Abstract:
A rotating blade guide assembly includes a blade guide carrier and means for rotating the carrier from a first position to a second position. The support structure for the assembly provides a means of supporting the assembly in both positions while allowing an opening for the band to be inserted without twisting in the first position. The first position would be that blade orientation when the blade is placed about a pair of band wheels. The second position would be the blade orientation when the blade is rotated 90° to a cutting position. In this way, the orientation of the blade is changed when the blade guide carrier is rotated from the first position to the second position. The assembly further provides means for securing the blade guide carrier in the second position to provide accurate alignment and prevent rotation of the carrier during use.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to sawing machines, band saws, including vertical band saws, and to assemblies that are used with such sawing machines and band saws. More specifically, this invention relates to a rotating blade guide assembly that is used to facilitate the mounting of a continuous blade onto the band wheels of a sawing machine and to capture a portion of the blade within the blade guide whereby the operator is then able to rotate a portion of the blade about 90° from its mounting position to a cutting position. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many sawing machines and vertical band saws, in particular, have an endless band-like blade that is mounted about two substantially flat, co-planar band wheels. Typically, the band wheels are situated such that there is an upper band wheel that is positioned above a horizontal work surface and a lower band wheel that is positioned below the horizontal work surface. The blade is then tensioned such that the blade moves with and along a portion of the outer perimeter of the band wheels, the blade having a toothed cutting edge that is used to cut material or stock that is located at the horizontal work surface. This is well known in the art of sawing machines. 
         [0003]    In the art of such sawing machines and blades for such machines, it is also known that it is advantageous to rotate a portion of the blade at the horizontal work surface by 90° or so. Materials being cut are generally produced in long lengths that must be cut into shorter lengths to produce stock for downstream manufacturing operations or finished parts. Rotating the blade 90° allows this “cross cut” operation to take place without the return strand of the blade interfering with the workpiece. Rotation is typically effected by means of stationary guide means located above and below the horizontal work surface. 
         [0004]    In sawing machines of this type, it is also necessary to replace the band-like blade, or band, with another from time to time. This is accomplished by releasing the tension between the upper and the lower band wheels, then removing that portion of the band from within the stationary guide means and finally removing the band from the machine. To install a new band, the operator must position a portion of the band above the upper band wheel and along its perimeter, position another portion of the band below the lower band wheel and about its perimeter, partially tension the band, and then, by hand, twist a portion of the band at the horizontal working surface about 90° in order to place that portion of the band into the stationary guide assemblies one at a time. In the current art, this is done with some difficulty since, under full tension, it is too difficult to twist and insert the blade into the guides and, under partial or no tension, the blade tends to slip off of the band wheels due to the torque applied to the band by the twisting motion. The guide mechanism typically consists of two guide assemblies, one above the working surface and one below, each having a slot within which the band is inserted. Typically, the blade guide assemblies will include carbide guides that are used to support the sides of the blade and a carbide-faced pressure block that is used to support the back edge of the blade. In this fashion, the guide assemblies apply a slight, forward pre-load to the band blade which effectively reduces noise and vibration during cutting. Once the band is in place, the band is properly tensioned and the sawing machine is ready for cutting. 
         [0005]    In the view of this inventor, what is needed is an assembly that provides a blade guide that is rotatable such that the band can be placed about the band wheels and then, with the band in that position, the band can also be placed into the blade guide. The blade guide, with the band placed within it, can then be simply rotated by hand using the integral torque arm under full band tension such that the desired cutting position of the blade is accomplished, as described above. What is also needed is a way to effectively secure the rotated blade guide in its rotated position for proper cutting. What is also needed is a way to provide two such rotating blade guide assemblies such that one can be located above the working surface and one below it. What is also needed is such a blade guide assembly that also guides and supports the band during normal use by using any variety of guiding means of current manufacture that can be built into, or used with, the rotating blade guide assembly of the present invention. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides for a rotating blade guide assembly that includes a blade guide carrier and means for rotating the blade guide carrier from a first position to a second position. The first position would be that blade orientation when the blade is initially placed about the band wheels. The second position would be the blade orientation when the blade is rotated about 90° to its cutting position. In this way, the orientation of the sawing machine blade is changed when the blade guide carrier is rotated from the first position to the second position, thus avoiding the need to do so by hand. The rotating blade guide assembly of the present invention further provides means for securing the blade guide carrier in the second position so as to prevent rotation of the blade guide carrier during use of the sawing machine. 
