The present invention is directed to a cart for transporting cargo that is capable of climbing stairs. In the preferred embodiment, the cart has two three-wheel assemblies and a frame. The three-wheel assemblies are designed to rotate when contact is made with stairs, thereby allowing the cart to climb the stairs.

Stair climbing cart

A wheeled apparatus has a pair of first-size wheels attached in a spaced apart arrangement to a main frame at its first end portion. A subframe is moveably attached at its first end portion to the main frame at a position between the first-size wheels and a second end portion of the main frame. The subframe is attached to the main frame for allowing the subframe to be freely moved between a first position and a second position. The subframe and the main frame jointly limit movement of the subframe to be between the first and second positions. A pair of second-size wheel is attached to a second end portion of the subframe. The first-size and second-size wheels jointly provide a first wheelbase length when the subframe is in the first position and jointly provide a second wheelbase length when the subframe is in the second position.

Wheeled apparatus having multiple wheelbase configurations

A dolly includes a frame having rear and bottom sections directly conjoined to each other. The frame further includes a pair of oppositely disposed leverage arms having opposed end portions directly connected to the rear section and terminating rearward therefrom respectively. The dolly further includes an elongated drive axle directly connected to the leverage arms. First and second pairs of wheels are directly and operably mounted to the end portions of the axles. The dolly further includes a plurality of washers directly engaged with laterally spaced ones of the first and second pairs of wheels Each of the first and second pairs of wheels include a plurality of bearings directly intercalated between the axle end portions and associated rims of the first and second pairs of wheels. A plurality of spacers are nested between the first and second pairs of wheels for preventing undesirable contact therebetween.

Cargo transportation dolly

A portable load transporting dolly having a mechanism manually operable for selectively ascending or descending steps is shown. The dolly has generally cross-shaped wheels and a pivotal driving lever is located at its handle. A cable couples the pivotal driving lever to the rotating shaft of the cross-shaped wheels through a plurality of pulleys and ratchet gears such that the wheels may be rotated easily by gripping the lever. The radial arms of the cross-shaped wheels have sliding reciprocative rods which react with the steps of the staircase to enhance the climbing action of the dolly on the staircase.

Portable stair-climbing load transporting dolly

A dolly transport system includes a dolly cart assembly having a dolly frame having at least one gripping handle, at least one lifting fork extending from the dolly frame to a distal end, and a handle grip structure located at the distal end of the lifting fork. The dolly cart assembly includes a first supporting location that includes the gripping handle and a second supporting location remote from the first supporting location that includes the handle grip structure.

Dolly transport systems

A stair climbing hand truck utilizes two pairs of wheels which are attached to a secondary frame forming a part of the hand truck and which are mounted in an overlapping relationship. The first pair of wheels is mounted exteriorly of the secondary frame so as to lie outside of the hand truck's main frame structure, and the second pair of wheels is mounted interiorly of the main frame structure wherein all wheels are of the same diameter.

Dominick DeMartino

Papers

Stair climbing hand truck