Abstract:
A securing mechanism for use with a recreational vehicle (RV) slide out assembly. The securing mechanism structurally interconnects the slide out assembly to the RV when the slide out assembly is in a retracted position and when it is in an extended position. Specifically, loads in the RV induced from the road, from passengers, from equipment, and other various sources are distributed through the slide out assembly. Advantageously, flexure of the RV walls around the slide out opening is reduced. As a result, walls and their fixtures are less likely to be damaged due to flexure, seals between the RV walls and the slide out are more likely to stay intact, and the size of slide outs can be increased without compromising the structural integrity of the RV.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent No. 60/230,600 which was filed on Sep. 6, 2000. This application hereby incorporates the above application by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to recreational vehicles and, in particular, relates to motor homes and travel trailers that are adapted to expand in size so as to increase the effective interior living space of the vehicle. 
     2. Description of the Related Art 
     Recreational vehicles (RVs) have become an increasingly popular and common means of recreation. RVs are vehicles that include a living space inside and can be either self-propelled as in a motorhome or can depend on another vehicle for their motive power as in campers or trailers. 
     A typical RV comprises a chassis and a frame upon which coach bodywork is mounted. The coach bodywork, which provides and encloses the living space of the RV, typically comprises a floor and vertical walls that extend upwards from the floor. A roof usually rests on and depends on the vertical walls of the body for structural support. 
     Inside the coach body, RVs typically provide sleeping areas, cooking facilities, and self-contained water supplies and toilet facilities. More elaborate RVs can include refrigerator/freezer units, showers and/or bathtubs, air conditioning, heaters, built in generators and/or power inverters, televisions, VCRs, and clothes washer and dryers. RVs provide many of the amenities of a residential home while on the road away from home and are popular for this reason. 
     RV users will typically use the RV to travel to a recreational area and live in the RV for some period of time. RV users often have families with children and, as their trips are often of a recreational nature, will often invite friends or family along on the trip. Some people even use a RV as their primary residence. 
     It can be understood that since a RV will often be used by a large number of people and often for an extended period of time, the RV manufacturers and customers will seek to maximize the amount of usable living space inside their RVs. However, vehicle codes restrict the maximum width and length of vehicles that may be driven on public roads. Also, as a vehicle increases in size, it might become difficult to drive or even become too large to fit into desired destinations. In addition, as the RV gets physically larger, more fuel is required to move it, which increases the cost of operation. 
     One feature that RV manufacturers have used to increase available living space in RVs without increasing the overall vehicle size is the incorporation of slide outs. Slide outs are movable sections of the RV that can extend outward from the RV coach body and effectively increase the interior floor space. Slide outs typically have rigid walls on three sides as well as a rigid roof and floor. The fourth wall space is open to the interior of the RV to provide access between the interiors of the slide out and the RV. 
     Slide outs typically have two normal positions of use: the live-in and the travel position. When the RV reaches its destination and comes to rest, the slide out can be extended to its live-in position. By extending the slide out to the live-in position, the footprint of the RV is increased along with the available interior floor space. When the user wants to move the RV, the slide out is retracted to the travel position. In the travel position, the outer wall of the slide out typically lies flush with the outer walls of the RV coach and the slide out is secured in some manner to allow the RV to travel. 
     Designers of the RV preferably take into account the loading that the RV will undergo when designing the slide out. For example, the RV body will likely undergo static loading due to the weight of the passengers and cargo, and the RV body will likely undergo dynamic loading due to forces induced by the various driving surfaces over which the RV drives. 
     As stated, an opening must be provided in the wall of the RV body to accommodate the slide out. As a result, structural support is lost from the RV body at the opening and the stiffness and strength of the RV body is degraded. It will be understood that as the slide out gets larger and the size of the opening in the side of the RV increases, the stiffness and strength of the RV body become further degraded. 
     More specifically, as the recreational vehicle is travelling down the road, vibrations and other mechanical forces are transmitted to the walls via the wheels. At the opening for the slide out, portions of the wall are not connected to each other which results in these portions having a greater tendency to move with respect to each other. For example, the bottom of the RV wall below the opening is likely to flex with respect to the top of the RV wall above the opening because structurally supportive material has been removed to make the opening. Similarly, the RV wall on one side of the opening is likely to flex with respect to the RV wall on the other side of the opening because structurally supportive material has been removed to make the opening. Over time, these movements may result in damage to the walls of the recreational vehicle. For example, there are often cabinets, surface treatments and fixtures mounted on interior surfaces of the walls. If these items are mounted on the interior surface immediately adjacent the slide out opening, these items may ultimately work loose from the wall presenting a less pleasing appearance. 