         [0007]    The foregoing and other features of the rotating blade guide assembly of the present invention will be apparent from the detailed description that follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a left side elevational view of a sawing machine that utilizes a pair of rotating blade guide assemblies, each of which is constructed in accordance with the present invention. 
           [0009]      FIG. 2  is an enlarged top, rear and right side perspective view of the upper rotating blade guide assembly that is used in the sawing machine illustrated in  FIG. 1 . 
           [0010]      FIG. 3  is the same view of the upper guide rotation assembly illustrated in  FIG. 2 , but showing a portion of the assembly rotated 90°. 
           [0011]      FIG. 4  is front elevational view illustrating an upper guide rotation assembly and a lower guide rotation assembly used in the sawing machine illustrated in  FIG. 1  and taken along line  4 - 4  of  FIG. 1 . 
           [0012]      FIG. 5  is a partially sectioned top plan view of the upper guide rotation assembly illustrated in  FIG. 2  and taken along line  5 - 5  of  FIG. 2 . 
           [0013]      FIG. 6  is a partially sectioned top plan view of the upper guide rotation assembly illustrated in  FIG. 3  and taken along line  6 - 6  of  FIG. 3 . 
           [0014]      FIG. 7  is a further enlarged right side elevational view of the upper guide rotation assembly illustrated in  FIGS. 3 and 6 . 
           [0015]      FIG. 8  is a further enlarged cross-sectioned top plan view of the upper guide rotation assembly of the present invention. 
           [0016]      FIG. 9  is a further enlarged and partially cross-sectioned right side elevational view taken along line  9 - 9  of  FIG. 8 . 
           [0017]      FIG. 10  is a further enlarged and partially cross-sectioned top plan view taken along line  10 - 10  of  FIG. 8 . 
           [0018]      FIG. 11  is a front elevational view of the blade guide carrier of the rotating blade guide assembly of the present invention. 
           [0019]      FIG. 12  is a right side elevational view of the blade guide carrier illustrated in  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring now to the drawings in detail, wherein like numbers represent like elements throughout,  FIG. 1  illustrates a sawing machine  1  that utilizes a pair of rotating blade guide assemblies, generally identified  10  and  110 , of the type that are constructed in accordance with the present invention. For the sole purpose of describing a preferred embodiment of the present invention, it is to be understood that the present invention is not limited to a specific sawing machine, the sawing machine  1  here being in the form of a vertical band saw. The sawing machine  1  has a base member  2 , the base member  2  including a working surface  9 . Extending upwardly from the work surface  9  of the base member  2  is a blade-carrying column or support member  3 . The support member  3  is used to cantilever an upper blade guide assembly  4  above the work surface  9  of the base member  2  and to carry a portion of an endless, or continuous, band-like blade  7  within it. Within the upper blade guide assembly  4  is an upper band wheel  8 . The upper band wheel  8  cooperates with a lower band wheel  6  that is situated within the base member  2  to form a oval-shaped band path about which the blade  7  is carried. 
         [0021]    As shown in  FIG. 1 , the sawing machine  1  further includes an upper guide rotation assembly  10  that is configured as part of the upper blade guide assembly  4 . The sawing machine  1  also includes a lower guide rotation assembly  110 , which is part of the support member  3 . While each of the upper and lower guide rotation assemblies  10 ,  110  are intended to functionally cooperate with each other, it is to be understood that each is separately movable in the preferred embodiment as will be explained in more detail later in this detailed description. 
