The invention pertains generally to wheeled vehicles, and more particularly to dollies.
Applicant's prior U.S. Pat. No. 3,717,357, issued Feb. 20, 1973, disclosed an adjustable dolly for transporting doors or other construction materials. Other dollies are shown in U.S. Pat. No. 2,816,771 issued Dec. 17, 1957 to E. R. Hunt, and U.S. Pat. No. 3,090,635 issued May 21, 1963 to M. I. Masterson, Jr. None of these prior constructions are suitable for selectively raising a door for hanging. When hanging a large or heavy door, for example a fire door or hospital door, it is nearly impossible for a single workman to accomplish it alone. It is desirable therefore, to provide a dolly which serves a dual purpose -- for transporting a door and as an aid in hanging the door.
The present invention relates to an improved dolly and to a method of using it to hang a door.
An object of the present invention is to provide a dolly which may be used both for transporting and hanging a door.
Another object is to provide a dolly which is manually pivotable about the axis of the wheels to selectively lift the item supported on the dolly.
Still another object is to provide a dolly in accordance with the foregoing object and having an outwardly extending lever arm which can be used for the lifting operation.
Yet another object is to provide an improved method for hanging a door, which method can be performed quickly and easily by one workman.
These, and other objects and advantages of the present invention, will become apparent as the same becomes better understood from the following detailed description when taken in conjunction with the accompanying drawings.
FIG. 1 is an elevational view of a door mounted on a dolly constructed in accordance with the present invention;
FIG. 2 is a larger-scale view of the dolly, partly in elevation and partly in cross-section;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2 and showing a moved position in phantom lives; and
FIG. 4 is a fragmentary perspective view illustrating the dolly being used to hang a door.
Reference is now made more particularly to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the several views.
The dolly, indicated generally by the numeral 10, includes an elongated, U-shaped door-receiving frame formed of opposite side members 11, 12 having lower ends interconnected by a bight portion 13. The side members are spaced apart slightly greater than the thickness of a door 16 so that the bottom or edge of the door is supported on the bight portion 13. Coaxially arranged horizontal axles 17, 18 are welded or otherwise suitably secured to the outer side of side members 11, 12, respectively. A pair of upright, parallel, floor-engaging wheels 20 are each rotatably mounted on one of the axles.
Lever arms 21 and 22 extend outwardly from the top end of side members 11 and 12, respectively. By engaging one of the lever arms with one's foot F, the frame may be swung about the axis of the wheels and axles to raise the bight portion 13 and thereby lift the door. For this purpose, the lever arms are advantageously at about 90° to the side members and extend outwardly a distance sufficient to be easily engaged by a workman's foot. To provide leverage, the axles 17 and 18 are preferably below the vertical center of the side members and, in the embodiment shown, are at about the quarter point from the bottom. This gives about a 3 to 1 leverage.
In the embodiment illustrated, the U-shaped frame and lever arms 21, 22 are unitary, being formed from 3/16 × 13/4 inch steel. The lever arms 21, 22 extend outwardly about 21/4 inch and their upper surfaces, as well as the inside of the U-shaped frame, are covered by a layer of cushioning material 30. The cushioning material serves to protect the surface of the door 16, and is preferably of fiberous material, such as thin carpeting, but may also be sheet rubber or equivalent material. The bight portion 13 is positioned 1/4 inch above a floor 31, as shown by dimension A in FIG. 3. The axles 17, 18 are 13/4 inch above the bottom of the bight portion. The side members 11, 12 are 7 inches long and spaced apart to receive the door 16 therebetween. For this purpose the side members diverge slightly, for example 1/16 inch. In the embodiment illustrated, the distance between the layers of cushioning material at the axles is 13/4 inch. The wheels are 4 inches in diameter and advantageously have rubber tires and ball bearings for ease in running. Preferably, the lever arms 21, 22 terminate inwardly of the wheels 20.
By swinging the side members 11, 12 about 30° from the vertical, as shown by angle B in FIG. 3, the cushioning material on the bight portion 13 will have one end raised about 1 inch above the floor, as shown by dimension C. Greater or lesser swinging will adjust the level of the bottom of the door 16 so that its hinge portion 32 will align with the hinge portions 33 on the door frame 34. It is necessary that the dolly be swingable through an arc sufficient to achieve such alignment and, as seen in FIG. 3, the present construction is such that the bight portion 13 never touches the floor 31.
In use, the door 16 is supported on the dolly 10 with the bottom of the door on the bight portion 13. The door is wheeled into position adjacent the door frame 34. The workman may then step on the lever arm 21 or 22, causing the U-shaped frame to pivot about the axles 17, 18. This raises the bight portion 13 and lifts the door 16. Adjusting the portion of the lever arm, as described above, align the hinge portions 32 and 33, and the hinge pin is then dropped into place. This can be performed by a single workman even if the door is quite large and/or heavy.
While a preferred embodiment of the invention has herein been illustrated and described, this has been done by way of illustration and not limitation, and the invention should not be limited except as required by the scope of the appended claims.