Abstract:
A blade lubrication system for a sawmill having a blade, chain or band saw, and a control mechanism for activating said blade, chain or band. The blade lubrication system automatically activates cooling and cleaning of the blade, or band when the control mechanism is activated, and automatically deactivates the cooling and cleaning of the blade, chain or band when the control mechanism is deactivated.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to an integrated blade lubrication controller for a sawmill such as a portable sawmill having a cutting mechanism for sawing lumber. The integrated blade lubrication controller is linked to the throttle controller, so that lubricant is applied to the saw blade only when the throttle is deployed. 
         [0002]    There are several prior inventions for portable sawmills. 
         [0003]    U.S. Pat. No. 5,784,941 describes a portable sawmill in which the functions of adjusting a cut and making a cut are divided between two separate devices. The invention discloses a vertical chain saw, ideally operated in an upward direction, which moves horizontally along a track. The device has a throttle actuator, that, in conjunction with a chain, operates the throttle of the chain saw, so that the motor of the chainsaw is at full power when cutting, but returns to idle when not cutting. A cooling system is not disclosed. 
         [0004]    U.S. Pat. No. 4,275,632 describes a portable sawmill comprising a U-shaped support or carriage, holding a band saw. When in use, a log is placed between the two guide rails and is supported in place by a jacking mechanism with adjustable shelves. The band saw is in a generally horizontal position (though with one end slightly elevated), and does not adjust in a vertical direction; instead, the log itself is moved up and down using a jacking mechanism. The band saw is equipped with a release mechanism for automatically disengaging the drive between the motor and the saw at the end of a cutting stroke. Though the band saw does not have a throttle mechanism per se, the band saw has a lever which can be latched in position in which an idler pulley engages the belt causing power to be transmitted to the band saw. Once the band saw carriage has passed entirely through the log to be sawed, the latch strikes against a top plate, causing the latch to disengage the lever and stop the band saw through disengagement of an idler pulley with the band saw belt. A cooling system is not disclosed. 
         [0005]    U.S. Pat. No. 4,235,140 describes a sawmill having a saw carriage having a vertical slide slidable on a vertical post of the sawmill frame, and adjustable vertically thereof by a cable secured at its upper end to a hook hooked into the top of the post. The lower end of the cable is attached to a reel, rotatable by a manual crank. The sawmill is equipped with a handle having a Bowden-wire control to the throttle of the chain saw, such that the chain saw internal throttle mechanism can be activated and controlled from the handle. A cooling system is not disclosed. 
         [0006]    U.S. Pat. No. 3,965,788 describes a saw guide for use with a vertically operated portable chain saw. The saw guide comprises support means for the chain saw, to which the saw is attached. The vertical displacement of the chain saw along the support means is by way of a slidable engagement which can be clamped to a desired height using adjusting clamps. The operator uses the chain saw&#39;s built in trigger and internal throttle mechanism to operate the chain saw. A cooling system is not disclosed. 
         [0007]    U.S. Pat. No. 3,926,086 describes a portable sawmill that uses a complex pulley system to move the chain saw and supporting platform in a horizontal direction. Vertical displacement of the chain saw relative to the log and sawmill frame is through a pair of transversely-spaced vertically-movable racks having their lower ends operatively connected to the bar of the chain saw, a transverse shaft rotatably mounted on the frame, and a pair of transversely-spaced pinions fastened to the shaft and engaging the tracks. The racks and the attached chain saw is raised or lowered relative to the frame and to the log by rotation of the shaft. The chain saw is disclosed to have a pivotal throttle trigger which may be squeezed to adjust the speed of the operating saw between a relatively slow idle speed and a relatively fast cutting speed. The portable sawmill may also have trigger disengagement means engaging the chain saw throttle trigger and operative to cause the saw to return to an idle speed when the trigger deactivating means strikes an object as the cutting saw exits a log being sawed. The trigger disengagement utilizes a detent mechanism on the chain saw trigger, so that the trigger disengagement further depresses the throttle trigger so that the detent is disengaged, snapping the throttle trigger outwardly to its extended position, and returning the operating saw to its idle speed when the saw exits a log being sawed. A cooling system is not disclosed. 
