STATEMENT OF FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to slide-out rooms for recreational vehicles, and particularly to slide-out room support systems in which a single set of rails is required to support the room.
2. Discussion of the Prior Art
In order to increase available interior space of recreational vehicles, e.g., motor homes and trailer homes, slide-out rooms or sections are provided. During transit, these rooms are retracted and stored in the interior of the vehicle or trailer, with the exterior end wall of the slide-out room approximately flush with the adjacent exterior wall of the vehicle or trailer. To use the slide-out room, the vehicle is parked and leveled. The slide-out room is then slid outward from the vehicle using the slide-out room support system thereby increasing the interior space of the vehicle.
The slide-out rooms usually include a floor, a roof, an end wall and one or more side walls. In the retracted position the roof, floor and side walls are typically inside the stationary part of the vehicle, concealed from exterior view, and the room end wall forms a portion of the vehicle's side wall. A gasket is usually provided which is compressed between the inner ends of the slide-out room walls (which may include the floor) and the vehicle walls so as to keep wind, rain, dirt and bugs out when the vehicle is extended. A similar set of gaskets may also be provided between the two outer walls of the respective vehicle and room to seal the room when it is retracted.
Sets of telescoping support rails are usually used to support the slide-out room and these rails may be power driven in and out or manually pulled out and pushed back in. Any number of sets of rails may be used, depending upon the size of the room to be moved.
When two or more sets of rails are used, they are spaced apart and mechanically linked to one another so that they extend or retract together. They may be mechanically linked, for example, with a rack and gear system in which each inner rail is provided with a rack and pinions engaging the racks are connected by a shaft, or with a cable and pulley system, to ensure that the rails extend and retract together.
For small rooms, such as a wardrobe or closet, a single rail is sufficient to support the room and may be all that there is space for. However, a problem with using a single rail is racking of the inner rail relative to the outer rail from side to side. Another problem is providing a single rail with sufficient strength which is still of a low profile to fit in a tight space beneath the room being moved. The present invention provides a solution to these problems.
SUMMARY OF THE INVENTION
The present invention provides a slide-out support rail system that is particularly adapted for use as a single set of rails, which may be power operated or manually operated.
In particular, the invention provides a slide-out support rail system for supporting a slide-out section of a recreational vehicle. The system includes an inner rail mounting a rack on top of a longitudinally extending upper wall so as to mesh with a drive pinion. An outer rail slidably mounts the inner rail on a pair of support rollers spaced apart longitudinally to support the inner rail and maintain engagement of the rack and pinion.
The gear rack of the telescoping inner rail has teeth that face upwardly and mesh with the pinion gear which is journaled relative to the outer rail above the gear rack. Rollers are preferably provided on both sides of the pinion which roll along the top side of the inner rail so as to counteract upward forces exerted upon them, which would otherwise be transferred to the pinion gear. Another set of rollers is also provided at the outer end of the outer rail beneath the inner rail to support the inner rail.
To assure engagement of the rack with the pinion, the inner rail is made in three pieces, not including the gear rack. As such, the inner rail consists of an open U-channel, which opens upwardly, a rectangular tube approximately centered in the open U-channel, and a top wall plate which covers the tube and extends between the side walls of the U-channel. The rectangular tube is positioned beneath the gear rack, so that the tooth forces exerted on the gear rack by the pinion, which tend to push the gear rack away from the pinion, are counteracted not only by the U-channel and the top plate, but also by the rectangular tube within the U-channel.
In addition, directly beneath the pinion gear which drives the gear rack, another roller is provided, to maintain the gear rack in meshing engagement with the pinion.
In another aspect, the inner rail is made at least two times as wide as it is tall. This improves the resistance to racking of the inner rail.
In addition, between the side walls of the outer rail and the side walls of the inner rail, wear pads are preferably provided, which also contribute to the resistance to racking of the entire unit.
The foregoing and other objects and 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.
Thus, in a slide-out system of the invention, the rack is affixed to the top of the inner rail, and a pinion gear in meshing engagement above the rack drives the inner rail in and out. A roller is provided on each side of the rack, preferably on the shaft of the pinion gear. In a preferred aspect, the inner rail is made relatively short and wide, for example at least two, and preferably closer to at least three, times as wide as it is tall. The rack is centered on the top wall of the inner rail, and a reinforcement is provided below the top wall directly beneath the rack, to maintain engagement of the rack with the pinion. A support roller is provided beneath the bottom wall of the inner rail, directly below the pinion, to support the inner rail and rack in engagement with the pinion.