June 28, 1949. c, C JR 2,474,725
SAFETY JACK BASE Filed Aug. 6, 1945' Patented June 28, 1949 UNITED STATES PATENT OFFICE SAFETY JACK BASE Harry 0. Clark, Jr., Belvidere, Ill.
Application August 6, 1945, Serial No. 609,275
This invention relates to lifting jacks, and more particularly to a base structure for a lifting jack.
A main object of the invention is to provide a novel and improved base structure for a lifting jack which insures safety in using the jack to lift vehicles on an inclined road surface.
A further object of the invention is to provide an improved jack base having a plurality of jack mountings corresponding to various degrees of inclination of the road surface so that the jack may be mounted in a safe manner on the base for a wide range of angular inclinations of the road surface.
Further objects and advantages of the invention will appear from the following description and claims, and from the accompanying drawings, wherein:
Figure 1 is an elevational view of a jack mounted on a jack base made in accordance with this invention as employed to lift a vehicle on an H inclined road surface.
Figure 2 is a plan view of the jack base employed in Figure 1.
In lifting a vehicle to change a tire on a road surface of substantial inclination, the conventional jack base provides a very unstable and unsafe support since the lifting force is applied at right angles to the base and the weight of the vehicle produces a moment tending to tip the jack over on its lowermost edge. It is a main purpose of this invention to provide a jack base which is arranged to receive the lower end of a conventional jack shaft and to support the shaft in substantially vertical position where the road surface is inclined.
Referring to the drawings, the base comprises leg members ll, l2 and I3 connected rigidly together at a central junction point M and spaced angularly approximately 120, said leg members lying in a common plane. Integrally formed therewith, as by welding, and projecting upwardly between the adjacent leg members are socket members [5, l6 and I1, each being adapted to receive the lower end of the shaft is of a jack l9 and to rigidly support the jack with respect to the leg members. The socket members 15, I6 and I! have their axes at different angles with respect to the plane of the leg members. Thus, socket member l may be at an angle of 90 with respect to the base plane, socket member I! may be at an angle of 85, and socket member 16 may be at an angle of 70 with respect to the base. For a horizontal road surface socket I5 is employed, for a slight inclination socket I1 is em ployed, and for a relatively steep inclination socket I6 is employed, whereby the lifting force of the jack may be applied in a substantially wertical direction to insure safety in the use of the jack.
The leg members l5, I6 and I! are of substantial length to provide stability under all required conditions of use.
Although shown as having three leg members and three socket members, any desired number of leg members and socket members may be employed in the base within the contemplation of this invention.
While a specific embodiment of a safety jack base has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention other than as defined by the scope of the appended claims.
What is claimed is:
1. A jack base comprising a plurality of radially disposed leg members of substantial length rigidly joined together, and a plurality of socket elements rigidly secured to the base adjacent the junction point of said legs, the axes of said socket elements being at different angles with respect to the base.
2. A jack base comprising three leg members rigidly joined together at their inner end portions to define a Y-shaped structure, said leg members being of substantial length, and a plurality of socket members rigidly secured between adjacent leg members adjacent the junction point thereof, one of said socket members being at an angle of 90 to the plane of said base and the others having their axes at different angles with respect to the base, each socket member being adapted to receive the lower end of a jack shaft and to hold said shaft rigidly with respect to the base.
3. The structure of claim 2, and wherein there are three socket members, the one socket member being at the stated angle of 90, a second being at an angle of approximately 85 and the third being at an angle of approximately to the base. I
HARRY C. CLARK, JR.
REFERENCES CITED The following references are of record in the file of this patent: