Abstract:
A system for use in a multi-story building is provided. The system may include a pipe apparatus having an inlet and an outlet. The inlet is coupled to a supply of fluid and the outlet directs the fluid. The system may include a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor. The system may include an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus. The system may include a power supply having a power source located remotely from said electrically controlled fluid delivery device and supported by the frame assembly.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/454,803, filed Mar. 21, 2011, titled AN APPARATUS AND METHOD OF SUPPORTING AND POWERING A MONITOR MOUNTED TO A MULTI-FLOOR PIPE APPARATUS, docket ELK01-P-351, the disclosure of which is expressly incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention generally relates to an apparatus for supporting and delivering power to a monitor, which is mounted to the outlet end of a multi-floor pipe apparatus and, further, to a frame to support the multi-floor pipe apparatus. 
       BACKGROUND 
       [0003]    As described in U.S. Pat. No. 7,299,883, it is often difficult to extinguish fires in a multi-floor building where one or more floors in which the fire is located are inaccessible due to excessive heat or due to compromised flooring. To address this problem, the &#39;883 patent describes a pipe apparatus that is supported on a frame, which allows the outlet end of the pipe apparatus to be extended through an opening in the building, such as a window, and then raised so that the outlet end of the pipe apparatus can direct water to a floor above where the frame is located. 
       SUMMARY 
       [0004]    In an exemplary embodiment of the present disclosure, a fire fighting system for use in a multi-story building is provided. The fire fighting system including a pipe apparatus having an inlet and an outlet, the inlet for coupling to a supply of fire fighting fluid, and the outlet for directing the fire fighting fluid; a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fire fighting fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor; an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus; and a power supply having a power source, said power source being located remotely from the electrically controlled fluid delivery device and supported by the frame assembly and is proximate to the inlet of the pipe apparatus. In an example thereof, the power source is operatively coupled to the electrically controlled fluid delivery device to control an operation of the electrically controlled fluid delivery device. In another example thereof, the fire fighting system further comprises at least one electrical cord which operatively couples the power source to the electrically controlled fluid delivery device. In a variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, the extension arm including a conduit through which the at least one electrical cord passes. The pipe apparatus may include a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion. The conduit extending through the telescoping portion resulting in the at least one electrical cord passing through the telescoping portion. In another variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, the extension arm including a telescoping portion, and the at least one electrical cord passing through a conduit mounted to the telescoping portion. In a further example, the pipe apparatus is moveable relative to the frame assembly. In a variation thereof, the fire fighting system further comprises a plurality of bearings carried by the pipe apparatus which are received by a plurality of tracks carried by a plurality of guide members of the frame assembly, the plurality of bearings being located proximate a bend in the pipe apparatus. In a further variation thereof, the frame assembly further includes a pivot structure which is engaged by the bearings at a terminal end of the plurality of tracks such that when the plurality of bearings engage a portion of the pivot structure the pipe apparatus pivots relative to the frame assembly resulting in the outlet of the pipe apparatus being raised relative to the frame assembly. In still a further variation thereof, the pivot structure includes a lower ramped surface for guiding the plurality of bearings carried by the pipe apparatus and a generally vertically oriented portion which meets the lower ramped portion at a transition, the transition being the portion of the pivot structure. In another variation, the plurality of guide members and the pivot structure are steel metal components coupled together. In yet another example, a plurality of tips extend downward from the frame assembly, the plurality of tips being configured to reduce slippage of the frame assembly relative to a floor of the building. In still another example, the fire fighting system further comprises wheels which support the frame assembly, the wheels being moveable relative to the frame assembly between a deployed position and a stowed position. In yet still another example, the pipe apparatus is moveable relative to the frame assembly and the power supply is carried by the pipe apparatus. In a variation thereof, the fire fighting system further comprises an extension arm coupled to the pipe apparatus, wherein the pipe apparatus includes a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion, the power supply being carried by the extension arm. In a variation thereof, the power supply includes a housing including at least one electrical connector which are operatively coupled to the at least one electrical cord, the at least one electrical cord operatively coupling the power supply to the electrically controlled fluid delivery device. In a further variation thereof, the power source includes at least one electrical connector, the at least one electrical connector of the power source aligns with the at least one electrical connector of the housing. In still a further variation thereof, the housing includes an open end to receive the power source and an opening opposite the open end. 
