Portable sawmill

Abstract

A portable sawmill has an elongate central portion, at least one hinged foldable extension portion, laminated rails, and a tow bar. An elongate tubular axle retaining member is mounted to the base. A pair of torsion axles, to which wheels and tires are attached, are received telescopically in opposite ends respectively of the axle retaining member and detachably attached thereto. A plurality of legs are attached to the base. The legs are height-adjustable to raise the base to a height such that the tires are raised above the ground so that the axles with the attached wheels may be removed.

What is claimed is: 
     
         1 . A sawmill comprising
 an elongate base including a pair of parallel elongate rails which extend longitudinally of said base,   a carriage including rollers which engage said rails for moving of said carriage along said rails,   said base further including elongate support structures to which said rails are respectively rigidly attached,   said base further including a plurality of longitudinally spaced structural members interconnecting said support structures for supporting a log between said rails,   said carriage further including a saw operable for cutting a log on said structural members as said carriage is moved along said rails,   a tow bar attached to said base,   an elongate tubular axle retaining member mounted to said base, a pair of axles received telescopically in opposite ends respectively of said axle retaining member and detachably attached thereto, a pair of wheels attached to said axles respectively, and tires mounted on said wheels respectively, and   a plurality of legs attached to said base for supporting said base, wherein said legs are height-adjustable to raise said base to a height such that said tires are raised above the ground so that said axles with said attached wheels may be removed.   
     
     
         2 . A sawmill according to  claim 1  wherein said rails are laminated to said support structures respectively. 
     
     
         3 . A sawmill according to  claim 2  further comprising spacers between said rails and said support structures. 
     
     
         4 . A sawmill according to  claim 1  wherein each of said legs comprises a first elongate member having at least three walls and attached to a respective one of said structural members at a position inwardly of said respective one of said rails in a manner wherein said first elongate member slopes outwardly relative to a respective side of said base while extending downwardly, a second elongate member having at least three walls and telescopingly receivable in said first elongate member, wherein one of said first and second elongate members has at least one aperture therein, wherein an other of said first and second elongate members has at least two longitudinally spaced apertures therein, means for roughly adjusting height of the sawmill, said means for roughly adjusting height of the sawmill including a pin receivable in a selected one of said at least two spaced apertures and in said at least one aperture to attach said first and second elongate members at a roughly adjusted height of the sawmill, and means for finely adjusting height of the sawmill, said means for finely adjusting height of the sawmill including a flange attached to a lower end of said second elongate member, a ground engaging foot pad, and a screw connecting said flange to said foot pad in a manner to finely adjust height of the sawmill when said screw is turned. 
     
     
         5 . A sawmill according to  claim 4  wherein said second elongate member is skewed relative to said flange so that said flange is oriented horizontally. 
     
     
         6 . A sawmill according to  claim 4  wherein said second elongate member is at an angle relative to vertical of between about 10 and 20 degrees. 
     
     
         7 . A sawmill according to  claim 1  wherein said elongate base includes an elongate central base portion and at least one base extension portion hingedly attached to said central base portion at an end of said central base portion in a manner which allows said base extension portion to be folded from a first position for use to a second position at least partially over onto said central base portion. 
     
     
         8 . A sawmill according to  claim 7  wherein said tow bar is attached to said central base portion and, when said base extension portion is in said second position, said tow bar extends below and outwardly from said base extension portion. 
     
     
         9 . A sawmill according to  claim 8  further comprising a box-shaped member attached to said central base portion and in which an end portion of said tow bar is receivable, and means for quickly attaching and detaching said tow bar to and from the sawmill, wherein said means for quickly attaching and detaching said tow bar to and from the sawmill includes a pin and apertures in the end portion of said tow bar and the box-shaped member for receiving said pin. 
     
     
         10 . A sawmill according to  claim 1  wherein at least one of said axles is a torsion axle. 
     
     
         11 . A sawmill according to  claim 1  wherein said axles include elongate tubes telescopingly received in opposite ends respectively of said axle retaining member and having terminal ends, the sawmill further comprising means for quickly detaching said axles from said axle retaining member, wherein said means for quickly detaching said axles from said axle retaining member comprises apertures in said elongate tubes and in said axle retaining member for receiving pins respectively, whereby removal of the pins allows removal of said axles from said axle retaining member. 
     
     
         12 . A sawmill according to  claim 11  wherein at least one of said axles is a torsion axle. 
     
     
         13 . A sawmill according to  claim 1  wherein said rails are laser cut. 
     
