Abstract:
A saw frame that may be folded and locked in a more compact position. One saw frame disclosed comprises a first section of the frame that is pivotably attached to a second section of the frame so that the first section can pivot upward and fold back down onto the second section, resulting in a considerably more compact structure when folded. The pivot point is located so that, when folded, the frame can be lifted from a handle or lifting point at the frame&#39;s folded center of gravity without substantially tilting. Locking pins secure the frame in its folded or open configurations, so that the frame is not permitted to pivot when not desired.

Description:
RELATED APPLICATIONS  
       [0001]     This non-provisional application claims the benefit of U.S. Provisional Application Ser. No. 60/564,161, filed Apr. 21, 2004 and entitled “Folding Saw Frame,” the entire contents of which are incorporated by this reference. 
     
    
     FIELD OF INVENTION  
       [0002]     This invention relates to a saw frame for cutting felled trees to length and, more particularly, to a saw frame that is foldable to a relatively compact configuration.  
       BACKGROUND  
       [0003]     In the logging industry, it is known to use a saw to cut felled trees to length. Typically, the saw is mounted to a large saw frame. In use, the operator places one or more felled trees on the frame and then activates the saw, which pivots down to remove a length of the tree or trees.  
         [0004]     In order to accommodate large felled trees, saw frames typically are large, bulky structures. The frames typically have an elongated shape, in which the length is substantially greater than the width. The substantial length of such frames makes lifting the frame awkward and difficult. Further, the length of the frame requires a very large transport vehicle to carry the frame from one worksite to another.  
         [0005]     Thus, there is a need for an improved saw frame that can be folded to a relatively compact configuration for easier lifting and transport  
       SUMMARY OF THE INVENTION  
       [0006]     This invention is a saw frame that may be folded to a more compact configuration and locked in position. The invention may be embodied in a variety of ways.  
         [0007]     The saw frame of this invention supports felled trees in a horizontal position with a series of support members positioned to be transverse to the tree trunks to support the trunks while they are cut into shorter lengths. The support members can be horizontal, vee-shaped to cause the tree trunks to slide into a central location or have other desired configurations. The frame provides a structure that holds the support members during use, spaced apart from each other over a fairly substantial length, typically connecting the support members in some appropriate fashion. Vertical frame members may be located at frame longitudinal edges to prevent tree trunks from sliding off of the frame.  
         [0008]     In the saw frame of this invention, a first section of the frame is pivotably attached to a second section of the frame so that the first section can pivot upward and fold back down onto the second section. By careful selection of the lengths of frame components and appropriate positioning of the frame components, most components of the first and second frame sections do not contact each other when folded but instead more or less “interweave” so that the first section can rotate to a position above and almost parallel with the second section, thereby resulting in a considerably more compact structure when folded.  
         [0009]     Furthermore, the pivot point is located so that, when folded, the frame can be lifted from a handle or lifting point at the center of gravity of the folded frame without substantially tilting. This makes it easy to lift the frame and move it from one location to another, including from the ground to a truck or trailer on which it is to be transported.  
         [0010]     Locking pins secure the frame in its folded or open configurations, so that the frame is not permitted to pivot when not desired.  
         [0011]     The present invention may be better understood by reference to the description and figures that follow. The invention is not limited in its application to the specific details as set forth in the following description and figures. The invention is capable of other embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     These and other features, aspects, and advantages of the present invention are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:  
         [0013]      FIG. 1  is a perspective view of one embodiment of the saw frame of this invention in an open position.  
         [0014]      FIG. 2  is a fragmentary perspective view of a saw frame of  FIG. 1  shown while being rotated from an open position to a folded, compact configuration.  
         [0015]      FIG. 3  is a perspective view of the saw frame of  FIG. 1  in a fully-folded, compact configuration. 
     
