Abstract:
A tree pusher for safely felling trees. The tree pusher controls and determines the direction in which the tree falls, using a base, a frame, a detachable head which engages the tree trunk, and an extendable screw-type trailer jack that is repairable/replaceable during operation and capable of bearing the weight of a large tree, for urging the frame and the head against the trunk of the tree. For use on uneven ground, the tree pusher is provided with a base extension. A chain is used to connect the base of the tree pusher to the trunk of the tree, to prevent movement of the base when the jack is activated. The tree pusher can be readily moved to the job site, and can be used on any type of terrain, including hard surfaces, and for any type of tree, including trees with rotten wood.

Description:
BACKGROUND OF INVENTION 
     The present invention relates to felling trees. More particularly, the present invention relates to felling trees in a safe and efficient manner by controlling the direction in which the tree falls. 
     When felling trees, it is a constant problem to determine the direction in which the tree will fall. The problem is especially severe when the tree is leaning in an undesirable direction; e.g., in the direction of a nearby house. When the tree is not leaning in any direction, there is still the problem of preventing the tree from falling on the person or persons who is/are felling the tree. The present invention provides a device and a method for causing the tree to fall in a desired direction. 
     Attempts have been made to solve these problems, but they have not been successful. 
     U.S. Pat. No. 4,184,462 to Jessup discloses a tree-felling device adapted to engage a tree being cut down, and to exert a force thereagainst in a particular direction, in order to cause the tree to fall in a selected area. The tree-felling device includes a jacking device of the basic bumper type which is adapted to support an elongated pusher having a tree-engaging head secured at one end thereof, and which is preferably tied to the tree to be cut. As a part of the jacking device, there is provided a ratchet mechanism having an anchoring stud secured thereto for generally receiving and stabilizing one end of said pusher, while the jacking assembly is provided with a support clip about the top portion thereof for holding the pusher. 
     U.S. Pat. No. 4,564,173 to Atherton et al. discloses an apparatus for pushing a tree over when the tree is being cut down. When a base connected to a bumper jack is placed on a ground surface, the apparatus is tipped at an angle between the ground surface and the tree. A jack handle operates a mechanism to rise along a jack post, causing a support member to push a shaft through an aperture in a guide member until points on a tip member contact the tree, pushing the tree over when the tree is being cut down. 
     The principal defects of these prior-art inventions are the following: 
     (a) A bumper jack is not capable of handling the weight of a large tree. 
     (b) A bumperjack cannot extend its length to a jack post if a longer jack is needed to push the tree over. 
     (c) The bumper-jack post would bear the entire weight of the tree. If the post should break, the tree could very possibly fall on the person or persons felling the tree, or fall in some other undesirable direction. 
     (d) If the jack should fail or break under the load, the jack could not be repaired or changed out during the tree-felling operation. 
     (e) In the case of the Jessup patent, the head plate ( 36 ) which engages the tree is not embedded in the wood of the tree. If the tree turns or twists, the head plate will move, slip, or become disconnected from the tree. 
     (f) Neither device could be used to fell dead or rotten trees, because neither head is designed to engage dead or rotten wood. 
     (g) In the case of the Jessup patent, there is nothing to hold the head plate ( 36 ) up while the tree-felling device is placed in position to fell the tree. 
     (h) In the case of the Jessup patent, once the tree is lying on the ground, it would be difficult to disconnect and remove the chain ( 38 ) from the tree trunk. 
     (i) In the case of the Jessup patent, there is nothing to prevent the pusher ( 34 ) from sliding off the head plate ( 36 ) when pressure is applied by the jack. 
     (j) In the case of the Jessup patent, in the event that the tree twists or turns, there is nothing to hold the pusher ( 34 ) against the head plate ( 36 ). 
     (k) The bumper jack lifts the load with a ratcheting action that allows for a rocking motion of the tree. This can cause the wood in the hinge point to break. 
     (I) Bumper jacks have a large number of moving parts, and have springs which may weaken and break. 
     (m) Under load, the support plate for the jack would flip or rise up in front, causing the plate to skid or to be pushed backwards. 
     (n) There is nothing to prevent the jack support plate from being pushed into the ground or away from the tree. 
