Abstract:
A method and apparatus for identifying a place where a saw may be performed. An oscillating laser beam is provided to a target according to a user preference. The user selects at least one characteristic of the oscillating laser beam in order to identify the target in an outdoor environment. The selected at least one characteristic is then provided to a motor which executes the oscillating.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is the first application filed for the present invention. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to the field of sawmills. More precisely, this invention relates to the adjusting of a cut in a sawmill.  
         BACKGROUND OF THE INVENTION  
         [0003]    It is highly desirable for a timberland owner to manufacture himself his own lumber products. A large number of portable sawmills is now available on the market, with prices ranging from a few thousand dollars to a hundred thousand dollars depending on various parameters.  
           [0004]    In order to saw lumber commercially, it is important to perform a precise cut on a log. Such precise cut on the log is performed by precisely select a place on the log where the cut will be performed.  
           [0005]    Lasers have been used in some embodiments for selecting a place of the log where the cut must be performed. Unfortunately, it is not easy to precisely locate a laser beam in an outdoor environment such as when a portable saw is used.  
           [0006]    Two types of apparatus are commonly found in laser-based calibrating apparatus. A first type of apparatus relates to a laser which provides a single laser line on the log, while the second type of apparatus relates to a laser which provides a point on the log where the saw must be performed.  
           [0007]    Unfortunately, the two apparatus still suffer from a non-easy location of the laser.  
           [0008]    As someone skilled in the art will note, a non-easy location of the laser beam slow as a consequence a cutting process, decreasing therefore the efficiency of the sawmill. Furthermore, as a further consequence, such drawback may be a source of error when a saw is performed.  
           [0009]    It is an object of the invention to provide a method and apparatus which overcome the above-mentioned drawbacks.  
         SUMMARY OF THE INVENTION  
         [0010]    It is an object of the invention to provide a method for locating a place, using a laser, where a cut may be performed.  
           [0011]    It is another object of the invention to provide an apparatus for locating a place where a cut may be performed using a laser.  
           [0012]    According to a first aspect of the invention, there is provided an apparatus for providing a visual indication of a location of an object using a laser beam provided by a laser, the apparatus comprising a laser source providing a laser spot beam, a user selecting unit providing a selected laser beam controlling scheme signal according to a chosen vicinity of a location of interest on an object, the selected laser beam controlling scheme signal enabling a moving of the laser spot beam provided by the laser source in the chosen vicinity of the location of interest of the object and a positioning unit, positioning the laser spot beam using the selected laser beam controlling scheme signal; wherein the positioning of the laser spot beam according to the selected controlling scheme signal enables a precise visual indication of a location on the object using the laser spot beam.  
           [0013]    According to another aspect of the invention, there is provided a method for sawing a log, the method comprising the steps of providing an oscillating laser spot beam on a selected cut line on a log to saw in alignment with a saw blade, selecting a cut line on the log to saw guided by said oscillating laser spot beam and performing a cut with said saw blade in accordance with the provided oscillating laser spot beam on the selected cut line on the log to saw.  
           [0014]    According to another aspect of the invention, there is provided an apparatus for sawing a log at a region of interest on the log, the apparatus comprising a rotating laser spot beam providing apparatus comprising a laser and providing an oscillating laser spot beam defining a plane on a region of interest of the log and a saw adjustable with respect to the plane defined by the oscillating laser spot beam for sawing the log, wherein the adjustable saw performs a sawing of the log at the region of interest using the rotating laser spot beam. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:  
         [0016]    [0016]FIG. 1 is a perspective view of the preferred embodiment of the invention;  
         [0017]    [0017]FIG. 2 is a block diagram of a cut adjusting laser in the preferred embodiment of the invention; the cut adjusting laser comprises a processing unit, a laser, a motor and a user interface;  
         [0018]    [0018]FIG. 3 is a flow chart which shows steps performed according to the preferred embodiment of the invention;  
         [0019]    [0019]FIG. 4 is a flow chart which shows how a user controls the cut adjusting laser using the user interface according to the preferred embodiment of the invention;  
         [0020]    [0020]FIG. 5 is a perspective view of the preferred embodiment of the cut adjusting laser; and  
         [0021]    [0021]FIG. 6 is a perspective view of an alternative embodiment of the cut adjusting laser.  
         [0022]    [0022]FIG. 7 is an exploded view of a cut adjusting laser which is located in a removable unit. 