         [0005]    In another exemplary embodiment of the present disclosure, a method of fighting a fire in a multi-story building is provided. The method comprising the steps of supporting a fire fighting system at a first floor of the multi-story building; positioning an electronically controlled fluid delivery device proximate an exterior of the multi-story building at an opening in the exterior of the multi-story building corresponding to a second floor of the multi-story building; positioning a portable power source of the electronically controlled fluid delivery device below the second floor of the multi-story building, the second floor being above the first floor; and delivering a fire fighting fluid from an interior of the first floor of the multi-story building to the exterior of the building and then to the second floor of the multi-story building through the opening in the exterior of the multi-story building corresponding to the second floor of the multi-story building with the fire fighting system and the electronically controlled fluid delivery device. In an example thereof, the method further comprises the steps of providing a frame assembly supported by the first floor of the multi-story building; moveably coupling a pipe apparatus to the frame assembly, the pipe assembly being pivotable relative to the frame assembly to extend from the first floor of the multi-story building to the second floor of the multi-story building; and supporting the power source on the pipe assembly. 
         [0006]    In a further exemplary embodiment of the present disclosure, a system for use in a multi-story building is provided. The system including a pipe apparatus having an inlet and an outlet, the inlet for coupling to a supply of fluid, and the outlet for directing the fluid; a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to the supply of fluid at a first floor of the building and enabling the outlet to deliver fluid to a higher floor of the building relative to the first floor; an electrically controlled fluid delivery device mounted at said outlet and in fluid communication with the pipe apparatus; and a power supply having a power source, said power source being located remotely from the electrically controlled fluid delivery device and supported by the frame assembly and is proximate to the inlet of the pipe apparatus. In one example, the power source is operatively coupled to the electrically controlled fluid delivery device to control an operation of the electrically controlled fluid delivery device. In another example, the system further comprises at least one electrical cord which operatively couples the power source to the electrically controlled fluid delivery device; and an extension arm coupled to the pipe apparatus, the extension arm including a conduit through which the at least one electrical cord passes, wherein the pipe apparatus includes a first portion and a second portion which telescopes relative to the first portion resulting in the outlet being moveable relative to the input and the extension arm includes a telescoping portion. 
         [0007]    In still a further exemplary embodiment of the present disclosure, a method of providing a fluid in a multi-story building is provided. The method comprising the steps of supporting a system at a first floor of the multi-story building; positioning an electronically controlled fluid delivery device proximate an exterior of the multi-story building at an opening in the exterior of the multi-story building corresponding to a second floor of the multi-story building; positioning a portable power source of the electronically controlled fluid delivery device below the second floor of the multi-story building, the second floor being above the first floor; and delivering a fluid from an interior of the first floor of the multi-story building to the exterior of the building and then to the second floor of the multi-story building through the opening in the exterior of the multi-story building corresponding to the second floor of the multi-story building with the system and the electronically controlled fluid delivery device. In an example thereof, the method further comprises the steps of providing a frame assembly supported by the first floor of the multi-story building; moveably coupling a pipe apparatus to the frame assembly, the pipe assembly being pivotable relative to the frame assembly to extend from the first floor of the multi-story building to the second floor of the multi-story building; and supporting the power source on the pipe assembly. 
         [0008]    The present disclosure provides a fire fighting system, which includes a pipe apparatus, a frame assembly for supporting the pipe apparatus and enabling the inlet of the pipe apparatus to couple to a supply of fire fighting fluid at a first floor of a building and enabling the outlet to deliver fluid to another location at a different floor than the first floor, and an electrically controlled fluid delivery device mounted at the outlet of the pipe apparatus. A power supply is provided that includes a power source operable to power the electrically controlled fluid delivery device, with power source located remotely from the electrically controlled fluid delivery device so that it is at or in close proximity to the inlet end of the pipe apparatus. 
         [0009]    The frame assembly may be assembly from one or more metal blanks to provide a light weight frame that improves the portability of the system. 
