Patent Publication Number: US-8991890-B2

Title: Slide-out room system having wall-mounted drive mechanisms

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/775,020 filed Mar. 8, 2013, and is a continuation-in-part of U.S. patent application Ser. No. 13/660,619 filed Oct. 25, 2012, and U.S. patent application Ser. No. 13/660,739 filed Oct. 25, 2012, which claim the benefit of U.S. Provisional Patent Application No. 61/664,542 filed Jun. 26, 2012, U.S. Provisional Patent Application No. 61/647,908 filed May 16, 2012, U.S. Provisional Patent Application No. 61/565,730 filed Dec. 1, 2011, and U.S. Provisional Patent Application No. 61/551,719 filed Oct. 26, 2011, the disclosures of all of which are hereby incorporated by reference for all purposes. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     FIELD OF THE INVENTION 
     This invention generally relates to slide-out rooms of recreational vehicles, and more particularly, slide-out rooms having multiple compact wall-mounted drive mechanisms. 
     BACKGROUND OF THE INVENTION 
     Some recreational vehicles include extendable slide-out rooms to increase the size of the living quarters while also providing an appropriate size for highway travel. Such slide-out rooms are driven by various types of mechanisms, such as hydraulic cylinders, electric drive screws, or rack-and-pinion gear drives. Rack-and-pinion drive mechanisms sometimes connect to a recreational vehicle within the aperture in which the slide-out room moves. These slide-out mechanisms are considered aesthetically pleasing because the components, except for the gear racks mounted to the side walls of the slide-out room, are relatively inconspicuous. 
     Nevertheless, wall mounted rack-and-pinion drive mechanisms have several drawbacks. For example, the side walls that mount the gear racks are typically skewed (that is, not parallel) relative to the direction in which the room moves or each other due to manufacturing tolerances. As such, the gear racks are typically skewed relative to the drive direction, which in turn may cause several problems. First, the gear racks may simply move away from and disengage the pinions as the slide-out room moves. Second, if the drive mechanism includes some type of feature that attempts to hold the gear rack in engagement with the pinion (for example, a pinion support bracket that engages the gear rack), the slide-out room wall may bend or deform because the rack urges it away from its manufactured position. 
     Some designs have attempted to address the above problems. These designs typically include a pinion mounting bracket that is movably mounted to the vehicle in a transverse direction (that is, a direction perpendicular to the drive direction). As such, the pinion moves relative to the vehicle and remains in engagement with the gear rack even if the gear rack is skewed relative to the drive direction. 
     However, these designs introduce yet another problem. To permit the mounting bracket and pinion to move in the transverse direction, a small clearance space (about 0.5 inch) is provided in the transverse direction between the bracket and a channel that houses the bracket. As such, the pinion mounting bracket, the gear racks, and the slide-out room may shift in the transverse direction as the vehicle moves. In particular, when the vehicle comes to a stop, the large mass of the room may cause the room to shift over the clearance space, and the pinion mounting bracket may abruptly strike the support channel. Such an action could damage the drive mechanism and could be relatively loud for the vehicle&#39;s occupants. 
     This problem is difficult to address because of the pinion mounting bracket&#39;s position within the support channel. Furthermore, even if the mounting bracket can be accessed, fixing the bracket in the transverse direction again causes the original problem of the gear rack disengaging the pinion. 
     As another example of the limitations of rack-and-pinion drive mechanisms, the components that support the weight of the slide-out room are also disposed within the aperture and are typically relatively small due to the limited space. These small supports can only carry a relatively small load, which essentially limits wall mounted rack-and-pinion mechanisms to use with relatively small and light slide-out rooms. Similarly, the weight of the slide-out room is transmitted to the supports from the rack, which is in turn supported by one of the slide-out room walls. The slide-out room walls typically comprise a light-weight (and low-strength) material such as wood and, as such, the slide-out room walls can only carry a relatively small load. This again limits wall mounted rack-and-pinion mechanisms to use with relatively small and light slide-out rooms. 
     Another drawback of wall mounted rack-and-pinion mechanisms is that the slide-out room typically only moves horizontally between the retracted position and the extended position and vice versa. As such, the slide-out room cannot act as a so-called “flush floor” room in which the floor of the slide-out room moves downwardly and is level with the floor of the vehicle in the extended position to eliminate the step between the vehicle and slide-out room. 
     As yet another example of the limitations of rack-and-pinion drive mechanisms, a speed reducer (for example, a gearbox) connecting a drive motor to the pinion is not sufficient for inhibiting unintentional movement of the slide-out room while the vehicle travels, or to maintain the seals in compression over extended periods of time when the vehicle is parked. That is, the speed reducer provides a relatively large reduction ratio and is difficult to back-drive. Nevertheless, the speed reducer may be back-driven by the large forces imparted by the slide-out room when the vehicle accelerates or turns, or wind or other lateral forces applied to the vehicle over time even if stationary. As such, the slide-out room may unintentionally move out or in. 
     Therefore, what is needed is a slide-out room drive mechanism that addresses one or more of the drawbacks described above. 
     SUMMARY OF THE INVENTION 
     The invention provides an in-wall drive mechanism for a flat floor slide-out system. The slide-out room is disposed in an aperture of a side wall of a vehicle and is movable from an upper retracted position to a lower extended position. A drive assembly is supported by the side wall of the vehicle and a driven assembly driven by the drive assembly is connected to a wall of the slide-out room. The slide-out room moves with the driven assembly generally horizontally from the retracted position to the extended position in the drive direction is movable in a generally vertical direction transverse to the drive direction relative to the wall of the vehicle. The driven assembly is moved in the generally vertical direction from an upper position at full retraction to a lower position at full extension. 
     In one preferred aspect, the driven assembly is moved vertically between the upper position and the lower position while horizontal movement of the room is stopped. 
     In another preferred aspect, the drive assembly includes a drive support along a side of the room that moves generally vertically with the room. 
     In another aspect, the drive assembly includes a pinion that moves generally vertically with the room. The pinion may slide vertically along its drive shaft to do so. 
     In another preferred aspect, the apparatus compensates for variations in spacing between the wall of the slide-out room and a perimeter of an opening in the side wall of the vehicle in which the slide-out room moves that occur as the slide-out room moves. 
