Abstract:
A saw for cutting an overhead object is provided. The saw including: an elongated pole having a first end held by a user and a second end; a holding mechanism disposed at the second end of the elongated pole, the holding mechanism having an opening for holding the overhead object; and a cutting blade movably disposed on one of the elongated pole or holding mechanism so as to define a cutting stroke within the opening.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/668,349, filed Apr. 5, 2005, the entire contents of which is incorporated herein by its reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to saws for cutting overhead objects and more particularly, to a tree saw for cutting high branches. 
         [0004]    2. Prior Art 
         [0005]      FIG. 1  shows a typical garden saw  100  used to cut branches located at heights well above normal reach. The saw usually consists of a blade  101  having teeth (not shown) and a long extension pole  102 . The saw only cuts the branch  104  on the cutting stroke, the direction of which is indicated by the arrow  103 . In order for the user to make an effective cutting stroke, the saw must be mined in the direction of the arrow  103 , while at the same time the saw must be forced against the branch  104 . In  FIG. 1 , the force between the saw  101  and the branch  104 , which is exerted by the user through the pole  102 , is shown by the force  105 . The force  105  (F N ) is nearly normal to the branch  104 . If the distance from the point of contact between the blade  101  and the branch  104  to where the user is holding the pole  102  is l. (indicated as  106  in  FIG. 1 ), and if the contact force  105  is indicated as F N , then the user must have provided a moment M ( 107 ) to the pole  102 , where M is given as: 
         [0000]      M−I,F N   (l) 
         [0006]    Therefore to cut the branch  104  by the saw  101 , the user must also produce a sawing force F( 108 ) and a couple moment M to generate the normal contact force  105  between the saw blade and the branch  104 , as indicated in  FIG. 1 . The sawing force  108  is independent of the length of the extension pole  102  and depends on the level of the normal force  105  and the generated resistance due to the cutting action. The moment  107 , however, is directly proportional to the length of the extension pole  102 , i.e. the further the branch  104  is from the user, the longer is the pole  102  and the larger the moment that the user has to produce for a given normal force  105 . To make an efficient cut, the user has to produce a considerable normal force  105 , thereby has to also provide a considerable amount of moment  107  (normally by producing a couple by two hands holding the pole a certain distance apart), furthermore, the saw only moves and cuts the branch  104  due to the work done by the sawing force  108  (F). The moment  107  on the other hand has to be provided by the user just to produce the required normal force  105 , which does only a negligible amount of work (equal to the cutting movement of the saw into the branch as the cutting edge of the blade  101  moves forward). Thus, the energy spent by the user to produce the applied couple (moment  107 ) is not converted into usable mechanical work and is wasted. Considering the fact that such tree branch saws are intended to cut high branches, the amount of energy that the user has to spend to generate the moment  107  very quickly becomes overwhelming and the user tires fast, making it impractical to cut a branch which is more than 6-7 feet above the holding position in any reasonable amount of time. The process is even more tiring since the user has to assume an awkward posture by keeping to look up most of time so that the saw does not slip off the branch, while pulling at one point on the pole and pushing at another point, preferably far apart. The process is even more difficult when the branch is relatively flexible and moves with the applied normal force, a situation that is encountered not only when the branch has a small diameter but also when a part of the branch a certain distance from the truck of the tree is being cut. 
         [0007]    Therefore, there is a need for hand-operated saws that could be used to cut high branches and other overhead objects of various sizes. 
         [0008]    There is also a need for hand-operated saws that are ergonomic, thereby allowing the user to cut branches or other overhead objects without having to assume an awkward posture and to have to exert excessive forces that do not significantly contribute to the work done to cut the branch or other object by the saw. 
         [0009]    There is also a need for hand-operated saws that could hold on to a branch or other overhead object to be cut, particularly smaller and more flexible branches, and allow the user to cut them without having to struggle to keep the saw blade at the cutting location and being able to maintain a considerable amount of force between the blade and the cutting surface. 
       SUMMARY OF THE INVENTION 
       [0010]    The saws disclosed and claimed herein not only overcome the aforementioned shortcoming of the existing saws used to cut tree branches, but also allow cutting of very high branches or other overhead objects of almost any size. The following are some of the advantages of the saws disclosed and claimed herein: 
         [0011]    Can be used to cut branches and other overhead objects of various sizes. 
