Automobile jack and wheel dolly
A wheel dolly is disclosed that is suited to serve as both an automobile jack, capable of holding large loads aloft for extended periods, relying on only mechanical systems and eliminating hydraulic systems. In a further aspect, the wheel dolly of the present invention does not include extended arms, handles, or levers for pumping or rotating the lifting mechanisms. Each lifting element terminates in only a single nut exposed to the user. Preferably, each nut of each lifting system has the same plan dimensions as the other, thus providing the advantage of allowing the user to operate the dolly with a driver and only one socket.
1. A wheel dolly comprising:
two support arms for engaging a wheel, the support arms being spaced a horizontal distance from each other, wherein each support arm comprises a four bar linkage including a lower linkage and an upper linkage, each four bar linkage being configured to permit the upper linkage of each support arm to move upwardly in relation to the lower linkage;
a base arm having two ends, each end being connected to one of the support arms;
wherein, the base arm includes:
a first member configured to have an adjustable length and extending along a first axis;
a second member configured to have an adjustable length and extending along a second axis, the second member being configured to be movable in relation to the first member such that the second axis moves apart from the first axis;
a first rotatable threaded rod extending within the first member, the first threaded rod configured, when rotated, to adjust the length of the first member and also to adjust the length of the second member;
two lifting arms each having first and second ends, each lifting arm being pin connected at the first end to the second member of the base arm, and pin connected at the second end to one of the upper linkages; and
a second rotatable threaded rod configured, when rotated, to move the second member in relation to the first member, whereby the second axis is moved apart from the first axis and each lifting arm is lifted, thereby lifting each upper linkage.
2. The wheel dolly of claim 1 , wherein the second rotatable threaded rod is configured to move the second axis in an arc in relation to the first axis.
3. The wheel dolly of claim 1 , wherein each upper linkage has a roller connected to the upper linkage, and each roller has an axis and is configured to engage the wheel and to rotate the wheel about an axis of the wheel.
4. The wheel dolly of claim 1 , wherein the dolly includes a plurality of casters for moving the dolly horizontally.
5. The wheel dolly of claim 1 wherein the dolly includes at least one threaded stud for restricting the horizontal movement of the dolly, the threaded stud being configured to be extended downward to make contact with a horizontal floor surface.
6. The wheel dolly of claim 1 , wherein the first member is adjustable in length by telescoping action of a first outer element slidable along the outside of a first inner element, and the second member is adjustable in length by telescoping action of a second outer element slidable along the outside of a second inner element, and further wherein the first outer element is held translationally immovable in relation to the second outer element by one of the two lifting arms, and wherein the first inner element is held translationally immovable in relation to the second inner element by the other of the two lifting arms.
7. The wheel dolly of claim 6 , wherein the second outer element includes a portion that is free to rotate in relation to a remaining portion of the second outer element.
8. The wheel dolly of claim 6 , wherein the second inner element is configured to rotate in relation to the second outer element.