     Moreover, excessive flexing of the walls of the recreational vehicle with respect to the slide out opening can cause the walls of the RV to come into contact with the walls of the slide out. This may result in deformation of the interface between the walls and the slide out member. This deformation may further result in the slide out no longer sealing with respect to the main housing of the recreational vehicle or can further inhibit unimpeded motion of the slide out between the deployed and retracted configuration. 
     On a related note, the unsupported sections of the RV walls may vibrate against the walls of the slide out and thereby create audible noise. Disadvantageously, this vibratory noise may create an annoyance for the RV users when travelling. 
     These problems have resulted in recreational vehicle manufacturers limiting the size of the slide out openings in the side walls of the recreational vehicle. As such, the slide outs themselves are also being limited both in terms of their height and their length. It will be appreciated that slide outs generally have a lower ceiling height than the main housing of the recreational vehicle due to the floor and ceiling of the slide out being inset from the floor and ceiling of the main housing. The loss of structural reinforcement as a result of the slide out opening further induces recreational vehicle manufacturers to further reduce the height of the opening so as to reduce the loss of structural reinforcement. This further reduces the height of the slide out area, thereby limiting its use and comfort when in the deployed configuration. 
     Moreover, the length of the slide out opening is also often limited to limit the loss of structural support along the side wall of the recreational vehicle. This reduces the overall floor area of the slide out and thus the overall available living space of the recreational vehicle when the slide out is in the deployed configuration. 
     From the foregoing, it is apparent that there is a need for a recreational vehicle having a slide out that allows for greater dimensioned slide outs. To this end, there is a need for a slide out assembly that can be expanded both in length and in height without a significant loss of structural support in the main housing so that the potential for damage or loss of integrity of the recreational vehicle housing when the slide out is in the retracted position during travel is reduced. 
     SUMMARY OF THE INVENTION 
     The aforementioned needs are satisfied by the recreational vehicle of the present invention with the reinforced slide out mechanism. In one aspect, the present invention is a recreational vehicle comprising a chassis having a first and second end and a first and a second lateral side, a set of wheels attached to the chassis to permit rolling movement over the ground, and a main housing. The main housing has a floor positioned on the chassis, a first side wall and a second side wall and a first side wall and a second end wall and a roof mounted atop the first side wall, the second side wall, the first end wall, and the second end wall so as to define an interior living space. The first side wall defines an opening therein that extends a first lateral distance in the first side wall and a first vertical distance such that the opening in the first side wall defines an upper portion and a lower portion of the first side wall. 
     The recreational vehicle further comprises a slide out housing that is mounted in the opening in the first side wall, and the slide out housing is movable between a retracted position and an extended position. When in the retracted position, the slide out housing is retracted into the opening so as to be substantially positioned within the main housing. When in the extended position, the slide out housing is extended outward from the opening so that a portion of the slide out housing is extended outward from the first side wall. Furthermore, the recreational vehicle comprises a securing mechanism that engages with the slide out housing and the upper portion and the lower portion of the first side wall such that the securing mechanism, in combination with the slide out housing, inhibits movement between the upper portion of the first side wall and the lower portion of the first side wall of the main housing when the slide out housing is in the retracted position. The securing mechanism engages with the slide out housing and the upper portion and the lower portion of the first side wall such that the securing mechanism, in combination with the slide out housing, inhibits movement between the upper portion of the first side wall and the lower portion of the first side wall of the main housing when the slide out housing in the extended position. 
     In another aspect, the present invention is a recreational vehicle comprising a chassis having a first end and a second end and a first lateral side and a second lateral side, a set of wheels attached to the chassis to permit rolling movement over the ground, and a main housing. The main housing has a floor positioned on the chassis, a first side wall and a second side wall and a first end wall and a second end wall and a roof mounted atop the first side wall, the second side wall, the first end wall, and the second end wall so as to define an interior living space. The first side wall defines an opening therein that extends a first lateral distance in the first side wall and a first vertical distance such that the opening in the first side wall defines an upper portion and a lower portion of the first side wall. 
     The recreational vehicle further comprises a slide out housing that is mounted in the opening in the first side wall, and the slide out housing comprises a plurality of walls. The slide out housing is movable between a retracted position and an extended position. When in the retracted position, the slide out housing is retracted into the opening so as to be substantially positioned within the main housing. When in the extended position, the slide out housing is extended outward from the opening so that a portion of the slide out housing is extended outward from the first side wall. Furthermore, the recreational vehicle comprises a securing mechanism that structurally interconnects the roof of the recreational vehicle to the frame of the recreational vehicle via the walls of the slide out housing. 