         [0012]    Can cut branches and other overhead objects that are located significantly higher than those that could be cut with current saws. 
         [0013]    The cutting process requires significantly less effort. 
         [0014]    During the cutting, the user does not have to provide a stabilizing force and coordinate hand motion with the location of the saw on the branch or other overhead object being cut to prevent the saw from being moved past the branch or other object being cut. In which case, the user has to provide a very large balancing force (moment) to prevent the saw from falling. 
         [0015]    Unlike existing saws, during the cutting process, the pole is not subject to buckling (compressive force as the user pushes the pole up before pulling it down). The saw poles disclosed herein are in tension during the entire sawing cycle. As a result, the pole needs only to be rigid enough in bending to allow the saw to be lifted to the desired height, and could be used to reach very high branches or other overhead objects to be cut. 
         [0016]    Pulling a rope or cable produces the cutting action, which the user could hold where it is most comfortable. As a result, the cutting action is ergonomic. 
         [0017]    During the cutting process, the weight of the saw pole and part of the moving parts, including the saw mechanism, is born by the branch or other overhead object to be cut and not by the user, unlike existing tree saws. 
         [0018]    Unlike existing tree saws, the user may stop the cutting process at any time without having to remove the saw before stopping the cutting process and resting or leaving the area for a short time (and position it back on the branch or other overhead object to resume the cutting process). 
         [0019]    The user has to spend significantly less energy to cut a branch or other overhead object using the saws disclosed and claimed herein than is necessary with existing tree saws. 
         [0020]    Branches or other overhead objects to be cut that are flexible (bend under the applied normal force  105 ) or rigid (do not bend under the applied normal force  105 ) may both be readily cut. 
         [0021]    With the saws disclosed and claimed herein, the user need only generate the equivalent of the cutting force  105  and not the couple moment  107  (the user need to apply a small force to the pole to keep it from moving during the cutting action). As a result, a significantly more efficient overhead saw is provided. In addition to the improved efficiency of such a device, its reach is not limited by the user&#39;s ability to provide the moment  107 . 
         [0022]    Accordingly, a saw for cutting an overhead object is provided. The saw comprising: an elongated pole having a first end held by a user and a second end: a holding mechanism disposed at the second end of the elongated pole, the holding mechanism having an opening for holding the overhead object: and a cutting blade movably disposed on one of the elongated pole or holding mechanism so as to define a cutting stroke within the opening. 
         [0023]    The saw can further comprise a biasing member for biasing the cutting blade against the overhead object. 
         [0024]    The holding mechanism can have a first member disposed at the second end of the elongated pole and a second member disposed at an end of the first member to define the opening. The holding mechanism can further have a curved transition portion disposed between the first and second members. The curved transition portion can be a flexible member. The holding mechanism can also have a curved portion disposed on an end of the second member for facilitating capturing of the overhead object into the opening. 
         [0025]    The holding mechanism can have a curved member disposed at the second end of the elongated pole to define the opening. The holding mechanism further having a curved portion disposed on an end of the curved member for facilitating capturing of the overhead object into the opening. 
         [0026]    The holding mechanism can comprise a first member attached to the second end of the elongated pole and a second member movably supported on the first member, at least a portion of the first and second members defining the opening. 
         [0027]    The holding mechanism can comprise: a member rotatably supported on the elongated pole: and one or more elastic elements for biasing the member towards the elongated pole. The member can have one or more curved sections for holding overhead objects of differing sizes. The saw can also further comprise a mechanism for constraining the member to move in a parallel manner. 
         [0028]    The saw can further comprise one or more stops for limiting the movement of the cutting blade. 
         [0029]    The holding mechanism can comprise: a first member disposed at the second end of the elongated pole: and a second member removably disposed on the first member, the first and second members defining the opening and the second member being interchangeable with second members of differing size. 