         [0010]    These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a side elevation view of a multi-floor pipe apparatus and support frame therefor; 
           [0012]      FIG. 2  is a side elevation view of the multi-floor pipe apparatus of  FIG. 1 , which incorporates a power supply system; 
           [0013]      FIG. 3  is a similar view to  FIG. 2  illustrating the pipe apparatus in an extended configuration; 
           [0014]      FIG. 4  is a fragmentary enlarged cross-sectional view of the extension arm of the pipe apparatus forming a passageway for the power supply cable; 
           [0015]      FIG. 5  is an exploded perspective view of the power supply system housing and battery; 
           [0016]      FIG. 6  is an exploded perspective view of the frame of another embodiment of the support frame for the pipe apparatus; 
           [0017]      FIG. 7  is a side elevation view of a frame with a retractable wheel in a deployed position; 
           [0018]      FIG. 8  is a similar view to  FIG. 7  illustrating the retractable wheel in a retracted position; 
           [0019]      FIG. 9  is a representative view of the multi-floor pipe apparatus and support frame of  FIG. 1  and a multi-story building. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    The embodiments disclosed herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. While the present disclosure primarily involves the delivery of a fire fighting fluid to combat fires, it should be understood, that the invention may have application to other scenarios. In one embodiment, the systems and methods disclosed herein may be implemented to provide a fluid for neutralizing one or more chemical substances. For example, the systems and methods disclosed herein may be used to neutralize or otherwise alter chemicals used in explosives, drugs, or other items. Further, the systems and methods disclosed herein may be implemented to immobilize individuals. 
         [0021]    Referring to  FIGS. 1-3 , the numeral  10  generally designates a multi-floor firefighting system, which is adapted to direct the flow of water from one floor of a building to another floor of the building, as will be more fully described below. Multi-floor firefighting system  10  includes a multi-floor pipe apparatus  12  and a frame assembly  14 . Frame assembly  14  supports pipe apparatus  12  and forms a guide for the pipe apparatus  12  and so that the pipe apparatus may be supported while it is pushed, for example to the right as viewed in  FIG. 1 , and guided so that the outlet end  16  of pipe apparatus  12  can be extended through an opening in the building, for example through a window, and then raised to direct firefighting fluid to the floor above. To increase the range of pipe apparatus  12 , pipe apparatus  12  includes a telescoping portion that is extendible using an extendible arm  18 . For further details of pipe apparatus  12 , frame  14 , and extension arm  18 , reference is made to U.S. Pat. No. 7,299,883 and pending U.S. application Ser. No. 12/099,247 entitled APPARATUS AND METHOD FOR EXTINGUISHING FIRES IN A MULTI-FLOORED BUILDING, which are hereby incorporated in their entireties. 
         [0022]    In order to increase the range, direction and/or control of the flow of firefighting fluid from the outlet end  16  of pipe apparatus  12 , an electronically controlled fluid delivery device  30  may be mounted to the outlet end  16  of pipe apparatus  12 . Exemplary electronically controlled fluid delivery devices include a nozzle or a monitor and nozzle. A monitor may increase the reach of the fluid flowing through pipe apparatus  12  and, further, provides enhanced control over the direction of flow from the outlet. Suitable nozzles and monitors are sold by Elkhart Brass Manufacturing Company, Inc. (Elkhart Brass) of Elkhart, Ind., with suitable monitors sold under the trademarks STINGER™ and SIDEWINDER® EXM available from Elkhart Brass. Exemplary electronically controlled monitors are disclosed in U.S. patent application Ser. No. 12/174,866, titled FIREFIGHTING DEVICE FEEDBACK CONTROL, the disclosure of which is expressly incorporated by reference herein. 
         [0023]    In order to operate the power-operated actuators, such as motors  32 , on the nozzle and/or monitor, power must be supplied to the actuator(s)  32  and control unit  34 . However, locating a power supply at the nozzle or monitor potentially exposes the power source of the power supply to excessive heat and other detrimental environments and increases the effort to extend the pipe apparatus. Accordingly, the present invention provides a power supply system, illustratively a battery  20  that can deliver power to the monitor without subjecting the source of the power supply to the same environment as the monitor and/or nozzle and, moreover, that is accessible to the firefighter without putting the firefighter to greater risk of injury. For ease of description, the description hereafter references a monitor and nozzle application, but the invention is not so limited and also includes just the use of a nozzle or other fluid delivery devices. The illustrated battery  20  is an example of a portable power supply. 