    
    
     By structurally interconnecting the slide out walls to the walls of the main housing, the amount of flex of the main housing walls during travel is reduced. This further reduces the likelihood of damage to the wall or associated structures and the loss integrity of the seal between the slide out housing and the main housing. These and other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a perspective view of a motorhome with a slide out in, the extended live-in position; 
     FIG. 1B is a perspective view of a trailer with a slide out in the extended live-in position; 
     FIG. 2A is a top, cutaway view of a motorhome with a slide out assembly in the retracted travel position; 
     FIG. 2B is a top, cutaway view of a motorhome with a slide out assembly in the extended live-in position; 
     FIG. 3A is a section view of the motorhome with the slide out assembly in the extended live-in position; 
     FIG. 3B is a section view of the motorhome with the slide out assembly in the retracted travel position; 
     FIG. 4 is a detail view of a slot taken from FIG. 3B; 
     FIG. 5A is a section view of a coach of an alternative embodiment of the actuating mechanism of the slide out assembly; and 
     FIG. 5B is a section view of a coach with an alternative embodiment of the actuating mechanism of the slide out assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     References will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1A illustrates one embodiment of a recreational vehicle (RV)  100   a  comprising a motor home having a generally rectangular frame  102   a  attached to a plurality of wheels  104   a  so as to permit rolling movement of the RV  100   a  over the ground. As is also shown in FIG. 1A, a main housing  106   a  is mounted above the frame  102   a  and is essentially formed of a plurality of planar walls that are joined together and mounted to the frame  102   a  in a well known manner so as to define an inner living space  110   a  having a floor. Furthermore, an exterior slide out assembly  112   a  is shown attached to a first side wall  114   a  of the main housing  106   a  and extended from an opening  116   a  of the main housing  106   a  in an extended position. 
     FIG. 1B illustrates another embodiment of a recreational vehicle (RV)  100   b  comprising a fifth wheel trailer having a generally rectangular frame  102   b  attached to a plurality of wheels  104   b  so as to permit rolling movement of the RV  100   b  over the ground. Furthermore, a male hitch assembly  103   b  is shown at the front of the RV  100   b  and is designed to couple with a known female hitch assembly of a towing vehicle so that the RV  100   b  can be towed by the towing vehicle. As is also shown in FIG. 1B, a main housing  106   b  is mounted above the frame  102   b  and is essentially formed of a plurality of planar walls that are joined together and mounted to the frame  102   b  in a well known manner so as to define an inner living space  110   b . Furthermore, an exterior slide out assembly  112   b  is shown attached to a first side wall  114   b  of the main housing  106   b  and extended from an opening  116   b  of the main housing  106   b  in an extended position. 
     As will be described in greater detail below, the exterior slide out assembly  112   a ,  112   b  shown respectively in FIGS. 1A and 1B can either be placed in the deployed configuration so as to effectively increase the inner living space  110   a ,  110   b  of the RV  100   a ,  100   b  or be placed in a retracted configuration so as to provide the RV  100   a ,  100   b  with a more suitable size and shape for being driven or towed on a road. 
     The exterior slide out assembly  112  is formed of a plurality of walls that join together to form a supplemental living space therein. The plurality of walls include an outer vertical wall  120 , a front lateral vertical wall  122 , a rear lateral vertical wall (not shown), an overhead horizontal wall  126 , and a lower horizontal wall  130 . 
     As will be described in detail below, the exterior slide out assembly  112  moves between the extended and the retracted positions in a known manner. Furthermore, although the preferred embodiments shown FIGS. 1A and 1B illustrate the exterior slide out assembly  112  extending from the left side of the RV  100   a ,  100   b , it can be appreciated that the exterior slide out assembly  112  could be adapted to extend from the right side of the RV  100   a ,  110   b.    
     It will be understood that key elements of the present invention are shared by the motor home RV  100   a  and the trailer RV  100   b . Therefore, for the sake of clarity, the remaining portion of this application will primarily refer to the motor home RV  100   a  only. However, it is understood that the disclosure applies equally to the trailer RV  110   b  without departing from the spirit of the invention. Similarly, the remaining portion of this application will refer to the slide out assembly  112  generally as applied to the motor home RV  110   a . Again, it is understood that the disclosure applies equally to the trailer RV  110   b  without departing from the spirit of the invention. 
