Tiltable carriage assembly and sawmill incorporating same

A sawmill assembly comprising a bed, a carriage and a tilting device. The bed has a pair of substantially parallel rails that define a first plane, a first axis perpendicular to the first plane, and a second plane perpendicular to both the first plane and a longitudinal axis of the rails. The carriage is movably supported along the rails. The tilting device allows a user to adjust a tilt angle of the carriage in the second plane, relative to the first axis. Also disclosed are methods of adjusting a blade angle of the sawmill assembly, and methods of cutting a tapered piece from a workpiece material.

This application claims priority to PCT/CA2020/000037, filed on Mar. 11, 2020, and to Canadian Patent Application No. 3,037,514, filed on Mar. 21, 2019, the contents of each of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of sawmills. More particularly, the present invention relates to portable sawmills having a band saw cutting blade.

BACKGROUND OF THE INVENTION

A sawmill typically includes three main components, namely, a bed, a carriage, and a saw head. The bed is adapted to support a log extending horizontally along the bed. The carriage is mounted to the bed for horizontal movement along the length of the log, and the saw head is mounted to vertical posts on the carriage. The vertical posts of the carriage permit vertical movement of the saw head relative to the carriage, and the carriage is adapted for horizontal movement along the bed. The saw head typically includes a band saw blade to cut the log as the carriage is moved horizontally along the bed. U.S. Pat. No. 4,275,632 to Ross, and U.S. Pat. No. 7,784,387 to Dale disclose examples of such a sawmill.

A problem with the sawmills disclosed in the U.S. '632, and '387 patents, and others like them, is that the angle of the blade is fixed in a horizontal orientation, allowing an operator to only make flat cuts along the log to form flat boards, i.e. boards having parallel top and bottom surfaces.

One attempt for overcoming this problem was to provide a jig that is mountable to the bed and allows the operator to tilt the log on the bed. However, the requirement for the additional jig adds to the cost and complexity of the sawmill and adds another component that needs to be stored when not in use. Another disadvantage of the jig is that the user must install and remove it frequently, because the jig can not be on the sawmill bed when milling a round log to a square cant. Once the log is made into a square cant, the cant is removed, the jig installed and then the cant is secured into the jig. This requires multiple steps and is very inefficient. By way of example, one such jig manufactured by Wood-Mizer LLC, Indianapolis, Ind., U.S.A and referred to as a Shingle & Lapsider option or SLR.

Other attempts include sawmills with stationary saw heads, that may be pivoted by the operator to position the blade between a horizontal orientation and an angled orientation, and adapting the bed to allow the operator to feed the log into the saw head. U.S. Pat. No. 4,805,500 to Saito, U.S. Pat. No. 6,772,665 to Hurdle, U.S. Pat. No. 6,966,246 to Yeh, disclose examples of such sawmills.

However, there is a continuing need for improvements in sawmills.

SUMMARY OF THE INVENTION

What is desired therefore, is a sawmill which overcomes at least some of the problems associated with the prior art.

According to a preferred embodiment of the present invention, there is disclosed a sawmill assembly comprising a bed, a carriage and a tilting device. The bed is sized and shaped to support a workpiece material such as a log or other piece of wood. The bed has a pair of substantially parallel rails that define a first plane, a first axis perpendicular to the first plane, and a second plane perpendicular to both the first plane and a longitudinal axis of the rails. The carriage is movably supported along the rails and carries a saw head. According to the preferred embodiment of the invention the saw head comprises a band saw having a cutting blade adapted for cutting wood. The tilting device allows a user to adjust a tilt angle of the carriage in the second plane, relative to the first axis, to set the cutting blade in a range of angles between 0 and 10 degrees, inclusive, relative to the first plane. For ease of understanding, the first plane may be considered to be a horizontal plane, which is substantially parallel to the ground or surface on which the bed of the sawmill is situated. In this way, a cutting angle of the cutting blade may be set by a user within a range of angles between substantially horizontal, and a maximum tilt angle relative to horizontal (i.e. 10 degrees above horizontal). Once the cutting angle of the cutting blade is set by adjusting the tilt angle of the carriage, the user can operate the sawmill to make an angled cut along the length of the workpiece material length being supported on the bed of the sawmill. The ability to set the cutting angle of the cutting blade in this manner enables the user to cut tapered pieces from the workpiece material, such as, for example, lap siding boards, roof shingles, roof shakes, and wood shims, i.e. pieces having non-parallel top and bottom surfaces.

