Patent Publication Number: US-2022234875-A1

Title: Timber jack with arcuate fulcrum

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     Not applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     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. 
     II. Discussion of the Prior Art 
     Many forms of log jack devices are known in the art, one type of which is shown in  FIG. 1  hereof. It is seen to comprise an elongate wooden cylindrical handle  2  that is fitted into a tubular steel collar  4  at a distal end thereof. A curved arm  6  is joined at one end by a clevis connection  8  and the arm  6  is terminated at an opposite end in a sharply pointed hook  10 . Also rigidly connected to the steel collar  4  at its distal end is a perpendicularly extending leg  12  terminating in a transversely extending bar  14  that functions as a ground-engaging foot. 
     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. 
     SUMMARY OF THE INVENTION 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a perspective side view of a prior art timber jack; 
         FIG. 2  is a side view of a timber jack in accordance with a first embodiment of the invention; 
         FIG. 3  is a perspective view of a second embodiment of the invention; 
         FIG. 4  is a view showing the second embodiment positioned on a log in advance of elevation of the log; and 
         FIG. 5  is a view showing the log elevated from the ground and supported on the second embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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  FIG. 2 , in accordance with a first embodiment of the invention, it is seen to comprise an elongate pole  20  preferably of a hard wood, but alternatively a metal rod or pole. Affixed to a distal end portion of the pole  20  is a frustoconical collar member  22 , also of a metal, such as steel. An arm  24  having a somewhat C-shaped contour is attached to the collar member  22  proximate a first end thereof by a clevis  26  which allows the arm to pivot about a bolt  28 . The free end of the arm terminates in a sharp point  30  designed to penetrate into the bark of a log to be elevated from the ground. Also welded to the distal end of the collar  22  at a location aligned with the clevis  26  is a pointed barb  31 . 
     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  FIG. 2  is placed against a log to be lifted with the handle  20  perpendicular to the ground and the arm  24  partially encircling the log to be elevated. Here, the arcuate fulcrum leading end abuts the ground. As the handle is now forced from the vertical start position toward a horizontal orientation, the barb  31  and the pointed end  30  on the end of the arm are made to penetrate into the log&#39;s bark, as the log is elevated by a rolling action of the arcuate fulcrum  32  so as to end up resting on the collar  22  and with the cylindrical rod foot member  42  and the proximal end of the handle  20  engaging the ground. Based on unscientific testing, it is estimated that the force required to roll logs onto the timber jack of  FIG. 2  is about 75% less than that required to elevate the same log using the prior art timber jack of  FIG. 1 . 
     Turning next to  FIG. 3 , there is illustrated a second embodiment of the present invention. Here, the handle member is generally U-shaped having a pair of legs  52  and  54  joined by a cross member  57 . The handle member may be formed as a single piece in a bending operation or, as shown, may be formed as three separate pieces that are designed to be fastened together and secured by bolts, as at  59 , such that it thereby facilitates packaging and shipping when disassembled. The handle member  50  may comprise tubular or solid steel stock. 
     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  FIG. 2 , the arms  60  and  62  have a curved contour and with a pointed piercing member  64  at the free ends thereof. Again, in the view of  FIG. 3 , cooperating barbs  61  are welded to an upper surface of the legs  52 ,  54  on a distal end portion thereof. 
     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  FIGS. 4 and 5 , the manner in which the embodiment of  FIG. 3  is used will next be explained. 
     As seen in  FIG. 4 , the timber jack is positioned adjacent a side of a log  80  to be raised at an approximate midpoint of the log&#39;s length with the pointed barb  61  digging into the bark of the log on its near side, the U-shaped handle assembly  50  generally perpendicular to the ground and with the dual arms  60 ,  62  wrapped partially about the top and far side of the log  80 . Now, by first pulling on the cross member  57  as a hand grip and then forcing the handle  50  down and thus rotating the handle counterclockwise when viewed in  FIG. 4 , the arcuate fulcrums  68  and  70  rotating will result in the log being securely lifted without slippage and brought to rest laying across the distal end portions of the legs  52 ,  54  when the leveling member  76  is made to rest on the ground, as seen in  FIG. 5 . 
     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.