Miter saw with adjustable fence

A miter saw includes a base, a turntable rotatable in relation to the base and including a work piece support surface, a support assembly attached to the turntable, and a saw assembly attached to the support assembly and configured to cut a work piece supported on the turntable. A fence assembly includes an elongate fence body that extends along a first axis. The elongate fence body is supported by the base and positioned over the turntable. The fence body has a first connecting structure, and a fence insert defining an elongate work piece abutment surface and having a second connecting structure. The fence assembly is positionable in a first configuration and a second configuration. In the first configuration, the second connecting structure cooperates with the first connecting structure to secure the fence insert at a first position in relation to the fence body. When the fence assembly is positioned in the second configuration, the second connecting structure cooperates with the first connecting structure to secure the fence insert at a second position in relation to the fence body. A second axis intersects the first axis in a perpendicular manner. When the fence insert is secured at the first position, the elongate work piece abutment surface is positioned to intersect the second axis at a first point. When the fence insert is secured at the second position, the elongate work piece abutment surface is positioned to intersect the second axis at a second point, and the first point is offset from the second point along said second axis.

FIELD

This invention relates to the field of power saws, and particularly to power miter saws that have a fence.

BACKGROUND

A power miter saw is a cutting tool used to make crosscuts in a work piece, such as a piece of wood. Miter saws typically include a base equipped with a turntable and fence. The turntable is rotatable in relation to the base and has an upper surface that supports a work piece during cutting operations. The fence extends over the turntable to provide an abutment surface for locating an edge of the work piece at a predetermined position on the base.

The saw assembly of the miter saw includes a bevel arm, a cutting arm, and a cutting assembly. The bevel arm is pivotably attached to the turntable for pivotal movement about a bevel axis. The cutting arm is in turn pivotably attached to the bevel arm for pivotal movement toward and away from the turntable. The cutting arm supports the cutting assembly, comprising a circular saw blade and a motor, above the turntable. During cutting operations, the cutting arm is pivoted downwardly to bring the saw blade into contact with a work piece positioned on the turntable.

Miter saws have a cut capacity that defines the maximum sizes and dimensions of work pieces that a miter saw is capable of cutting through. The cut capacity includes a vertical component, also referred to as the cut height capacity, and a horizontal component, also referred to as the cut width capacity. The cut height and cut width capacity of a miter saw depend on a number of factors, such as the size of the saw blade, the depth that the blade is able to plunge below the upper surface of the turntable, the pivot location of the support arm with respect to the abutment surface of the fence, and the size of the motor, gearbox, and blade arbor.

The cut height capacity of a miter saw may have to be adjusted to accommodate taller work piece sizes. One method used to increase the cut height capacity of a miter saw is to attach a sacrificial fence to the front of the fence.FIGS. 8 and 9depict the cut width and cut height capacity of a miter saw before and after attaching a sacrificial fence to the miter saw fence. As depicted inFIG. 8, the miter saw has a cut width capacity of 190 mm, and a cut height capacity of 88 mm. As depicted inFIG. 8, the sacrificial fence has a thickness on the front of the fence of approximately 20 mm that results in an increase in cut height capacity to 102 mm and a decrease in cut width capacity to 150 mm. The use of the sacrificial fence allows the miter saw to have a cut capacity capable of cutting a 100 mm×100 mm cross section beam.

While effective in increasing cut height capacity, the use of sacrificial fences requires that time be spent selecting and/or fabricating a fence with a desired width and suitable shape for attachment to the miter saw fence. Time must also be spent in the installation and removal of the sacrificial fence. Because sacrificial fences are often made with scrap materials, sacrificial fences are often discarded after use requiring that another sacrificial fence be selected and/or fabricated to increase the cut height capacity of the miter saw for another job.

What is needed is a method or device that enables the cut height capacity of a miter saw to be increased without requiring the fabrication and installation of a separate sacrificial fence or spacer.

SUMMARY

A miter saw includes a base, a turntable rotatable in relation to the base and including a work piece support surface, a support assembly attached to the turntable, and a saw assembly attached to the support assembly and configured to cut a work piece supported on the turntable. A fence assembly includes an elongate fence body that extends along a first axis. The elongate fence body is supported by the base and positioned over the turntable. The fence body has a first connecting structure, and a fence insert defining an elongate work piece abutment surface and having a second connecting structure. The fence assembly is positionable in a first configuration and a second configuration. In the first configuration, the second connecting structure cooperates with the first connecting structure to secure the fence insert at a first position in relation to the fence body. When the fence assembly is positioned in the second configuration, the second connecting structure cooperates with the first connecting structure to secure the fence insert at a second position in relation to the fence body. A second axis intersects the first axis in a perpendicular manner. When the fence insert is secured at the first position, the elongate work piece abutment surface is positioned to intersect the second axis at a first point. When the fence insert is secured at the second position, the elongate work piece abutment surface is positioned to intersect the second axis at a second point, and the first point is offset from the second point along said second axis.