         [0008]    Canadian Patent No. 1,200,180 describes a portable sawmill comprising a frame with a guide rail and a carriage moveable along the guide rail. A band saw is supported by the carriage. The carriage is moveable along the guide rail along two sets of wheels, one engaged with the upper side of the guide rail and the other with the lower side. The patent discloses a single lever control which enables the operator to positively engage or brake the band saw, and also to control the engine throttle. Specifically, a brake, a clutch, and a power speed control are all incorporated into a single lever which is actuated at the end of each cut to stop the band saw blade and to lower or stop power velocity. A cooling system is not disclosed. 
         [0009]    U.S. Pat. No. 4,210,049 describes an “x” frame for holding a log, with a chain saw affixed to the frame in cantilever position for cutting logs crosswise. The frame comprises a throttle control means including a fingertip throttle control lever pivoted to the end of a handle, and a corresponding lever pivoted at the base end, the levers being connected by a link and the lever being integral with a horizontal crank element so that its end actuates the chain saw throttle when the lever is actuated. A cooling system is not disclosed. 
         [0010]    The LumberLite™ 24 mid-size band sawmill and the Lumbermate 2000 full size portable band sawmill (http://www.norwoodindustries.com) are portable sawmills having two horizontal bases, each with a wheel assembly providing planar horizontal movement and fitted onto a set of rails of a sawmill base, two vertical saw supports extending vertically from the horizontal bases, and a top cross rail connecting the two vertical saw supports. The sawmills have a cable rod extending between the vertical saw supports, with a crank handle. The crank handle rotates the cable rod. The saw head is placed below the cable rod and slidably affixed to the vertical saw supports such that it can move vertically along the two vertical saw supports. A cable extends between the cable rod and the saw head, and reels around the cable rod, lifting or lowering the saw head. The saw head is kept in place using clamps on the saw head affixing it to the vertical saw supports. The saw head is displaced horizontally along the rails by pushing a handle. The handle has a lever which acts as a throttle control; the lever is connected to the saw head throttle through a Bowden cable. Thus, by squeezing the lever towards the handle, the throttle is activated. By releasing the lever (which is biased in an outwards position) the throttle is released. The LumberLite™ can be purchased with a saw blade/band cooling system, which consists of a flexible hose affixed to the saw head carriage in a manner such that, when water is run through the hose, it falls onto the saw blade/band. Thus, an operator would connect the opposing end of the hose to a water supply, such as a water tap, and would turn on the water tap before making each cut. The operator would then turn off the water tap, either after each cut, or when finished utilizing the sawmill. 
         [0011]    Many sawmills, including the aforementioned sawmills, work better when the saw blade, saw band, or saw chain (as appropriate) is kept cool. This helps keep the blade pitch-free, improves cutting performance, and extends the life of the blade, band or chain. Thus, many sawmills are retro-fitted, or modified, to have a blade lubrication system. Others are sold pre-equipped with a blade lubrication. Essentially, as discussed above with respect to the LumberLite™, the operator affixes one end of a hose, such as a rubber hose to a location proximal to the saw blade, saw band, or saw chain; the other end of the hose is attached to a water/lubricant supply, such as a container or cold water tap. Before use, the operator turns on a valve on the hose, which, in turn, releases water from the hose and onto the saw blade/band/chain, lubricating the blade/ban/chain. In order to conserve water and minimize a muddy or wet cutting environment, typically, the operator will turn the water off after cutting the log, will re-adjust the sawmill for the next cut, then will turn the water back on before starting the next cut. This adds steps, and time, to the log cutting. The existence of these steps also introduces the opportunity for operator error—the operator may forget to turn the water on, resulting in the blade or band overheating, or forget to turn the water off, resulting in mud or flooding. 
         [0012]    There is therefore a need for an improved portable sawmill having a blade lubrication system that automatically activates when the saw is in use, and deactivates when the saw is not in use. Such a blade lubrication system would preferably be simple and reliable. 