Also disclosed are methods of adjusting a blade angle of the sawmill assembly, and methods of cutting a tapered piece from a workpiece material.

Therefore, according to one aspect of the present invention, there is disclosed a sawmill assembly comprising:a bed, said bed comprising:a pair of substantially parallel rails, said rails defining a first plane, a first axis perpendicular to said first plane, and a second plane perpendicular to both said first plane and a longitudinal axis of said rails;a carriage movably supported along said rails, said carriage comprising:a tilting device for adjusting a tilt angle of said carriage in said second plane, relative to said first axis.

According to another aspect of the present invention, there is disclosed a method of adjusting a blade angle of the above sawmill assembly, said method comprising the step of:manipulating said tilting device to adjust said tilt angle of said carriage in said second plane.

According to another aspect of the present invention, there is disclosed a method of cutting a tapered piece from a workpiece material, said method comprising the steps of:providing a sawmill comprising:a bed, said bed comprising:a pair of substantially parallel rails, said rails defining a first plane, a first axis perpendicular to said first plane, and a second plane perpendicular to both said first plane and a longitudinal axis of said rails;a carriage movably supported along said rails; anda saw head attached to said carriage, said saw head comprising a band saw having a blade oriented perpendicular to a vertical axis of said carriage and parallel to said second plane;supporting said workpiece material on said bed;tilting said carriage in said second plane, at an angle to said first axis; andmoving said tilted carriage along said rails in one direction as said blade cuts through said workpiece material thereby cutting said tapered piece from said workpiece material.

According to another aspect of the present invention, there is disclosed a method of cutting a tapered piece from a workpiece material, said method comprising the steps of:supporting said workpiece material on a bed of a sawmill between a pair of substantially parallel rails of said bed, said rails defining a first plane, a first axis perpendicular to said first plane, and a second plane perpendicular to both said first plane and a longitudinal axis of said rails;tilting a carriage of said sawmill in said second plane, at an angle to said first axis, said carriage comprising a band saw having a blade oriented perpendicular to a vertical axis of said carriage and parallel to said second plane; andmoving said tilted carriage along said rails in one direction as said blade saws through said workpiece material thereby cutting said tapered piece from said workpiece material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described in more detail with reference to exemplary embodiments thereof as shown in the appended drawing. While the present invention is described below including preferred embodiments, it should be understood that the present invention is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embodiments which are within the scope of the present invention as disclosed and claimed herein.

A sawmill apparatus10according to an embodiment of the present invention is shown inFIG. 1. The sawmill10includes a bed12and a carriage14. The bed12has a pair of substantially parallel rails16, and the carriage14is movably supported along the rails16, on wheels18as shown. Preferably, the rails16may be formed from a plurality of rail sections20. Several log bunks22are positioned between the rails16and arranged to support a workpiece material24thereon. Log bunks22are preferably structural components of the bed12that support the workpiece material24during the milling operation. The workpiece material24rests on the log bunks22and in turn they carry the entire weight of the workpiece material24. Preferably, the log bunks22may also add to the overall structural strength of the bed12as they tie into the rails16to help keep them true and square. It has been found that providing a level square bed12is desirable for achieving wood boards of consistent thickness since the carriage14follows along the rails16.