     Reference will now be made to FIGS. 2A and 2B, which provide a detailed plan view of the living space  110   a  within the motor home  110   a  of FIG.  1 A. In particular, FIG. 2A illustrates the motor home  100   a  with the exterior slide out assembly  112  in the retracted position and FIG. 2B illustrates the motor home  110   a  with the exterior slide out assembly  112  in the extended position. It will be appreciated that the layout of the living space  110   a  illustrated herein is simply illustrative of one of a number of possible layouts and that a number of variations to this layout can be made without departing from the spirit of the present invention. 
     As shown in FIG. 2A, the exterior slide out assembly  112 , in the retracted position, extends into the main housing  106   a  so that the slide out assembly  112  is substantially positioned within the living space  110   a  of the RV  100   a . Consequently, the outer vertical wall  120  of the exterior slide out assembly  112  is aligned with the opening  116   a  of the main housing  106   a  so as to form the RV  100   a  with a more aerodynamic shape and so as to reduce the effective width of the RV  100   a  while the vehicle is being driven. 
     As shown in FIG. 2B, the exterior slide out assembly  112   a , in the extended position, extends out of the opening  116   a  of the first side wall  114   a  of the main housing  106   a  so that an opening  132  of the slide out assembly  112  aligns with the opening  116   a  of the main housing  106   a . Thus, the supplemental living space  134  provided by the deployed exterior slide out assembly  112  combines with the living space  110   a  of the main housing  106   a  to form an expanded living space  136   a  of the RV  100   a . Although the illustrated embodiment shows the exterior slide out assembly  112  spanning the entire length of the main housing  106   a , it can be appreciated that the slide out assembly  112  can be a variety of other suitable lengths, depending on the particular application. 
     As shown in FIG.  2 A and FIG. 2B, the RV  100   a  includes an internal expandable room  123 . In one embodiment, the internal expandable room  123  comprises a plurality of stationary walls  127   a-c  extending outward from the main housing  106   a  and a plurality of movable walls  128   a-d . Preferably, the internal expandable room  123  also comprises a roof (not shown) that lies only over the internal expandable room  123 . The movable walls  128   a-d  and the roof (not shown) are preferably rigidly attached together. The movable walls  128   a-d  and the roof are preferably slidably attached to the stationary walls  127   a-c . Like the slide out assembly  112  described hereinabove, the internal expandable room  123  can reside either in a retracted or extended position. When in a retracted position, the movable walls  128   a-d  slide toward the stationary walls  127   a-c  for space saving purposes. When in an extended position, the movable walls  128   a-d  slide away from the stationary walls  127   a-c  in order to increase the living space  110   a  inside the RV  100   a . The roof (not shown) also is expandable such that the internal expandable room  123  will stay completely covered in the extended positions. However, unlike the slide out assembly  112 , the internal expandable room  123  lies inside the main housing  106   a  of the RV  100   a  regardless of whether the internal expandable room  123  is in the retracted or extended position. As will be described below, a rod  125  connects both the slide out assembly  112  and the internal expandable room  123  such that both can extend and retract in tandem. The entire functional scope and advantages of the internal expandable room  123  is described in detail in Applicant&#39;s co-pending patent application Ser. No. 09/595,144 filed on Jun. 16, 2000 and entitled “RECREATIONAL VEHICLES WITH EXPANDABLE ROOM,” which is hereby incorporated by reference. 
     FIG.  2 A and FIG. 2B also show that the RV  100   a  includes a securing mechanism  118 . In the embodiment shown, the securing mechanism  118  is located at a midpoint  119  of the slide out assembly  112 . As will be described below, the securing mechanism  118  comprises a plurality of subcomponents which allow for the structural interconnection between the slide out assembly  112  and the main housing  106   a  of the RV  100   a  both when the slide out assembly  112  is in the extended position and when the slide out assembly  112  is in the retracted position. 
     Turning now to FIG.  3 A and FIG. 3B, cross-sectional views of the RV  100   a  with the slide out assembly  112  in the extended and retracted positions are shown. As shown in FIG. 3A, the securing mechanism  118  comprises a first upper flange plate  146 . In one embodiment, the first upper flange plate  146  is a plate that is rigidly attached to and extends upward from a first end  145  of the upper horizontal wall  126 . Similarly, the securing mechanism  118  also comprises a lower flange plate  147 . In one embodiment, the lower flange plate  147  is a thin plate that is rigidly attached to and extends downward from a first end  148  of the lower horizontal wall  130 . A pin  150   a ,  150   b  is attached to the first upper flange plate  146  and the lower flange plate  147  respectively, and both pins  150   a ,  150   b  face toward the center of the RV  100   a . In one embodiment, the pins  150   a ,  150   b  are substantially shaped like cylinders with a conic profile at their first ends  189 . As will be described below, the pins  150   a ,  150   b , the first upper flange plate  146  and the lower flange plate  147  structurally interconnect the slide out assembly  112  with the main housing  106   a  of the RV  100   a  when the slide out  112  is in the retracted position. 
