Abstract:
An operating mechanism for extending a slide-out section of a vehicle includes a pair of rail supports secured to a vehicle frame and a pair of rail members connected to the slide-out section with one rail member slidably engaging each rail support. Each rail member is driven by engagement of a rotary member with a linear intermeshing member, such as dedicated rack and pinion arrangements. A shaft connects the rotary engagers so that movement of the rail members is synchronized using a single drive unit. A pair of rollers are mounted to each rail support, one roller on each side of the racks, to support the rack relative to the associated rotary engager.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 10/378,030, filed Feb. 28, 2003 now U.S. Pat. No. 6,685,249, issue fee paid, which is a continuation of U.S. application Ser. No. 09/564,663, filed May 3, 2000, now U.S. Pat. No. 6,601,896, which claims benefit to U.S. provisional application Ser. No. 60/132,397, filed May 4, 1999 and is a continuation-in-part of U.S. application Ser. No. 08/823,170, filed Mar. 25, 1997, now U.S. Pat. No. 6,116,671, which is a continuation-in-part of U.S. application Ser. No. 08/563,043, filed Nov. 27, 1995, now U.S. Pat. No. 5,758,918. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to vehicles having extendable sections, and more particularly to an improved operating mechanism for moving a slide-out section between extended and retracted positions relative to the vehicle. 
     In order to increase the available Interior space of recreational vehicles or trailers, it is known to provide a slide-out section (such as a bedroom) as part of the structure of the vehicle or trailer. A slide-out section is a raised platform enclosed on all but one side. During transit, the slide-out section is retracted and stored in the interior of the vehicle or trailer, with the exterior wall of the slide-out section approximately flush with the exterior of the vehicle or trailer. To use the slide-out section after the vehicle is parked and leveled, it is slid outward from the vehicle to an extended position, thereby increasing the interior space of the vehicle. 
     The operating mechanism for moving the slide-out sections are typically devised to push the slide-out section away from the vehicle when extending the slide-out section, and pulls the slide-out section towards the vehicle when retracting the slide-out section. The mechanism for moving the slide-out section relative to the vehicle is fixed to the vehicle body and can include one or more sliding rails attached to the slide-out section. Typically, these sliding rails slide within rail supports fixed to the vehicle frame. Multiple sliding rails are typically utilized for wide slide-out sections. To conserve cost and spaces, typically the sliding rails are driven by a single drive unit. Thus, in mechanisms having multiple sliding rails, one rail is directly driven by the drive unit and the other rail moves in response to sliding of the slide-out section to which it is connected. Due to friction or an obstruction, it is possible for either of the driven or free sliding rails to lag behind the other rail during extension and/or retraction. This can cause the room to become skewed with respect to the vehicle. If this is not corrected, it can cause excessive wear, motor fatigue and/or an incomplete seal between the slide-out section and the vehicle when fully extended or retracted. 
     SUMMARY OF THE INVENTION 
     The present invention provides a multiple rail synchronized operating mechanism for moving a slide-out section of a recreational vehicle between retracted and extended positions. 
     In particular, the operating mechanism includes a pair of rail supports spaced apart and secured to a vehicle frame and a pair of rail members connected to the slide-out section. One rail member slidably engages each rail support, and each rail member has a linear intermeshing member which meshes with an associated rotary engager. The rotary engagers are coupled by a shaft to synchronize movement of the rail members with respect to the rail supports. An anti-friction member is mounted to each rail support to support each rail member in a direction away from the associated rotary engager. 
     In preferred forms, linear intermeshing members and rotary engagers are rack and pinion arrangements, and the anti-friction members are rollers rotatably mounted to the rail supports and engaging corresponding surfaces of the rail members. The rollers can define two roller surfaces, one on each side of the associated rack. Preferably, there are two pairs of rollers, one pair of rollers mounted to each rail support so that a rack is disposed between each pair of rollers. 
     The present invention thus provides a multiple sliding rail slide-out mechanism in which the sliding rails are synchronized. The rails are synchronized using a shaft to couple the pinions for each sliding rail. Synchronized movement of the rails allows the slide-out section to extend and retract substantially uniformly and prevents it from becoming skewed with respect to the vehicle. 
     The foregoing and other objects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a vehicle stationary floor having a slide-out section incorporating the present invention; 
     FIG. 2 is a side view of the slide-out actuator of FIG. 1 in a lower position; 
     FIG. 3 is a cross sectional view of the slide-out actuator along line  3 — 3  of FIG. 2; 
     FIG. 4 is a cross sectional view of the slide-out actuator along line  4 — 4  of FIG. 2; 
     FIG. 5 is a side view of the slide-out actuator of FIG. 1 in an upper position; 
     FIG. 6 is a cross sectional view of the slide-out actuator along line  6 — 6  of FIG. 5; 
     FIG. 7 is a cross sectional view of the slide-out actuator along line  7 — 7  of FIG. 5; 
     FIG. 8 is an exploded side view of the slide-out actuator of FIG. 1; 
     FIG. 9 is an exploded end view of the slide-out actuator of FIG. 1; and 
     FIG. 10 is a front plan view of the synchronized slide-out actuators of FIG. 1 in which the pinions are coupled by a shaft. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides an expandable bedroom slide-out attached to a known trailer or recreational vehicle which provides distinct advantages over the prior art as will be described and appreciated hereafter. In the preferred embodiment, the trailer or recreational vehicle (generally referred to as the vehicle) is equipped with a slide-out section used to provide additional interior room space. However, it should be understood that the invention can also apply to expandable sections or compartments provided on other vehicles for use in construction, military, medical, education, mobile broadcast and other applications, to expand the inside volume of the vehicle. 