    
     DETAILED DESCRIPTION  
       [0016]     Embodiments of the present invention include a saw frame that is foldable, allowing it to be easily lifted, moved, and transported.  
         [0017]     The frame may be constructed of welded tubular steel or any other suitable material.  
         [0018]     The frame  10  of this invention shown in the figures, when open, has two parallel rails  12  on which tree trunk supporting and saw supporting structures are mounted. In this embodiment  10 , the tree trunks (not shown) are supported by vee-shaped square tubular steel cradles  14  attached to upright posts  20 ,  22 ,  24 ,  26 ,  28 ,  30 ,  32 , each of which stands on one of the rails  12 . The cradles  14  are horizontally aligned so that each will provide some support for a straight tree trunk resting in the cradles  14 .  
         [0019]     Taller vertical posts  20 ,  22 ,  26 ,  30  extend above the ends  16  of the cradles  14 , to assist in keeping trunks in the cradles  14 . However, posts  24 ,  28 ,  32  are shorter to facilitate folding the frame  10  as described below.  
         [0020]     Rather than being continuous, each rail  12  has two pieces, a pivoting rail  34  and a stationary rail  36  and that lie more or less end to end. An upright  40  is attached to the end  38  of the pivoting rail  34 . An axle (or pivot rod)  42  passes through upright  40  and through an upright  44  attached to the stationary rail  36 . The pivoting rail  34  pivots about the axle  42 .  
         [0021]     Upright  28  is shorter than upright  30  so that, when the frame  10  is folded closed as shown in  FIG. 3 , the upper end of upright  30  will contact stationary rail  36 . By careful placement of the upright  28  on the pivoting rail  36 , upright  28  fits in between upright  22  and upright  24  when the frame  10  is folded closed. Similarly, when in the folded position, uprights  30 ,  32  extend down toward the stationary rail  36  without contacting upright  22 . The frame  10  contains a center section  46 , which does not have cradles. The lack of cradles in center section  46  provides an area of the frame  10  into which some of the upright members attached to the pivoting rail  34  may enter when the frame  10  is folded. However, in other embodiments, it is possible to position the upright members such that those attached to the stationary rail  36  interleave with those attached to the pivoting rail  34  when the frame  10  is folded.  
         [0022]     The center section  46  has multiple short uprights  48  and three rails  50  supported by the uprights  48 . The frame  10  is at rest in the closed (folded) position when the cradle attached to uprights  32  contacts the rails  50  of the center section  46 .  
         [0023]     Attached to the frame  10  is a saw  51 , which is contained in a vertical housing  52  and can pivot down to cut the tree trunks. When not in use, the saw  51  is pivoted up within the vertical housing  52  for safe storage. The saw  51  may be a bucksaw, ground-saw, slasher-saw, or any other saw suitable for cutting felled trees.  
         [0024]     The frame  10  may be locked in either an open position or a closed position by a locking pin  54 . When the frame  10  is in the open position, the locking pin  54  is placed through a hole in a member  55  attached to the pivoting rail  34  and through a hole in a tab  56 , which is attached to the stationary rail  36 . When the pin  54  is placed through both holes, the frame  10  is prevented from rotating about the axle  42 . The frame  10  may be locked in the closed position by placing a pin  54  through a hole in upright  30  and through a hole  57  in a tab  58 , which is attached to the stationary rail  36 . The pin  54  must be removed from the holes before the frame  10  can be rotated.  
         [0025]     The locking pin  54  may be attached to the frame  10  by a chain or other similar tether, but the tether must be long enough, based on where it is attached to the frame  10 , to allow the pin  54  to pass through either tab  56  or tab  58 . The frame  10  shown in the figures has one locking pin  54  on either side of the frame  10 . Other embodiments may have only one locking pin  54  or more than two locking pins  54 .  
         [0026]     Locking the frame  10  in the open position makes the frame  10  relatively rigid and able to support a tree trunk without substantial shifting. Locking the frame  10  in the closed position allows the frame  10  to be transported without the danger of the frame rotating back to an open position.  
         [0027]     Further facilitating the transport of the frame  10  is a handle  60  attached to the frame  10 . The handle  60  may be a steel rod or beam attached by connecting members to a cross member  18  and a base cross member  62 , which connects the two pivoting rails  34 . The handle  60  provides a convenient place at which a crane or grapple may grasp the frame  10  for lifting and transporting to another location.  
         [0028]     In order to minimize tilting of the frame  10  while it is being lifted, the handle  60  is positioned at or near the center of gravity of the folded frame  10 . The weight of the frame  10  when it is in the folded position, including the weight of the saw that is attached to the frame  10 , should be relatively balanced on either side of the handle  60 . If the weight is balanced on either side of the handle  60 , the frame  10  will not substantially tilt and the frame  10  will be more easily carried and placed onto a transport vehicle.  
         [0029]     The embodiment illustrated in the figures and described above is an example of the present invention; however, other embodiments are possible. For instance, the embodiment above describes attaching each of the members of the frame by welding, but other methods of attachment are possible. Several members may be bolted together or formed of one piece of steel and bent to the desired shape. In addition, the position and number of upright posts and cradles can vary.  
         [0030]     The above embodiment describes a frame with vee-shaped cradles  14  supported by cross members  18 , but another embodiment may exclude the cradles  14  and allow the tree trunk to rest on the cross members  18 . Further, the cross members  18  may increase in height such that each successive cross member  18 , moving away from the saw, is slightly higher than the cross member closer to the saw. This is known in the art as a “stair step frame” and allows a tree trunk to abut a cross member  18  or cradle  14  that is a known distance from the saw, so that the saw cuts the tree trunk to a desired length without the need to measure. The stair step frame may be used with or without cradles  14 . In the alternative, all cross members  18  may be positioned at the same height, with or without cradles.  
         [0031]     Further, the pivoting rails  34  may pivot about a hinge other than an axle  42 . For example, the hinge may be a ball-and-socket joint, a strap hinge, a T-hinge, or any other suitable hinge.  
         [0032]     Also, the locking pins  54  may be placed through holes in frame  10  at locations other than those described above. For example, the locking pins  54  may pass through holes in the stationary rail  36  itself rather than through tabs  56 ,  58  attached to the stationary rail  36 .  
         [0033]     The frame  10  may also comprise additional members not described above. For example, the frame  10  may contain a center support rail that is parallel to the rails  12  and supports the cross members  18  at the center of the cross members  18 . Also, the frame may comprise side support rails that are parallel to rails  12  and support uprights  40 ,  28 ,  30 ,  32 . These side support rails may provide more structural rigidity for the portion of the frame  10  that folds.  
         [0034]     The foregoing description of illustrative embodiments of the invention has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications and adaptations thereof will be apparent to those skilled in the art without departing from the spirit and scope of the present invention.