position is less than the stacking depth of the same number of eight (8) wheel trolleys  40  in storage. Since trolley  30  and eight (8) wheel trolley  40  both have the same load bearing capacity, it is advantageous to use trolley  30  over eight (8) wheel trolley  40  in a track and trolley system because the use of trolley  30  reduces stacking depth D without decreasing load bearing capacity. The compact design of trolley  30  with the enhanced load bearing and lubricant features of discs  32 ,  33  provide these advantages. Shown in FIG. 4, movable wall panel system  1  illustrates stacking depth D of movable wall panels  10 . Movable wall panels  10  are carried by trolleys  30  and are stored in a stacked arrangement on both sides of stacking switch  12 . Stacking depth D is a function of the number of movable wall panels  10 , i.e., as the number of movable wall panels  10  increase, stacking depth D increases. Stacking depth D is also a function of the respective sizes of trolleys  30  and movable wall panels  10 , i.e., as the sizes of trolleys  30  and/or movable wall panels  10  decrease, stacking depth D decreases as well. In accordance with the present invention, trolley discs  32 ,  33  of four (4) wheel trolley  30  are thicker than the trolley discs of an eight (8) wheel trolley used in a comparable track and trolley system. However, because trolley  30  has one-half (½) the number of trolley discs as does the eight (8) wheel trolley, trolley  30  is smaller in overall size than the eight (8) wheel trolley. As explained above, as trolley  30  size decreases, stacking depth D likewise decreases. Because four (4) wheel trolley  30  has thicker trolley discs  32 ,  33  than does the eight (8) wheel trolley and, hence, is smaller in overall size, trolley  30  is capable of bearing the same load as the eight (8) wheel trolley while reducing stacking depth D. In movable wall panel system  1  shown in FIG. 4 utilizing trolleys  30  of the present invention, stacking depth D is reduced by about twenty-five (25) percent in comparison to a stack of like number of movable wall panels in their stacked arrangement and supported by eight (8) wheel trolleys. This reduction in stacking depth D is based in part on the smaller size of trolleys  30 . In the particular stacking arrangement shown in FIG. 4, seventeen (17) movable wall panels  10  are stacked to the left side of stacking switch  12  and eighteen (18) movable wall panels  10  are stacked to the right side of stacking switch  12 . With the use of four (4) wheel trolleys  30  in movable wall panel system  1 , total stacking depth T is approximately five and five-tenth (5.5) meters. By comparison, with the use of eight (8) wheel trolleys in movable wall panel system  1 , total stacking depth T is approximately seven and two-tenths (7.2) meters. In this way, the use of four (4) wheel trolleys  30  in movable wall panel system  1  reduces total stacking depth T by a little more than twenty-two (22) percent of total stacking depth T in movable wall panel system  1  that uses eight (8) wheel trolleys. The use of four (4) wheel trolleys  30  in place of eight (8) wheel trolleys may reduce stacking depth T by at least twenty (20) percent and by as much as twenty-five (25) percent, depending upon the movable wall panel system in which trolleys  30  are utilized.  
         [0034]    The size of trolley discs  32 ,  33  of trolley  30  is directly proportional to the load bearing capability of trolley  30 . In an exemplary embodiment of the present invention, trolley discs  32 ,  33  each have a diameter of fifty-seven and three-twentieths (57 and {fraction (3/20)}) millimeters. The diameter of trolley discs  32 ,  33  is larger than that of typical trolleys with a load bearing capacity similar to that of trolley  30 . A typical eight (8) wheel trolley  40  with a similar load bearing capacity as trolley  30  and used in a comparable track and trolley system is shown in FIG. 6. Trolley discs  42 ,  43 ,  44 ,  45  each have a diameter of about thirty-five (35) millimeters. In this way, although trolley  30  is smaller than eight (8) wheel trolley  40 , because trolley discs  32 ,  33  of trolley  30  are larger than trolley discs  42 ,  43 ,  44 ,  45  of eight (8) wheel trolley  40 , trolley  30  is able to bear and carry about the same amount of weight as eight (8) wheel trolley  40 . In an exemplary embodiment of the present invention, trolley  30  may bear up to about four hundred and seventy-two (472) kilograms. In this way, trolley discs  32 ,  33  of trolley  30  are each capable of bearing up to one-fourth (¼) of trolley&#39;s  30  four hundred and seventy-two (472) kilogram load. That is, each of trolley discs  32 ,  33  is capable of bearing up to approximately one hundred and eighteen (118) kilograms. By comparison, trolley discs  42 ,  43 ,  44 ,  45  of eight (8) wheel trolley  40  shown in FIG. 6 are not capable of bearing such a heavy load. Because eight (8) wheel trolley  40  is capable of bearing about as much weight as four (4) wheel trolley  30 , each of trolley discs  42 ,  43 ,  44 ,  45  is capable of bearing up to one-eighth (⅛) of trolley&#39;s  40  four hundred and seventy-two (472) kilogram load, i.e., fifty-nine (59) kilograms.  
         [0035]    An alternative embodiment of the present invention is shown in FIGS. 7 and 8. Track  200  forms a continuous housing about trolley  300 . Track  200  includes track walls  210  and bottom flanges  220 ,  230 , and bottom flanges  220 ,  230  project longitudinally inward from track walls  210 . Bottom flanges  220 ,  230  define bottom disc-supporting surfaces  240 ,  250  on which trolley discs  320 ,  330  may move. Bottom flanges  220 ,  230  are horizontally separated to form channel  292 , and bottom flanges  220 ,  230  define vertically contoured lip members  260 ,  270 . Lip members  260 ,  270  define second disc-supporting surfaces  280 ,  290 .  
         [0036]    Trolley  300  consists of trolley body  310 , through which two rotational axle members  350 ,  360  are horizontally positioned. Attached to each end of rotational axle members  350 ,  360  is one disc of trolley discs  320 ,  330 . Trolley discs  320 ,  330  each define first region  320   a ,  330   a  and second region  320   b ,  330   b . First region  320   a ,  330   a  has a first radius and second region  320   b ,  330   b  has a second radius. The first radius of first region  320   a ,  330   a  is greater than the second radius of second region  320   b ,  330   b  by about the height of lip member  260 ,  270 . First region  320   a ,  330   a  also defines outer circumferential groove  340 . While only the circumference of first region  320   a ,  330   a  contacts disc-supporting surfaces  280 ,  290 , second region  320   b ,  330   b  distributes the weight borne by trolley  300  more evenly over axle members  350 ,  360 .  
         [0037]    In one form of the present invention, trolley discs  320 ,  330  move on track  20  shown in FIG. 2. Outer circumferential grooves  340   a  of first region  320   a ,  320   b  are used to accept and to maintain lubricant applied to trolley discs  320 ,  330 . Because trolley discs  320 ,  330  are capable of maintaining a lubricant reserve within outer circumferential groove  340   a  of first region  320   a ,  330   a , trolley discs  320 ,  330  move smoother on track  20  than trolley discs that are not capable of maintaining such a lubricant reserve. Trolley carrier  370  extends downward from trolley body  310  though channel  292 . Trolley carrier  370  is attached to movable wall panels and allows trolley  300  to carry movable wall panels along track  20 .  
         [0038]    While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.