     In another preferred aspect, the room is lowered and lifted by a mechanism that resides under the floor of the slide-out room. The room is preferably guided and stabilized by the drive and driven mechanisms at the sides of the room and in the side edges of the opening of the stationary wall of the vehicle. 
     In another preferred aspect; the present invention provides for extending a slide-out room in a flat floor mechanism in which the room is lowered to the floor level of the vehicle without applying shear stresses on the gaskets. 
     In another preferred aspect, applying an in-wall mounted mechanism of the invention to a flush floor room provides versatility in the sequence of operation in going between the retracted elevated position and the extended lowered position. In one aspect, the sequence may be, starting from full retraction, to extend the slide-out room to a position nearly fully extended but that is just short of compressing the gaskets, then drop the room and then extend the rest of the way to compress the interior gaskets. This produces a motion that is shaped like a square Z. 
     In an alternative sequence of operation, from full retraction, the room is extended fully to compress the gaskets and stall the extension and then retract the room a small distance to decompress the gaskets, then drop the room, and then extend once again to compress the gaskets. This produces a motion that is like a square lower case h in shape. 
     A third alternative is to extend all the way and then drop, although this would require special gasketing considerations as typical gaskets are not made to slide in shear as would be the case with typical gaskets with this L-shaped motion. For example, the gasket could be inflatable, with the gaskets inflated after the motion to the fully extended, lowered position has occurred, and deflation prior to beginning retraction. 
     The foregoing and other advantages of the invention will appear in the detailed description which follows. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a recreational vehicle with a slide-out room system according to the present invention; 
         FIG. 2  is a detail perspective view of a drive mechanism of the slide-out room system of  FIG. 1 ; 
         FIG. 3  is a detail perspective view of the drive mechanism within line  3 - 3  of  FIG. 2 ; 
         FIG. 4  is a side section view of an upper section of the drive mechanism along line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is a detail side section view of the drive mechanism within line  5 - 5  of  FIG. 4 ; 
         FIG. 6  is a top section view of the drive mechanism along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a side section view of a lower section of the drive mechanism of  FIG. 2 ; 
         FIG. 8  is a detail perspective view of a driven assembly of the drive mechanism of  FIG. 2 ; 
         FIG. 9  is a side section view of the drive assembly along line  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a top sectional view of a second embodiment of the drive mechanism illustrating an interface between a support channel and a drive support; 
         FIG. 11  is a top sectional view of a third embodiment of the drive mechanism illustrating an interface between the support channel and the drive support; 
         FIG. 12  is a perspective view of a roller mechanism supporting the slide-out room of  FIG. 1 ; 
         FIG. 13  is an exploded perspective view of the roller mechanism of  FIG. 12 ; 
         FIG. 14  is a section view of the slide-out room in the retracted position; 
         FIG. 15  is a section view of the slide-out room moving toward the extended position; 
         FIG. 16  is another section view of the slide-out room moving toward the extended position; 
         FIG. 17  is another section view of the slide-out room moving toward the extended position and the roller mechanism lowering the slide-out room in the elevation direction; 
         FIG. 18  is a section view of the slide-out room in the extended position with the slide-out room lowered in the elevation direction to provide a “flush floor” configuration; 
         FIG. 19  is a section view of a slide-out room including a non-flush floor roller; 
         FIG. 20  is a perspective view of the slide-out room system including float inhibiting mechanisms; 
         FIG. 21  is a detail side view of the slide-out room in the extended position with the float inhibiting mechanisms disengaged; 
         FIG. 22  is a detail side view of the slide-out room in the retracted position with the float inhibiting mechanisms engaged; 
         FIG. 23  is a perspective view of another embodiment of a support mechanism supporting the slide-out room of  FIG. 1 ; 
         FIG. 24  is another perspective view of the support mechanism of  FIG. 23 ; 
         FIG. 25  is a top view of the support mechanism of  FIG. 23 ; 
         FIG. 26  is a side view of an elevation assembly of the support mechanism along line  26 - 26  of  FIG. 25  in the slide-out room&#39;s retracted position; the elevation assembly is shown in phantom in the slide-out room&#39;s extended position; 
         FIG. 27  is a side view of a biasing assembly of the support mechanism along line  27 - 27  of  FIG. 25  in the slide-out room&#39;s retracted position; the biasing assembly is shown in phantom in the slide-out room&#39;s extended position; 
         FIG. 28  is a section view of the biasing assembly along line  28 - 28  of  FIG. 25  in the slide-out room&#39;s retracted position; the biasing assembly is shown in phantom in the slide-out room&#39;s extended position; 
         FIG. 29  is a section view of the slide-out room in the retracted position; 
         FIG. 30  is a section view of the slide-out room moving toward the extended position; 
         FIG. 31  is another section view of the slide-out room moving toward the extended position; 
         FIG. 32  is another section view of the slide-out room moving toward the extended position; 
         FIG. 33  is another section view of the slide-out room moving toward the extended position; 
         FIG. 34  is another section view of the slide-out room moving toward the extended position; 
         FIG. 35  is a section view of the slide-out room in the extended position; 
         FIG. 36  is a perspective view of another embodiment of a support mechanism supporting the slide-out room of  FIG. 1  in an elevated position; 
         FIG. 37  is a side view of the support mechanism along line  37 - 37  of  FIG. 36 ; 
         FIG. 38  is a perspective view of the support mechanism of  FIG. 36  in a lowered position; 
         FIG. 39  is a side view of the support mechanism along line  39 - 39  of  FIG. 38 ; 
         FIG. 40  is a perspective view of another embodiment of a support mechanism supporting the slide-out room of  FIG. 1  in an elevated position; 
         FIG. 41  is a side view of the support mechanism along line  41 - 41  of  FIG. 40 ; 
         FIG. 42  is a perspective view of the support mechanism of  FIG. 40  in a lowered position; 
         FIG. 43  is a side view of the support mechanism along line  43 - 43  of  FIG. 42 ; 
         FIGS. 44A and 44B  are perspective views showing position sensors on the operating mechanism; 
         FIG. 45  is a perspective view illustrating a support mechanism (lift) having limit switch sensors and is illustrated in a lower position; 
         FIG. 46  is a perspective view like  FIG. 45  but with the lift illustrated in an upper position; 
         FIG. 47  is a schematic view of a pattern of movement of a slide-out room; and 
         FIG. 48  is an alternative schematic view of a pattern of movement of a slide-out room. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Drive mechanisms for a slide-out room system according to the present invention are supported within the aperture of a vehicle. These mechanisms include gear racks that are movable relative to the slide-out room&#39;s walls. Such a construction permits use of other components or features that inhibit the slide-out room from shifting as the vehicle moves. Furthermore, in some embodiments, these mechanisms do not support the weight of the slide-out room and are configured to move or “float” vertically relative to the vehicle. This motion permits the slide-out room to descend near the extended position such that the floor of the slide-out room is flush with the floor of the vehicle. These aspects of the invention are described in further detail in the following paragraphs, beginning with the general structure of the vehicle, the drive mechanisms, support mechanisms that permit the slide-out room to descend near the extended position, and concluding with various alternative embodiments. 
