Load compensator for height adjustable table

Abstract

A support assembly including a first column having a length dimension parallel to a substantially vertical extension axis, a second column supported by the first member for sliding motion along the extension axis between at least an extended position and a retracted position, a spring that generates a variable spring force that depends at least in part on the degree of spring loading, the spring having first and second ends where the first end is supported by and stationary with respect to the second column, an equalizer assembly including a first end linked to the second end of the spring and a second end linked to the first column, the force equalizer assembly and spring applying a force between the first and second columns tending to drive the columns into the extended position wherein the applied force is substantially constant irrespective of the position of the second column with respect to the first column and one of a locking mechanism, a velocity governing assembly, a roller assembly and a counterbalancing adjustment assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 11 / 305,714 which was filed on Dec. 16, 2005 and is entitled “Height Adjustable Table” and also claims priority to U.S. Provisional Patent Application No. 60 / 637,031 which is entitled “Load Compensator for Height Adjustable Table” which was filed on Dec. 17, 2004.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] The inventive concepts described herein pertain to tables and, more particularly, to a vertical and adjustable support for tables or the like. [0004] Tables are used in many different environments for many different purposes. For instance, in an office environment, tables may be used in a partition space as a desk top to support a seated person, as a monitor support, as a conferencing table for seated conferees, as a standing conferencing table, as a work station supporting surface for a s...

AI Technical Summary

Benefits of technology

[0021] At least some embodiment include a support assembly, the assembly comprising a first elongated member having a length dimension parallel to a substantially vertical extension axis, a second elongated member supported by the first member for sliding motion along the extension axis between at least an extended position and a retracted position, a spring that generates a variable spring force that depends at least in part on the degree of spring loading, the spring having first and second ends where the first end is supported by and stationary with respect to the second elongated member and a velocity governor supported by at least one of the first and second elongated members for restricting the speed with which the second elongated member moves with respect to the first elongated member along the extension axis.

[0039] Other embodiments includes a support assembly, the assembly comprising a first elongated member having a length dimension parallel to a substantially vertical extension axis, a second elongated member supported by the first member for sliding motion along the extension axis between at least an extended position and a retracted position, a spring that generates a variable spring force that depends at least in part on the degree of spring loading, the spring having first and second ends where the first end is supported by and stationary with respect to the second elongated member, an equalizer assembly including a first end linked to the second end of the spring and a second end linked to the first member, the force equalizer assembly and spring applying a force between the first and second members tending to drive the elongated members into the extended position wherein the applied force is substantially constant irrespective of the position of the second elongated member with respect to the first elongated member and a velocity governor supported by at least one of the first and second elongated members for restricting the speed with which the second elongated member moves with respect to the first elongated member along the extension axis.

[0063] Still other embodiments include a support assembly comprising a first elongated member having a length dimension parallel to a substantially vertical extension axis, a second elongated member supported by the first member for sliding motion along the extension axis between at least an extended position and a retracted position, a spring that generates a variable spring force that depends at least in part on the degree of spring loading, the spring having first and second ends where the first end is supported by and stationary with respect to the second elongated member, an equalizer assembly including a first end linked to the second end of the spring and a second end linked to the first member, the force equalizer assembly and spring applying a force between the first and second members tending to drive the elongated members into the extended position wherein the applied force is substantially constant irrespective of the position of the second elongated member with respect to the first elongated member and a velocity governor supported by at least one of the first and second elongated members for restricting the speed with which the second elongated member moves with respect to the first elongated member along the extension axis.

Problems solved by technology

One problem with telescoped upper and lower columns that support a table top is that the upper column, table top and load thereon are often relatively heavy and therefore difficult for a person to raise and lower in a controlled fashion.

First, this solution provides no way of conveniently adjusting the counterbalance force to compensate for different table top loads.

Second, the '597 patent solution fails to provide a safety mechanism for arresting upper column movement when the table top is either overloaded or, given a specific counterbalance force, under loaded.

Thus, for instance, if the tabletop load is much greater than the counterbalance force when a locking mechanism is unlocked, the table top and load will drop quickly and unexpectedly.

Similarly, if the table top load is much smaller than the counterbalance force is on the table top when the locking mechanism is unlocked, the table top and load would rise quickly and unexpectedly.

Unexpected table movement can be hazardous.

Third, the amount of counterbalance force required to aid in raising the upper column, table top and load thereon in the '597 patent, in addition to depending on the size of the load, also depends on the distribution of the load.

In this regard, a considerable amount of friction results when the upper column moves with respect to the lower column as at least portions of the upper and lower columns make direct contact during movement.

The amount of friction is exacerbated if the load on the table top is unevenly distributed.

First, while the '075 patent teaches an overload / under load safety mechanism, the safety mechanism is only partially effective.

However, if table load changes while the locking mechanism is unlocked and the table is either moving up or down (i.e., a person places a heavy box on the table top or removes a heavy box from the top), the overload / underload protection mechanism will not activate and the table top will either rise or drop quickly and unexpectedly.

Second, the '075 patent solution is designed for raising two columns, not one, and requires space between the two columns for accommodating various components.

Third, the '075 patent solution does not appear to facilitate a constant upward force on the upper column and table top irrespective of the height of the table top along its stroke as is desired in many applications.

Fourth, the '075 patent solution requires a table user to either modify table top load or manually adjust the counterbalance force when a load and the counterbalance force are not sufficiently balanced prior to changing the table top height.

Here, changing the counterbalance force can be a tedious task as the table user has to estimate the amount of unbalance when adjusting the required amount of counterbalance which, in most cases, would be an iterative process.

While fast table top movement may seem advantageous, rapid movement can cause excessive wear and even damage to assembly components.

For example, if the top is forced rapidly downward toward the end of the movement stroke, the moveable column components may collide with excessive force with the stationary components.

As another example, if the locking mechanism is released while the table top is rapidly descending, the locking mechanism could be damaged as movement of the moving column is halted.

Similarly, if the top moves to rapidly, items such as displays, printers, etc., supported by the top could be damaged.

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