US3026091A - Leverage tool - Google Patents

Description

C. D. OAKS LEVERAGE TOOL March 20, 1962 Filed June 30. 1958 FIG.2

FIG.5

INVENTOR. CLARENCE OAKS JOHN W. GRAHAM ATTORNEY United States Patent 3,026,991 LEVERAGE TOOL Clarence I). Oaks, 'Biggsviile, 111. Filed June 30, 1958, Ser. No. 745,577 2Clain1s. (Cl. 254-25) This invention relates to a lever tool, and more particularly to a leverage tool of the type generally comprising crowbars, pinch bars and the like.

In tools of this general type, a mechanical advantage is provided whereby a force applied by a workman to the tool is effective to accomplish a greater magnitude of work than if the force were applied directly to the work object. In a general sense, the tool defines a fulcrum at a selected point therealong, and the Workmans force is applied to the tool at a greater distance from this fulcrum point than the distance of the work object therefrom. Thus, from the basic principle of mechanics that torque is equal to the magnitude of a force times the distance between the pivotal axis or fulcrum and the point of force application, it will be apparent that if the leverage tool is properly designed, a workman can accomplish tasks requiring strength greatly in excess of physical capabilities.

As stated, tools of this general class are well known, and an object of the present invention is to provide an improved leverage tool having advantages far superior to any such tools heretofore known.

Another object of the invention is in the provision of a leverage tool that can be manipulated with ease by a single workman, and which is useful in conjunction with a variety of tasks.

Still another object is that of providing a leverage tool that is useful in extracting nails, spikes and the like, and which is also useful in lifting or raising heavy objects.

Still a further object is to provide a tool of the type described, equipped with a foot rest that facilitates manipulation thereof by a workman, and which is also provided with a support platform that maintains a heavy object in a horizontal plane as the tool is pivoted about a fulcrum defined thereby.

Additional objects and advantages of the invention will become apparent as the specification develops.

An embodiment of the invention is illustrated in the accompanying drawing, in which:

FIGURE 1 is a broken perspective view of a leverage tool embodying the invention; FIGURE 2 is a broken side view in elevation of the tool, but in which portions thereof are shown in section; FIGURE 3 is a broken side view in elevation similar to that of FIGURE 2, but showing the tool in use as a lifting device; FIGURE 4 is a broken side view in elevation, again similar to those of FIGURES 2 and 3, but showing the device in use as a nail-extractor; and FIGURE 5 is a horizontal sectional view taken along the line 55 of FIGURE 2.

The tool comprises an elongated bar that may be of rectangular cross section, as shown. The bar 10 is equipped intermediate the ends thereof with laterally extending foot rests 11 and 11' that project from opposite sides of the bar in longitudinal alignment with each other. As a result, the tool has the general configuration of an inverted cross. Though intermediate the ends of the bar, the foot rests 11 and 11' are adjacent one end 13 thereof which defines a fulcrum for the tool. It will be apparent that the foot rests are substantially normal to the respective longitudinal edges of the bar.

Intermediate the foot rests 11 and 11 and the fulcrumequipped end 13 of the bar is a support arm 12 which is substantially normal to the face of the bar, and also at right angles to the foot rests 11 and 11. The support arm 12 and foot rests are all rigid with the bar 10, and such rigidity may be provided by welding these elements 3,32%,991 Patented Mar. 20, 1932 to the bar if they are all formed of metal, as preferred. Extending through the support arm 12 is a pivot pin 14 having an axis substantially parallel to the axis defined by the foot rests 11 and 11. Carried by the pivot pin 14 for rotational movement about the longitudinal axis thereof is a support platform or lifting member 15.

The platform 15 is of generally U-shaped configuration, having spaced legs integrally connected at one end 16 thereof. The spaced legs of the platform extend along the longitudinal edges of the support arm 16, and thus substantially contain the support arm therebetween. The spaced legs of the platfomi at the other ends thereof are interconnected by a plat 17.