     (o) Neither tree-felling device is usable on hard surfaces. 
     (p) The tree-felling devices could not be used on banks or inclines. 
     (q) There is no effective way of transporting the tree-felling devices to the job site. 
     The present invention provides an effective solution to these problems. 
     SUMMARY OF INVENTION 
     In general, the present invention in a first aspect provides a tree-pusher for safely felling trees. The tree-pusher comprises (a) a base, (b) a frame mounted on the base, (c) a detachable head which engages the tree, and (d) a screw-type propeller trailer jack for urging the frame and the pronged head against the tree. 
     The frame comprises first, second, third, and fourth rectangular tubes. The first tube is pivotally connected to the base. The second tube is disposed in the first tube. The third tube is constructed and arranged to slide over the second tube. The fourth tube is constructed and arranged to be inserted in and pinned to the third tube. 
     The head is constructed and arranged to be disposed in the fourth tube, to attach itself to a trunk of a tree, and to detach itself from the frame and remain attached to the trunk as the tree falls. 
     The jack, which is attached to the frame, is extendable, capable of bearing the weight of a large tree, and capable of being repaired or changed out under load during a tree-felling operation. 
     In a second aspect the invention provides a method for felling a tree. The method comprises (a) providing a tree-pusher having a base, a frame, a detachable head which engages the tree trunk, and a screw-type propeller trailer jack for urging the frame and the head against the trunk of the tree; (b) securely connecting the base of the tree-pusher to the trunk of the tree; (c) attaching the head and frame of the tree-pusher to one side of the tree trunk; (d) cutting a notch in the trunk of the tree above the point of attachment of the tree pusher and on the side opposite the attachment of the head and frame thereto; and (e) using the jack to urge the head and frame of the tree-pusher against the tree trunk to fell the tree, and detach the head from the frame of the tree pusher as the tree falls. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is an isometric side elevation of a first embodiment of a tree pusher, made in accordance with the principles of the present invention. 
     FIG. 2 is an isometric rear view of the tree pusher shown in FIG.  1 . 
     FIGS. 3 and 3A are enlarged schematic representations of a portion of the tree pusher shown in FIGS. 1 and 2. 
     FIG. 4 is a schematic representation of a modified portion of the tree pusher shown in FIGS. 1 and 2. 
     FIGS. 5A,  5 B,  5 C, and  5 D are schematic representations of various stages of felling a tree, using the tree pusher shown in FIGS. 1 and 2. 
     FIG. 6 is an isometric side elevation of a second embodiment of a tree pusher made in accordance with the principles of the present invention, the tree pusher engaging a tree that is to be felled. 
     FIGS. 7A and 7B are enlarged schematic representations of opposite faces of a portion of the tree pusher shown in FIG.  6 . 
     FIG. 8 is an isometric side elevation of a third embodiment of a tree pusher made in accordance with the principles of the present invention, the tree pusher engaging a tree that is to be felled. 
     FIG. 8A is an enlarged isometric view of a portion of the tree pusher shown in FIG.  8 . 
    
    
     DETAILED DESCRIPTION 
     More specifically, reference is made to FIGS. 1 and 2, in which is shown a first embodiment of a tree pusher, made in accordance with the principles of the present invention, and generally designated by the numeral  100 . 
     The tree pusher  100  comprises a base  32 , a frame  35 , a detachable pronged head  68  which engages a tree, a screw-type propeller trailer jack  40  for urging the frame  35  and head  68  against the tree, and a wheel  36  for moving the tree pusher 
     The base  32  comprises a split plate  32   a  having first and second portions  32   f  and  32   g . First and second parallel channel irons  32   b  and  32   c  are spaced apart from one another and fastened to the first portion  32   f  of the split plate  32   a  in a perpendicular orientation. A hook  33  is fastened to the first portion  32   f  of the split plate  32   a , for attachment of a chain to the hook  33  and thereby to the base  32 . 
     A pair of parallel plates  32   h  having openings therein are spaced apart and fastened to the second portion  32   g  of the split plate  32   a . The plates  32   h  are identical to those shown in FIG. 8A at  65   a  with openings  65   b . Only one of the plates  32   h  is shown in FIG. 1 , and the opening in plate  32   h  is not shown in that drawing. 
