1. Field of the Invention
The present invention relates to a stand or table with a vertically adjustable work surface. More particularly, this invention relates to an improved table which provides a stationary work surface on which the user may place office machines such as a visual display terminal (VDT) and an adjustable work surface on which the user may place the keyboard of the visual display terminal.
2. Description of the Prior Art
Work stations for visual display terminals generally include a table which provides a work surface and support for the terminal. Many tables also include an adjustable platform for supporting detachable keyboards. Typically, an adjustable support connects the keyboard platform to the table and allows the operator to adjust the platform vertically to a desired height.
To assure comfort and safety for office machine operators, various organizations including the Human Factors Society, have instituted various standards for visual display terminal work station construction. These standards include loads which certain components of the station must support and leg space dimensions for a wide range of body sizes, from a very small woman (fifth percentile) to a very large man (ninety-fifth percentile). Thus, as an initial consideration, a work station table must have a table top which lies a substantial distance above the supporting floor surface to accommodate this wide range of body sizes. Consequently, the adjustable support for the platform must allow the user to place the platform in position along a substantial vertical range.
In addition to the minimum requirements provided by the industry standards, the work station table should include a platform support which maintains the platform in the desired horizontal position without any undesired deflections or movements. In addition, this support should allow the operator to quickly and easily adjust the platform to the desired elevation and should not expose the operator to injury from moving parts. Finally, the support should be of simple construction, durable and easy to maintain.
The adjustable table of the present invention provides a construction which maximizes unobstructed leg space and allows the operator to quickly and easily move the adjustable platform to any position over a vertical range. It provides a construction which minimizes the expense of manufacture and assembly and gives precise, uniform and reliable performance. It comprises a small number of components with sufficiently accurate and consistent tolerances to produce the required mechanical action and place the platform in proper position and alignment without exposing the operator to injury from moving parts.