         [0024]    As shown in  FIG. 9 , multi-floor firefighting system  10  is shown with frame assembly  14  mounted to a window sill  200 A of a building  202 . Window sill  200 A is part of a floor  204 A of building  202  while a window sill  200 B is part of a floor  204 B of building  202 . As illustrated in  FIG. 9 , floor  204 B is positioned above floor  204 A. In one embodiment, at least one additional floor is provided between floor  204 A and floor  204 B. In one embodiment, floor  204 A and floor  204 B are both above a ground floor level of building  202 . Pipe apparatus  12  of multi-floor firefighting system  10  extends through an opening  206 A of floor  204 A of building  202  and electronically controlled fluid delivery device  30  is positioned adjacent an opening  206 B of floor  204 B of building  202 . A supply of fire fighting fluid, illustratively a water source  210 , is coupled to inlet  24  of pipe apparatus  12 . Other fire suppression agents may be used instead of water. 
         [0025]    Water source  210  provides water to pipe apparatus  12  which travels through pipe section  12 A generally in direction  212 . The water then travels upward in generally direction  214  and exits monitor  30  which is in fluid communication with the pipe apparatus  12  generally in direction  216  to combat a fire on floor  204 B. An operator through control unit  34  may control motors  32  to adjust a nozzle of electronically controlled fluid delivery device  30  or to change an orientation of electronically controlled fluid delivery device  30  to direct the water in various directions. In one embodiment, an operator provides input signals to control unit  34  through a control input device  37 . The control input device  37  may be a portable handheld device or attached to frame assembly  14 . In one embodiment, the control input device  37  communicates with the control unit  34  over a wired connection. In one embodiment, the control input device  37  communicates with the control unit  34  over a wireless connection. 
         [0026]    Referring to  FIGS. 2 and 3 , the power supply system includes a battery  20  and a housing  22 , which is mounted to the extension arm  18  and which holds battery  20 . In the illustrated embodiment, housing  22  is supported on the fixed end of the extension arm  18 A adjacent its connection to inlet pipe section  12 A, which forms inlet end  24  of pipe apparatus  12 . 
         [0027]    As described in the referenced application, pipe apparatus  12  has a curvilinear structure, which forms inlet  24  for receiving a fluid from a source of fluid pressure, and an intermediate portion  12 B, which is located between the inlet  24  and outlet  16  and which is adapted to extend from a lower floor to an upper floor. Pipe apparatus  12  is formed from a rigid material, such as a metal material, including steel, stainless steel, or aluminum or an alloy thereof, but may also be produced from a polymeric material, such as polyvinyl chloride. Pipe apparatus  12  is generally formed from several pipe sections, which are joined end to end and, further as described, includes an extendible intermediate portion that includes a telescoping portion  12 C, so that the length of the pipe apparatus  12  may be increased to extend the position of outlet  16 . 
         [0028]    Referring to  FIGS. 1-3 , as noted, pipe apparatus  12  also includes an extendible arm  18  with one end attached adjacent outlet  16  and the other end attached to inlet pipe section  12 A. In addition to providing stiffness to pipe apparatus  12 , extendible arm  18  retains the pipe apparatus in its desired length and, further, supports the telescoping portion  12 C when it is extended. 
         [0029]    As previously noted, frame  14  is adapted to support pipe apparatus  12  in a manner so that pipe apparatus  12  may be laterally guided and, further, may be pivoted to allow the outlet of the pipe apparatus to initially be extended through an opening in the wall of the building, for example through a window, and then raised so that it extends up to the floor above. As best seen in  FIGS. 2 and 3 , mounted to either side of the pipe apparatus is a pair of bearings, such as rollers  40 , which are guided along tracks formed by a pair of rails in frame assembly  14 . Rollers  40  are guided along the tracks to a terminal end of the tracks where continued forward movement of the pipe apparatus translates the motion into pivoting of the pipe apparatus to thereby raise the outlet  16 . To facilitate the movement of the pipe apparatus along frame assembly  14 , extension arm  18  includes a pair of transverse bars  42 , which may be used as handles to push the pipe apparatus along the guide tracks provided by the rails. 