     
    
       [0023]    It will be noted that throughout the appended drawings, like features are identified by like reference numerals.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    Now referring to FIG. 1, there is shown a preferred embodiment of the invention.  
         [0025]    The portable sawmill comprises at least two support arms  10 , a log  12 , a rotating band saw  14  located between an idler pulley  13  and an actuated pulley  15 , a motor  16  and a cut-adjusting laser  17 .  
         [0026]    The log  12  is supported by the support arms  10  and is directed towards the rotating band saw  14 .  
         [0027]    The rotating band saw  14  is located between the idler pulley  13  and the actuated pulley  15 .  
         [0028]    The actuated pulley  15  is actuated by a motor  16 .  
         [0029]    The cut-adjusting laser  17  enables a user to select a place where the log is to be cut by the rotating band saw  14 . More precisely, the cut-adjusting laser  17  provides a moving laser beam  18  on the log  12 .  
         [0030]    Height of the rotating band saw  14  is adjusted according to a place selected by the user using the laser beam provided by the cut adjusting laser  17 .  
         [0031]    Now referring to FIG. 2, there is shown a block diagram of the cut-adjusting laser  17  according to the preferred embodiment of the invention.  
         [0032]    According to the preferred embodiment of the invention, the cut-adjusting laser  17  comprises a laser driving unit  20 , a feedback unit  22 , a laser  24 , a processing unit  26 , a memory  27  storing a processed motor controlling scheme, a motor driving unit  28 , a motor  30  and a user interface  32 .  
         [0033]    The laser  24  comprises a lens for focusing a laser beam.  
         [0034]    The processing unit  26  provides a laser controlling signal to the laser driving unit  20 . In the preferred embodiment of the invention, the laser controlling signal comprises a ON/OFF signal controlling the operating to the laser  24 . Still in the preferred embodiment, the laser controlling signal comprises an intensity signal for modifying laser beam intensity.  
         [0035]    The processing unit  26  provides a motor controlling signal to the motor driving unit  28 . In the preferred embodiment of the invention, the motor driving unit  28  is a H-Bridge and the motor controlling signal is a Pulse Width Modulation (PWM) signal. Alternatively various other types of signal modulation, motor driving unit  28  and motor controlling signal may be used in accordance with a motor type.  
         [0036]    The memory  27  stores a motor controlling signal and is connected to the processing unit  26 . Upon power up, the motor controlling signal stored in the memory  27  may be provided to the driving unit  28 .  
         [0037]    The driving unit  28  provides a motor driving signal to the motor  30 . Still in the preferred embodiment, the motor  30  is a stepper motor.  
         [0038]    In one embodiment of the invention, and as shown in FIG. 6, the laser  24  is seated on an horizontal rotating disk actuated by the motor  30  according to the motor driving signal provided by the driving unit  28 .  
         [0039]    As shown in FIG. 5 and in the preferred embodiment of the invention, the laser  24  is located above a rotating disk  25  and the laser beam is pointing vertically the center of the rotating disk  25  located below the laser  24 , where a mirror  29  is located. As the rotating disk  25  rotates, a rotating laser beam is created by a reflection of an incoming laser beam provided by the laser  24  on the mirror  29 .  
         [0040]    A gearbox is advantageously used in order for the motor  24  to actuate the rotating disk  25 .  
         [0041]    The feedback unit  22  provides information with respect to a reference located on the rotating disk  25  to the processing unit  26 . The feedback unit  22  comprises a photo sensor, which may detect a reference and then provide a reference detection signal to the processing unit  26 , indicative of said detection. More precisely, and in the preferred embodiment of the invention, the reference is located on the rotating disk and the feedback unit  22  provides the reference detection signal to the processing unit  26  when the reference is detected by the photo sensor.  
         [0042]    Alternatively, a limit switch may be used instead of the photo sensor or any other sensors. In another embodiment of the invention, no feedback unit  22  is used for providing a reference detection signal to the processing unit  26 . The user interface  32  may also comprise a push button which enables the providing of a signal for actuating the driving unit  28  to drive the motor  30  until it reaches a start position. In another embodiment, the push button drives the motor  30  to a fixed position.  
         [0043]    A user provides as explained below a user interface data via the user interface  32 .  
         [0044]    Now referring to FIG. 3, there is shown how the cut adjusting laser  17  operates.  
         [0045]    According to step  34 , the user selects a controlling scheme.  