     Referring first to  FIGS. 1 and 2 , a recreational vehicle  10  supports a slide-out room  12  in an aperture  14  of a vehicle side wall  16 . An interior of the slide-out room  12  is defined by a leading or outside wall  18 , side walls  20 , a ceiling  22 , and a floor  24 . The leading wall  18  includes a fascia  26 , and the plane of the fascia  26  is parallel to the respective planes of the aperture  14  and the side wall  16 . The surface of the fascia  26  facing the side wall  16  includes a seal (not shown). The seal is compressed between the fascia  26  and the side wall  16  when the slide-out room  12  is retracted to prevent leaks between the cabin of the recreational vehicle  10  and the outside environment. The side walls  20  of the slide-out room  12  also include flanges (not shown) located inside the vehicle  10 . The surface of the flanges facing the side wall  16  also includes a seal (not shown) to prevent leaks between the cabin of the recreational vehicle  10  and its environment when the slide-out room  12  is extended. 
     The slide-out room  12  is moved in a drive direction between the extended and retracted positions by two drive mechanisms  28  and  30  ( FIG. 1 ), and one of the drive mechanisms  28  and  30  connects to each of the side walls  20 . The drive mechanisms  28  and  30  are generally identical except for being disposed in mirrored relation to one another. As such, only the drive mechanism  30  will be described below for simplicity. 
     Referring to  FIGS. 2-9 , the slide-out room drive mechanism  30  generally includes a drive assembly or pinion assembly  31  that is partially disposed in a support channel  32  positioned in the aperture  14  of the vehicle side wall  16 . The drive assembly  31  drives a driven assembly  33  (which generally includes a rack  35  as described in further detail below) connected to one of the side walls  20  of the slide-out room  12 . As shown most clearly in  FIG. 2 , the drive mechanism  30  includes upper and lower sections that are disposed adjacent upper and lower sections of the slide-out room side wall  20 , respectively. 
     Referring specifically to  FIGS. 3-5  and turning first to the upper section, the drive mechanism  30  includes a prime mover  34  that receives power from a dedicated battery (not shown), the vehicle&#39;s alternator (not shown), or the like. The prime mover  34  may include a high-speed permanent magnet or brushless 12V DC motor  36  or the like. In some embodiments, the motor  36  includes a rotary encoder (e.g., a Hall effect rotary encoder) and/or dynamic brakes  37  that are operatively connected to the same electrical circuit as the motor  36 . Such dynamic brakes  37  automatically engage when power to the motor  36  is interrupted. 
     Alternatively, the dynamic brakes  37  may be replaced by other types of brakes that are adapted to arrest movement of the drive mechanism  30 . The brake  37  prevents the drive train from moving in the reverse direction and thus maintains the gasket seals in a compressed state in the retracted position and/or the extended position of the room  12 . When in the retracted position, this also inhibits the room  12  from moving in the direction of vehicle travel due to inertia (e.g., when the vehicle  10  abruptly slows or stops) because of friction of the gasket seals in compression. 
     The prime mover  34  further includes a speed reducer  38 , such as a planetary gear transmission, a spur gear transmission, or the like, driven by the motor  36  and having a rotatable output shaft  40  ( FIG. 4 ). The speed reducer  38  significantly reduces the rotational speed provided by the motor  36  and significantly increases the torque. An appropriate torque may be determined based on the size and weight of the slide-out room  12 . Appropriate prime movers  34  including the motor  36 , the dynamic brakes  37 , and the speed reducer  38  are available from Merkle-Korff Industries of Elk Grove Village, Ill. Other appropriate prime movers  34  are available from Rexnord Corporation of Milwaukee, Wis., Stature Electric, Inc. of Watertown, N.Y., and the like. 
     Turning to  FIGS. 4-6 , the motor  36  and the speed reducer  38  are supported by a drive support  42  disposed therebelow. The drive support  42  may comprise various materials, such as molded plastics, machined metal, or the like. Internally, the drive support  42  is hollow and defines a passageway  44  that receives a combined coupling/bushing  46  connecting the output shaft  40  to a drive shaft  48  (e.g., a square cross-sectional drive shaft). Within the passageway  44 , the combined coupling/bushing  46  and a lower bushing  47  support the drive shaft  48 . Vertically near the middle of the drive support  42 , the passageway  44  is sized to receive a pinion gear  50  supported by the drive shaft  48 . The passageway  44  also has an opening  54  ( FIG. 6 ) to permit the pinion  50  to engage the driven assembly  33 , specifically the rack  35 , which will be described in further detail below. 
     Externally, the surfaces of the drive support  42  engage several components. For example, the drive support  42  includes an upper surface that abuts a mounting bracket  49  connected to the prime mover  34 . The mounting bracket  49  is connected to the drive support  42  via an extension spring  51  fastened to the drive support  42 . 
     In addition, the side surfaces of the drive support  42  are not fixedly connected to the support channel  32 . Instead, the side surfaces of the drive support  42  include keyways  56  ( FIG. 6 ) that extend in the longitudinal direction of the support channel  32  and receive keys (not shown) on the inner sides of the support channel  32 . As shown in the figures, the keyways  56  have square cross-sectional shapes, although other shapes may be used provided that they permit the drive support  42  to “float” in the longitudinal direction of the support channel  32  (that is, to move in an “elevation” or vertical direction generally perpendicular to the drive direction). This ability to “float” permits the slide-out room  12  to act as a “flush floor” room in some embodiments and ensures the weight of the slide-out room  12  is supported by relatively strong components spaced apart from the drive mechanism  30 . That is, rollers disposed on the underside of the room  12  support the weight of the slide-out room  12  whether it acts as a flush floor room or a non-flush floor room (i.e., a “flat floor” room; see  FIG. 19  and the associated description). This aspect is described in further detail below. 