         [0030]    The saw can further comprise a linkage mechanism for movably disposing the cutting blade relative to the opening. The saw can further comprise one of a cable and rope attached to at least a portion of the linkage mechanism for actuating the blade through the cutting stroke. The linkage mechanism can be a first parallelogram linkage having one end rotatably disposed on the elongated pole and another end rotatably connected to a second parallelogram linkage rotatably connected to the cutting blade, the first and second parallelogram linkages confining the cutting blade to a linear motion. The saw can further comprise one or more biasing members acting on one or more links of the first and second parallelogram linkages for biasing the cutting blade into a predetermined position. The linkage mechanism can be a link member having a first end rotatably connected to the elongated pole and a second end rotatably connected to the cutting blade. The saw can further comprise one or more biasing members acting on one or more of the link member and the cutting blade for biasing the cutting blade into a predetermined position. 
         [0031]    Also provided is a method of cutting an overhead object. The method comprising: holding the overhead object within an opening; and actuating a cutting blade through the opening to cut the overhead object. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    These and other features, aspects, and advantages of the apparatus of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
           [0033]      FIG. 1  illustrates a schematic view of a conventional tree saw of the prior art. 
           [0034]      FIGS. 2   a - 2   c  illustrate variations of fixed holding mechanisms for holding a branch to be cut. 
           [0035]      FIG. 2   d  illustrates a section view of any of the hook members of  FIGS. 2   a - 2   c.    
           [0036]      FIGS. 3   a  and  3   b  illustrate variations of adjustable holding mechanisms for holding a branch to be cut. 
           [0037]      FIG. 3   c  illustrates a variation of the adjustable holding mechanism of  FIG. 3   b.    
           [0038]      FIG. 3   d  illustrates another variation of the adjustable holding mechanism of  FIG. 3   b.    
           [0039]      FIG. 4  illustrates an embodiment of a tree saw. 
           [0040]      FIGS. 5   a - 5   c  illustrate a sequence of a cutting stroke using the saw of  FIG. 4 . 
           [0041]      FIG. 6  illustrates a variation of the saw of  FIG. 4 . 
           [0042]      FIG. 7  illustrates a top portion of an embodiment of a tree saw. 
           [0043]      FIG. 8  illustrates the saw of  FIG. 7  retaining a branch. 
           [0044]      FIG. 9  illustrates the saw of  FIG. 8  cutting a branch. 
           [0045]      FIGS. 10   a  and  10   b  illustrate variations of the saw of  FIG. 7  having elastic elements for biasing the saw blade. 
           [0046]      FIG. 11  illustrates a top portion of a saw. 
           [0047]      FIG. 12  illustrates the saw of  FIG. 11  retaining and cutting a branch. 
           [0048]      FIGS. 13   a  and  13   b  illustrate another embodiment of a saw in which  FIG. 13   a  illustrates capturing a branch and  FIG. 13   b  illustrates retaining the branch once it is captured. 
           [0049]      FIGS. 14 and 15  illustrate operation of the tree saws from a ground position by one or two users, respectively. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0050]    Although the present invention is applicable to cutting overhead objects, it is particularly useful in the environment of cutting branches from a tree and particularly high branches from a tree. Therefore, without limiting the applicability of the present invention to cutting branches from a tree and particularly high branches from a tree, it will be described in such environment. 
         [0051]    The tree saws disclosed herein are held in place relative to the branch by fixed or adjustable structures, a number of variations of which are shown in  FIGS. 2   a - 2   d  and  3   a - 3   d , and are hereinafter called “holding mechanisms.” The holding mechanisms provide a means of holding the tree saw onto the branch at the location where the saw blade is to cut the branch. The holding mechanism can handle branches of a wide range of size (diameter) by providing a fixed ( FIGS. 2   a - 2   d ), manually adjustable ( FIG. 3   a ), or spring-loaded adaptable ( FIG. 3   b ) hook width. The holding mechanism may also be adjustable from the ground by the user by, e.g. pulling a cable (not shown). The holding mechanism supports the weight of the entire tree saw and would require minimal force by the user to keep it in properly oriented while the branch is being cut. In addition, since the holding mechanism provides a stable means to suspend the tree saw from the branch, the user may leave it in place while resting or attending to other tasks. 