By way of example, the workpiece material24may be made from wood, such as a log, as best seen inFIG. 2. Preferably, one or more log supports26and clamps28are also provided on the bed12and configured to secure the workpiece material24to the bed12between the rails16. As will be appreciated, the log supports26and clamps28may be used to help prevent movement of the workpiece material24during operation of the sawmill10. Additionally, a plurality of adjustable feet30may be provided under the bed12and configured to permit a sawmill operator to level the bed12during installation and setup and provide uniform support for the rails16when the bed12is installed on uneven ground. Preferably, the bed12will also be provided with wheel stops32at both ends of the rails16to ensure that the carriage14does not inadvertently roll off of the rails16at one end34or the other36. Preferably also, the log supports26and clamps28may be removably, and slidably retained in holders38, to allow their heights above the rails16to be adjusted. In this way, the heights of the log supports26and clamps28may be individually adjusted by the operator, or they may be individually removed from the bed12, as needed so as not to interfere with the movement of the carriage14along the rails16between the one end34of the bed12and the other end36of the bed12. Preferably, the bed12may be configured as a kit of parts, to be assembled by the operator without the need for specialized tools.

With continued reference toFIG. 1, the carriage14has a frame40with two sides42,44that straddle the bed12, and is moveably supported along the rails16on wheels18, between the one end34and the other end36. The wheels18preferably include annular grooves to limit lateral movement on the rails16. Preferably, the frame40is configured to carry a saw head46attached or mounted thereto. Preferably, the saw head46includes a band saw, having a blade48adapted to cut the workpiece material24, a motor50(i.e. electric or internal combustion motor) to drive the band saw, and other components that may be necessary or desirable to operate and control the band saw, such as, for example, a fuel tank52, and a throttle54.

As shown inFIG. 2, the saw head46is preferably configured to cut the workpiece material24supported on the bed12, as the carriage14is moved along the rails16in at least one direction56, for example, the from the one end34of the bed12to the other end36of the bed12, as shown. Of course, it will be appreciated that the saw head46may also be configured to cut the workpiece material24in a direction opposite to the at least one direction56. More preferably, the saw head45may be configured to cut the workpiece material24in both directions, for example, by providing the blade48with cutting surfaces facing both the one end34and the other end36. All such embodiments are comprehended by the present invention.

Preferably, the carriage14may be configured to be moved along the rails16by the operator between the one end34and the other end36, while the band saw is on and driving the blade48. For example, the operator may apply force to the carriage14to cause it to move in the one direction56or the opposite direction. A handle58may preferably be provided on the frame40to facilitate the pushing or pulling the carriage14by the operator.

According to a preferred embodiment of the present invention, the saw head46is attached to the frame40together with means to raise or lower the saw head46in the carriage14along a vertical axis60of the carriage14, with the blade48remaining substantially perpendicular to the vertical axis of60of the carriage14. Preferably, the raising and lowering of the saw head46may be achieved by slidably mounting the saw head46to a pair of vertically oriented posts62at the sides42,44of the frame40, and operatively connecting the sliding saw head46to a winch and pulley assembly. By way of example, as best seen inFIG. 5, a preferred means to raise or lower the saw head46may include at least one guide sleeve64adapted to slidingly accommodate a vertically oriented post62on one side42of the frame40. More preferably, the saw head46includes two guide sleeves64adapted to slidingly accommodate vertically oriented posts62on both sides42and44of the frame40. A cable66connects a winch68and a pulley70mounted to the frame40, to the sliding saw head46to allow the operator to raise and lower the saw head46by manipulating the winch68. It will be appreciated that raising or lowering the saw head46translates into raising or lowering of the blade48of the saw head46above the bed12, enabling the operator to adjust the height of the blade48above the bed12. Accordingly, the operator may manipulate the means to raise or lower the saw head46to cut the workpiece material24supported on the bed12at a desire height relative to the bed12. In this way, the operator may cut a piece from the workpiece material24, such as for example, a flat board, having a desired thickness. However, the person skilled in the art will recognize other known ways of raising and lowering the saw head46. All such other known ways of raising or lowering the saw head46are comprehended by the present invention.

Preferably, the carriage14may also be configured as a kit of parts, to be assembled by the operator without the need for specialized tools.

With reference toFIGS. 1 to 3, the rails16define a first plane72, a first axis74perpendicular to the first plane72, a longitudinal axis76of the rails16, and a second plane78that is perpendicular to both the first plane72and the longitudinal axis76. For ease of understanding, the first plane72may be considered to be a horizontal plane, which is substantially parallel to the ground or surface on which the bed12of the sawmill10is situated.