     As shown in FIG. 3B, the securing mechanism  118  further comprises a second upper flange plate  170 . The second upper flange plate  170  is rigidly attached to and extends upward from a second end  172  of the upper horizontal wall  126 . Attached to the second upper flange plate  170  is a pin  150   c  substantially similar to the other pins  150   a ,  150   b  except that it faces in the opposite direction as the others. 
     FIG.  3 A and FIG. 3B also illustrate the first side wall  114   a  of the main housing  106   a  of the RV  100   a  having a slot  180 . In one embodiment, the slot  180  comprises an oblong shape wherein the slot  180  has a longer length that is positioned in the vertical direction, and the shorter width is positioned in the horizontal direction as is shown in FIG.  4 . Preferably, the width of the slot  180  is slightly larger than the diameter of the pins  150   a ,  150   c . Similarly, the depth of the slot  180  is preferably at least equal to the length of the pins  150   a ,  150   c . As will be described in greater detail below, the slide out  112  primarily moves in the horizontal direction; however, the slide out  112  can also move in the vertical direction when it is almost fully extended and when it begins to retract. Thus, the slot  180  is preferably configured to allow for vertical movement of the pins  150   a ,  150   c  inside the slot  180 . 
     Moreover, FIG.  3 A and FIG. 3B show that the main housing frame  102  further comprises an aperture  181  mounted on a lower section of the main housing frame  102 . In one embodiment, the aperture  181  is circular, and the diameter of the aperture  181  is slightly larger than the diameter of the pin  150   b . Also, the depth of the aperture  181  is approximately the same as the length of the pin  150   b . The aperture is located in the frame  102  so as to be longitudinally aligned with the pin  150   b . 
     As will be described in greater detail below, when the slide out assembly  112  is in the retracted position, one pin  150   a  resides inside the slot  180  while the other pin  150   b  resides inside the aperture  181 . Similarly, when the slide out assembly  112  is in the extended position, the pin  150   c  resides inside the slot  180 . As will be described in greater detail, positioning the pins  150   a-c  in such a manner allows the slide out assembly  112  to support the otherwise unsupported first side wall  114   a  and reduce movement between the upper and lower portions of the first side wall  114   a.    
     FIG. 4 is a detail view of the slot  180 . As shown, the pin  150   a  resides inside a lower end  182  of the slot  180  when the slide out assembly  112  is in the retracted position. In one embodiment, when the slide out assembly  112  has reached the fully retracted position and the pin  150   a  is positioned at the lower end  182  of the slot  180 , a solenoid  184  throws a bolt  185  substantially perpendicular to the major axis of the slot  180 . The bolt  185  is sized such that when it is thrown, the periphery of the bolt  185  lies closely adjacent to the upper periphery pin  150   a . Thus, in this position, the periphery of the pin  150   a  is surrounded both by the periphery of the lower end  182  of the slot  180  and by the bolt  185 . As will be described below, this feature aids in structurally interconnecting the slide out assembly  112  to the main housing  106   a  of the RV  100   a.    
     Similarly, when the slide out assembly  112  is in the extended position, the pin  150   c  resides inside the slot  180 . The bolt  185  of the solenoid  184  then shifts into position above the pin  150   c  such that the bolt  185  in combination with the periphery of the slot  180  retains the pin  150   c . As will be described below, this increases the structural integrity of the RV  100   a.    
     In another embodiment, the solenoid  184  automatically shifts the bolt  185  into position. A controller (not shown) sends an electronic signal to the solenoid  184  when the slide out assembly  112  reaches its fully extended or fully retracted position. The solenoid  184  then shifts the bolt  185  into position over the pins  150   a ,  150   c.    
     Referring back to FIGS. 2A and 2B, the retaining structures  118 , in this embodiment, are located at the midpoint  119  of the slide out assembly  112 . In the embodiment shown in FIGS. 2A and 2B, the retaining structure  118  supports the midpoint  119  of the slide out assembly  112  to support the otherwise unsupported midpoint  119  of the first side wall  114   a . As such, the loss in stiffness of the first side wall  114   a  caused by the removal of material to make the opening  116  is counteracted by the support given by the retaining structure  118 . It will, however, be appreciated that while the retaining structures are shown as being mounted at the mid-points, any number of retaining structures positioned about the interface between the slide out and the main housing can be implemented without departing from the spirit of the present invention. 
