US2693935A

US2693935A - Log jack

Info

Publication number: US2693935A
Application number: US374773A
Authority: US
Inventors: Eddie J Halbert
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-08-17
Filing date: 1953-08-17
Publication date: 1954-11-09
Anticipated expiration: 1971-11-09

Description

Nov. 9, 1954 E. J. HALBERT 2,693,935

LOG JACK Filed Aug. 17, 1955 2 BY Eddie JfJfallwzj, 9%) Mwo ATTORNEYS.

This invention relates to improvements in implements formanually lifting logs and the like during lumbering and sawing operations and is particularly usefulin handling timber after it has been felled but prior to having the branches stripped away.

It is a primary object of this invention to provide a simple, rugged, compact, one-piece log jack which is light in weight, readily transported, and which may be easily operated by one man to lift a log end or section of felled timber from the ground and securely hold it in. an elevated position.

.Another object of this invention is to provide an improved log jack which can elevate felled, untrimmed timher without the necessity of canting or rolling the timber about its longitudinal axis.

It is a further object of this invention to provide. an improvement in log jacks whichis particularly-suited for elevating timber to a position conveniently accessible to workmen standing on the round, prior to stripping the timber of its foliage.

It is a still further object of this invention to provide an improved log jack which is stable in the log e1evating position thereby eliminating the need for lever hold down attachments or the services of an extra work man to hold the jack in the elevated position during log ging operations.

Further objects and advantages of the invention appear in connection with the description of the illustrative embodiment shown in the accompanying drawings, wherein Figure 1 is a side elevation of a preferred embodiment of the invention showing the jack positioned prior to elevating an end of a log.

Figure 2 is a side elevation of a log jack similar to that disclosed in Fig. 1 in which the jack is rotated doWnwardly so as to elevate a log end above the ground.

Figure 3 is a top plan view of the log jack illustrated in Figs. 1 and 2.

Figure 4 is a section taken on the line 44 of Fig. 3.

Figure 5 is a section taken on the line 55 of Fig. 3.

Figure 6 is a side elevation of a modified form of the log jack, and

Figure 7 is a side elevation of a second modification of the preferred embodiment of the invention illustrated in Figs. 1, 2 and 3.

There are many presently available pole gins and log lifting devices, such as the cant hook variety, but none of these devices are suitable for the use to which the present invention is intended. When a tree has been first felled it is not easy to elevate one end with the ordinary cant hook type log lifting jack since by its very nature it is necessary to cant or roll the log to some extent in the process of elevating it. It is very difficult to cant a newly felled tree because the branches prevent such rotation. Accordingly, in normal logging operations it is customary to trim all branches from the tree before working the timber into log sections. With the present invention, however, a timber piece can be cut into log sections without the necessity of first trimming it since this device does not depend on rolling the body of the timber while lifting. Rather, the present invention is expressly adapted to lift the tree without the necessity of any rolling action whatsoever.

In addition to the aforementioned advantages of the present log jack over jacks of the cant hook variety, the present invention is a one-piece light weight sturdy implement which is as fully efficient for handling logs as any Patented Nov. 9, 1954 of the presently known devices but is far superior for use'with untrimmed timber.

A preferred embodiment of the present invention comprises a unitary angularly shaped member 10 (Figs. 1 and 2) having a work engaging portion 12 and a lever portion-14. The'free end 16 of the work engaging memberrisarcuate in configuration to more easily slide under the lower portion of a felled tree, as best shown in Fig. 1. The, free end 18 of the lever portion 14 is of hollow tubularconstruction; adapteclto receive. a wooden stock orwhandle 20 therein sons to increase the length and effectiveness ofthelever. portion. In the-preferred embodiment of this invention, shown in Figs. 1 and '2;ithe unitary member 10 is of. U-shaped channel cross-section (Figs..4 and 5) which lends to this embodiment simplicity of construction, aswell as rigidity and strength. The flanges 22 and24 (Fig. 4) are flared downwardly on opposite sides-of the lever 14 adjacent its free end in order to'provide a bearingsurface for :the lever when it has been rotated downwardly into a horizontal position, as shownin Fig. 2. These flanges. space the lever 14 and stock 20. above-the. groundso that it will-be possible to obtain a good hand grip about the stock when in' this lowered horizontalposition. If. it were not for these flared'portions the handle would tend to bear solidly against theground and be very difiicult to' grasp prior to rotating'thellever upwardly.

5A fulcrum 26 .istransversely and rigidly secured to the portion ofthe work engaging arm 12 adjacent the intersection-of the longitudinal center lines of the arm portion'an'rl thelever'po'rtion. This fulcrum 26 is'made from a hollow cylindrical piece of tube, and provides a means for rotating the member about the axis which passes through the center of the fulcrum.

