Variable height support

What is this patent about?

’391 is related to the field of adjustable support structures, specifically height-adjustable platforms designed for use in demanding environments like military vehicles. These platforms must provide a stable standing surface for operators while allowing for rapid, reliable vertical repositioning. The background context highlights the need for a mechanism that can be operated easily—often with a single hand—in confined spaces where traditional two-handed locking pins are impractical or difficult to align.

The underlying idea behind ’391 is a one-way ratcheting lift mechanism that allows a user to raise the platform simply by pulling it upward without needing to engage any manual releases. The core inventive insight is the integration of a spring-biased toothed bar that automatically yields to upward movement but immediately locks against downward force. This creates a “step-and-lock” functionality where the platform can be incrementally elevated and securely held at various heights through a continuous lifting motion, while requiring a deliberate actuator movement only for descent.

The claims of ’391 focus on a control assembly featuring a pivoting toothed bar and a secondary safety lock. The independent claims specify a ratchet subassembly where the toothed bar is biased toward an engaged position to block downward movement across a range of vertical locations. A critical limitation in the claims is the inclusion of a locking pin that physically passes through both the platform and the toothed bar. This pin must be moved to an unlocked state before the main actuator can shift the toothed bar into a disengaged position to allow the platform to be lowered.

In practice, the platform is supported by a scissors-link base where the ends of the links translate horizontally along tracks as the height changes. One of these translating ends includes a post that interacts directly with the teeth of the pivoting bar. When the platform is lifted, the post pushes past the ramped edges of the teeth; however, when the lifting force is removed, the flat blocking surface of the tooth catches the post to prevent collapse. To lower the unit, the user must first disengage the safety pin and then move the handle-style actuator to pivot the entire toothed bar away from the path of the post.

This design differs from prior approaches by eliminating the need for simultaneous two-handed manipulation of spring-loaded pins on opposite sides of a frame. By using a centralized ratchet and a single actuator, the system allows for “on the fly” adjustments even when the operator has limited visibility or dexterity. Unlike traditional ball-lock pins that require precise hole alignment, the ratcheting teeth provide automatic, discrete locking points, while the secondary locking pin ensures that the platform remains at the chosen height even under the heavy vibration and shifting loads typical of off-road vehicle use.