       BRIEF SUMMARY OF THE INVENTION 
       [0013]    The present invention provides a blade lubrication system for a sawmill, having a hose having a saw end and a tap end, whereby the tap end is capable of being affixed to a blade lubricant source. The hose is sufficiently malleable, elastic or flexible to allow clamping or restriction of water/blade lubricant flow within said hose by applying pressure to an external surface of said hose. A control is positioned such that it is capable of applying sufficient pressure to the external surface of the hose to restrict blade lubricant flow within said hose. The control is biased in a first configuration whereby sufficient pressure is applied to the external surface of the hose to restrict blade lubricant flow. The control also has a second configuration wherein blade lubricant flow is not restricted. The saw end of said hose can be positioned so that blade lubricant flowing out of said saw end cools and cleans a blade or band chain of a saw of said sawmill. The control can be attached to the sawmill such that the control is moved into said second configuration when the saw is activated by a user. 
         [0014]    Typically, the blade lubricant is water and the blade lubricant source is a water tap or blade lubrication reservoir. 
         [0015]    The control can be a slam latch, having a bolt biased in an outward direction when the slam latch is in the first configuration; and a pull attached to the sawmill such that, when the pull is displaced, the bolt moves in a direction causing the slam latch to move into said second configuration. In a preferred embodiment, the control also has a cable having a first end attached to said pull, and a second end attached to a throttle control on said sawmill, wherein, when said throttle control is activated, the first end of said cable displaces said pull to move said slam latch to said second configuration. 
         [0016]    The present invention also teaches sawmills having the blade lubrication system of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0017]    The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
           [0018]    In the drawings: 
           [0019]      FIG. 1  is a rear right perspective view of a sawmill according to one aspect of the present invention, and is labeled with its major components. 
           [0020]      FIG. 2  is a front right perspective view of the sawmill of  FIG. 1 . 
           [0021]      FIG. 3  is a close-up of a handle of a sawmill according to a further aspect of the present invention. 
           [0022]      FIG. 4  is a further close-up of the handle of  FIG. 3 , showing the throttle and water cables in more detail. 
           [0023]      FIG. 5  is a close up of a further element of the sawmill of  FIG. 3 , showing the water hose and the opposing end of the water cable. 
           [0024]      FIG. 6  is a further close up of the sawmill of  FIG. 5 . 
           [0025]      FIG. 7  shows, in  FIGS. 7A ,  7 B, and  7 C, respectively, three different latches, each in isolation, each that can be utilized to control flow of water in the sawmill. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    The present invention provides a simple, versatile, cost-effective and portable sawmill which can be readily assembled, disassembled, carried, and used by one person. It is particularly suitable for use by hunters, “do-it-yourselfers”, and people situated in remote areas, who need to saw boards, clapboards, shingles, etc. The sawmill&#39;s design enables it to be manufactured from extremely sturdy, reasonably inexpensive materials. 
         [0027]    While there are several prior inventions for portable sawmills, none provide the advantages of the present invention, which has several inventive features not found in the prior art. Notably, the present invention provides an improved blade lubrication mechanism for sawmill blades, bands or chains (collectively referred to as sawmill blades for ease of reference, throughout the remainder of this document). The blade lubricating mechanism is triggered in conjunction with the triggering of the saw throttle, such that the blade is lubricated only when it needs to be, i.e., when the throttle is on (and, typically, the blade is cutting a log). The invention provides a simple and elegant solution, using off-the-shelf parts that are known to be reliable and essentially maintenance free. 
         [0028]    An embodiment of the present invention will now be described as shown in  FIGS. 1-7 . 
         [0029]      FIGS. 1 and 2  are perspective views of a sawmill according to one aspect of the present invention.  FIGS. 1 and 2  show the entire sawmill, with a basic configuration as follows. 