         [0052]      FIGS. 2   a - 2   c  a show a first embodiment of the holding mechanism, which is a relatively rigid hook member  109   a ,  109   b  and  109   d  and is attached to an end  102   a  of the pole  102 . The hook member  109  can be an integral part of the top portion of the pole  102  or attached separately. The hook member  109  is shaped such that its open end accommodates the largest branch  104   a  to be cut and narrows down to also accommodate the smallest branch  104   b  to be cut.  FIG. 2   a  shows an inverted V shaped hook member  109   a .  FIG. 2   b  shows an inverted V shaped hook member  109   b  with a curved transition  109   c  and  FIG. 2   c  shows a curved hook member  109   d . The tip of the hook shaped portion  109   a ,  109   c  and  109   d  can have a curved portion  110  to make it easier for the user to place it over a branch high up on the tree. As shown in  FIG. 2   d , the inside surfaces of the hook member  109   a ,  109   c  and  109   d  can have a Hat portion  111  to increase the surface of contact between the hook member and the branch  104  and to also resist rotation of the hook member relative to the branch, thereby minimizing the application of lateral force and or bending moment on the saw blade (described below) as it cuts through the branch as a result of unavoidable slight movements of the pole (tree saw) during the cutting process. The surfaces of the hook member  109   a ,  109   b ,  109   d  and/or pole  102  (see  FIG. 2   c ) contacting the branch  104  can be treated or coated to increase holding and reduce slippage, for example, surface  111  can have a rubberized coated. 
         [0053]    In another embodiment, the width of the hook holding mechanism can be adjustable to hold various size branches to be cut.  FIG. 3   a  illustrates an adjustable width hook holding mechanism  120  having a relatively rigid member  122 , which is rigidly attached or integral with the pole  102 . An adjustable relatively rigid structural element  123  is then fastened to the member  122  at an appropriate position to provide a wide enough opening  119  to accommodate the branch to be cut. One or both elements  122  and  123  are provided with an adjustment means, such as holes or slots and corresponding fasteners  121  along their length to allow for the desired range of variations in the holding mechanism opening. Such adjustment means are well know in the art. The provided opening is then variable to accommodate a range of branch sizes. 
         [0054]    Similarly,  FIG. 3   b  illustrates an adjustable width hook holding mechanism for accommodating a variety of branch sizes. The adjustable width hook holding mechanism  130  has one or more links and is attached to the pole  102  with one or more rotary or sliding joints  124 , for the sake of simplicity, an adjustable hook holding mechanism  130  with a single link  123 , which is attached to the top  121  of the pole  102  with a rotary joint  124  is shown. In one embodiment, at least one elastic element  125 , which can be an integral part of the structure of the hook and or mechanism  130  or provided separately therefrom is provided to bias the single link  123  to close, i.e. to tend to bring the branch support link  123  closer to the pole side of the branch support surface. For example, the elastic element  125  can be one or more of a torsional spring at the joint  124 , an extension spring connected between the link  123  and pole  102  or an elastic material stretched between the link  123  and pole  102 . The branch support link  123  is preferably constructed with a curved portion  110  to facilitate placement of the link  123  over a branch  104 . Once the link  123  is placed over the branch  104 , the user pulls the pole down until the branch is firmly held by the holding mechanism  130 . The elastic element(s)  125  are preferably preloaded to provide an initial resistance to the opening of the link  123  relative to the pole  102 . 
         [0055]    Even though in  FIG. 3   b  an adjustable holding mechanism  130  consisting of only one straight link is used for the sake of simplicity, the mechanism  130  can be constructed with a curved link  126  as shown in  FIG. 3   c  to better hold branches of various sizes. 
         [0056]    Referring now to  FIG. 3   d , there is illustrated an adjustable width hook holding mechanism having multiple links. The adjustable holding mechanism  140  provides for holding surfaces that are close to being parallel. The mechanism  140  shown in  FIG. 3   d  is a parallelogram mechanism with upper and lower equal and parallel links  134 , and a portion of the pole  102  and link  133  constituting the second pair of equal and parallel links of the parallelogram. Fink  133  would therefore stay parallel to the pole at all times, thereby forcing the holding member  135 , which is fixed to the coupler link  133 , to undergo parallel motion only. An elastic element  125  can be used to provide for the branch holding force. 
