1. Field of the Invention
The present invention relates to a drawer slide, and more particularly, to a slide which suspends a drawer from a framework and/or within an enclosure, permits the drawer to be opened and closed, and limits the travel of the drawer.
2. Description of the Prior Art
Drawer slides are well known and have been practiced for centuries, numerous alternative designs having been implemented. The present state of the art includes a variety of drawer slide pairs comprised of cooperating tracks, one of which is usually attached to the sidewalls of a cabinet, the other being attached to the drawer. U.S. Pat. No. 4,162,114 to Litchfield et al. is representative of such systems. Single track drawer slide systems having a track affixed to a cabinet below the drawer load for cooperating with a drawer mounted track rider have been developed. U.S. Pat. No. 4,389,079 to Cosme and U.S. Pat. Nos. 3,981,553, 3,702,717, 3,694,049 and 3,650,577 to Gutner disclose this type of bottom situated single track drawer slide. Numerous wheeled drawer slide systems have been designed to aid in reducing sliding friction between a stationary track portion affixed to a cabinet and a moveable track rider portion affixed to a drawer. U.S. Pat. No. 3,851,943 to Afful and the patent to Anderson, U.S. Pat. No. 3,375,051 teach such systems. The use of friction reducing pads composed of a material having a lower coefficient of friction than the unimproved slide assembly components and interposed between bearing surfaces is also common, and an example of such use is illustrated in the patent to Kanzelberger, U.S. Pat. No. 3,129,988.
The prior art does not include, however, a drawer slide for suspending a drawer from a single slide positioned above the drawer, nor a pair of such slides each being interchangeable, for suspending a drawer from a top portion of the drawer and for supporting the drawer's weight from below. Known drawer slides frequently permit a carried drawer load to skew and bind within its cabinet and/or the slide and also permit the drawer to be pulled from the cabinet inadvertently. Most common drawer slides have components which, when worn, permit the drawer to wrench free of its slide and become stuck within its cabinet or fall free of the cabinet. The higher quality, better operating slide systems currently available most often employ numerous and expensive parts such as wheels and ball bearings for carrying the drawer load reliably and with less effort. Known drawer slide designs are not amenable to carrying heavier loads and require extra-sturdy drawers to prevent torsional stress from deforming the drawer and pulling a drawer mounted component from a cooperating track. Common drawer slides are usually deficient in that they are not easy to disassemble and an unwieldy compromise is generally reached with regard to the ease with which a drawer may be removed from it's cabinet and how well it is retained when inadvertently pulled beyond its intended limit of travel.
An example of a drawer load not adequately carried by known drawer slides is the typical electrical equipment drawer. Frequently, the electrical circuitry of complex electrical devices is housed within pull-out electrical equipment drawers. Such drawers house plug-in circuit cards and other electrical components, their pull-out feature providing access to the components for installation and repair. Often, the numerous electronic components affixed to a pull-out component drawer have substantial weight and a sturdy drawer slide system to support them is required. Thus this application requires a drawer slide and support system which does not obstruct access to the front and back planes of the component drawer, but is capable of withstanding high loading forces in a vertical direction.
It is therefore an object of the present invention to provide a drawer slide composed of a pair of slides vertically arranged above and below a drawer load to which they are attached.
It is another object to provide a drawer slide having the capacity to operate above or below a load to suspend it or support it.
It is a further object to provide a drawer slide having a greater load capacity in the vertical direction than afforded by present designs.
It is an additional object to provide a high load capacity drawer slide which minimally restricts access to the side surfaces of a drawer.
It is yet another object to provide a drawer slide which is simple in construction and inexpensive to manufacture yet exhibits a long and dependable useful life.
It is still yet a further object to provide a drawer slide which ensures retention of the drawer securely within the holding means in which the drawer is installed but is also easy to disassemble.