         [0022]    Referring now to  FIG. 2 , it illustrates a perspective view of a preferred embodiment of an upper guide rotation assembly  10  that is constructed in accordance with the present invention.  FIG. 2  also illustrates a guide arm  12 , which is part of the upper blade guide assembly  4 , that extends downwardly from the upper blade assembly  4  of the sawing machine  1 . The upper guide rotation assembly  10  is attached to the bottom-most portion of this guide arm  12  of the assembly  4 . The upper guide rotation assembly  10  includes a blade guide carrier  30  that is effectively “captured” within a portion of the guide arm  12  and includes several essential features. 
         [0023]    Referring now specifically to  FIGS. 11 and 12 , it will be seen that the blade guide carrier  30  is a unitary structure that includes a bottom portion  32 , a central portion  34  and an upper portion  38 . It should be noted, however, that the blade guide carrier  30  is not limited to a unitary construction, the equivalent structure being obtainable by a number of individual structures assembled to effect the same functionality. The blade guide carrier  30  also is not limited to the specific blade guide arrangement disclosed in this detailed description. Other blade guide carrier  30  configurations and blade guide arrangements could be used without deviating from the scope of the present invention. 
         [0024]    In the embodiment disclosed and illustrated herein, it will be seen that the bottom portion  32  of the blade guide carrier  30  includes an aperture  31  and a front face  33 . The front face  33  extends upwardly in a plane along the central portion  34  of the blade guide carrier  30  as well. Opposite the front face  33  of the central portion  34 , and to the rear thereof, is a substantially cylindrically-shaped outer arcuate surface  35 . At the uppermost portion of the front face  33 , and extending forwardly of the front face  33  of the central portion  34  of the blade guide carrier  30 , is a pair of shoulder members  36 . The shoulder members  36  are separated by a slot  76 . The upper portion  38  of the blade guide carrier  30  also includes a substantially cylindrically-shaped outer arcuate surface  37  and a flat top portion  39 . The slot  76  between the shoulder portions  36  extends upwardly through the upper portion  38  of the blade guide carrier  30 . The front face  33  of the blade guide carrier  30  further includes a first counter-bore  71 , the first counter-bore  71  being a generally circular structure and having an axially-aligned aperture  72 . The front face  33  also includes a second counter-bore  73  and an aperture  74 . The function and purpose of both counter-bores  71 ,  73  and apertures  72 ,  74  will be apparent later in this detailed description. In this embodiment, the blade guide carrier  30  includes another vertically-disposed slot  77 , the purpose of which is to carry a pressure block (not shown) against a blade  7  situated within the assembly  10 . The pressure block would be movable by means of an eccentric fastener  79  (see  FIG. 7 ) that would be inserted into and be rotatable within an aperture  78  also disposed within the blade guide carrier  30 . 
         [0025]    Referring back to  FIGS. 2 and 3 , it will be seen that the blade guide carrier  30  is effectively “captured” by or retained within the guide arm  12 . More specifically, it will be seen that the guide arm  12  includes a first forwardly-extending guide arm member  14 . Disposed below it is a second forwardly-extending guide arm member  16 . Referring now to  FIGS. 5 and 6 , it will be seen that the first forwardly-extending member  14  of the guide arm  12  includes a forwardly-facing arcuate surface  15 , the cylindrical contour of the arcuate surface  15  extends approximately 230° substantially matching the arcuate surface  37  of the upper portion  38  of the blade guide carrier  30 . The opening of approximately 130° allows an open area for band insertion and operation in the first and second positions as shown in  FIGS. 2 and 3  and in  FIGS. 5 and 6 . Similarly, the second forwardly-extending guide arm member  16  of the guide arm  12  includes a forwardly-facing arcuate surface  17  as well, this arcuate surface  17  having a cylindrical contour and being similarly dimensioned as that of the rear arcuate surface  35  of the central portion  34  of the blade guide carrier  30 . See  FIG. 3 . In this fashion, the blade guide carrier  30  is allowed to be captured within and is rotatable within the forwardly-extending guide arm members  14 ,  16  of the guide arm  12 . 
