초록 ▼

A cart includes a frame, a leg attached to the frame, and a wheel movable relative to the frame. A handle is operatively associated with the wheel and with the frame, whereby the work surface is in a normally stationary, inoperative position, and positive movement of the handle causes the wheels to

A cart includes a frame, a leg attached to the frame, and a wheel movable relative to the frame. A handle is operatively associated with the wheel and with the frame, whereby the work surface is in a normally stationary, inoperative position, and positive movement of the handle causes the wheels to engage the floor and place the work surface in an operative, movable mode. The work surface is engineered so that it is automatically returned to its stationary mode when no user is actively placing the work surface in its movable mode.

대표청구항 ▼

A cart comprising: a) a frame having a front and a rear; b) at least one leg attached to said frame and extending away from said frame for normally engaging a support surface; c) at least two wheels movably attached to said frame, said at least two wheels including a front wheel and a rear wheel mov

A cart comprising: a) a frame having a front and a rear; b) at least one leg attached to said frame and extending away from said frame for normally engaging a support surface; c) at least two wheels movably attached to said frame, said at least two wheels including a front wheel and a rear wheel movable between respective operative and inoperative positions; d) said at least two wheels extending away from said frame, and said at least two wheels normally being in said inoperative position substantially free of contact with the support surface; e) a handle attached to said at least two wheels; f) said handle being normally disposed in an inoperative position in which said at least two wheels are substantially free of contact with the support surface; g) said handle being movable relative to said frame to an operative position in which said at least two wheels are moved to said operative position of said at least two wheels, said operative position of said at least two wheels being a support-surface engaging position in which said at least two wheels support said cart for movement relative to the support surface; h) a linkage attached to said handle and to said at least two wheels, said linkage being configured for causing said at least two wheels to return from said operative position of said at least two wheels under the force of gravity, and for causing said handle to move from said operative position of said handle to said inoperative position of said handle under the force of gravity; and i) said linkage including: 1) front and rear pivot elements disposed on said at least one leg on said frame at said front and rear thereof, respectively; 2) front and rear pivot plates pivotably attached to said front and rear pivot elements, respectively; 3) said front and rear wheels being attached to said front and rear pivot plates, respectively; 4) front and rear pivot points disposed on said front and rear pivot plates, respectively; 5) said front and rear pivot points being laterally offset from said front and rear pivot elements, respectively; 6) a tie rod disposed between said front and rear pivot plates, and being pivotably attached to said front and rear pivot points, respectively; and 7) a connecting member disposed between and substantially rigidly connecting said rear pivot plate to said handle.