Abstract: A healthy equipment has at least one height-adjustable wheel set mounted on its bottom, so that the healthy equipment can be operated to move on a ground. Each height-adjustable wheel set has a swing seat that can be rotatable between a first angle and a second angle, a wheel that can be moved up or down along with rotation of the swing seat, and a pushing member that can be movable between a retracted position and an abutting position. When the pushing member rotates from the retracted position to the abutting position, the swing seat will rotate from the first angle to the second angle to lower the wheel to contact the ground. At the same time, a reaction force from the ground is applied to the pushing member in a direction corresponding to a rotational direction of the pushing member from the retracted position to the abutting position.

Abstract: A two-piece tool changing device is described. The changing device includes a base and a plate that nests with the base. The base includes a body along with guide brackets and a manifold attached to, or defined within, the base at a point along the peripheral edge of the base. The plate includes shoulders that reversible engage with the guide brackets. A standing section extends from the manifold toward the guide brackets, and defines a channel between the standing section and the body. A spring-biased plunger is optionally disposed within an aperture in the standing section, and the spring plunger is movable between a first position extending into the channel and a second position withdrawn from the channel. At least one conduit is optionally defined in the manifold and a corresponding conduit is defined in the plate, such that the conduit in the manifold and the conduit in the plate are in registration when the plate is nested in the base.