     The frame  35  comprises first, second, third, and fourth rectangular tubes  63 ,  42 ,  44 , and  46 , respectively. The first tube  63  is disposed between first ends of the channel irons  32   b  and  32   c  and pivotally connected thereto by a first pin  32   d . The first ends of the channel irons  32   b  and  32   c  are fastened to one another and pivotally connected to the first rectangular tube  63  by the first pin  32   d . Second ends of the channel irons  32   b  and  32   c  are fastened to one another by a second pin  32   e , thereby fastening the first and second portions  32   f  and  32   g  of the split plate  32   a  to one another. 
     The second tube  42  is disposed in the first tube  63 . The third tube  44  is constructed and arranged to slide over the second tube  42 . The fourth tube  46  is constructed and arranged to be inserted in and pinned to the third tube  44  by a third pin  45 . 
     As will be seen most clearly in FIGS. 3A and 3, the pronged head  68  comprises a cylindrical fifth tube  48  having first and second ends  48   a  and  48   b , and a plurality prongs  68   a  fastened to a cap  68   c  at the first end  48   a  of the fifth tube  48 . The fifth tube  48  and each prong  68   a  define therebetween an angle  68   b  of from about five to about thirty degrees. The fourth tube  46  is provided with a flange  46   a  upon which the cap  68   c  rests when the fifth tube  48  is disposed as shown in the fourth tube  46 . 
     Referring again to FIGS. 1 and 2, the jack  40  comprises a jack base  76  fastened to the second tube  42  by a shaft  38 ; a body  40   a  mounted on the jack base  76 , fastened to the third tube  44  by a union  40   d , and constructed and arranged for movement parallel to the frame  35  of the tree pusher  100 ; and a crank  40   b  having a handle  40   c , for moving the body  40   a  of the jack  40 . 
     The wheel  36  is mounted on an axle  36   a , which is in turn mounted on the shaft  38  to which the jack base  76  is fastened. 
     The third tube  44  includes an opening  44   a , and a handle  44   b  for moving the tree pusher  100 . In order to lock the second and third tubes  42  and  44  to one another, so that the body  40   a  of the jack  40  can be extended to provide an extended range for the jack  40  and a means for removing the jack  40  from the frame  35  in the event the jack  40  should break or fail, a pin  44   c  is inserted into the opening  44   a.    
     The jack  40  is extendable, capable of bearing the weight of a large tree, and capable of being removed, repaired, or changed out under load during a tree-felling operation. 
     The jack  40  has fifteen inches of movement or extension. When this point has been reached, one would insert pin  44   c  in opening  44   a  to lock the second and third tubes  42  and  44  together, thus holding the weight of the tree on the frame  35  of the tree pusher. Then one would pull out the jack pin  44   c , and screw the jack  40  back down to start there, by pulling the jack base  76  out to gain another thirteen inches of travel or push in the tree pusher  100 . When the jack  40  has been screwed back down to the bottom or starting point, one would reinsert the jack pin  40   d  in the jack body  40   a , thereby locking the jack body  40   a  in the jack  40 . Then one would start to screw the jack  40  again to push the tree, at which time one would remove pin  44   c  from opening  44   a , thus allowing the jack  40  to push the tree for an added thirteen inches of push if needed. 
     Reference is now made to FIG. 4, in which is shown a modification of the base  32  shown in FIGS. 1 and 2. The modified base comprises first and second plates  60  and  32   i . The second plate  32   i  is fastened to the second tube  42 , preferably by welding. First and second parallel plates  60   a  and  60   b  are spaced apart and fastened perpendicularly to the first plate  60 . Instead of the first rectangular tube  63  shown in FIGS. 1 and 2, a first rectangular tube  62  is disposed between the first and second parallel plates  60   a  and  60   b , and the plates  60   a ,  60   b , and the first tube  62  are fastened to one another by a pin  62   a . The first tube  62  is pivotally attached to the first and second parallel plates  60   a  and  60   b  and to the first plate  60 , and extends through the second and third tubes  42  and  44 . The modified base provides a modest degree of elevation for the tree pusher when used on unlevel ground that is slightly below the ground level of a tree to be cut down. A tree standing on ground below the level of ground on which the tree pusher rests presents no problem; one simply ends up with a tall stump after the tree has been cut down. 