         [0030]    Carriage  32  is supported on two horizontal bases  28 ,  30  which can be longitudinally displaced on the sawmill base  26  along rails  22 ,  24  (respectively), utilizing wheels (not shown). Mounted onto horizontal bases  28 ,  30  and extending upwards in a generally vertical direction are vertical supports  34 ,  36 ,  38 , and  40 , with vertical supports  34 ,  36  mounted onto horizontal base  30  and vertical supports  38 ,  40  mounted onto horizontal base  28 . Cross rail  78  extends between the top of vertical support  36  and  38 . Bases  26 ,  28 , vertical supports  34 ,  36 ,  38 ,  40 , and cross rail  78  form carriage  32  which can be longitudinally displaced, and which supports sawhead platform  42 . Sawhead platform  42  can be displaced in a vertical direction along vertical supports  38 ,  36  using a variety of means; as shown, using a crank  46  attached to a rod (not shown) which acts as a reel for a cable (not shown) connected to saw head platform  42 . 
         [0031]    In the illustrated embodiment, sawhead platform  42  supports sawband cover  43  which houses sawband  45 . Sawband  45  is rotated by motor  44  when motor  44  is activated. Of course, a person of skill in the art would realize that sawhead platform  42  could utilize a wide variety of saw heads; though a band saw is illustrated, an appropriate reciprocal saw, chain saw, or circular saw may also be used. 
         [0032]    Handle  48  is used to displace the carriage  32  (and, as a result, sawhead platform  42 ) longitudinally along the sawmill base  26 . In use, but not shown, a log would be placed longitudinally on sawmill base  26 , and affixed in place using conventional means, such as log dogs or clamps. Thus, when the saw is operated, the longitudinal displacement of carriage  32  using handle  48  will cut longitudinal planks out of the log. The operator of the sawmill would adjust the vertical placement of saw head platform  42  to a desired height, then displace the carriage  32  along the sawmill base  26  by pushing or pulling (typically, and as shown, pushing) on handle  48 . Once the log is cut, the operator would adjust the vertical placement of saw head platform  42  down a desired distance, and perform a second cut. The operator can cut the entire log, or at least a large portion of it, in this manner. 
         [0033]    Handle  48  is shown in more detail in the photograph of  FIG. 3 . Handle  48  has attached thereto throttle control  50 . Throttle control  50  is generally parallel to handle  48 , and is pivotable thereto in a manner such that it can be squeezed towards handle  48  by an operator. Throttle control  50  is biased in an outward orientation, but is pivotable about a pivot point  60  whereby, as throttle control  50  is squeezed towards handle  48 , lever  54 , which is on the opposing end of throttle control  50 , moves away from handle  48 . The throttle control  50  is biased by means of a Bowden cable: spring cable  63 , located within spring cable sheath  65 , and attached to a spring (not shown). A spring on a slam latch (described in more detail below) at the other end of the cable forces the control  50  back open again when released. Attached to lever  54  are at least two additional Bowden cables, described as follows: 
         [0034]    Throttle inner cable  52 , encased in throttle cable sheath  56 , has a lever end attached to lever  54 . The distal end of throttle inner cable  52  is attached to the band saw motor  44  such that it activates the band saw throttle (not shown). As is the well understood mechanism of Bowden cables, when throttle control  50  is squeezed towards handle  48 , the throttle inner cable  52  is displaced relative to throttle cable sheath  56 , and the distal end of the throttle inner cable  52  is displaced. The distal end of throttle inner cable  52  is attached to throttle (not shown) such that, when the throttle inner cable  52  is displaced in this manner, the throttle is activated and the saw band  45  rotates at a speed for cutting wood. 
         [0035]    Blade lubrication inner cable  58  is also encased in blade lubrication cable sheath  62  which also has a lever end attached to lever  54 . When throttle control  50  is squeezed towards handle  48 , blade lubrication inner cable  58  is also displaced relative to blade lubrication cable sheath  62 , generally transmitting a pulling force to the distal end of blade lubrication inner cable  58 . 