         [0057]    Referring now to  FIG. 4 , there is shown a saw  150  having a holding mechanism. Although shown with a fixed width hook holding mechanism of a particular shape, any hook holding mechanism can be used. In the embodiment of  FIG. 4 , the tree saw  150  consists of a saw blade  101  and a holding mechanism in the shape of a hook  141 . The saw blade  101  is rotatably attached to the hook  141  with a pin joint  142  at point A. The rotation of the saw blade  101  is preferably limited between upper  143  and lower  144  rotation limiting stops as shown in  FIG. 4 . At least one spring element  145  is provided between the blade  101  and the hook  141  to bias the blade  101  towards a cutting surface of the branch  104  to provide a near normal pressure between the cutting edge of the blade and the branch  104 . 
         [0058]    Referring now to  FIGS. 5   a - 5   c , there are shown three sequential images of the saw  150  performing a cutting stroke on a tree branch (with the stops and spring element not shown for simplicity). As shown in  FIG. 5   a , the saw  150  is raised above the branch  105  to clear hook portion  110  and then lowered in direction  151  so that the branch  104  makes contact with the cutting edge of the blade  101  and an inner surface of the hook  141 .  FIG. 5   b  shows the saw  150  being pulled downward relative to the tree branch in the direction  151 . The blade  101  begins to swing clockwise relative to the hook  141 . The preloading provided by the spring element  145  (not shown in  FIGS. 5   a - 5   e ) biases the blade against the branch  104 .  FIG. 5   c  shows downward movement of the saw  150  to the end of the cutting stroke. In order to perform a second or subsequent cutting stroke, the entire device is raised back upward opposite to the direction  151 . The saw of  FIGS. 4 and 5   a - 5   e  does not require a rope or cable for actuation of the blade. The biasing of the blade against the branch and the up and down movement of the saw (in and opposite to the direction  151 ) provides the cutting stroke. 
         [0059]    Referring now to  FIG. 6 , the holding mechanism  141  of the saw of  FIG. 4  can be made adjustable to accommodate branches of various sizes. This can be done, for example, by making the hook with a front piece  154 , which is attached to a back piece  155  by at lest one fastener  156  as shown in  FIG. 6 . The front and back pieces are preferably provided with a number of coinciding holes to allow for a range of adjustments for a wide range of branch sizes to be cut. Thus, the front piece  154  can be exchanged with another front piece to provide for a larger or smaller opening  157  to accommodate various size branches or ranges of branch sizes. 
         [0060]    Another embodiment of a saw is shown in  FIG. 7 . In  FIG. 7 , the head (top portion) of the tree saw and only a small part of the pole  102  is shown. The head of the saw consists of a hook with side piece  128 , top piece  125  and end  129 , which can be provided with a curved piece  133  for ease of engaging a branch. A saw blade  126  with a sawing edge  127  is attached to the hook or the top of the pole  102  or a portion in-between  134  via two parallelogram linkages  121  and  122  (shown as simple lines for simplicity). The parallelogram linkage  121  is attached to the portion  134  by a pair of pin joints  123  on one side and to the relatively rigid element  124  by a second pair of pin joints  123  on the (top) side. The parallelogram linkage  122  is attached to the element  124  by a pair of pin joints  123  on one side and to the element  135  by a second pair of pin joints  123  on the other side. The saw is fixed to the element  135 , which also acts as a stop against the side piece  128  of the hook to prevent the saw from moving past the hook area when moving to the left. Another stop  132  is fixed to the opposite end of the saw  126  to prevent it from moving past the side piece  129  of the hook while moving to the right. As known in the art, portions of the stops engage corresponding portions of the hook sides to prevent further motion of the blade. As a result, the saw blade  126  is constrained to back and forth motion with the cutting edge  127  staving within the hook opening  157  at all times. The function of the parallelogram linkages  121  and  122  is to allow the saw blade  126  to traverse the length of the hook (up and down in  FIG. 7 ) and hack and forth relative to the hook in parallel motions, i.e. without any rotation relative to the hook. A stop  131  is provided to limit downward movement of the saw. Stops  130  prevent the saw from moving up past the hook area. Elastic elements (e.g. springs, elastic materials) (not shown) bias the saw down against the stop  131  and to the left, forcing the stop  135  against the side  128  of the hook. 
