초록 ▼

An auxiliary wheel set adapted for aftermarket installation on two-wheeled hand trucks. The apparatus includes a right vertical support and left vertical support, each having a leg portion with an upper section and a lower end, and a shoulder at its upper portion from which an upper arm extends outw

An auxiliary wheel set adapted for aftermarket installation on two-wheeled hand trucks. The apparatus includes a right vertical support and left vertical support, each having a leg portion with an upper section and a lower end, and a shoulder at its upper portion from which an upper arm extends outwardly substantially perpendicular to the leg. Each upper arm terminates in a curved elbow which connects the upper arm to a lower arm which extends inwardly and substantially parallel to the upper arm. A spreader bar is welded between the vertical supports to provide bracing. Locking caster wheels are disposed on the respective lower ends of the legs. The lower arms are journalled in bushings, which are, in turn, removably installed onto the side rails of a hand truck with U-bolts attached to first and second integral pivot plates. The wheel set selectively pivots between a stored position and a deployed position.

대표청구항 ▼

What is claimed as invention is: 1. An auxiliary wheel set adapted for aftermarket installation on two-wheeled hand trucks and having a stored position and a deployed position, said apparatus comprising: a right vertical support having a right leg portion with a right upper portion and a right lowe

What is claimed as invention is: 1. An auxiliary wheel set adapted for aftermarket installation on two-wheeled hand trucks and having a stored position and a deployed position, said apparatus comprising: a right vertical support having a right leg portion with a right upper portion and a right lower end, a right arm portion connected to said right upper portion and extending inwardly and substantially perpendicular to said right leg portion; a left vertical support having a left leg portion with a left upper portion and a left lower end, a left arm portion connected to said left upper portion and extending inwardly and substantially perpendicular to said left leg portion; bracing means interposed between said right and left vertical supports; a first swiveling caster wheel assembly disposed on said right lower end of said right vertical support; a second swiveling caster wheel assembly disposed on said left lower end of said left vertical support; first pivot connection means to which said right arm portion is pivotally connected; second pivot connection means to which said left arm portion is pivotally connected; and side rail connection means for removably installing said first and second pivot connection means on the side rails of a hand truck; whereby said first and second pivot connection means and said side rail connection means cooperate to permit said right and left vertical supports to pivot between the stored and deployed positions. 2. The apparatus of claim 1, wherein said right arm portion comprises a right shoulder extending from said right upper portion; a right upper arm extending outwardly and substantially perpendicular to said right leg portion; a right lower arm extending inwardly and substantially parallel to said right upper arm; a right curved elbow having first and second ends and connected at its first end to said right upper arm and at its second end to said right lower arm; and wherein said left arm portion comprises a left shoulder extending from said left upper portion; a left upper arm extending outwardly and substantially perpendicular to said left leg portion; a left lower arm extending inwardly and substantially parallel to said left upper arm; a left curved elbow having first and second ends and connected at its first end to said left upper arm and at its second end to said left lower arm. 3. The apparatus of claim 1, wherein said bracing means is a cross brace. 4. The apparatus of claim 1, wherein said first and second pivot connection means comprise first and second pivot tubes. 5. The apparatus of claim 4, wherein said first and second pivot tubes are welded to first and second pivot plates, respectively. 6. The apparatus of claim 5, wherein said side rail connection means comprises means to clamp said first and second pivot plates to the side rails of a hand truck. 7. The apparatus of claim 4, further including right and left locking collars, said right locking collar installed on an end of said right arm portion to secure it within said pivot tube and to restrict lateral movement of said right arm portion; and wherein said left locking collars is installed on an end of said left arm portion to secure it within said pivot tube and to restrict lateral movement of said left arm portion. 8. The apparatus of claim 1, further including a locking pin for locking said apparatus in each of the stored and deployed positions. 9. The apparatus of claim 1, wherein said first and second vertical supports each include a skid plate at their respective lower ends. 10. An auxiliary wheel set adapted for aftermarket installation on two-wheeled hand trucks, said apparatus comprising: a right vertical support having a right leg portion with a right upper portion and a right lower end, a right shoulder extending from said right upper portion, a right upper arm extending outwardly and substantially perpendicular to said right leg portion, said right upper arm terminating at one end in a curved elbow, and a right lower arm connected to said curved elbow at the other end, said right lower arm extending inwardly and substantially parallel to said right upper arm; a left vertical support having a left leg portion with a left upper portion and a left lower end, a left shoulder extending from said left upper portion, a left upper arm extending outwardly and substantially perpendicular to said left leg portion, said left upper arm terminating at one end in a curved elbow, and a left lower arm connected to said curved elbow at the other end, said left lower arm extending inwardly and substantially parallel to said left upper arm; a spreader bar interposed between and bracing said right and left vertical supports; a first swiveling caster wheel assembly disposed on said right lower end of said right vertical support; a second swiveling caster wheel assembly disposed on said left lower end of said left vertical support; a first bushing into which said right lower arm is journalled; a second bushing into which said left lower arm is journalled; and connection means for removably installing said bushings on the side rails of a hand truck, characterized in that said connection means permits said wheel set to pivot between a retracted position and an extended position. 11. The auxiliary wheel set apparatus of claim 10, wherein said bushings comprise pivot tubes, and wherein said connection means comprises: first and second pivot plates integral with said first and second bushings, respectively, each of said plates having at apertures through which the ends of U-bolts may be inserted and secured by nuts to the side rail of a hand truck so that said plate is approximated to the side rail; and a pivot tube locking collar slidably inserted over the end of said lower arm to secure said lower arm in said pivot tube. 12. The auxiliary wheel set of claim 11, wherein said connection means further includes at least one helical tension spring installed around one of said upper arms and having ends connected to an arm of a U-bolt, said spring adapted to hold said auxiliary wheel set in tension so that said auxiliary wheel set does not move between the retracted and extended without manual force. 13. The auxiliary wheel set of claim 10, further including a lock to selectively lock said auxiliary wheel set in either the retracted or extended positions.