         [0036]      FIG. 4  is a close-up of lever  54 , showing throttle inner cable  52 , throttle cable sheath  56 , inner cable  58 , and cable sheath  62 , as they relate to lever  54  and handle  48 . Also shown is pivot point  60 , spring cable  63 , and cable sheath  65  [ 63  and  65  are not spring cables. The cables activate the mechanical clutch mechanism in the same way that the throttle cable and blade lubrication cable activate their respective systems. The spring action which restores throttle control to its neutral position are integral to the systems that the cables activate. 
         [0037]      FIGS. 5 and 6  show close-ups of blade lubrication controller  67 . Blade lubrication controller  67  can be located almost anywhere on the sawhead platform  42  or carriage  32 , so long as it doesn&#39;t interfere with the operation of the sawmill. For example, blade lubrication controller  67  can be located on sawhead platform  42 , vertical support  38 , or on sawband cover  43 . A hose conduit  74  within controller  67  houses hose  70 . One end of blade lubrication hose  70  is attached to a blade lubrication source, such as a water tap (not shown) or preferably a blade lubricant reservoir (and insert identifier number). The other end of blade lubrication hose  70  is affixed to the sawhead platform  42  or carriage  32  such that, when blade lubricant emerges, the blade lubricant contacts saw band  45 , cooling and cleaning the saw band  45  and keeping the blade pitch free. Conduit  74 , in general, affixes blade lubrication hose  70  in place without significantly restricting blade lubrication flow within it. Blade lubrication controller  67  also comprises means for clamping or restricting blade lubrication flow within blade lubrication hose  70 . Such means are biased such that blade lubricant flow within blade lubrication hose  70  is restricted. The means for clamping or restricting blade lubricant flow within blade lubrication hose  70  are connected to the distal end of blade lubrication cable  58  such that, when a pulling force is transmitted to the distal end of blade lubrication cable  58 , blade lubricant controlling means allow blade lubricant to flow within blade lubrication hose  70 . As would be understood by a person of skill in the art, blade lubrication hose  70  must be sufficiently malleable, elastic or flexible to allow clamping or restriction of blade lubricant flow by applying pressure to its external surface. 
         [0038]    As shown, the blade lubricant controlling means comprise a simple, commercially available slam latch  64 , having pull  66  and bolt  68 . Bolt  68  is spring biased in an outwards configuration. When pull  66  is pulled in an outwards direction, bolt  68  moves inwards, into the body of slam latch  64 . Slam latch  64  is affixed to blade lubrication controller  67  in a configuration such that bolt  68  clamps blade lubrication hose  70  in its natural, biased state, but, when pull  66  is pulled in an outwards direction, bolt  68  moves inwards into the body of slam latch  64  and blade lubrication hose  70  becomes unclamped, allowing blade lubricant to flow. Distal end of blade lubrication inner cable  58  is attached to pull  66 , such that, when throttle control  50  is squeezed towards handle  48 , pull  66  is pulled in an outwards direction. 
         [0039]    While the embodiment shown in the Figures utilizes a spring biased bolt, it will be appreciated that other means, such as a lever, pedal, or cam could be utilized to control the blade lubricant/water flow. 
         [0040]    Thus, when throttle control  50  is squeezed towards handle  48 , the saw throttle is activated and the saw band  45  begins to turn at a speed for cutting wood. At the same time, blade lubrication controller  67  is activated, and blade lubricant begins to flow to cool and clean the saw band  45 . At the end of the cut, the operator releases the throttle control  50  the saw band stops. At the same time, blade lubricant stops flowing to the saw band. In this manner, the cooling and cleaning of the saw band is synchronized with the operation of the saw, minimizing waste and automatically starting, and stopping, the blade lubrication flow at appropriate times. 
         [0041]    Further examples of simple, commercially available slam latches (see, e.g. Spaenaur Co. catalogue, 2009) that can be used are seen in isolation in  FIG. 7A-C . Note that the slam latch of  FIG. 7C  further features a strike plate  72 ; if a slam latch with a strike plate  72  is utilized, as would be understood by a person of skill in the art, the blade lubrication hose  70  would be positioned between bolt  68  and strike plate  72 . 
         [0042]    It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.