Patent Application
20220234875
Not applicable
Not applicable
The present invention relates generally to logging tools and, more particularly, to logging jacks used to elevate downed logs from the ground to facilitate the cutting of logs into smaller lengths using a chain saw without worry that the chain saw blade member will engage the ground and become dull.
Many forms of log jack devices are known in the art, one type of which is shown in
In use, the handle is raised so as to be generally perpendicular to the ground and with the collar 4 against a side surface of a log and with the arm 6 extending over a top surface of the log. At this time, the foot 14 will be elevated only slightly above the ground. Now, a user rotating the handle from the vertical toward the horizontal will cause the foot 14 to act as a lever fulcrum of a lever of the first class and the log, being held by the arcuate arm and a barb 18 also welded to the collar 4, will be elevated as determined by the length of the leg 12 and made to rest on the collar 4 when the proximal end 16 of the handle is made to rest on the ground. Depending on the weight of the log being lifted, this can require considerable effort by the user to lift the log even though levering action is involved.
The present invention involves a modification of the above-described prior art timber jack that significantly reduces the manual effort involved in elevating logs from the ground.
In accordance with one embodiment of the present invention, there is provided an improved timber jack for elevating cut logs, such as tree trunks, from the ground to facilitate the cutting thereof into shorter lengths using a chain saw. It comprises at least one elongate handle member having proximal and distal ends and a curved arm having one end connected by a clevis at a position on the elongate handle that is a predetermined distance from the distal end and when the curved arm terminates at its free end in a log piercing member. Rather than having a leg and foot member, as in the above-described prior art, an arcuate fulcrum member is rigidly affixed at the distal end of the elongate handle member. As such, the effort needed to elevate a log is reduced due to a rolling action rather than a lifting action, as in the prior art.
In accordance with a further embodiment, the elongate handle member is U-shaped, defining first and second legs connected together at their proximal ends by a cross bar element and where each of the pair of legs has one of the curved arms connected by a clevis at a location that is a predetermined distance from the distal ends thereof and having one of the arcuate fulcrum members rigidly affixed at a distal end of each of the pair of legs.
The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts:
This description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “connected”, “connecting”, “attached”, “attaching”, “join” and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressively described otherwise.
Referring to
Also secured to the distal end of the collar 22 is an arcuate fulcrum assembly indicated generally by numeral 32. It comprises a convexly rounded plate 34 that is suspended from an ear 36 welded to the underside of the collar 22 by a strap 38 bolted to the ear 36 at one end and that is welded at its other end to an inner surface of the convexly rounded plate 34. A brace 40 is welded at one end to the ear 36 and its opposite end is also welded to the inner surface of the rounded plate 34 at a location offset from the strap 38 connection to the rounded plate. Welded to a free end of the rounded plate is a foot member in the form of a transversely extending cylindrical rod 42.
In use, the timber jack of
Turning next to
The legs 52 and 54 each have a clevis type connector 56, 58 welded to it a predetermined location for pivotally joining arm members 60, 62 to the handle member 50. As with the embodiment of
A second cross member 66 is welded or otherwise fastened to the legs 52 and 54 close to the distal ends 68 and 70 of the legs such that they remain parallel to one another.
Arcuate fulcrum members 68 and 70 are affixed at the distal ends of the leg members 52 and 54. More particularly, each of the arcuate fulcrum members comprise a convex curved steel strip 72 welded at a first end to the free ends of the legs and to a tubular brace, as at 74, that is welded to and extends perpendicularly downward from each of the leg members 52, 54.
Completing the assembly is a somewhat V-shaped leveling member 76 that is joined to the cross member 57 and projects laterally therefrom for a distance corresponding to the length of the brace members 74 so that the U-shaped handle 50 will remain in a generally horizontal disposition when the arcuate fulcrum members 68, 70 and the leveling member 76 are resting on the ground.
Referring next to
As seen in
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.