A second work engaging portion or rest 28 is of arcuate configuration having one end 30 integrally secured to the work engaging arm intermediate the free end 16 of the arm and the fulcrum 26. A structural brace 32 is rigidly secured to the top surface of the lever portion at one end 34 and at the other end to the free end 36 of the work engaging rest.

It is to be noted that the work rest 28 is forward or to the left of the fulcrum 26 (Fig. 1) when the free end 16 of the work engaging arm 12 and the fulcrum rest upon substantially the same horizontal plane, and that the work rest is substantially rearward or to the right of the fulcrum when the lever is in a substantially horizontal position. Because of the location and shape of the work rest 28, once the work engaging arm 12 is secured beneath a timber piece A, rotation upwardly of this arm will cause the work to cradle against the concave surface 38 of the work rest (Fig. 2).

It is also to be noted that with the work rest so situated with relation to the work engaging arm, that the center of gravity 40 of the work A so cradled shifts from forward of the axis 42 of the fulcrum 26 to a point rearwardly of the fulcrum when the lever has been rotated into a horizontal plane. Accordingly, it will be apparent that the weight of the timber A will hold the jack securely in this position until the lever 14 is rotated upwardly sufficient to again shift the center of gravity 40 of the work forwardly of the axis 42 of the fulcrum 26. Thus, no retaining hooks or other securing means are required to hold the lever in a lowered position while the timber is being worked upon.

Since it is the relationship of the work engaging arm 12, work rest 28 and fulcrum 26, one with the other, that is critical for proper functioning of this implement so as to keep a log or timber in a stable raised position, it is possible to have many mechanical equivalents of the work rest 28 so long as the critical relationship is maintained. Examples of modifications of the basic disclosure are shown in Figures 6 and 7. In Figure 6 the work rest 44 extends upwardly from the lever 14, terminating in a saddle 45. This work rest is braced thereto without having any connection to the work engaging arm 12. Since in this modification there is no inter-bracing between the work engaging portion 12 and the lever portion it will of course be necessary to obtain sufficient rigidity through adequate bracing at the base 46 of the work rest 44.

A second modification of the preferred embodiment has an arm extending inwardly from the work engaging arm 12 so as to form a crotch or yoke therebetween, in which case the work would be supported in bearing contact against the inside portions of the work engaging arm'and work rest at points 50 and 52 respectively. In both of these arrangements, of course, the center of gravity of the work is shifted from a position forward of the fulcrum to a position sufiiciently rearward to hold the work in a stable elevated position.

7 Thus, from the above set forth disclosure it is apparent that the present invention teaches the use of a new and useful log jack which is simple in construction, rugged in design and which may be employed to lift logs or freshly felled timber and the like without the need to first trim the branches from the trees and without the necessity of canting or rolling the log or timber as it is being lifted.

It will thus be seen that there has been provided by this invention structure in which the various objects hereinbefore set forth, together with many practical advantages are successfully achieved. As various possible embodiments may be made of the individual features of the above invention, all without departing from the scope thereof, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.

I claim:

1. A timber lifting device comprising a work engaging'arm, a lever rigidly secured to one end of said arm and angularly disposed thereto in a vertical plane, a fulcrum secured to the underside of said device adjacent the vertex of the included angle formed by said arm and said lever, and a work rest secured to the top side of said device and positioned so as to be forwardly of said fulcrum when the free end of said arm and said fulcrum are in the same horizontal plane, and rearwardly of said fulcrum when said lever is in a horizontal plane, whereby the center of gravity of work cradled between said arm and said rest is rearwardly of said fulcrum when said lever is in the aforedescribed horizontal plane.

2. The device set forth in claim 1, whereby said work rest comprises a concave member having one end secured to said arm intermediate the free end of said arm and said fulcrum, a structural brace secured to and outwardly projecting from said lever for rigid engagement with the other end of said work rest.

3. The device set forth in claim 1, whereby said work rest comprises a structural brace rigidly secured to and outwardly projecting from said lever, and a concave arcuately shaped work contact saddle secured to the free end of said brace.

4. The device set forth in claim 1, whereby said work rest comprises a second work engaging arm rigidly secured to and inwardly projecting from said first mentioned work engaging arm whereby said arms form a work supporting crotch.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,635,291 Smith et a1 July 12, 1927 2,162,668 Stocker June 13, 1939 2,439,122 Baker Apr. 6, 1948 2,539,231 Davis Jan. 23, 1951 2,539,711 Varabeau Ian. 30, 1951 FOREIGN PATENTS Number Country Date 40,987 Sweden June 7, 1913