     The front face of the drive support  42  includes a mounting support  62  that is disposed proximate the opening  54  and between the pinion gear  50  and the slide-out room wall  20 . The mounting support  62  also engages the rack  35  and is disposed between the rack  35  and the slide-out room wall  20 . As such, the mounting support  62  inhibits the rack  35  from disengaging the pinion gear  50 . Furthermore, the mounting support  62  may include front and rear convex surfaces  69  and  71  that generally face in a transverse direction (i.e., a direction generally perpendicular to both the drive direction and the elevation direction, or the direction of vehicle movement over the road). The convex surfaces  69  and  71  advantageously reduce friction forces between the mounting support  62  and the rack  35  and, similarly, permit the rack  35  to be skewed relative to the slide-out room side walls  20 . 
     Referring specifically to  FIGS. 3 ,  8 , and  9 , the driven assembly  33  includes the rack  35  and two room engaging brackets  72  secured to the side wall  20  and supporting opposite ends of the rack  35 . The rack  35  is a generally elongated component in the drive direction and may comprise various materials, such as hobbed aluminum or the like. The rack  35  also includes a plurality of gear teeth  74  that engage teeth of the pinion gear  50  and permit the rack  35  to be driven by the pinion gear  50 . 
     The room engaging brackets  72  each have a horseshoe-like shape as viewed in the transverse direction. A base  75  of each bracket  72  includes transversely-elongated slots  76  for receiving pins  77  extending in the elevation direction and connecting the rack  35  to the bracket  72 . This “pin-in-slot” connection permits the rack  35  to move in the transverse direction as the slide-out room  12  moves in the drive direction. 
     Each bracket  72  also includes a plurality of through holes  78  for receiving fasteners (not shown) that connect the bracket  72  to the slide-out room wall  20 . 
     Turning again to  FIGS. 2 and 7 , the drive shaft  48  extends below the drive support  42  to the lower section of the drive mechanism  30 . In general, the lower section of the drive mechanism  30  is identical to the upper section below the prime mover  34 . That is, the lower section of the drive mechanism  30  generally includes a drive support  42  that rotatably mounts a pinion gear  50  and holds a rack  35  in engagement with the pinion gear  50 , and can slide up and down vertically in the channel  32 . 
     From the above it should be apparent that both drive mechanisms  28  and  30  receive power to move the slide-out room  12  relative to the rest of the vehicle  10 . In some embodiments, the prime movers  34  of the drive mechanisms  28  and  30  may be synchronized to ensure that the slide-out room side walls  20  move in an appropriate manner relative to one another. The prime movers  34  may be synchronized as described in U.S. patent application Ser. No. 13/197,291, U.S. Pat. App. Pub. 2009/0261610, U.S. Pat. No. 6,536,823, U.S. Pat. No. 6,345,854, U.S. Pat. No. 6,471,275 or U.S. Pat. No. 6,696,813, the disclosures of which are hereby incorporated by reference. The prime movers  34  may alternatively be synchronized in other manners not described explicitly herein. For example, the prime movers  34  may be mechanically synchronized (via a shaft and gears, a chain and sprockets, or the like, connecting the two drive mechanisms  28  and  30 ). 
     The drive mechanisms  28  and  30  may be operated by a single rocker switch (not shown) with one position for extending and one position for retracting. The switch is part of a control panel that is connected to a battery powered control unit that receives sensor and switch inputs and produces outputs to control the slide-out system motors, locks, etc., as is well known and described in the above mentioned patents. In addition, sensors as illustrated in  FIGS. 44A and 44B  may be mounted to the mechanisms  28  and  30  to provide inputs to the control unit. These sensors detect the horizontal and vertical position of the slide-out room so the control unit, in conjunction with its other inputs (e.g., the rocker switch input by the operator, the rotary encoder counts from the rotary encoders of the drive motors and the motor current values), can control the room extension and retraction in a desired sequence of movement. For example, in a square Z pattern of movement, more fully described below, from retraction the slide-out room  12  is extended to a first partially extended position, just short of compressing the room interior gaskets. In that position, the horizontal prime movers  34  are de-energized and a vertical prime mover (e.g.,  346 ; see below) is energized to lower the room  12  to a lower position of the room. The sensors detect when the slide-out room  12  has attained the partially extended position to stop further horizontal movement and initiate lowering and then detect the lower position to stop lowering and re-initiate extension. Extension continues to compress the gaskets and then is stopped by sensing motor current, which increases as the gaskets are compressed. 
     Hall Effect or other sensors may be used for these sensors, with down sensor  82  and up sensor  84  mounted to the support channel  32  and extension sensor  86  mounted on the drive support  42 . Magnet  86  actuates the down sensor  82  when the room is in the down position, magnet  88  actuates the up sensor  84  when the room is in the up position, and magnet  90  actuates the extension sensor when the room is at a partially extended position that is just short of compressing the interior gaskets, during both extension and retraction. That is the horizontal position at which the room is lowered during extension and is raised during retraction. The up sensor  84  remains actuated when the room is in the up position and the down sensor  82  remains actuated when the room is in the lower position, and the up sensor becomes de-actuated and remains so when the room is moved to the lower position and the down sensor  82  becomes de-actuated and remains so when the room is moved to the up position. Magnets  87  and  88  are mounted on the drive support and magnet  90  is mounted on the room engaging bracket  72 . Other positions of the sensors are possible, either on the mechanism or on the room or stationary portion of the RV, and other types of sensors, such as mechanically operated limit switches or other sensors, may be used. 
     In an alternate sensing configuration, electronic synchronization as discussed in the above referenced patents is used to detect extension and retraction of the room (by counting revolutions of the extension/retraction drive motor via a rotary encoder). In combination with that mode of determining horizontal position, elevation is detected with sensors in the room lift. For example, mechanically operated limit switches as illustrated in  FIGS. 45 and 46  may be used to detect whether the room is up or down.  FIG. 45  illustrates the down position with down limit switch  94  actuated and  FIG. 46  illustrates the up position with up limit switch  96  actuated by cam actuator  98  that is mounted to one of the threaded support blocks. The lift  91  illustrated in  FIGS. 45 and 46  is similar to the lift  702  of  FIGS. 36 and 37 , more fully described below, except for having a segmented roller and both sides of the drive shaft being threaded with one side reverse threaded so the threaded support blocks move together or apart in unison, when the common threaded shaft is turned, depending on which direction it is turned. 