     Reference is now made to FIGS. 5A to  5 D, which illustrate a method for felling a tree in accordance with the principles of the present invention. FIG. 5A shows the pronged head  68  of the tree pusher  100  engaging a tree  30  which is to be felled. The tree  30  and the tree pusher  100  are on substantially level ground  30   g . The base  32  is connected to the tree  30  by a chain  34  attached to the hook  33  (not shown) of the base  32 . The person (not shown) operating the tree pusher  100  has oriented the tree pusher  100  by pivoting the frame  35  on the base  32  so that the tree  30  will fall in the direction indicated by the arrow when force is applied to the tree  30  by the jack  40 . 
     As shown in FIG. 5B, after the tree  30  has been engaged by the tree pusher  100 , a V-shaped notch  30   a  is cut in the trunk of the tree  30  on the side of the tree  30  opposite that of the tree pusher  100 , and above the point of attachment of the chain  34 . Cutting the notch  30   a  in the trunk of the tree  30  prepares the tree for felling and reinforces the action of the tree pusher  100  in causing the tree  30  to fall in the chosen and desired direction. 
     The head  68  remains attached to the trunk of the tree  30  as the tree  30  falls, leaving a stump of the tree  30 , as shown in FIGS. 5C and 5D. 
     Reference is now made to FIG. 6, in which is shown a second embodiment of a tree pusher, made in accordance with the principles of the present invention, and generally designated by the numeral  200 . The second embodiment  200  differs from the first embodiment  100  of the tree pusher only in the construction of the wrap-around head  69 . 
     The pronged head  68  is used when the wood of the trunk is reasonably solid. The wrap-around head  69  is used only when the wood is rotten or for some other reason cannot be securely engaged by the prongs  68   a  of the pronged head  68 . 
     The structure of the wrap-around head  69  can be best understood by reference to FIGS. 7A and 7B, which show opposite faces of the head  69 . The wrap-around head  69  is constructed and arranged to be wrapped around the trunk of a tree. 
     FIG. 7A shows a first face of the head  69 . The first face comprises first, second, and third plates  10 ,  18   a , and  18   b . The second and third plates  18   a  and  18   b  are spaced apart, and are fastened to a first face of the first plate in a perpendicular orientation. The second and third plates  18   a  and  18   b  each includes a substantially central opening  18   c.    
     A cylindrical tube  12  has an end  12   a  pivotally attached to the second and third plates  18   a  and  18   b  by a bolt  14  disposed in the central openings  18   c . The rest of the tube  12  is disposed in tube  46 , as shown in FIG. 6. A ratchet binder  22  and a hook  24  are fastened to opposite sides of the first face of the first plate  10 . A Nylon strap  26  has a first end  26   a  connected to the ratchet binder  22 , and a second end  26   b  connected to the hook  24  through an eye  26   c.    
     FIG. 7B shows a second and opposite face of the wrap-around head  69 . A plurality of teeth  10   a  fastened to a second and opposite face of the first plate  10  penetrate and embed themselves in the dead wood of the tree trunk and, in combination with the strap  26  which is wrapped around the tree trunk, hold the tree pusher  200  firmly and securely to the trunk of the tree  30 . 
     Reference is now made to FIG. 8, in which is shown a third embodiment of a tree pusher, made in accordance with the principles of the present invention, and generally designated by the numeral  300 . This embodiment of the tree pusher is used on unlevel ground that is substantially below the level of a tree to be cut down. 
     A base extension  65  (shown in FIG. 8A) comprises a first plate  104  to which are fastened in a perpendicular orientation a pair of parallel second plates  65   a  spaced apart and having openings  65   b . A rectangular tube  61  has an end  61   a  disposed between the plates  65   a . The tube  61  includes a plurality of openings  61   b  along its length. One of the openings  61   b  is at the end  61   a  of the tube  61 , and is used to lock the tube  61  to the plates  65   a  and thereby to the base  65 , by inserting a locking pin  62   a  in and through the openings  63   b  and  61   b.    