         [0046]    Now referring to FIG. 4, there is shown how a user selects a controlling scheme.  
         [0047]    According to step  50 , a user interface  32  is provided to the user. In one embodiment, the user interface  32  comprises a screen with a keyboard. In an alternative embodiment, the user interface  32  is a touchscreen display. In another alternative embodiment, the user interface comprises a plurality of predetermined function keys.  
         [0048]    According to step  51 , an operating time is selected by the user. According to step  52 , the user selects between a continuous mode and a non-continuous mode. The continuous mode refers to a mode where the laser beam has a continuous power emitting intensity, while the non-continuous mode refers to a mode where the laser beam has a non-continuous power emitting intensity.  
         [0049]    If the non-continuous mode is selected and according to step  56 , the user selects a shape for the laser beam. The shape may be any ones of a sine shape, cosine shape, triangular shape, a square shape, etc. The shape selected relates to a variation of the laser beam power emitting intensity with time.  
         [0050]    According to step  58 , the user selects between a distance mode and a angle mode.  
         [0051]    If the user selects the distance mode and according to step  60 , the user provides operating distances using the user interface. The operating distances comprises a distance to the target as well as a scanning amplitude. Now referring to FIG. 5, there are shown the target distance and the scanning amplitude. In fact, in the preferred embodiment, the target distance is defined as a distance between the mirror and the target to identify, which is the log  12 . The scanning amplitude is defined as a distance between which the laser beam may oscillate.  
         [0052]    If the user selects the angle mode and according to step  62 , the user selects an operating angle α. The operating angle is defined by the angle created by two extreme laser beams of an oscillating laser beam.  
         [0053]    According to step  64 , the user selects between a providing of a linear speed or a providing of an angular speed.  
         [0054]    According to step  66 , the user provides an angular speed using the user interface  32 .  
         [0055]    According to step  68 , the user provides a linear speed using the user interface  32 .  
         [0056]    It will be appreciated that FIG. 4 is an example of an implementation of the invention, the user interface  32  may enable the user to access directly one or another step of FIG. 4.  
         [0057]    Now referring back to FIG. 3 and according to step  36 , the controlling scheme provided according to step  34 , using the user interface  32 , is processed using the processing unit  26 . In the preferred embodiment of the invention, the processing comprises the converting of data provided to create the motor controlling signal which comprises a speed signal, an angle signal and a direction signal for driving the motor.  
         [0058]    According to step  37 , the motor controlling signal is stored in the memory  27 .  
         [0059]    According to step  38 , the motor controlling signal is provided to the driving unit  28 .  
         [0060]    According to step  40 , the driving unit  28  provides a motor driving signal to the motor  30  in accordance with the controlling scheme selected by the user via the user interface  32 .  
         [0061]    A moving laser beam according to the present invention provides therefore a solution in outdoor lighting situation.  
         [0062]    In the preferred embodiment of the invention and at power up of the cut adjusting laser  17 , a rotation of the rotating disk  25  is performed until the photo sensor detects the reference in order to calibrate the cut adjusting laser  17 .  
         [0063]    In the preferred embodiment, a watchdog device, not shown in the figures, is connected to the processing unit. The watchdog device detects abnormal operations such as a power surge for instance. For instance, in case of a power surge, the cut adjusting laser  17  may be shut down in order to protect at least the motor  30 .  
         [0064]    Still in the preferred embodiment of the invention, and as shown in FIG. 7, the cut adjusting laser  17  is embedded in a casing  81  which may be removed from the portable sawmill in order to at least protect fragile components from vandalizing. In one embodiment of the invention, a laser module casing  80  is mounted over a mounting plate  82 . The mounting plate  82  may be placed on a height adjusting handle  92 . The height adjusting handle  92  may be rotated over rotating axis  93 . The rotation over the rotating axis  93  may be performed manually or using a motor  84 . The height adjusting handle  92  may be used to translated on a sliding rail  88  using a manual rotating handle  93  or a motor  97 . The sliding rail  88  is fixed on a saw mill machine structure  90 .  
         [0065]    In an alternative embodiment, the height adjusting handle  92  may be translated on a female-type sliding rail.  
         [0066]    Still in the preferred embodiment, the laser driving unit  20  may provide a laser driving signal which puts the laser into a power saving mode if the cut adjusting laser  17  is in idle mode by setting the operating time for a predefined period.  
         [0067]    The embodiment of the invention described above is intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.