InFIGS. 3 and 4, the blade48is oriented perpendicular to the vertical axis60of the carriage14, and parallel to the second plane78. With reference toFIG. 3, the sawmill10has the carriage14oriented relative to the bed12such that the blade48of the saw head46is positioned above the bed12, substantially parallel to the first, horizontal plane72, analogous to a conventional sawmill. The vertical axis60of the carriage14is aligned with the first axis74. With the sawmill10in the configuration shown inFIG. 3, the blade48is substantially parallel to the first, horizontal plane72, as well as being substantially perpendicular to the longitudinal axis76of the bed12. What is important is that the tilt angle80of the carriage14is about 0 degrees relative to the first axis74, which results in the blade48being positioned at an angle82of 0 degrees relative to the first, horizontal plane72.

Accordingly, it will be appreciated that operation of the sawmill10in the configuration shown inFIG. 3permits the operator to make substantially horizontal cuts through the workpiece material24by pushing or pulling the carriage14from the one end34to the other end36of the bed. Furthermore, it will be appreciated that by using the sawmill10in the configuration shown inFIG. 3to make a pair of sequential, horizontal cuts in the workpiece material24, and manipulating the winch68to lower the saw head46between the pair of cuts, the operator may cut a piece from the workpiece material24, such as for example, a flat board, having a desired thickness.

Although, the saw head46according to a preferred embodiment of the present invention includes a band saw having a blade48oriented substantially parallel to the first, horizontal plane72, it is contemplated that the band saw may be replaced with another known type of saw such that the blade48is held in the carriage14substantially parallel to the horizontal plane72. By way of example only, such other known type of saw may include a chain saw, a reciprocating saw, or a circular saw. All such embodiments are comprehended by the present invention.

With reference toFIG. 4, the carriage14is tilted as compared to the carriage14shown inFIG. 3. In particular, the sawmill10shown inFIG. 4has the carriage14oriented relative to the bed12such that the blade48of the saw head46is positioned above the bed12, but at an angle to the first, horizontal plane72. The vertical axis60of the carriage14is no longer aligned with the first axis74defined by the rails16, but is instead at an angle80away from the first axis74, in the second plane78. With the sawmill10in the configuration shown inFIG. 4, the blade48is positioned at an angle82to the first, horizontal plane72, while remaining substantially perpendicular to the longitudinal axis76of the bed12. What is important is that the tilt angle80of the carriage14is greater than 0 degrees relative to the first axis74, which results in the blade48being positioned at an angle82that is greater than 0 degrees relative to the first, horizontal plane72. Preferably, the carriage14may be configured to permit the operator to adjust the tilt angle80of the carriage to provide a maximum tilt angle80of about 6 to 10 degrees, inclusive, relative to the first axis74, which corresponds to a maximum blade angle82of about 6 to 10 degrees, inclusive, relative to the first, horizontal plane72. However, it is contemplated that the maximum tilt angle80of the carriage14may be greater than 10 degrees, provided that additional safeguards are implemented into the sawmill10prevent the carriage14from tipping over completely. All such embodiments are comprehended by the present invention.

Accordingly, it will be appreciated that operation of the sawmill10in the configuration shown inFIG. 4permits the operator to make angled cuts through the workpiece material24by pushing or pulling the carriage14from the one end34to the other end36of the bed12. Furthermore, it will be appreciated that by using the sawmill10in the configuration shown inFIG. 4to make a pair of successive horizontal and angled cuts in the workpiece material24, and manipulating the winch68to lower the saw head46between the pair of successive horizontal and angled cuts, the operator may cut a tapered piece from the workpiece material24, such as for example, a lap siding board, a roof shingle, a roof shake, or a wood shim, i.e. pieces having non-parallel top and bottom surfaces. Other tapered pieces may be cut from the workpiece material24by making pairs of successive angled cuts, wherein the blade angle82is different between successive cuts.

With reference now toFIGS. 5 to 8, a tilting device84will be described according to an embodiment of the present invention. The tilting device84preferably allows the operator to adjust the tilt angle80of the carriage14relative to the first axis74in the second plane78, and thus the blade angle82, between the configuration shown inFIG. 3and the configuration shown inFIG. 4. Preferably, the tilting device84may be configured to adjust the tilt angle80in a range sufficient to allow the operator to use the sawmill10to cut lap siding boards, roof shingles, roof shakes, wood shims, and the like, from the workpiece material24. For example, although the angles provided on lap siding and shingles is variable, they are typically in the range of 3 to 10 degrees, inclusive. Accordingly, the preferred tilting device84may be configured to adjust the tilt angle80of the carriage14relative to the first axis in a range between 0 and 10 degrees, inclusive, which translates into a blade angle82ranging between 0 and 10 degrees, inclusive, relative to the first, horizontal plane72. However, good results have been obtained by configuring the tilting device84to provide a maximum tilt angle between 6 and 10 degrees, inclusive. What is important is that the tilting device84is configured to enable the operator to adjust the tilt of the carriage14, to provide a tilt angle80greater than 0 degrees relative to the first axis74, which results in the blade48being positioned at an angle82that is greater than 0 degrees relative to the first, horizontal plane72, yet sufficient for making the angled cuts required by a particular application. Although, it is contemplated that the maximum tilt angle80of the carriage14may be greater than 10 degrees, additional safeguards may need to be implemented into the sawmill10to prevent the carriage14from tipping over completely. All such embodiments are comprehended by the present invention.

FIGS. 5 and 6show the one side42of the carriage14supported on a section of rails16. The frame40of the carriage14has vertically oriented posts62secured to, and sandwiched between pairs of frame plates86, with fasteners88, on both sides42,44of the carriage14. The tilting device84shown inFIGS. 5 and 6includes two wheels18on one side42of the carriage14, a pair of sprocket assemblies90carrying the wheels18, a chain92, chain guides94, and a chain tensioner96. Although not visible inFIGS. 5 and 6, a pair of wheels18is also included on the other side44of the carriage14, as best seen inFIG. 1. The wheels18on the other side44are fixedly attached to the inner frame plate86, facing towards the longitudinal axis76of the bed12, and configured to roll on rail16. By providing the wheels18facing inwardly on the carriage in this way, the carriage14may be provided with a wider cutting opening, with a bed12that has a narrower foot print. However, it is contemplated that the wheels18may be attached in the space formed between the pair of frame plates96, or the wheels18may be attached to the outer frame plate86to face away from the longitudinal axis76of the bed12. All such embodiments are comprehended by the present invention.

FIG. 5shows the tilting device84set to position the wheels18on the one side42in a retracted position. With the wheels18in the retracted position, the one side42is substantially the same height as the other side44. Thus, setting the tilting device84to position the wheels18on the one side42in the retracted position, places the sawmill10in the configuration shown inFIG. 3, namely, the vertical axis60of the carriage14being aligned with the first axis74of the bed (i.e. the tilt angle80is 0 degrees), such that the blade48is parallel to the horizontal, first plane72(i.e. the blade angle82is 0 degrees). In other words, the carriage14is substantially level.

FIG. 6, on the other hand, shows the tilting device84set to position the wheels18on the one side42in an extended position. With the wheels18in the extended position, the one side42is longer as compared to the other side44. Thus, setting the tilting device84to position the wheels18on the one side42in the extended, places the sawmill10in the configuration shown inFIG. 4, namely, the vertical axis60of the carriage14being angled away from the first axis74of the bed (i.e. the tilt angle80is greater than 0 degrees), in the second plane78, such that the blade48is angled away from the horizontal, first plane72(i.e. the blade angle82is greater than 0 degrees). In other words, the carriage14is tilted in the second plane78, from the rail16on the one side42towards the rail on the other side44.

The tilting device84discussed above with respect toFIGS. 5 and 6is more clearly shown inFIGS. 7 and 8. In these figures, the outer frame plate86has been removed to show the components of the tilting device84contained in the space between the two frame plates86, on the one side42. As can be seen, the tilting device84is configured to pivotably extend or retract the wheels18on the one side42, to lengthen or shorten the one side42of the carriage14, independently of the other side44.

