Lifting desktop with a compact structure

What is this patent about?

’149 is related to the field of height-adjustable furniture, specifically sit-stand desktop converters. These devices typically employ scissor-lift mechanisms to allow a user to transition between sitting and standing positions. Conventional designs often struggle with a lack of compactness when fully collapsed and require significant manual force to initiate the upward movement from a completely flat state, where mechanical leverage is at its weakest.

The underlying idea behind ’149 is to decouple the initial lifting force from the primary structural geometry by using a specialized actuating lever that converts horizontal spring tension into vertical thrust. By integrating a rod with an obtuse corner that acts as a force multiplier, the invention ensures that even when the scissor legs are nearly horizontal, a pneumatic or hydraulic cylinder can exert an immediate upward push against the desktop. This solves the 'dead center' problem where traditional gas springs provide negligible vertical assistance at the start of the stroke.

The claims of ’149 focus on a lifting assembly where the support legs are spanned on two sides of a lower side-plate containing a central slot designed to accommodate the scissor pivot. This specific geometry allows the legs to fold perfectly parallel and flush with the base. Furthermore, the independent claims protect the use of an assistance assembly comprising an elastic element coupled to an actuating lever, which features a ram portion that rotates about a fulcrum to physically bear against the desktop platform or base during the initial unfolding stage.

In practice, the invention functions by utilizing the elastic element to drive the arm-of-force portion of the lever, causing the ram portion to swing upward like a jack. As the desktop rises and the scissor legs reach a more favorable angle, the lever completes its primary task, and the elastic element transitions into providing traditional lifting assistance. To manage the height, a locking bar with specifically spaced holes allows for either equidistant height steps or progressive adjustments, ensuring the platform remains stable at the user's preferred elevation.

This approach differs from prior art by achieving a truly flat-folding profile without sacrificing ease of use. While previous designs either remained bulky when collapsed or required high-torque motors to overcome poor initial leverage, the ’149 patent uses the mechanical advantage of the obtuse-angled lever to bridge the gap between a fully retracted state and the active lifting range. The inclusion of the central slot in the side-plates further distinguishes this design by allowing the central pivot to 'sink' into the frame, minimizing the collapsed height of the entire unit.