     
         14 . A sawmill according to  claim 1  wherein said carriage further includes
 a pair of spaced bandwheels upon which said saw blade is mounted, 
 a pair of stationary spindles upon which said bandwheels respectively are mounted, and 
 means for applying a predetermined amount of tension to said saw blade, 
 wherein said means for applying said predetermined amount of tension includes an elongate non-rotatable threaded rod which when moved longitudinally effects lateral movement of one of said spindles thereby changing the distance between said spindles to change the amount of tension on said saw blade, 
 a member threaded engaged to said threaded rod to effect the longitudinally movement of said threaded rod upon rotation of said member, and 
 a torque limiter attached to said member to effect rotation of said member as said torque limiter is rotated, 
 wherein the torque limiter is adjusted to limit the amount of torque applied to said member to a torque which provides said predetermined amount of tension. 
 
     
     
         15 . A sawmill according to  claim 1  wherein said carriage further includes
 a pair of spaced bandwheels upon which said saw blade is mounted, 
 a clutch for transmitting power to one of said bandwheels, and 
 means for varying speed of said bandwheels, 
 wherein said means for varying speed of said bandwheels includes a shaft, a drive pulley on said shaft which receives power from said clutch, and a driven pulley on said shaft for transmitting power to one of said bandwheels. 
 
     
     
         16 . A sawmill according to  claim 1  wherein said carriage further includes
 a pair of spaced vertical members upon which said carriage is movable vertically for positioning said saw blade vertically, and 
 means for structurally supporting upper ends of said vertical members, 
 wherein said means for structurally supporting includes a tank for holding and supplying a fluid for use in operation of the sawmill, said tank extending between and attached to the upper ends of said vertical members. 
 
     
     
         17 . A sawmill according to  claim 1  further comprising
 an engine having a throttle for operating said saw, 
 at least one device, 
 an actuation lever movable by a person from a de-actuation position to an actuation position and holdable by the person in said actuation position, 
 a cam pivotally movable between a first position and a second position, 
 a first member attaching said cam to said actuation lever for pivotally moving said cam from said first position to said second position by moving said actuation lever to said actuation position, 
 a second member attaching said throttle to said cam and responsive to movement of said cam to said second position for effecting actuation of said throttle for powering of said engine, 
 at least one third member attaching said at least one device to said cam and responsive to movement of said cam to said second position for effecting actuation of said at least one device, and 
 means including springs attached to said cam, said throttle, and said at least one device respectively to return said cam to said first position, said throttle to a de-actuated position thereof, and said at least one device to a de-actuated position thereof when said actuation lever is released from said actuation position. 
 
     
     
         18 . A sawmill according to  claim 1  further comprising
 at least one means for clamping a log cant to said base, 
 wherein said means for clamping includes a first clamp member attachable to one of said structural members for clampingly engaging one side of a log cant, 
 wherein said means for clamping also includes a second clamp member which is attached to said one of said structural members and which includes means for moving said second clamp member in a direction longitudinally of said one of said structural members, 
 wherein said means for moving includes a threaded rod extending longitudinally of said one of said structural members and attached to said base in a manner to be rotatable, a handle attached to an end of said rod to effect rotation of said rod, a pair of walls of said second clamp member which have a pair of aligned vertically oblong apertures respectively for receiving said rod, a half nut fixedly attached to the bottom of one of said apertures and having threads which mate with threads on said threaded rod so that said rod can threadedly engage said half nut, 
 wherein said apertures are sized such that said second clamp member can be tilted so that said threads of said threaded rod and said threads of said half nut are disengaged and said second clamp member slid along said threaded rod to an approximate position for clamping, then, with said second clamp member positioned upright and said threads of said threaded rod and said threads of said half nut re-engaged, said handle can be turned to apply clamping force to an other side of the log cant. 
 
     
     
         19 . A sawmill according to  claim 1  further comprising a pair of elongate ramps for loading logs onto the sawmill, wherein at least one of said ramps has a first end portion configured for engaging the ground and a second end portion configured for resting on one of said support structures, said at least one ramp comprising two plates attached side-by-side, a plurality of longitudinally spaced safety catches sandwiched between said plates, a pin attaching each said catch to said plates so that said catch is rotatable about said pin between a first position wherein said catch extends outwardly of said respective ramp and a second position wherein said catch lies within said respective ramp so that logs may be moved up said ramps pushing said catches forwardly from said first position to said second position, said at least one ramp further comprising a stop member attached to said plates for restraining said catch from rotating backwardly from said first position, said at least one ramp further comprising means for effecting return of said catches from said second position to said first position once a log has passed to thereby restrain a log if it thereafter falls backwardly, wherein said means for effecting return comprises a weighted portion on each said catch which is positioned on said catch to bias said catch to fall back to said first position due to gravity.