         [0026]    The first forwardly-extending guide arm member  14  further includes a bottom flat surface  13  that is intended to rest against the shoulders  36  of the blade guide carrier  30 . Disposed at the top surface  39  of the blade guide carrier  30  is a cap  40 . The cap  40  includes a centrally-disposed slot  42  and is secured or attached to the upper portion  38  of the blade guide carrier  30  by means of fasteners  44 . The slot  42  of the cap  40  substantially matches the dimensioning of the slot  76  that is defined within the blade guide carrier  30 . When used as intended, a portion of the band saw blade  7  passes through the slot  42  of the cap  40  and also through the slot  76  of the blade guide carrier  30 . In this regard, and when comparing  FIGS. 2 and 3  to one another, it will be seen that the saw blade  7  is “twisted” 90°. As shown in  FIG. 3  (and in  FIG. 7 ), this “twisting” is greatly exaggerated to be shown to occur in a relatively short portion of the blade  7 . This is for purposes of demonstrating a preferred embodiment of the invention. In reality, the twisting of the blade  7  would occur over a significantly greater length of the blade  7 . 
         [0027]    Referring again to  FIG. 3 , it will be seen that the bottom portion  32  of the blade guide carrier  30  has a fork  50  attached to it. The fork  50  includes a pair of like-configured fork extension members  52 ,  54  which are attachable to opposing sides of the bottom portion  32  of the blade guide carrier  30 . Attachment is accomplished by means of a pivot pin  51  that is retained within the fork members  52 ,  54  and the aperture  31  of the blade guide carrier bottom portion  32 . 
         [0028]    Extending upwardly from the fork  50  is shaft  56  and a handle  58 . A portion of the shaft  56  is receivable within a spring clip  60  that is attached to the first forwardly-extending guide arm member  14  of the guide arm  12 . The fork  50  allows the operator to apply torque to the blade guide carrier  30  to effect rotation of the carrier  30  within the upper guide rotation assembly  10  when the assembly  10  is used as intended. The spring clip  60  allows the handle  58  to be secured when the assembly  10  is in position where the blade  7  can be used to cut stock. The fork members  52 ,  54  effectively “straddle” an extension member  62  having a drive screw  64  which is provided to allow for fine adjustment of the guide rotation assembly  10  as may be desired or required. The length of the drive screw  64  is equal to the distance between the inner surfaces of the fork members  52 ,  54  providing accurate rotational location of the carrier  30  when the fork  50 , and the handle  58  are rotated upward into the locked position. 
         [0029]    The upper guide rotation assembly  10  also includes a pair of blade guides  91 ,  93  that are attached to the central portion  34  of the blade guide carrier  30  by means of fasteners  92 ,  94  respectively. It should be noted that the blade guides  91 ,  93  are functionally adapted to be held within the counter-bores  71 ,  73  that are defined within the central portion  34  of the blade guide carrier  30 . It should also be noted that the fasteners  92 ,  94  are receivable within the apertures  72 ,  74  also defined within the central portion  34  of the blade guide carrier  30  to retain the blade guides  91 ,  93  respectively, within the counter-bores  71 ,  73 , respectively. It should also be noted that the aperture  72  to one side of the central portion  34  of the blade guide carrier  30  is located somewhat higher than its counterpart aperture  74  to the other side of the central portion  34  of the blade guide carrier  30 . The purpose and functionality of this arrangement will be apparent later in this detailed description. However, it is again to be noted that the positioning and use of the particular blade guides  91 ,  93  described is for purposes of explanation only, the invention not being limited to the specific blade guide arrangement described herein. Other blade guide arrangements could be used without deviating from the scope of the present invention. 