     For the square Z movement described above, the fully retracted position is illustrated as position 1 in  FIG. 47 . In this position, the slide-out room is fully retracted and in the up position, and the up position sensor and the fully retracted position sensor (if provided) are actuated. A fully retracted sensor is not necessary, and neither is a fully extended sensor, since full retraction or extension can be detected positionally by the counts of the rotary encoder of the motor  36  or by detecting when the motor current rises to a certain level indicating compression of the gaskets, either at full extension or full retraction. 
     Still referring to  FIG. 47 , starting from the fully retracted position (position 1), when the extend button is pressed by a human operator, the motors  36  on both sides of the room are synchronously driven to extend the room evenly to the partially extended position 2 while the room is supported in the up position by one or more of the support mechanisms described below. Position 2 is not fully extended but is extended most of the way, just short of compressing the gaskets that seal the inside room flanges against the stationary RV walls. For example position 2 would typically be to within 0.25 to 1 inches of full extension, a distance so as not to compress the gaskets and leave a small clearance so the gasket does not rub on a wall when the room is raised or lowered. Preferably, an adjustment is provided to adjust this spacing (the distance from position 3 to position 4), either by a slide adjustment of the sensor  86  or magnet  90  (they could be mounted in slots to allow sliding them to change position), or if the counts of the rotary encoder are used to determine position 2, by adjusting the counts to horizontal position 2. In the case of using sensor  86  for horizontal positioning, rather than the counts of the rotary encoder, extension sensor  86  is actuated by magnet  90  at position 2 and at position 3. Whether a sensor or the counts are used, attaining position 2 stops horizontal extension and initiates lowering of the room by the lift(s), i.e., the drive motors  36  are stopped and the motor(s) that operate the lifts are operated to lower the room. Lowering continues until the fully down position, position 3, is reached, which will either be sensed by the sensor  82  being actuated by the magnet  87  in the embodiment of  FIGS. 44A  and B, or by the limit switch  94  in the lift embodiment of  FIGS. 45 and 46 . In either embodiment, obtaining position 3 stops the motor(s) that lower(s) the room and initiates further horizontal extension of the room until full extension is sensed either by obtaining the required number of counts from the motor  36  encoders or by sensing that the motor  36  current has exceeded a current indicating acceptable compression of the interior gaskets. 
     For retraction, the motion is reversed, so as to go 4-3-2-1 in  FIG. 47 . The mechanism stops at full retraction either by attaining the required number of counts from the motor  36  encoders or by sensing that the motor(s)  36  current(s) have exceeded a current indicating acceptable compression of the exterior gaskets. In reverse, when the operator presses the retract button, from full extension in the lower position, in which sensor  82  is actuated by magnet  87 , retraction begins and magnet  90  actuates sensor  86  when position 3 is reached, which stops retraction and initiates elevation. When elevating the room, sensor  82  becomes de-actuated and when the upper position is reached, magnet  88  actuates sensor  84 , which stops elevation and re-initiates retraction. At the onset of retraction when the room leaves position 2, sensor  86  becomes de-actuated while up position sensor  84  stays actuated and the retraction is continued at the upper position until position 1 is reached, in which position the exterior gaskets are fully compressed and the horizontal retraction motion is stopped, either by obtaining the required number of counts by the rotary encoders of the motors  36  or by sensing that the current drawn by the motors has exceeded a current value indicating adequate compression of the gaskets. 
     An alternative sequence for extending is illustrated in  FIG. 48 , which can use the same sensor configuration as described above. In this sequence, upon extension of the room from full retraction (position 1), the room is first fully extended to full compression of the interior gaskets (position 2), stopped and is then retracted enough to decompress the gaskets, which is at partially extended position 3, which corresponds to position 2 in the embodiment of  FIG. 47 . This results in a more precise placement of the room near the end of its extension but without compressing the gaskets. Preferably, the distance the room is retracted in  FIG. 48  from position 2 to position 3 is adjustable as described above, and would typically be about 0.25 to 1 inches. At position 3, the room is lowered to position 4 and then the room is fully extended in the lowered position to the fully extended and lowered position 5 in which the gaskets are fully compressed. This produces a path of movement in a square h pattern. 
     For retraction, the movement would be 5-4-3-1 for the pattern of  FIG. 48 . During retraction, there is no need to go from position 3 to position 2 and back so those steps are skipped, so retraction is a reverse square Z pattern. 
     It is noted that if acceptable gaskets were provided that could withstand shear or could be actuated after the final lowered extended position was attained, or otherwise permit vertical movement of the room in the fully extended position, the distance from position 2 to position 3 in  FIG. 48  could be adjusted to zero, or the distance from 3 to 4 in the pattern of  FIG. 47  could be adjusted to zero. In such a case, the shape of the motion from retraction to full extension would be L shaped, with the room being driven to full extension and then lowered and stopped. 
     As described above, any of the disclosed methods of sensing may be used for these patterns, or other methods, e.g., Hall Effect sensors for horizontal and/or vertical position sensing, motor  36  rotary encoder counts for horizontal position sensing, lift motor rotary encoder counts for vertical position sensing (rotary encoders could also be provided on the lift motors), mechanical limit switches for horizontal or vertical position sensing, or a combination of motor rotary encoder counts for horizontal position sensing and mechanical limit switches at the lifts, drive mechanism or room structure for vertical position sensing, or other sensing configurations. 
     The drive mechanisms  28  and  30  may also be controlled in an “automatic jog mode”. That is, if the sensors detect no movement of one of the drive mechanisms  28  or  30  in one direction, the other mechanism  28  or  30  will also be de-energized. Subsequently, movement of the mechanisms  28  and  30  in the same direction is not allowed, and movement of the mechanisms  28  and  30  in the opposite direction is the only direction permitted. If the sensors detect no movement of the same drive mechanism  28  or  30  in the opposite direction, the other mechanism  28  or  30  will be de-energized and the system is put into an emergency retract mode or “automatic jog mode”. In this mode, the system only permits a short time of movement in the direction of a button push. Instead, multiple button pushes are needed to fully retract or extend the room  12 . 