     More specifically, it is understood that once the opening  116  is formed (i.e., when material is removed from the first side wall  114   a  to form the opening  116 ), structural support is lost from the first side wall  114   a . As such, the portions of the first side wall  114   a  at the periphery of the opening  116  have a greater ability to flex and bend toward/out from the middle of the opening. However, the securing mechanism  118  restores some of the structural support into the first side wall  114   a . When the slide out assembly  112  is in the retracted position, forces in the first side wall  114   a  transfer into the pins  150   a ,  150   b  and into the walls of the slide out assembly  112 . Because the walls of the slide out assembly  112  are rigid, the walls counteract those forces and cause the pins  150   a ,  150   b  to push opposite to the direction of flexure (i.e., support the periphery of the opening  116 ) such that flexure is reduced. Similarly, when the slide out assembly  112  is in the extended position, forces in the first side wall  114   a  transfer into the pin  150   c  and into the walls of the slide out assembly  112 . Because the walls of the slide out assembly  112  are rigid, the walls counteract those forces and cause the pin  150   c  to push opposite to the direction of flexure (i.e., support the periphery of the opening  116 ) such that flexure is reduced. 
     Reduction in flexure allows for several advantages. First, the walls of the main housing  106  are less likely to deform due to flexure, and there is less likelihood for damage to the walls or for damage to components that attach to the wall (e.g., cabinets, surface treatments, etc). Additionally, the interfacing members between the main housing  106  and the slide out assembly  112  are less likely to make contact and deform due to flexure, and thus any seals or other like members are more likely to remain functional and watertight. Finally, noisy vibrations between the first side wall  114   a  and the slide out assembly  112  are likely to be advantageously reduced. This is because the portions of the first side wall  114   a  around the periphery of the opening  116  are less likely to flex and make contact with the slide out assembly  112 . 
     It is understood that as slide out assemblies  112  become larger, the opening  116  becomes larger, there becomes more unsupported length of the first side wall  114 , and the amount of potential flexure of the first side wall  114  increases. As stated, use of the securing mechanism  118  counteracts the loss of support in the first side wall  114  and there is less potential for flexure even though the opening  116  is larger. Therefore, the securing mechanism  118  advantageously allows RV manufacturers to incorporate larger slide out assemblies  112  into their RVs. Advantageously, the usable living space inside the RV  100   a  can be increased with the larger slide out assembly  112 . 
     In other embodiments, a plurality of securing mechanisms  118  are integrated into the RV  100   a . For instance, in one particular embodiment, there are securing mechanisms  118  located at each of the four corners of the slide out assembly  112 . In other embodiments, multiple securing mechanisms  118  are positioned intermittently along the length of the overhead horizontal wall  126  and the lower horizontal wall  130  of the slide out assembly  112 . It is understood that as the number of securing mechanisms  118  increases, there are more locations where the first side wall  114   a  is supported, and there is advantageously less flexure of the first side wall  114   a.    
     FIG.  3 A and FIG. 3B also show components that help to move the slide out assembly  112  between the extended and retracted positions. The slide out assembly  112  moves between its retracted position and its extended position in a known manner. In one embodiment, a motor (not shown) engages an actuator (not shown), such as a worm gear or screw drive, and the actuator moves the slide out assembly  112  between its extended and retracted position. In other embodiments, hydraulic components are used to move the slide out assembly  112  and in still other embodiments, the slide out assembly  112  is moved manually. It is understood that movement of the slide out assembly  112  could be achieved in numerous ways without departing from the spirit of the invention. 
     FIG.  3 A and FIG. 3B also show components that aid in the movement of the slide out assembly  112 . As shown, a roller  164  is attached to the underside of a second end  168  of the lower horizontal wall  130  of the slide out assembly  112  to allow for rolling movement of the slide out assembly  112  across a floor  107  of the main housing  106   a  of the RV  100   a . More specifically, when the slide out assembly  112  is in the retracted position, the lower horizontal wall  130  of the slide out assembly  112  rests above the floor  107  of the RV  100   a . Then, as the slide out assembly  112  moves between the retracted position and the extended position, the roller  164  rolls down a ramp  166  cut into the floor  107  of the RV  100   a . As shown in FIG. 3A, once the slide out assembly  112  reaches its fully extended position, the lower horizontal wall  130  lies flush with the floor  107  of the RV  100   a.    