         [0030]    Referring now to  FIGS. 5 ,  6  and  8 , in addition to  FIGS. 2 and 3 , it will be seen that the upper guide rotation assembly  10  also includes a front guard  82  that is attached to the guide arm  12  by means of one or more fasteners  83 . The front guard  82  is a flat, plate-like member that is intended to keep the moving parts of the upper guide rotation assembly  10  from being accessible by an operator of the sawing machine  1  during normal cutting operations. The upper guide rotation assembly  10  also includes a side guard  86  which is a similar plate-like member that is L-shaped in vertical configuration. The side guard  86  is rotatably attached to the front guard  82  by means of a hinge  84  and a hinge pin  85 . See  FIGS. 5 and 6 . This structure is also greatly variable and such variations are within the scope of the present invention. 
         [0031]    It is to be understood that the lower guide rotation assembly  110 , as is illustrated in  FIGS. 1 and 4 , would contain essentially the same elements as those described above for the upper guide rotation assembly  10 . That is, it is to be understood by those skilled in the art that the blade guide rotation assemblies  10 ,  110  disclosed in accordance with the detailed description herein are preferably like-configured and would function in essentially the same, if not identical, fashion. 
         [0032]    In application, it will be assumed that the operator needs to install a new blade  7  into the sawing machine  1 . It will also be assumed that the upper guide rotation assembly  10  has been left in the position it would normally be in following removal of the blade  7  that was last used in the sawing machine  1 . That position would be as is illustrated in  FIGS. 2 and 5 . With the upper guide rotation assembly  10  in that position, and the lower guide rotation assembly  110  in the same position, the operator would place the blade  7  around the peripheral edge of the lower wheel  6  and around the peripheral edge of the upper wheel  8 . The operator would then place a portion of the blade  7  within the slot  42  of the cap  40 , within the slot  76  of the blade guide carrier  30 , and between the blade guides  91 ,  93 . During this placement of the blade  7 , the handle  56 ,  58  and fork  50  are in a generally horizontal position. 
         [0033]    With the blade  7  inserted as described above, and the blade  7  fully tensioned, the handle  56 ,  58  and fork  50  are rotated to the position shown in  FIGS. 3 ,  6  and  7 . This rotation also serves to rotate the blade guide carrier  30  within the outwardly extending members  14 ,  16  of the guide arm  12 , thereby twisting the blade  7  about 90°. With this movement, the arcuate surface  37  of the upper portion  38  of the blade guide carrier  30  slidingly moves across the arcuate surface  15  of the first forwardly-extending guide arm member  14  and the arcuate surface  35  of the central portion  34  of the blade guide carrier  30  slidingly moves across the arcuate surface  17  of the second forwardly-extending guide arm member  16 . With the blade  7  and the guide carrier  30  in this position, the fork  50  is rotated upwardly to a vertical position as shown in  FIGS. 7 and 8 . In this position, the shaft  56  of the handle  58  is captured within the spring clip  60 . In this position, the fork members  52 ,  54  straddle the extension member  62  and drive screw  64 , restricting motion of the fork  50  and keeping it in position which, in turn, keeps the blade guide carrier  30  from rotating. Finally, as is shown in  FIG. 8 , the front guard  86  can be swung into position to keep the operator away from the band  7  of the assembly  10 . It is to be understood that the lower rotating blade guide assembly  110  would operate in the same fashion and the two assemblies  10 ,  110  would functionally cooperate to accomplish the intended function. After tensioning of the band  7  and rotation of carrier  30  is completed, the sawing machine  1  can be activated. During operation, the blade guide assemblies  10 ,  110  will each include carbide guides  91 ,  93  that are used to support the sides of the blade  7  and a carbide-faced pressure block (not shown) that is used to support the back edge of the blade  7 . In this way, the guide assemblies  10 ,  110  apply a slight, forward pre-load to the band blade  7  which effectively reduces noise and vibration of the blade  7  during cutting as the blade  7  moves through the slot  90  defined within the working surface  9 . See  FIG. 4 . 
         [0034]    Although a preferred embodiment of the invention has been disclosed above, it will be understood that modifications may be made within the spirit and scope of the invention. Accordingly, it is intended that the invention no be limited by the foregoing description but solely by the scope of the appended claims.