     Turning now to  FIG. 10 , a second embodiment of the drive mechanism  130  is generally as described above. However, the support channel  132  includes one or more lips  134  that connect to an edge proximate the slide-out room side wall  120  and extend in the drive direction. The lips  134  also extend between the drive support  142  and the slide-out room side wall  120 , or “wrap” around the drive support  142 , to inhibit the drive support  142  from moving out of the channel  132  in the transverse direction. However, the lips  134  permit the drive support  142  to float in the elevation direction as described above. 
     Referring to  FIG. 11 , a third embodiment of the drive mechanism  230  is also generally as described above. However, the support channel  232  and the drive support  242  include an interface  234  proximate the rear wall of the channel  232  to connect the two components. As shown in the figures, the interface  234  may have a dovetail shape. Other shapes may be used provided that they inhibit the drive support  242  from moving out of the channel  232  in the transverse direction and permit the drive support  242  to float in the elevation direction. 
     Referring to  FIGS. 12-18  and as briefly described above, in some embodiments the ability of the drive supports  42  to float in the elevation direction permits the slide-out room  12  to be used as a flush floor room. As the name implies, the floor of such a flush floor room moves downwardly and is level with the floor of the vehicle in the extended position (see  FIG. 18 ). To facilitate such downward movement of the slide-out room  12 , the vehicle  10  mounts one or more roller or support mechanisms  320  between its floor  322  and the floor  24  of the slide-out room  12 . 
     Generally, the support mechanism  320  includes a roller support bracket  324  that eccentrically and rotatably mounts an inner roller  326 . The inner roller  326  concentrically and rotatably mounts an outer roller  328  that engages the floor  24  of the slide-out room  12 . 
     As shown most clearly in  FIGS. 12 and 13 , the roller support bracket  324  is a generally U-shaped component as viewed in the drive direction and may be a stamped and bent piece of metal or the like. The roller support bracket  324  includes a base  330  that engages the vehicle floor  322 , and two edges of the base  330  connect to upwardly extending side walls  332 . Each side wall  332  includes a notch  334  ( FIG. 13 ) for receiving the inner roller  326 , and each side wall  332  connects to a support link  336  that holds the inner roller  326  in the notches  334 . 
     The inner roller  326  is a generally cylindrical component and may be a molded plastic or the like. The inner roller  326  also includes internal walls  338  to connect to the roller support bracket  324 . In particular, the walls  338  engage an axle  340  that is supported by the support links  336 . The axle  340  extends eccentrically through the inner roller  326 , and the axle  340  rotatably fixedly connects to the inner roller  326  via a non-circular cross-sectional shaped portion  342  (for example, a hexagonal cross-sectional shape as shown in  FIG. 13 ) that is received in a non-circular cross-sectional shaped passageway  344  defined by the internal walls  338 . As such, a prime mover  346  (for example, an electric motor or the like as shown in  FIG. 12 ) may drive the axle  340  and eccentrically rotate the inner roller  326 . 
     The outer roller  328  is a generally cylindrical component and may be a molded plastic or the like. The outer roller  328  concentrically and rotatably mounts over the inner roller  326 . The inner roller  326  may also support snap rings  348  on the sides of the outer roller  328  to inhibit the outer roller  328  from moving axially relative to the inner roller  326 . 
     Together, the inner roller  326  and the outer roller  328  lower the slide-out room  12  in the elevation direction as follows. The inner roller  326  and the outer roller  328  are first disposed in the position shown in  FIG. 14  when the slide-out room  12  is in the retracted position; that is, the inner and outer rollers  326  and  328  hold the slide-out floor  24  above the vehicle floor  322 . As the slide-out room  12  begins to move toward the extended position as shown in  FIG. 15 , the outer roller  328  rotates as the slide-out floor  24  moves thereover and the inner roller  326  remains stationary. When the slide-out room  12  is nearly fully extended as shown in  FIG. 16 , the prime mover  346  is energized to eccentrically rotate the inner roller  326  in a clockwise direction as shown in  FIG. 17 . This action lowers the slide-out room  12  relative to the vehicle floor  322 , and the prime mover  346  is de-energized to stop the inner roller  326  when the slide-out floor  24  is flush with the vehicle floor  322  as shown in  FIG. 18 . 
     The support mechanism  320  and the slide-out room  12  generally move in the opposite manner to raise the slide-out room  12  as the room  12  moves from the extended position to the retracted position. 
     Referring to  FIG. 19 , in the embodiments described above the slide-out room need not act as a flush floor room. That is, the floor  422  of the vehicle may fixedly mount brackets  430  (only a single bracket is shown) that each rotatably support a roller  432 . The rollers  432  simply permit the slide-out room  412  to move in a generally horizontal direction when moving from the retracted position to the extended position and vice versa. In addition, the rollers  432  support the weight of the slide-out room  12 . 
     Referring to  FIGS. 20-22 , any of the above embodiments may further include one or more float inhibiting mechanisms  530  that, as the name implies, inhibit the slide-out room  512  from floating in the transverse direction as the vehicle moves. In the embodiments shown in the figures, the float inhibiting mechanisms  530  each include a frusto-conical shaped post  532  supported by the fascia  526  and facing the side wall  516  of the vehicle. Each post  532  may comprise a resilient material, such as rubber or the like. In the retracted position ( FIG. 22 ), each post  532  is received in a corresponding frusto-conical shaped blind hole  534  defined by the vehicle side wall  516 . As such, engagement between the posts  532  and the side wall  516  within the holes  534  inhibits the slide-out room  512  from floating in the transverse direction (i.e., the direction of vehicle movement over the road) as the vehicle moves. 
     The float inhibiting mechanisms  530  may take other forms and shapes provided that some portion of the mechanism  530  engages or nearly engages the side wall  516  in the retracted position. Alternatively, a positive feature (for example, a post) may be supported by the side wall  516  and a corresponding feature (for example, a hole) may be defined by the fascia  526 . 
     Referring to  FIGS. 23-35 , another embodiment of a flush floor support mechanism  602  is shown (the vehicle  10  mounts two mechanisms  602 , although only one of which is shown). The support mechanisms  602  are disposed between the floor  604  of the vehicle  10  and the floor  24  of the slide-out room  12 . The support mechanisms  602  are generally identical except for being disposed in mirrored relation to one another. As such, only one support mechanism  602  will be described below for simplicity. 