     The base  32  shown in FIGS. 1 and 2 is mounted on the tube  61  and the base extension  65  by inserting and locking the pin  32   e  in one of the other openings  61   b , by appropriate choice of the specific opening  61   b , the base  32  and the tree pusher  100 / 200 , signifying either embodiment  100  or  200 , can be raised to the appropriate height to engage and fell the tree  30 . The head  68 / 69  may be either the pronged head  68  or the wrap-around head  69 . 
     Attachment of the hook  33  to the plate  104  provides a modified base that can be used to replace the base  32  of the first and second embodiments  100  and  200  when the tree pusher is to be used on substantially level ground. 
     It is critically important that both heads  68  and  69  be detachable from the frame  35 , and that they remain attached to the tree trunk as the tree falls. For this reason it is critical that the tubes  48  and  12  be cylindrical, not rectangular. A cylindrical tube can freely rotate in the tube  46  as the tree falls; a rectangular tube would bind. Detachability of the heads  68  and  69  is a very important advantage of the present invention over the prior art. 
     The construction of the pronged head  68 of the tree pusher is critical because in order to attach itself to the tree, the head  68  must embed itself and remain embedded in the wood of the tree. Otherwise, the bark of pine and hardwood trees will break, and the head  68  will come loose and slide off the trunk of the tree. With the head  68  constructed as shown, having prongs  68   a  which define an angle  68   b  of from about five to about thirty degrees with the fifth tube  48 , the pronged head  68  will remain in contact with the tree  30  as the tree is pushed over the center of gravity of the tree to the point where the tree will fall. The center of gravity of a tree that is leaning e.g. ten degrees with limbs on the side toward which the tree is leaning is not in line with the trunk, but somewhere out on the limbs. A tree with this type of lean has to be pushed far over center before the tree will fall. The angle  68   b  of the prongs  68   a  keeps the pronged head  68  in contact with the trunk until and as the tree falls. 
     For trees that are twisted or crooked, the pronged head  68  must embed and remain embedded in the wood, because the tree will twist or move while being felled. The head  68  must remain embedded in the wood, and must be able to turn in the frame of the tree pusher so as not to lose contact with the tree, or move the frame of the tree pusher during the felling operation. The head  68  cannot be fastened or remain attached to the frame of the tree pusher, because if the tree twisted or turned, the head  68  would twist or turn the frame of the tree pusher, causing loss of control of the tree-pushing operation. As constructed, the pronged head  68  will turn or twist with the movement of the tree, and not move or twist the frame of the tree pusher. 
     As constructed and arranged, the heads  68  and  69  will detach from the frame of the tree pusher and stay with the falling tree, leaving the rest of the tree pusher safe and unmoved, after which the head  68  or  69  can and would be removed and recovered from the trunk of the fallen tree, to be reused in future operations. 
     Prior-art tree pushers do not have this important feature. Consequently, either the head will pull out of the tree and remain with the frame as the tree falls, or the entire tree pusher will be pulled over along with the falling tree. In the former case, control of the operation will be lost; in the latter, a very dangerous situation will be created, which could possibly cause serious injury to personnel and/or major damage to the tree pusher. 
     A second improvement over the prior art is the use of a screw-type trailer jack which is extendable, which is capable of handling the weight of a large tree, and which can be repaired or changed out under load during the tree-felling operation. 
     A third improvement is the securing of the tree pusher to the base of the tree by a chain or equivalent means. This enables the tree pusher to be used in and on any type of terrain including hard surfaces, and to maintain the tree pusher steady in the desired location while the operation is in progress. Tying the base of the tree pusher to the base of the tree which becomes a stump enables easy removal of the chain therefrom after the tree has been cut down. 
     A fourth advantage is the capability of transporting the tree pusher to the job site, made possible by the wheel  36 . 
     A fifth advantage is the capability of using the tree pusher on unlevel ground or terrain. 
     Other improvements and advantages over the prior art will be apparent to those skilled in the art from the above detailed description of the invention. 
     While certain embodiments and details have been described to illustrate the present invention, it will be apparent to those skilled in the art that many modifications thereof can be made without departing from the spirit, scope, and basic concept of the invention.