DESCRIPTION

Referring now toFIG. 1, an embodiment of a miter saw10including an adjustable fence assembly12is depicted. As explained below, the adjustable miter fence12includes an elongate body54,56having an insert component66,68. The insert component66,68includes a work piece abutment surface60. The insert component66,68is positionable in a first position and a second position with respect to the elongate body54,56. In the first position, the abutment surface60is arranged at the normal or default position in relation to the base14. In the second position, the abutment surface60is offset a predetermined distance in front of the elongate body52. The offset position of the abutment surface60increases the cut width capacity of the miter saw10and causes a corresponding increase in the cut height capacity of the miter saw10.

In addition to the adjustable fence assembly12, the miter saw10includes a base14, a turntable16, and a saw assembly18. The base14is designed to sit in a stationary position on a solid surface or support structure. The base14is generally comprised of a hard metal material, such as aluminum, and provides a structure that supports the remaining components of the miter saw10. The turntable16is rotatably supported on the base14. The turntable16has a generally planar upper surface20that defines a slot22. The planar upper surface20serves as a horizontal support surface for supporting a workpiece, such as wood or lumber. The slot22provides clearance for the saw blade24to extend below the horizontal support surface20during cuts so that a particular cut width capacity is provided.

The saw assembly18of the miter saw10includes a bevel arm26, a cutting arm28, and a cutting assembly30. The bevel arm28is pivotably attached to the turntable14for pivotal movement about a bevel axis32. The bevel arm30is pivotable about the bevel axis32between a vertical orientation (90°), as shown inFIG. 1, to an angle of 45° or more left of vertical (not shown). This pivoting allows the blade24to approach the turntable16from a bevel angle to perform angled cuts.

The cutting arm28is pivotably attached to the bevel arm26for pivotal movement about an axis34toward and away from the turntable14. The cutting arm28supports the cutting assembly30above the turntable14. The cutting assembly28includes a motor42, a circular saw blade24, a handle44, a switch46, and a blade guard48. The motor42that is operable to rotate the circular saw blade24. The handle44is connected to the bevel arm30to facilitate movement of the cutting head28in relation to the turntable16. The handle44is designed and dimensioned to be grasped by a human hand when performing a cutting operation. This allows the user to easily pivot the cutting head28about axis34. The switch46is positioned on the handle44to allow the user to easily energize and de-energize the motor42during a cutting operation. The blade guard48covers the top portion of the circular saw blade24. During cutting operations, the cutting arm28is pivoted downwardly to bring the saw blade24into contact with a work piece positioned on the turntable14.

As depicted inFIG. 1, the adjustable fence assembly12the elongate fence body includes a left lateral body portion54and a right lateral body portion56that define a first gap62therebetween. A part of the elongate work piece abutment surface60is positioned on each side of the gap62. The fence insert includes a left lateral insert portion66and a right lateral insert portion68that define a second gap64therebetween. The first gap62and the second gap64are aligned with each other and with the slot22defined in the turntable16. The gaps62,64provide clearance for the saw blade24to pass therethrough and toward the slot22.

Each fence body portion54,56extends along an axis A defined on the turntable support surface20. Each fence body portion54,56is positioned at least partially over the turntable16and is attached to the base14at each side of the turntable. Each fence insert portion66,68is removably secured to a body portion54,56and includes a part of the elongate work piece abutment surface60that is arranged substantially perpendicular to the turntable support surface20. When a work piece is positioned on the support surface20of the turntable, an edge of the work piece is held against the elongate work piece abutment surface60to facilitate accurate cuts at desired angles with respect to the fence assembly12.

In accordance with the present disclosure, the fence assembly12is positionable in a first configuration (FIG. 1) and a second configuration (FIG. 2) based on the position of the fence insert portions66,68in relation to the fence body portions54,56. The fence body portions54,56and the fence insert portions66,68include complementarily configured connecting structures70,72(FIG. 3) that cooperate to removably secure the fence insert66to the fence body54in at least a first position and a second position with respect to each other. In the first position, the abutment surface60of the insert portions66,68and the abutment surface76of the body portions54,56are aligned at the normal or default position for the fence assembly12, as depicted inFIG. 1. In the second position, the abutment surface60of the insert portions66,68is offset a distance F from the abutment surface76of the body portions54,56. Offsetting the abutment surface60from the fence body causes the cut height capacity to be increased. The offset distance F selected is dependent upon the configuration and dimensions of the miter saw10and the desired increase in cut height capacity. In one embodiment, the offset distance F is approximately 20 mm.