         [0030]    To accommodate the extension of the pipe apparatus  12 , extension arm  18  includes a fixed tubular member  18 A and a telescoping tubular member  18  B, which can be fixed in position along member  18 A to fix the length of intermediate pipe section  12  B by pins  44 , which extend through transverse openings provided in tubular members  18 A and  18  B. As previously noted, battery housing  22  is mounted to fixed tubular member  18 A and further remote from outlet  16 . In order to accommodate the extension of extension arm  18  (and the extension of the monitor mounted to outlet  16 ), the electrical cord that provides the connection between battery  20  and the monitor and nozzle motors may comprise a coiled electrical cord  44 . Cord  44  may be routed through a conduit  46 , which may be mounted to telescoping tubular member  18 B or as noted below through extension arm  18 . 
         [0031]    Housing  22  may be fixedly mounted to tubular member  18 A by a bracket  22 A or may be movably mounted to tubular member  18 A by a sleeve, such as a sleeve with low friction liner to allow movement of housing  22  along tubular member  18 B when a sufficient force is applied. As best seen in  FIGS. 2 and 3 , housing  22  is mounted near or adjacent the proximal end of tubular member  18 A to facilitate replacement of the battery when apparatus  12  is in use. When located at the proximal end of tubular member  18   a , the housing and battery are either in the building or at least easily accessible from the building even when pipe apparatus  12  is extended from the building. 
         [0032]    Referring to  FIG. 4  alternately coiled electrical cord  44  may be extended through extension arm  18 . The extension arm provides protection from the harsh environment and protection to the cable. 
         [0033]    Referring to  FIG. 5 , battery housing  22  optionally incorporates one or more electrical connectors  48 . Connectors  48  couple to the electrical cord (or cords)  44  and which correspond to and align with corresponding connectors  50  provided on battery  20  so that when battery  20  is inserted in housing  22 , connectors  50  will mate with and connect to connectors  48  to provide automatic electrical connection of the battery to the power cord. Furthermore, connections  48  and  50  are configured to provide mechanical or frictional coupling between the respective connectors to retain the battery  20  in housing  22  when inserted. 
         [0034]    In the illustrated embodiment, housing  22  includes an opening  52  on one end of the housing, which includes a recess  54  that extends into the side of housing  22 . Positioned below recess  54  and mounted to the exterior surface  22 A of housing  22  are connectors  48 . Battery  20  similarly includes surface mounted connectors  50 , which align with recess  54  when inserted into housing  22  so that connectors  50  can be aligned with and guided into connection with connectors  48 . Furthermore, housing  22  is sized so that when battery  20  is inserted into housing, the upper end  56  of battery  20  is substantially flush with the end of housing  22 . Optionally, the battery may incorporate a handle or an engagement structure to facilitate removal of the battery from the housing. Alternately, as shown, the battery may be ejected from the housing by way of an opening  58  provided at the opposed end of the housing, such as shown in  FIG. 5 . Opening  58  is sized large enough to allow a gloved hand to extend into the housing and push battery  20  from the opposed opening  52 . When mounted to extension arm  18 , the opening  58 , for example may be oriented toward the inlet pipe section  12 A to provide easy access to a firefighter. 
         [0035]    As would be understood, by locating the battery at the proximal end of extension arm  18 , the battery is located below and away from the high heat area when apparatus  10  is deployed in a firefighting situation. Furthermore, the location provides a firefighter easier access to the battery and reduces the force required to raise the pipe apparatus. 
         [0036]    Referring to  FIG. 6 , the numeral  114  generally designates a multi-floor pipe apparatus support frame assembly. In one embodiment, frame assembly  114  is formed from a plurality of metal sheets that are stamped into a blank and assembled together, by a combination of folding portions of the blank and then securing some of them in place, by welding, bolting or riveting, to simplify the frame assembly and, further, to optionally reduce the weight of the frame assembly and increase the manufacturability. In one embodiment, additional non-sheet metal components may form part of frame assembly  114 . It should be understood that apparatus  10  is often carried by one or more firefighters to a location in a building, which may require them to maneuver up several flights of stairs; therefore, weight is a significant consideration for such firefighting equipment. 