Preferably, two sprocket assemblies90are pivotally attached between the frame plates86on the one side, as shown inFIGS. 7 and 8. Each sprocket assembly90has a sprocket98, that is attached to the frame plate86on its axis. One end of an arm100is attached to each sprocket98, and the other end of each arm100is attached to a wheel18. One end of chain92is attached to the chain tensioner96, and wrapped around the sprocket assemblies98and guides94to terminate at an attachment point102on the frame plate86. Preferably, a spring104may be provided between the attachment point104and the chain92.

Accordingly, it will now be appreciated that the preferred tilting device84may be manipulated by the operator to control the degree of extension or retraction of the wheels18on the one side42, to thereby adjust the tilt angle80of the carriage, and thus the blade angle82of the blade48. For example, the operator may manipulate the chain tensioner96to pull the chain92, which in turn rotates the sprockets98of the sprocket assemblies90, causing the arms100to pivotably extend the attached wheels18. In this case, the spring104releases the length of chain92taken up by the chain tensioner96. In reverse, the operator manipulating the chain tensioner96to release the chain92in turn allows the wheels18to pivotably retract under the weight of the carriage14. In this case, the spring104takes up the length of chain92released by the chain tensioner96.

What is important is that the two sprocket assemblies90are operatively interconnected by the chain92so that the pivotal extension and retraction of the wheels18may be synchronized.

Preferably, the chain tensioner96may be attached to the frame40, and provided with a grippable member, such as a handle106, operatively connected to the chain92. The greppable member may be gripped by the operator's hands to enable him or her to selectively pull or release the chain92to adjust a degree of extension or retraction of the wheels18on the one side42of the carriage14. By way of example, the handle106may be arranged to drive a mechanical lead screw type actuator with its operative end attached to the chain92by a pin108. Preferably, the chain tensioner96may be provided with a tilt angle limit stop110, which may be set by the operator to limit the maximum tilt angle80. As can be seen inFIG. 8, the tilt angle limit stop110interferes with the upward travel of the pin108, to limit the maximum length of chain92that can be pulled by operation of the chain tensioner96, thereby limiting the maximum extension of the wheels18, which in turn limits the maximum tilt angle80.

Although the tilting devices84described above are configured to change the length of one side42, while the other side44remains unchanged, to tilt the carriage14towards the other side44, it is contemplated that the tilting device84may be configured to change the length of the other side44, while the one side42remains unchanged, enabling the operator to tilt the carriage14towards the one side42, instead. Furthermore, it is contemplated that the tilting device84be configured to enable the operator to selectively change the length of the one side42or the other side44, to cause the carriage14to be tiltable towards both the one side42and the other side44. All such embodiments are comprehended by the present invention.

FIGS. 9 to 14show tilting devices84according to other embodiments of the present invention, that enable the operator to selectively change the length of the one side42, to cause the carriage14to tilt from the one side42to the other side44, to adjust the blade angle82.

For example,FIGS. 9 and 10show a tilting device84employing a parallel motion linkage mechanism. The tilting device84is attached to the frame plate86. The outer frame plate86is removed for illustrative purposes, to show the components of the tilting device84contained in the space between the two frame plates86, on the one side42. As can be seen, the tilting device84is configured to pivotably extend (FIG. 10) or retract (FIG. 9) the wheels18on the one side42, to lengthen or shorten the one side42of the carriage14, independently of the other side44. As shown, the tilting device84includes a pair of lever assemblies112. Each lever assembly112includes a lever arm114operatively connected to a wheel18. Each lever arm114is pivotably attached to the frame plate86on the one side42of the carriage14by a pivot pin116. Preferably, the lever arms114are interconnected by links118such that a pivoting movement of one lever arm114translates to the same pivoting movement of the interconnected lever arm114. The wheels18are attached to the ends of the lever arms114, such that pivoting the lever arms114in one direction causes the wheels18to extend (FIG. 10), while pivoting the lever arms114in the opposite direction causes the wheels18to retract (FIG. 9). Preferably, the arrangement of links118synchronizes the extension and retraction of the wheels18. In other words, the two lever assemblies112are operatively interconnected by the links118so that the pivotal extension and retraction of the wheels18may be synchronized.