As best seen inFIG. 3, the fence insert66includes a connecting structure72that comprises a pair of vertically oriented channel structures arranged at each lateral end of the fence insert. The fence body54defines an insert opening75for receiving the fence insert66. The connecting structure70of the fence body54comprises a vertically oriented rail positioned at each lateral end (only visible at one end) of the insert opening75. The rail74is configured to be received in a respective one of the channel structures72defined in the fence insert.

The pair of channel structures72includes a first channel structure72A and a second channel structure72B. The first channel structure72A corresponds to the first position of the fence insert66relative to the fence body52, and the second channel structure72B corresponds to the second position of the fence insert66relative to the fence body52. The vertical orientation of the channel structures72and rails70enables the fence inserts66to be switched between the first and second positions by sliding the inserts66upwardly until the rails70and channel structures72are disengaged. The inserts may then be reinserted into the fence bodies by aligning the channel structures and rails and sliding the inserts downwardly until the rails are received in the corresponding channel structures.

As seen inFIG. 3, a retaining mechanism91is utilized to secure the insert66to the fence body54. Any suitable type of retaining mechanism may be used. In the embodiment ofFIG. 3, the retaining mechanism91comprises a fastener or screw. The fastener91and the channel structures cooperate to secure the insert66to the fence body54once the insert has been seated in the fence body54. In one embodiment, head of the fastener defines a cut out section. When the head of the fastener91is turned to a first predetermined angle or orientation with respect to the fence body52, the cut out section is positioned to provide clearance for the channel structures72A,72B of the insert66to slide along the rail70. Once the insert66is seated in the fence body, the head of the fastener91is rotated to a second position to secure the insert66to the fence body54. In one embodiment, the channel structures72A,72B define cut-outs93(FIG. 3) that interlock with the head of the fastener91when the fastener is turned to the second position to secure the insert66to the fence body54. In an alternative embodiment, a spring loaded detent may be utilized in a similar manner to secure the insert66to the fence body54.

When the fence insert66is in the first position as depicted inFIG. 3, the rails70is received in the first channel structures72A at each end of the fence insert. Referring toFIG. 4, the fence body54has a front surface76that defines a portion of the work piece abutment surface of the fence assembly12. The front surface76of the fence body54lies in a plane C, and the front surface60of the fence insert66lies in a plane D. With the fence insert66and fence body54in the first position with respect to each other, the plane C is coplanar with the plane D and perpendicular to the plane E defined by the turntable support surface20.

When in the second position, the work piece abutment surface60of the fence insert66lies in a plane D that is parallel to and offset the distance F from the plane C. The fence insert66is offset from the fence body54along an axis B that intersects the axis A in a perpendicular manner, as depicted inFIG. 4. When the fence insert66is in the first position relative to the fence body52, the work piece abutment surface60of the fence insert66and the abutment surface76of the fence body54are each positioned to intersect the axis B at a first point57along the axis B. When in the second position, the abutment surface60of the fence insert intersects the axis B at a second point59along the axis B that is offset from the first point57.

Referring toFIGS. 5A and 5B, the fence inserts66may be configured so that the lower edge78of the work piece abutment surface60is lowered when the insert is moved from the first position to the second position. The inserts66define channel structures72A,72B at the lateral ends of the inserts66that are used to removably secure the inserts to the fence bodies52. In one embodiment, the channel structures72A,72B are provided with varying lengths to enable the lower edge78of the work piece abutment surface60to be lowered when the insert66is moved to the second position. As depicted inFIG. 5A, the channel structure72A is positioned a distance G from the lower edge78, and the channel structure72B is positioned a distance H from the lower edge78. When the insert is positioned in the second position (channel structure72B), the lower edge78is moved closer to the turntable surface20. When the insert66is moved forward, the lower edge78is moved closer to the support surface20to limit the ability of a work piece to pass under the lower edge78during cutting operations.