     Generally, the support mechanism  602  includes an elevation assembly  608  that facilitates raising and lowering the slide-out room  12 . The support mechanism  602  also includes a biasing assembly  610  that further facilitates raising and lowering the slide-out room  12  and advantageously assists in raising the room  12  when moving from the extended position to the retracted position. 
     Turning first to the elevation assembly  608  and  FIGS. 23-26 , this assembly includes a support bracket  618  that is generally U-shaped as viewed in the drive direction, such as a stamped and bent metal bracket. The support bracket  618  also defines guide paths  620  (e.g., j-shaped slots,  FIG. 26 ) that each movably receive a guide pin  622  of a roller linkage  624 . This structure ensures the roller linkage  624  maintains its connection to the support bracket  618 . 
     The roller linkage  624  is a generally flat and upside-down U-shaped component, such as a stamped piece of metal. One of the legs mounts the guide pin  622 , the intersection between two of the legs pivotally mounts a first elevation roller  612  that engages the slide-out floor.  24 , and the other intersection between two of the legs pivotally mounts a non-slip second elevation roller  614  that engages the slide-out floor  24 . As such, the guide pin  622 , the first elevation roller  612 , and the second elevation roller  614  remain spaced apart from each other by constant distances as the roller linkage  624  translates relative to the support bracket  618 . The leg opposite the guide pin  622  connects to one end of an extension spring  623 , and the opposite end of the spring  623  connects to the support bracket  618 . As such, the extension spring  623  biases the linkage  624  and the rollers  612  and  614  toward the configuration shown in full lines in  FIG. 26 . 
     As shown in  FIG. 26 , the roller linkage  624  moves between the position shown in full lines in the slide-out room&#39;s retracted position and the position shown in phantom lines in the slide-out room&#39;s extended position. In the retracted position, the pins mounting the rollers  612  and  614  are supported at stable locations  626  and  628 , respectively, defined by the walls  629  of the support bracket  618 . As such, and also due to the shape of the guide paths  620 , the rollers  612  and  614  do not move downwardly under the weight of the slide-out room  12  in the retracted position. Similarly, in the extended position, the roller pins are supported at stable locations  630  and  631 , respectively, defined by the walls  629  of the support bracket  618 . As such, the rollers  612  and  614  do not move downwardly under the weight of the slide-out room  12  in the extended position. 
     Movement of the roller linkage  624  and the rollers  612  and  614  is guided a guide assembly of the elevation assembly  608 . Pinions  632  of this assembly are fixedly mounted to the second elevation roller  614 . As such, as the second elevation roller  614  rotates, the pinions  632  rotate and translate along guide members or racks  634  supported by the support bracket  618  and extending at an acute angle to the drive direction. The interaction of these components and the motion of the roller linkage  624 , the rollers  612  and  614 , and the pinions  632  will be described in further detail below. 
     To ensure the second roller  614  rotates and translates along the gear rack  634  as the slide-out room  12  engages and moves thereover (i.e., to prevent the slide-out room  12  from slipping on the second roller  614 ), the second roller  614  may be a non-slip or relatively high friction component. To this end, the second roller  614  may include a relatively high friction cover  615  (e.g., a rubber or sandpaper-like cover). In other embodiments, the lower surface of the floor  24  may support a relatively high friction outer layer. 
     Turning now to the biasing assembly  610  and  FIGS. 23-25 ,  27 , and  28 , this assembly includes a support bracket  636  that is generally U-shaped as viewed from the side, such as a stamped and bent metal bracket. However, the support bracket  636  also includes side walls  638  that pivotally support several components. In particular, each side wall  638  pivotally supports a roller bracket  640 , which are flat and elongated components, such as stamped pieces of metal. Opposite their pivotal connection to the side walls  638 , the roller brackets  640  together rotatably mount a floor-engaging biasing roller  642 . 
     The roller brackets  640  also pivotally support a biasing bracket  644  connected therebetween. The biasing bracket  644  is generally right angle-shaped as viewed from the side except for side walls  646  ( FIG. 24 ) that connect to the roller brackets  640 . As such, the biasing bracket  644  may be a stamped and bent metal bracket. 
     The biasing bracket  644  engages ends of compression springs  648 . The other ends of the compression springs  648  engage a rear wall  650  of the support bracket  636 . As such, the compression springs  648  are compressed between the rear wall  650  and the biasing bracket  644 . This urges the biasing bracket  644  outwardly in the travel direction, which in turn urges the biasing roller  642  generally upwardly in the elevation direction. As described in further detail below, the biasing roller  642  thereby biases the slide-out room  12  upwardly in the elevation direction. 
     The biasing assembly  610  further includes a threaded screw  652  extending between the support bracket  636  and the biasing bracket  644 . A threaded nut  654  connects to the threaded screw  652  on the outside of the rear wall  650  to limit the maximum distance between the rear wall  650  and the biasing bracket  644 . This essentially provides a “stop” that defines the position to which the roller brackets  640  and the biasing roller  642  are biased. 
     The support mechanism  602  generally causes the room  12  to descend when moving to the extended position as follows. The first elevation roller  612 , the second elevation roller  614 , and the biasing roller  616  are disposed in the positions shown in  FIGS. 26-27  when the slide-out room  12  is in the retracted position ( FIG. 29 ) and over most of the range of motion apart from the extended position ( FIG. 30 ). That is, the first elevation roller  612  and the biasing roller  616  support the room  12  and the second elevation roller  614  does not. When the slide-out room  12  approaches the extended position ( FIG. 31 ), the first elevation roller  612  engages an inclined lower surface  656  of the slide-out room  12  that is disposed at an acute angle to the drive direction. As the first elevation roller  612  continues to rotate and pass over the inclined lower surface  656 , the slide-out room  12  begins to descend. The slide-out room  12  descends instead of tipping backwards because the pinions  50  and  94  are driven at the same speed, and therefore the ceiling  22  and the floor  24  of the slide-out room  12  are driven at the same speed. Furthermore, the biasing roller  616  descends as the room  12  descends, and the compression springs  648  are thereby loaded. 