         [0037]    As best seen in  FIG. 6 , frame assembly  114  includes a pair of rollers or bearing guides  116  and  118 , a pivot structure  120 , which joins guides  116  and  118  on one end, and a retaining member  122 , which joins the other ends of guides  116  and  118  to form a frame. Retaining member  122  includes an opening  124  to form an entryway for the bearings or rollers ( 40 ) on pipe apparatus  12  into the guide tracks  116 A and  118 A formed by the guides  116  and  118 . Pivot structure  120  provides a pivot surface for the rollers and a terminal end of the tracks so that when rollers reach pivot structure  120 , forward motion of pipe apparatus  112  will be translated into pivoting and raising of the outlet  16 . 
         [0038]    Each of the respective components  116 ,  118 ,  120 , and  122  are stamped or otherwise cut from a sheet of metal, including aluminum or other metal sheet stock, which are then folded into the configurations as shown in  FIG. 6 . For example, the guide members  116  and  118  are folded into a channel-shaped configuration to form tracks  116 A,  118 A with a pair of upwardly and downwardly extending flanges  126  and  128 , which may form additional guide surfaces for the pipe apparatus as it is moved along the guide path formed by guide tracks  116 A and  118 A. Cut out from the channel-shaped section at the pivot end of the frame are flanges  130  and  132 , which include mounting openings  130 A,  132 A for receiving shafts of wheels or rollers or brackets such as described in reference to  FIGS. 7 and 8 . Optional additional intermediate cut-outs  134  and  136  may be provided in the web  140  of the channel-shaped section to provide mounting structures for anchoring stabilizing structure, such as described in U.S. Pat. No. 7,299,883 and pending U.S. application Ser. No. 12/099,247 entitled APPARATUS AND METHOD FOR EXTINGUISHING FIRES IN A MULTI-FLOORED BUILDING, which are hereby incorporated herein in their entireties, to anchor frame assembly  114  to the floor of a building. Further, additional cut-outs may be made to reduce the weight of frame assembly  114 . 
         [0039]    Pivot guide structure  120  is cut and folded together as shown in  FIG. 6  to form a lower channel-shaped section  142 , which is sized and arranged to join with the respective ends of the guide members  116  and  118 . Lower channel-shaped section  142  forms a ramped surface  144  for guiding the rollers and, hence the pipe apparatus  12 , upwardly until the rollers reach the transition  146  between the lower ramped surface  142  and the generally vertically oriented portion  148  of guide  120 . Once the rollers reach transition  146 , the intermediate pipe section  18  will pivot about rollers to raise the outlet of the pipe, which is guided through upper channel shaped member  150 . As noted, the respective components of the frame assembly may be bolted together, riveted together, or welded and, further, may be reinforced using conventional techniques. 
         [0040]    Referring to  FIGS. 7 and 8 , as previously noted, the frame assembly ( 114  or  14 ) may incorporate bearings, such as wheels  60 , to facilitate the transportation of system  10 . Further, wheels  60  may be provided that are retractable. In the illustrated embodiment, wheels  60  may be mounted to the frame assembly ( 114  or  14 ) by a generally L-shaped bracket  62 , which is pinned on one leg by a pin  64  to frame assembly, and supports a shaft  66  of wheel  60  at its other leg  62 B. When deployed, the wheels are generally located beneath the frame assembly ( 114  or  14 ) for engaging the ground or floor, but then can be pivoted along an accurate path about pins  64  to a stowed position to prevent the frame from moving when in use. For example, pins  64  may incorporate torsion control mechanisms, which limit free movement of the bracket  62  about pins  64  but allow rotation of the bracket when a sufficient force is applied. 
         [0041]    To reduce slippage of the frame assembly ( 114  or  14 ), the frame assembly may incorporate pointed tips  68 , which are mounted to the underside of the frame assembly that engage the floor or surface on which the apparatus is located. For example, suitable tips include carbide tips, which can extend through carpet or other floor coverings to engage the concrete or subfloor to prevent slippage of the frame assembly relative to the floor (or to a ground surface). 
         [0042]    While several forms of the invention have been shown and described, other changes and modifications will be appreciated by those skilled in the relevant art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention which is defined by the claims which follow as interpreted under the principles of patent law including the doctrine of equivalents.