     Referring now to FIG. 1, a bedroom slide-out  10  is mounted to a vehicle stationary floor  11 . The bedroom slide-out  10  has a movable platform  12 , such as suitable for use as a bed base, mounted to each end of a rail member, in this case a U-shaped channel  14 . The U-shaped channel  14  is slidably mounted in an actuator  16  which forcibly moves the platform  12  between extended and retracted positions. The actuator  16  is rigidly mounted to the vehicle stationary floor  11 , and extends and retracts the movable platform by forcibly sliding the U-shaped channel  14  with a rack and pinion drive. The moveable platform  12  is disposed above the actuator frame  18 , and is mounted to both ends of the U-shaped channel  14 . 
     The channel  14  is slidably disposed in the rail support or actuator frame  18 , which simultaneously pushes and pulls the platform  12  to provide a smooth transition between the extended and retracted positions. The U-shaped channel  14  has a top surface  38 , bottom surface  32 , and the two ends  33 ,  35 . A rack  40  mounted to the U-channel bottom surface  32  engages a pinion  42  rotatably mounted in the actuator  16  to urge the channel  14  in the desired direction. 
     As shown in FIG. 1, the slide-out actuator  16  has a rail support of frame  18  mounted to the vehicle floor  11 . Looking particularly at FIGS.  3 , 4 ,  6 , and  7 , the actuator frame  18  includes opposing sides  20  joined by a top plate  22  and a bottom plate  24 . Each side  20  is formed from a pair of vertical slidably movable overlapping inner and outer plates  26 ,  28 . The top plate  22  is fastened to the inner side plates  26  by methods known in the art, such as welding to form a frame upper assembly  17  which supports frame operating components, such as rollers  34 , the pinion  42 , a motor mount  50 , a shaft  44 , and the like. The bottom plate  24  is similarly mounted to the outer side plates  28  to form a frame lower assembly  19 , and Is mounted to the vehicle to secure the actuator  16  to the vehicle floor  11 . 
     The inner side plate  26  is substantially rectangular, and can be cutout to reduce the plate material required. The outer side plate  28  is substantially rectangular, and has upstanding legs  31 . The outer plate  28  is open between the legs  31  to provide room for the a shaft  44  and mount  50 . Holes  30  are formed In the upstanding legs  31 , and are in substantially the same plane as holes  30  formed in the inner plate  26  to allow alignment between a hole  30  in each plate  26 ,  28 . 
     The height of the frame  18  is adjusted by slidably moving the overlapping plates  26 ,  28  to obtain the desired height. Each frame side  20  has a lower position, shown in FIGS. 2-4 and  8 , and an upper position, with intermediate positions in between. The lower position is accomplished by aligning the lowest hole in the outer overlapping plate  28  on each side of the frame  18  with the lowest hole in the corresponding inner overlapping plate  26 , and then pinning the plates  26 ,  28  together using a pin, such as a bolt  37 . The upper position is accomplished by aligning the highest hole in the lower overlapping plate  28  on each side of the frame  18  with the lowest hole in the upper overlapping plate  26 , and then pinning the plates  26 ,  28  together. Intermediate positions, such as the position shown in FIGS. 5-7 and  9 , are accomplished by aligning various combinations of the holes  30 , and fastening the plates  26 ,  28  together. 
     The height of the actuator  16  is fixed by aligning at least one of the holes  30  in the Inner plate  26  with a hole  30  in the outer plate  28 , and then fastening the plates  26 ,  28  together. Preferably, bolts or pins are secured in at least one pair of aligned holes  30  to fix the height of the actuator  16 . Advantageously, the height adjustable frame  18  provides an easily adaptable actuator  16  for a plurality of applications. 
     The frame upper assembly supports the channel  14  and the pinion  42  for urging the channel  14  between the extended and retracted positions. In the preferred embodiment, the frame upper assembly includes two pairs of anti-friction members, preferably being two rollers  34  rotatably mounted to the plates  26  on opposing sides of the pinion  42 . The rollers  34  engage the U-channel bottom on opposing sides of the rack  40  to support the channel as it slides through the frame. Each pair of rollers  34  are rotatably mounted to the inner plates  26  of the upper frame assembly on opposing sides of the pinion  42 . 
     The pinion  42  Is mounted to a rotatable shaft  44 , journalled to the plates  26 , and driven by an electric motor (not shown). The electric motor is mounted to mount  50 , which is welded to plate  52 . Plate  52  is bolted to plate  26 , and shaft  44  extends through plate  26  and terminates in an end  54  which is engageable by the drive means. The opposite end of the shaft  44  may extend through the plate  26  on the opposite side of the frame  18 , and have end  56  to be engaged, for example, by a shaft  60  that connects to the pinion  62  of a second slide-out actuator  64 , acting as a synchronization mechanism, having a rail support or frame  66 , shaft  68 , rollers  70 , rail member or channel  72  and rack  74 , spaced laterally from the unit  16  as Illustrated in FIG. 10, so as to synchronize the two units  16  and  64 . Although an electric motor is disclosed, the shaft may be driven by other methods known in the art, such as manually. 
     A low friction block  36 , such as UHMW, is mounted to the frame top  22 , and engages the U-channel top  38  to keep the pinion  42  engaged with the rack  40 . Advantageously, the block prevents the U-channel  14  from pivoting on one of the roller pairs  34  when the channel is substantially fully extended or retracted. Although a block is disclosed, other methods for maintaining the engagement of the rack with the pinion can be used, such as by using rollers, without departing from the scope of the present invention. 
     While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the of the invention defined by the appended claims. 
     Therefore, various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.