     Eventually the slide-out room  12  descends a sufficient distance such that the floor  24  engages the second elevation roller  614  ( FIG. 32 ). As the room  12  continues to extend and rotates the second elevation roller  614 , the pinions  632  rotate and traverse along the racks  634  ( FIG. 33 ). The second elevation roller  614  moves together with the pinions  632 , and the first elevation roller  614  follows the second elevation roller  614  due to their connection to the roller linkage  624 . The first elevation roller  612  then engages a horizontal surface  658  adjacent the inclined surface  656  ( FIG. 34 ), and the slide-out room  12  stops descending. Finally, the slide-out room  12  moves horizontally to disengage the second elevation roller  614  from the floor  24  and reach the extended position ( FIG. 35 ). 
     To return the slide-out room  12  to the retracted position, the room  12  and the support mechanism  602  generally move in the opposite manner. However, it should be apparent that the springs  648  are more compressed in the extended position than the retracted position, and the springs  648  thereby urge the biasing roller  616  upwardly to provide an assist for lifting the slide-out room  12 . As such, the prime movers  34  advantageously do not need to be capable of providing sufficient power to lift the slide-out room  12  on their own. 
     Referring to  FIGS. 36-39 , another embodiment of a flush floor support mechanism  702  is shown (the vehicle  10  mounts two mechanisms  702 , although only one of which is shown). The support mechanisms  702  are disposed between the floor of the vehicle and the floor of the slide-out room. The support mechanisms  702  are generally identical except for possibly being disposed in mirrored relation to one another. As such, only one support mechanism  702  will be described below for simplicity. 
     The support mechanism  702  includes a roller  704  that is moved in the elevation direction to move the slide-out room in the elevation direction. The roller  704  is moved via an elevating mechanism that includes a prime mover (not shown), such as a DC motor connected to a speed-reducing gearbox. The prime mover drives a threaded shaft  706  that in turn translatably drives a first support block  708  along a base  710  (see  FIGS. 36 and 38 ). 
     The first support block  708  pivotally mounts first links  712  that pivotally connect to a roller mounting bracket  714  opposite the first support block  708 . Adjacent the first links  712 , the roller mounting bracket  714  also pivotally connects to second links  716 . The second links  716  also connect to a second support block  718  translatably mounted to the base  710 . As shown in the figures, the threaded shaft  706  may extend through the second support block  718 , although the shaft  706  does not directly drive the second support block  718 . 
     The ends of the first links  712  proximate the roller mounting bracket  714  include first gear tooth surfaces  720  ( FIGS. 37 and 39 ). These surfaces  720  drivingly engage second gear tooth surfaces  722  at the ends of the second links  716  proximate the roller mounting bracket  714 . Thus, engagement of the gear tooth surfaces  720 ,  722  cause the links  712 ,  716  to pivot and the support blocks  708 ,  718  to translate in coordinated manners. That is and as shown in  FIGS. 38 and 39 , as the threaded shaft  706  rotates in one direction, the support blocks  708 ,  718  move apart and the links  712 ,  716  pivot downwardly to lower the roller  704  and the slide-out room in the elevation direction. Conversely and as shown in  FIGS. 36 and 37 , as the threaded shaft  706  rotates in the opposite direction, the support blocks  708 ,  718  move toward each other and the links  712 ,  716  pivot upwardly to raise the roller  704  and the slide-out room in the elevation direction. 
     The support mechanism  702  is relatively stable compared to other similar mechanisms that do not include gear tooth surfaces (i.e., those in which the second support block  718  is fixed relative to the base  710 ). 
     Referring to  FIGS. 40-43 , another embodiment of a flush floor support mechanism  802  is shown (the vehicle  10  mounts two mechanisms  802 , although only one of which is shown). The support mechanisms  802  are disposed between the floor of the vehicle and the floor of the slide-out room. The support mechanisms  802  are generally identical except for possibly being disposed in mirrored relation to one another. As such, only one support mechanism  802  will be described below for simplicity. 
     The support mechanism  802  includes a roller  804  that is moved in the elevation direction to move the slide-out room in the elevation direction. The roller  804  is moved via an elevating mechanism that includes a prime mover (not shown), such as a DC motor connected to a speed-reducing gearbox. The prime mover drives a threaded shaft  806  that in turn translatably drives a first support block  808  along a base  810  (see  FIGS. 41 and 43 ). 
     The first support block  808  pivotally mounts first links  812  that pivotally connect to a roller mounting bracket  814  opposite the first support block  808 . Between their connection points to the first support block  808  and the roller mounting bracket  814 , the first links  812  also pivotally connect to second links  816 . At a first end, the second links  816  connect to a second support block  818  fixed to the base  810 . As shown in the figures, the threaded shaft  806  may extend through and be rotatably supported by the second support block  818 . At a second end, the second links  816  rotatably mount wheels  820  (one of which is shown in  FIGS. 41 and 43 ) that engage a lower surface of the roller mounting bracket  814 . 
     As shown in  FIGS. 42 and 43 , as the threaded shaft  806  rotates in one direction, the first support block  808  moves away from the second support block  818  and the links  812 ,  816  pivot toward a horizontal configuration to lower the roller  804  and the slide-out room in the elevation direction. Conversely and as shown in  FIGS. 40 and 41 , as the threaded shaft  806  rotates in the opposite direction, the first support block  808  moves toward the second support block  818  and the links  812 ,  816  pivot toward a vertical configuration to raise the roller  804  and the slide-out room in the elevation direction. 
     The slide-out system may also be modified in other manners that are not explicitly described herein. For example, instead of including float inhibiting mechanisms, the prime mover may be sufficiently powerful to firmly compress the seals in the retracted position and inhibit the slide-out room from floating in the transverse direction due to friction forces between the seals and the vehicle wall alone. Whether float inhibiting mechanisms are used or not in combination with the seals, it might be advantageous to apply a brake to the mechanism, preferably acting on the motor output shaft so the brake has the benefit of the gear reduction drive train to keep the room stationary. The brake would come on when the motor was turned off, to keep the seals compressed, and if a float inhibiting mechanism is used, to keep it engaged. 
     From the above, it should be apparent that the slide-out system according to the present invention provides a transversely floating drive mechanism that facilitates use of components or features that inhibit the slide-out room from shifting as the vehicle moves. Furthermore, in some embodiments, these mechanisms do not support the weight of the slide-out room and are configured to move or float vertically relative to the vehicle. This motion permits the slide-out room to descend near the extended position and act as a flush floor slide-out room. 
     It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as defined within the scope of the following claims.