Preferably, a grippable member120may be operatively connected to one lever assembly112to enable the operator to pivot the lever arm114in one direction or the opposite direction to adjust a degree of extension or retraction of the wheels18. By way of example, the grippable member120may be a handle that is attached to a lead screw122operably connected to the one lever assembly112.

As another example,FIGS. 11 and 12show a tilting device84employing a linear actuator mechanism. The tilting device84is attached to the frame plate86, and a supplemental frame plate124. As in the above examples, the outer frame plate86is removed for illustrative purposes, to show the components of the tilting device84contained in the space between the two frame plates86, on the one side42. As can be seen, the tilting device84is configured to linearly extend (FIG. 12) or retract (FIG. 11) the wheels18on the one side42, to lengthen or shorten the one side42of the carriage14, independently of the other side44. As shown, the tilting device84includes two linear actuators126each being operatively connected to a wheel18. One linear actuator126is attached to the frame plate86on the one side42of the carriage14, while the other linear actuator126is attached to the supplemental frame plate124. The wheels18are attached to the linear actuators126, such that extension of the linear actuators126causes the wheels18to extend (FIG. 12), while retraction of the linear actuators126causes the wheels18to retract (FIG. 11). Preferably, the linear actuators126are interconnected to synchronize the extension and retraction of the wheels18. Although not shown, it will be appreciated that the tilting device84will preferably include a means to allow the operator to power and control the linear actuators126.

By way of example only, the actuator may be a mechanical actuator, an electro-mechanical actuator, a hydraulic actuator, a pneumatic actuator, or a solenoid actuator.

As yet another example,FIGS. 13 and 14show a tilting device84configured to enable the operator to change the length of the one side42of the carriage14by expanding (FIG. 14) or contracting (FIG. 13) the one side42of the carriage14. As shown, the tilting device84includes a pair of cross members128interposed between a top portion130and a bottom portion132of the one side42of the carriage14.

Preferably, a grippable member134may be operatively connected to the pair of cross members128, to enable the operator to adjust the expansion (FIG. 14) and contraction (FIG. 13) of the length of the one side42. By way of example, the grippable member134may be a handle that is attached to a lead screw136operably connected to the pair of cross members128. In other words, the operator may manipulate the grippable member to force the pair of cross members128apart, or together, to selectively adjust the degree of expansion (FIG. 14) and contraction (FIG. 13) of the length of the one side42.

Having described preferred embodiments of the present invention above, it will now be understood that the operator may adjust the blade angle82of the sawmill10by the step of manipulating the tilting device84to adjust the tilt angle80of the carriage14in the second plane78.

Furthermore, it will now be appreciated that the operator may use a sawmill having a carriage14movably supported along rails16of a bed, to cut a tapered piece from a workpiece material24supported on the bed12between the rails16, by tilting the carriage14in the second plane78, at an angle to the first axis74, and moving the tilted carriage14along the rails16of the bed12in one direction as the blade48cuts through the workpiece material24, thereby cutting the tapered piece from the workpiece material24. By way of example only, the workpiece material24may be made from wood, and the tapered piece is a lap siding board, a roof shingle, a roof shake, or a wood shim.

Preferably, the operator may attach a tilting device84to the carriage14to facilitate the step of tilting the carriage14.

Preferably the method for cutting tapered pieces from the workpiece material24may also include the step of raising or lowering the saw head46or the blade48in the carriage14, along the vertical axis60of the carriage14, to set a desired thickness of the tapered piece.

While reference has been made to various preferred embodiments of the invention, other variations, implementations, modifications, alterations and embodiments are comprehended by the broad scope of the appended claims. Some of these have been discussed in detail in this specification and others will be apparent to those skilled in the art. Those of ordinary skill in the art having access to the teachings herein will recognize these additional variations, implementations, modifications, alterations and embodiments, all of which are within the scope of the present invention, which invention is limited only by the appended claims.