         [0061]      FIG. 8  shows the tree saw of  FIG. 7  hooked onto a tree branch  138 . The blade  126  has been forced upward by the branch  138  against stops  130  and the cutting edge  127  is in contact with the branch  138 . The blade  126  remains parallel and is forced downward against the branch and to the left by way of the elastic elements (not shown). The two stops  130  at the top of the hook may or may not be required to stop the blade depending on the size of the branch  138 . The stops  130  are, however, required to prevent the blade from coming away or out of the cutting area during transport or misuse. 
         [0062]    In order to perform a cut, the user must draw the blade to the right from the ground. This can be achieved, e.g. if one of the two lower links  139  and  140  of the parallel mechanism  121  is rotated clockwise. A user on the ground could accomplish this by pulling on a rope element  141  connected to one of the links, preferably the link  140 , as shown in  FIG. 9 , and pulling it in the direction of the arrow  142 . The blade will move to the extreme right before stopping as a result of the stop  132  on the left edge of the blade. This completes a single cutting stroke. Once the cut is complete, the user can release the rope, and the elastic elements would then force the blade to its aforementioned extreme right hand position. 
         [0063]    In  FIG. 10   a  the saw of  FIG. 7  is shown with at least one extension spring  143  and or at least one torsional spring  144 .  FIG. 10   b  illustrates the saw of  FIG. 7  with two extension springs  143 . The elastic element(s) ( 143 ,  144 ) are employed to ensure that the blade  126  will be biased to return to the indicated position, i.e., its left most position, after every cut, and that a desired amount of pressure is maintained between the cutting edge  127  of the saw and the branch  138 . It is, however, appreciated and any other type of spring and/or elastic element, and numerous other attachment configurations may be used to accomplish the same task. Alternatively, the links of one or both parallelogram linkages may be constructed with living joints, preferably only on the pole side  134 , and built with enough flexibility (with and without other elastic elements, possibly also as incorporated into the structure of the hook or the second parallelogram mechanism) to reduce or eliminate the need for any other spring element such as those of springs  143  and  144 . 
         [0064]    In a variation of the embodiment of  FIG. 7 , the hook is made with at least two pieces that are connected together to make the hook adjustable to tit different branch sizes (for example, using adjustment methods shown in  FIG. 3   a  or  6 ). 
         [0065]    In another variation of the embodiment of  FIG. 7 , other type of linkage mechanisms, e.g. a four-bar linkage mechanism may be used in place of either one of the two parallelogram mechanisms. As a result, the saw blade  126  would rotate as well as translate as it is used to saw a branch. This may be done to get a better mechanical advantage as the user pulls the rope  141 . In general, any type of mechanism, linkage type, pulley and cable type, gear type, cam type or any of their combination may be used as long as the user pulling on a rope (cable, link, etc.) can produce the back and forth cutting motion of the saw (with or without a simultaneous rotation). In addition, the stops that can be used to constrain the motion of the blade to the area of the hook. i.e. to the region in which a branch is being held captive, may be built into such mechanisms and frame (of the hook or the pole itself). 
         [0066]    In another embodiment shown in  FIG. 11 , a simple link  181  is used instead of the double parallelogram linkages of the embodiment shown in  FIG. 7 . The link  181  is attached to the pole  102  by a pin joint  182  and to the saw blade  126  by another pin joint  183 . In  FIG. 11 , the hook is indicated as  180 . At least one elastic element  184  is used to bias the link  181  towards the hook  180  (and pole  102 ) and bias the saw blade  126  downward (in the position shown in  FIG. 11 ) to provide an appropriate contact force between the saw  126  and the branch to be cut (to be positioned inside the hook as shown in the previous embodiments). Motion (rotation) limiting stops (not shown) are preferably built into the joints  182  and  183  to ensure that the link  181  and the saw blade  126  do not rotate excessively in the counterclockwise direction. The position of the link  181  and blade  126  shown in  FIG. 11  can be the maximum counterclockwise rotation that is allowed. 