Referring again toFIG. 4, positioning a fence insert66in front of the miter saw fence poses the risk of the fence insert66being placed in the path of the saw blade24when the saw assembly is fully mitered to the left or right. To prevent the fence insert66from being placed in the path of the saw blade when the saw is mitered, the end portions of the inserts66are made shorter than the length of the fence bodies so that when the fence inserts are in the forward position, i.e., the second position, the inner lateral extent of the inserts does not intersect the path of the blade. For example, referring toFIG. 4, the left lateral end portion54includes a body end portion84that is positioned contiguous with the first gap62, and the left lateral insert portion66includes an insert end portion86positioned contiguous with the second gap64. The body end portion84is located a first distance88from the axis B, and the insert end portion86is located a second distance90from the axis B with the distance88being greater than the distance90. Thus, when the insert66is in the forward position, the body end portion84and the insert end portion86are each approximately the same distance from the gaps62,64when the saw is in the fully mitered left position as depicted inFIG. 4. The distances88,90selected to space the insert end portion86from the gap64depends on the dimensions and configuration of the miter saw10. In one embodiment, the distances88,90are selected such that the difference between the first88and second distance90is between approximately 20.0 mm and 30.0 mm. In one particular embodiment, the difference between the first and second distances equals approximately 25.0 mm.

As mentioned above, the bevel arm26of the saw assembly enables the saw blade to be tilted with respect to turntable16to enable bevel cuts to be performed. In the embodiment ofFIG. 1, the bevel arm26enables the saw blade to be tilted from vertical to approximately 45° left of vertical. In alternative embodiments, the bevel arm26may be configured to allow the blade to be tilted to approximately 45° right of vertical as well. When the saw blade is tilted to perform bevel cuts, a portion of the fence may be located in the path of the blade24. To enable cuts to be performed with the saw tilted to the left (or right) of vertical, the fence assembly12is configured as a sliding fence. As a sliding fence, the upper portion of the fence on the left side of the turntable is configured to slide radially outwardly from the center of the turntable to provide clearance for the saw blade when it is beveled to the left. The upper portion of the fence to the right of the turntable may also be configured to slide radially outwardly if the saw assembly is capable of being beveled to the right.

Referring now toFIG. 3, to enable the slide functionality for the fence12, the left lateral body portion54of the fence includes a base attachment portion100and a sliding portion102. The base attachment portion100is fixed to the base14of the miter saw10, and the sliding portion102is slidably connected to the base attachment portion100. The sliding portion102of the fence body54includes the connecting structure70and opening75for the insert66so that the insert66is slidable with the sliding portion of the fence body54. The sliding portion is supported by the base attachment portion100in a manner that enables the sliding portion102to slide with respect to the base attachment portion100along axis A between a default position (FIG. 3) and a lateral position (FIG. 1). In the default position, the fence12provides full height support to perform cuts with the saw blade oriented vertically. In the lateral position, the upper portion of the fence is moved out of the way of the saw blade to allow bevel cuts to be performed. As best seen inFIG. 3, the sliding portion and the base attachment portion are slidably connected using a tongue and groove type connection104although any suitable type of connection or connecting structure may be used.

In the embodiment of the fence assembly depicted inFIGS. 1-5, the insert portion of the fence is adjustable between the normal position and the forward position by sliding the insert portion upwardly to remove the insert from the fence body and sliding the insert downward to install the insert to the fence body.FIGS. 6 and 7depict an embodiment of a fence assembly12′ in which the insert portion68of the fence is movable between the normal position and the forward position by sliding the insert generally horizontally with respect to the fence body56. Although only the right lateral body portion56of the fence assembly12′ is depicted inFIGS. 6 and 7, the discussion below is applicable to the left lateral portion of the fence assembly as well.

As depicted inFIGS. 6 and 7, the insert68includes a pair of beam-like structures106,108that protrude from the rear side110of the insert component68(i.e., the side opposite the abutment surface60). Each beam defines a longitudinal slot112,114that extends therethrough. The fence body56includes beam support surfaces116,118that support the beams106,108and allow movement of the beams along the axis B relative to the fence body56. The support surfaces116,118each define a bore120(FIG. 7) for receiving a fastener, such as a screw or knob, (not shown). As seen inFIG. 7, when the insert68is positioned on the fence body56, the longitudinal slots112,114are aligned with the bores120. A fastener is passed through each slot112,114and into the bores120to secure the insert68to the fence body56.

The longitudinal dimension of the slots112,114is arranged generally perpendicular to the abutment surface60of the fence to enable the insert to be slid in the forward and rearward directions along axis B with respect to the fence body56. The positions of the ends of the slots112,114in relation to the positions of the bores/fasteners120define the forward and rearward limits of movement for the insert. In the rearward position, the abutment surface60of the insert68is aligned with the front surface76of the fence body as depicted inFIG. 6. The insert68may be secured at any position between and including the forward and rearward positions by tightening and loosening the fasteners in the slots.