As is most evident in FIGURES 2 to 4, the plate 17 is a relatively thin element compared to the vertical dimension of the platform 15, whereby a recess 18 is defined between the plate and edge of the platform. As a result, the support arm 12 (as is most evident in EEG- URE 2) nests within the recess 18, and permits the plate 17 to bear thereagainst to maintain the platform in a generally horizontal plane, as shown in FIGURES 1, 2 and 5. The plate 17 is also provided with a notch or opening 19 adapted to engage the head of a nail 26, as shown in FIGURE 4. Preferably, the edges of the plate 17 adjacent the opening 19 therein are beveled or inclined to facilitate the insertion of the plate under the head of the nail. It will be noted in FIGURE 4 that the placement of the support arm 12 with respect to the fulcrurn end 13 of the bar, and with reference also to the vertical dimension of the support platform 15, is such that the platform abuts the support arm, as shown at 21, when the end 13 of the bar is in engagement with the ground or other support surface, so that the platform is rigidly related to the support arm and bar during nailextracting operations. The reason for this is clear since the frictional resistance of the nail applies a downward force upon the plate 17, which tends to rotate the p1atform 15 in a counter-clockwise direction as seen in FIG- URE 4, thereby effecting the abutment of the platform with the support arm The use of the tool is apparent from the illustrations thereof in the drawing and from the description set forth hereinbefore. However, it should be noted that when the tool is employed in raising a heavy object (which is shown by broken lines in FIGURE 3), the platform 15 may be maintained in a horizontal position since it is freely pivotal about the axis of the pin 14. Such horizontal relationship is maintained irrespective of the angular disposition of the support arm 12 with respect to the platform and support surface being engaged by the fulcrum 13. It will also be evident that during such lifting operations, the plate 17 is disposed along the upper surface of the support arm 12, and consequently the platform 15 is held in a substantially stationary position during the time it is inserted beneath the object to be raised.

When the tool is used in extracting nails and the like, the platform 15 is inverted so that the notched plate 17 is disposed along the surface of a floor containing the nails to be extracted. The nail is seated within the opening or notch 19 in a conventional manner, and the inclined edges adjacent thereto facilitate insertion of the plate beneath the head of the nail. When a force is applied to the tool to extract the nail, the platform 15 is rigidly related to the remaining components of the tool by engagement of the edge of the platform with the undersurface of the support arm 12.

During use of the tool, a workman may place one or both of his feet on the foot rests 11 and 11 to help him establish the leverage required toperform the specific operation. It will be noted that in a lifting operation, the length of the lever arm supporting the heavy weight is the distance between the fulcrum 13 and pivot axis 14 assuming that the weight is placed upon the platform so that the center of gravity is through the pivot pin. On the other hand, the effective lever arm for the workman is equal to the distance between the fulcrum 13 and the position along the handle 10 where he applies force thereto, which ordinarily will be the outer end portion thereof. Since the Workmans lever arm is substantially greater than that supporting the weight, it is clear that the torque he is able to develop about the fulcrum 13 will be suflicient to manipulate extremely heavy loads.

While in the foregoing specification an embodiment of the invention has been set forthin considerable-detail for the purpose of making a adequat disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in those details without departing from the spirit and scope of the invention.

I claim:

1. A tool selectively usable as a lifting implement and as a nail-extracting implement, comprising an elongated, longitudinally extending bar defining a fulcrum at one end thereof, a support arm extending laterally outwardly from said bar adjacent but spaced from said one end, a platform member having spaced apart legs respectively disposed along opposite sides of said support arm in straddling relation therewith and being pivotally connected thereto for selective movements between first and second work positions angularly separated by approximately 180 and respectively corresponding to such lifting and extracting uses of said tool, a plate element rigidly connecting said legs at one end thereof and being disposed in engagement with said support arm when said platform member is in such first position for employment in lifting a heavy object, and a rein-forcing member rigidly connected to said legs at the other end thereof for engagement with said support arm when said platform member is in such second position for employment in an extracting operation, the pivotal connection of said legs with said support arm being spaced substantially outwardly from the longitudinal axis of said elongated bar to enable said platform member to be elevated when said elongated bar is rotated about the fulcrum defined thereby and said pivotal connection being located along said legs at a position ofiset lengthwise from the center thereof so that said platform member is selectively maintained in such first or second position thereof.

2. The tool of claim 1 in which the longitudinal axes of said elongated bar and support arm at the intersection thereof define an acute angle in the direction of said fulcrum, and in which said elongated bar is equipped with foot-rests extending outwardly therefrom a spaced distance above said support arm.

References Cited in the tile of this patent UNITED STATES PATENTS 30,120 Card Sept. 25, 1860 79,587 Mead June 7, 1868 277,894 Flynn May 22, 1883 884,751 McBean Apr. 14, 1908 1,473,072 Anderson et al. Nov. 6, 1923 1,646,894 Basore Oct. 25, 1927 1,666,842 Carlson Apr. 17, 1928 1,929,956 Pehrsson Oct. 10, 1933 2,195,667 Baker Apr. 2, 1940 2,859,012 Oleson et a1. Nov. 4, 1958 FOREIGN PATENTS 649,570 Germany Aug. 27, 1937

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