         [0067]    The aforementioned limit positioning of the link  181  and the saw blade  126  is required so that as the hook is placed over a branch, the blade is positioned on the top of the branch with the elastic element(s)  184  providing the desired level of pressure between the saw blade  126  and the branch  138 , as shown in  FIG. 12 . In the position shown in  FIG. 12 , the elastic element(s)  184  are seen to be firmly forcing the saw blade  126  against the branch  138 . In the configuration shown in  FIG. 12 , the elastic element(s)  184  are also forcing the link  181  to its most counterclockwise position as provided by the limit stop at joint  182 . This allows the saw to be pulled back (to the right) to perform its cutting action by the user pulling the link  181  down by a rope  185  in the direction of the arrow  186 . 
         [0068]    In a variation of the embodiment of  FIG. 11 , the hook is made with at least two pieces that are connected together to make the hook adjustable to fit different branch sizes (for example, using adjustment methods shown in  FIG. 3   a  or  6 ). 
         [0069]    In a variation of the aforementioned adjustable width hook embodiments, the hook structure can have at least a relatively elastic portion or component to allow it to open and adjust to the larger branch sizes. An example of such an embodiment is shown in  FIGS. 13   a  and  13   b . In  FIGS. 13   a  and  13   b , the hook  160  is shown to consist of a relatively elastic segment  161 , which attaches the relatively rigid front portion  162  and a relatively rigid back portion  163 . The tip of the front portion can be a curved segment  110  to facilitate capturing of the branch  138 . The user first captures the branch  138  by positioning the hook above it as shown in  FIG. 13   a , using the pole  102 . The hook  160  is then pulled down in the direction of the arrow  164  to force the hook  161  tightly around the branch  138  as shown in  FIG. 13   b . The elastic element  161  is preferably stiff enough to provide enough resistance to the opening of the hook to allow a relatively firm gripping of the branch. The elastic element  161  can be any material known in the art for such purpose, such as spring steel. Any of the cutting mechanisms discussed above can be used together with the adjustable width hook mechanism of  FIGS. 13   a  and  13   b.    
         [0070]    In the above embodiments, the user is considered to be on the ground and cutting branches that are more or less horizontal relative to the ground. The tree saw hook is therefore positioned more or less in the vertical plane and the saw blade is also considered to be positioned and moving in such a more or less vertical plane. The aforementioned tree saws may, however be held at an angle, the amount of which is dependent on the height of the branch being cut (less angle is generally possible for higher branches). Alternatively, angle adjustment means may be provided that allow the plane of the hook (and the saw) to be tilled a certain amount, preferably not a large amount, such as less than 45 degrees in order to engage branches that are more vertical. The tilt angle is desired to be small in order not to hamper the transmission of force from the actuating rope (e.g. rope  155  in  FIG. 12 ) to the blade mechanism in the direction of operating the saw. In  FIG. 14 , such a hook tilt angled configuration is shown being used by a user. The user  174  is standing on the ground  171  below the tree  172  with a branch  173  that is to be cut at the position where the tilted hook and saw assembly  176  is placed on the branch as previously described for the earlier embodiments of the present invention. The hook and saw assembly  176  is tilted relative to the pole  175  and locked in place (to the pole  175 ). The user  174  holds and pulls on the pole  175  to firmly hold the hook onto the branch  173  by one hand and pulls on the actuating rope  177  by the other hand to operate the saw to cut the branch as previously described for the other embodiments. 
         [0071]    Alternatively, another person  178 , as shown in  FIG. 15 , may pull the actuating rope  177 . In  FIG. 15 , the hook and saw assembly  176  is shown to have a steeper angle relative to the pole  175 , thereby making it possible for the tree saw to cut even a near vertical branch or the tree trunk itself. At such steep relative angles, the actuating rope  175  can be operated by a second person  178  in order to efficiently transfer motion and force to the saw mechanism. Alternatively, a spatial mechanism could be employed to transmit the nearly vertical motion of the actuating rope (by the user  174  or  178 ) to the back and forth cutting motion of the saw blade in the desired (angled) plane, which could even be horizontal. An endless number of spatial mechanism types may be selected for this purpose where general methods for their design are well known in the art of mechanism synthesis. 
         [0072]    While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.