     Also, as shown in FIG.  3 A and FIG. 3B, the slide out assembly  112  also comprises a roller system  188  which supports the second end  172  of the overhead horizontal wall  126  as the slide out assembly  112  moves. The roller system  188  comprises a post  174 , which has a first end  173  and a second end  175 . The first end  173  of the post  174  is rigidly attached to the second upper flange plate  170 . A roller  176  is connected to the second end  175  of the post  174 . The roller  176  lies inside a track  178 . The track  178  is rigidly attached to the main housing  106   a  of the RV  100   a . In one embodiment, the track  178  comprises a long piece of bent metal, and its cross section resembles the letter “C.” In the embodiment shown in FIG. 3B, the track  178  is substantially straight except that, at a first end  180  of the track  178 , the track  178  is bent at substantially the same angle as the ramp  166  included in the floor  107  of the RV  100   a . When the roller  178  approaches the first end  180  of the track  178 , the roller  178  moves in a downward angle in the same direction as the roller  164  located at the second end  168  of the lower horizontal wall  130 . 
     When the slide out assembly  112  moves, the roller  176  moves along the track  178 . As such, the roller  176  in turn supports the second end  172  of the overhead horizontal wall  126  of the slide out assembly  112  via the post  174 . Thus, the weight of the slide out assembly  112  is distributed between the roller  164  at the bottom of the slide out assembly  112  and the roller  176  located in the track  178 . Advantageously, the slide out assembly  112  is easier to move because the distribution of weight puts less normal force on each roller  164 ,  176 , thereby reducing the resultant frictional force at the rollers  164 ,  176 . 
     On a related note, since the roller  176  is guided by the track  178  and is unlikely to come out of the track  178 , the slide out assembly  112  is more likely to slide out straight. Advantageously, the potential for damaging the interface between the slide out assembly  112  and the main housing  106   a  due to a lateral shift of the slide out assembly  112  is reduced. 
     It is understood that the roller systems  188  are designed to provide support sufficient enough to move the slide out assembly  112  from a retracted position to an extended position and vice versa. However, the roller systems  188  are not primarily designed to provide structural integrity between the main housing  106   a  of the RV  100   a  and the slide out assembly  112 . Instead, the securing mechanism  118  acts as a dedicated load-bearing device, taking the load off of the roller system  188 . Advantageously, the roller system  188  is less likely to deform or malfunction due to excessive loading. 
     Turning now to FIG.  5 A and FIG. 5B, another embodiment of the RV  100   a  with the slide out assembly  112  in the extended and retracted position is shown. In this embodiment, a different system is used to move the slide out assembly  112  between the retracted and extended positions. 
     More specifically, a slider assembly  142  allows the slide out assembly  112  to extend or retract. The slider assembly  142  comprises a pivot beam  144  including a first end  152 , which is pivotally attached to the lower flange plate  147 , and a second end  154 , which is pivotally and slidably attached to the frame  102  of the RV  100   a . 
     The slider assembly  142  further comprises a motor  156 , which generates mechanical motion. In the embodiment shown, when the motor  156  is turned on, the motor  156  engages a plurality of gears  158 , and at least one of the plurality gears  158  engages with the pivot beam  144  to shift the pivot beam  144  substantially horizontal with respect to the motor  156 . In this embodiment, the movement causes the pivot beam  144  to pivot about its second end  154  because the gears  158  of the motor  156  remain stationary and push upward on the pivot beam  144  as the pivot beam  144  slides. As the pivot beam  144  slides, the pins  150   a ,  150   b  align with their respective slots  180 ,  181  (in the case of retraction of the slide out  112 ) and the pin  150   c  aligns with its respective slot  180  (in the case of extension of the slide out  112 ). 
     It is understood that the slider assembly  142  is designed to provide support sufficient enough to move the slide out assembly  112  from a retracted position to an extended position and vice versa. However, the slider assembly is not primarily designed to provide structural integrity between the main housing  106   a  of the RV  100   a  and the slide out assembly  112 . Instead, the securing mechanism  118  acts as a dedicated load-bearing device, taking the load off of the slider assembly  142 . Advantageously, the slider assembly  142  is less likely to deform or malfunction due to excessive loading. 
     As stated previously, in one embodiment, the slide out assembly  112  is attached to the internal expandable room  123  via the rod  125 . As such, when the slide out assembly  112  moves into its retracted or extended position, the movable walls  128   a-d  of the internal expandable room  123  move with the slide out assembly  112 . 
     As FIGS. 5A and 5B illustrate, a second end  139  of the rod  125  is pivotally attached to a mounting bracket  212  formed on the upper surface  214  of an overhead covering  216  of the internal expandable room  123 . In particular, the second end  139  of the rod  125  is inserted through an opening  218  formed on the mounting bracket  212 . Furthermore, the diameter of the opening  218  is preferably sized to permit the rod  125  limited horizontal and vertical movements. Preferably, a first stop  208  and a second stop  210  are positioned near the second end  139  of the rod  125  to inhibit the first end  204  of the rod  125  from sliding out of the opening  218  while moving horizontally and to facilitate movement of the movable walls  128   a-d  of the internal expandable room  123 . 
     As is also shown in FIGS. 5A and 5B, a first end  137  of the rod  125 , comprises an L-section  206 . In one embodiment, the L-section  206  is an approximately ninety-degree bend in the rod  125 . The L-section  206  is rigidly attached to the second upper flange plate  170  of the slide out assembly  112 . Also, the pin  150   c  is rigidly attached to the L-section  206  at a position in which the pin  150   c  can lie inside the slot  180  when the slide out assembly  112  is in the extended position. 
     Preferably, the rod  125  is mounted in a manner such that outward movements of the slide out assembly  112  will exert a force on the rod  125 , causing the rod  125  to move in a substantially horizontal direction. During deployment of the slide out assembly  112 , the rod  125  is pulled outward by the slide out assembly  112  causing the second end  139  of the rod  125  to slide in generally the same direction through the opening  218  on the mounting bracket  212  until the first stop  208  of the rod  125  is adjacent the opening  218 . 
     Preferably, the second stop  210  is larger than the opening  218 , causing the rod  125  to stop sliding once it is adjacent the opening  218 . As such, a continued pulling of the rod  125  by the slide out assembly  112  will cause the second stop  210  to push against the mounting bracket  212  in an outward direction. Since the mounting bracket  212  is fixedly mounted to the overhead covering  216  of the internal expandable room  123 , the outward push exerted on the mounting bracket  212  by second stop  210  will deploy the movable walls  128   a-d.    
     In one embodiment, the first and second stop  208 ,  210  can be adjusted and spaced apart at a desired distance. As stated previously, the internal expandable room  123  will extend when the second stop  210  lies adjacent to the mounting bracket  212 , and the internal expandable room  123  will retract when the first stop  208  lies adjacent to the mounting bracket  212 . However, the movable walls  128   a-d  of the internal expandable room  123  will remain stationary when the mounting bracket  212  lies in between the stops  208 ,  210 . This allows the rod  125  to slide freely through the opening  218  for a first distance  220  (i.e., the first distance  220  equal to the distance between the first and second stop  208 ,  210 ). This allows the slide out assembly  112  to move independently from the internal expandable room  123  until one of the stops  208 ,  210  contacts the mounting bracket  212 . Advantageously, if the slide out assembly  112  requires more travel than the internal expandable room  123  to move between an extended position or a retracted position, this type of movement is possible due to the adjustable first and second stops  208 ,  210 . 
     As stated, this embodiment includes a slider assembly  142 , which causes the slide out assembly  112  a certain amount of vertical movement when the slide out assembly  112  moves from a retracted position to an extended position. Conversely, the slide out assembly  112  moves vertically upward when the slide out assembly  112  moves from an extended position to a retracted position. 
     Because of this vertical movement of the slide out assembly  112 , it is necessary for the rod  125  to be able to pivot as the slide out assembly  112  moves vertically or else the rod  125  will bend, permanently deform, or fracture. In one embodiment, the mounting bracket  212  allows the rod  125  to pivot. In one embodiment, the size of the opening  218  is large enough relative to the diameter of the rod  125  such that the rod  125  can pivot over its required range freely. In another embodiment, the rod  125  is allowed to pivot because the opening  218  of the mounting bracket  212  is defined by a flange (not shown), and the flange is attached to the remaining portion of the mounting bracket  212  by way of a roller bearing widely known in the art to allow for rotating motion while it remains fixed inside an outer structure. 
     As stated above, the entire functional scope and advantages of the internal expandable room  123  is described in detail in Applicant&#39;s co-pending patent application Ser. No. 09/595,144 filed on Jun. 16, 2000 and entitled “RECREATIONAL VEHICLES WITH EXPANDABLE ROOM,” which is hereby incorporated by reference. 
     Although the preferred embodiment of the present invention has shown, described and pointed out the fundamental novel features of the invention as applied to this embodiment, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description, but should be defined by the appended claims.