Patent Description:
In one aspect, the invention provides a handheld band saw includes a housing, a handle coupled to the housing and configured to be grasped by a user during a cutting operation, a motor supported by the housing, and a drive wheel assembly rotationally driven by the motor. The drive wheel assembly is at least partially disposed within the housing. The band saw further includes a saw blade driven by the drive wheel assembly. The saw blade is configured to cut a workpiece during the cutting operation. The band saw further includes a pipe reamer attachment coupled to the drive wheel assembly. The pipe reamer attachment is configured to deburr the workpiece after completion of the cutting operation.

The handheld band saw may further comprise a battery removably coupled to the handle, wherein the battery, when coupled to the handle, may be configured to provide power to the motor. The handheld band saw may further comprise a trigger disposed adjacent a gripping portion of the handle, wherein power from the battery may be supplied to the motor when the trigger is actuated. The motor may define a rotational axis, and the pipe reamer attachment may be rotationally driven by the motor about the rotational axis. The pipe reamer attachment may be removably coupled to the drive wheel assembly. The handheld band saw may further comprise a quick disconnect coupling that couples the pipe reamer attachment to the drive wheel assembly. The pipe reamer attachment may be integrally formed with at least one component of the drive wheel assembly to form a single piece. The drive wheel assembly may include a drive wheel driven by the motor and a driven wheel driven by the drive wheel via the saw blade, and the pipe reamer attachment may be disposed on the drive wheel. The pipe reamer attachment may include an annular shroud and a blade for engaging the workpiece, and the blade may be disposed within the annular shroud. The housing may include a deck and a guard coupled to the deck that cooperatively surround the saw blade in a shielded position, and the deck and guard may define a cut zone through which the saw blade passes in an exposed position to engage a workpiece.

<FIG> illustrates a band saw <NUM> including a frame or housing <NUM> supporting a motor <NUM> and a gear box <NUM> (<FIG>). In the illustrated construction of the band saw <NUM>, the motor <NUM> is configured as a DC brushless motor, and the band saw <NUM> includes a removable, rechargeable battery <NUM> for supplying power to the band saw <NUM>. The motor <NUM> is drivingly connected to a drive assembly <NUM> through a gear box <NUM>. The motor <NUM>, the drive assembly <NUM>, and the gear box <NUM> are supported by the housing <NUM>. The drive assembly <NUM> may include any of a number of bearing arrangements and different gear train arrangements configured to provide a low-speed, high-torque output from the high-speed, low-torque input provided by the motor <NUM>. The motor <NUM> and the drive assembly <NUM> are operable to drive a continuous band saw blade <NUM> to cut a workpiece (<FIG>).

With continued reference to <FIG>, the housing <NUM> includes a main handle <NUM> with a trigger <NUM> to provide power to the band saw <NUM>. The trigger <NUM> is disposed adjacent a gripping portion <NUM> of the handle <NUM> where a user grasps the band saw <NUM>. In the illustrated construction of the band saw <NUM>, the battery <NUM> is supported by the main handle <NUM> and is an <NUM>-volt power tool battery <NUM>. In other embodiments, the battery <NUM> may be supported on the housing <NUM>. The trigger <NUM> is operable to control operation of the motor <NUM>. Specifically, the battery <NUM> selectively supplies power to the motor <NUM> when the trigger <NUM> is actuated. The housing <NUM> of the band saw <NUM> also includes a deck <NUM> and a guard <NUM> coupled to the deck <NUM>. A combination of the deck <NUM> and the guard <NUM> defines an opening or U-shaped cavity <NUM>. The guard <NUM> includes a lip <NUM> that provides a recessed area <NUM> (<FIG>) in which the band saw blade <NUM> is positioned. The guard <NUM> substantially covers the band saw blade <NUM> when the blade <NUM> is in a shielded position (i.e., when the blade <NUM> is outside of a cut zone <NUM>; <FIG>). However, the U-shaped cavity <NUM> enables the band saw blade <NUM> to be in an exposed position (i.e., when the blade <NUM> passes through the cut zone <NUM>; <FIG>). In the exposed position, the blade <NUM> is fully exposed and unobstructed by the guard <NUM>, allowing workpieces to be cut when entering the cut zone <NUM>.

With reference to <FIG>, the deck <NUM> includes a motor support portion <NUM> and a separate motor cover <NUM> that together enclose the motor <NUM>. The band saw <NUM> further includes a drive wheel assembly <NUM> that supports and drives the saw blade <NUM>. The drive wheel assembly <NUM> includes a drive wheel <NUM> that is directly driven by the motor <NUM> and a driven wheel <NUM> that is driven by the drive wheel <NUM> via the saw blade <NUM>. The outer peripheral surface and the interior side of the drive wheel <NUM> and the driven wheel <NUM> are covered by the deck <NUM> and the guard <NUM>. The drive wheel <NUM> rotates about a drive wheel axis <NUM> (<FIG>) defined by a drive wheel spindle <NUM> (<FIG>). The drive wheel spindle <NUM> is rotationally supported by bearings <NUM> of the drive assembly <NUM>. The drive wheel <NUM> is drivingly connected to the motor <NUM> via the gear box <NUM>, the drive assembly <NUM>, and the drive wheel spindle <NUM>. In the illustrated construction of the band saw <NUM>, the rotational axis <NUM> of the motor <NUM> is coaxially aligned with the drive wheel axis <NUM>. In other embodiments, the rotational axis <NUM> and the drive wheel axis <NUM> may be parallel or at some other oblique angle relative to each other. A tire <NUM> is coupled to the outer peripheral surface of each of the wheels <NUM>, <NUM> (although only one of which is shown). Each tire <NUM> grips the saw blade <NUM> to drive motion thereof.

With reference to <FIG>, the band saw <NUM> further includes a pipe reamer attachment 90a that is coupled to and driven by the drive wheel assembly <NUM>. Although the pipe reamer attachment 90a of the illustrated embodiment is coupled to the drive wheel <NUM>, in other embodiments, the pipe reamer attachment 90a may alternatively be coupled to the driven wheel <NUM>. With the pipe reamer attachment 90a being coupled to the band saw <NUM>, a user can both cut and ream (i.e., deburr) a pipe with a single tool. In one embodiment, the pipe reamer attachment 90a is removably coupled to the drive wheel <NUM>, while in other embodiments, the pipe reamer attachment 90a may be permanently coupled to or integrated as part of the drive wheel <NUM> (<FIG>). In this embodiment, the pipe reamer attachment 90a is coupled to the drive wheel <NUM> via a quick disconnect coupling <NUM>, as shown in <FIG>. The quick disconnect coupling <NUM> includes spring detents <NUM> that mechanically interface with corresponding projections <NUM> to maintain the pipe reamer attachment 90a on the drive wheel <NUM>. More specifically, when attaching the pipe reamer attachment 90a to the drive wheel <NUM>, the projections <NUM> slide along the spring detents <NUM> to temporarily deform (i.e., flex) the spring detents <NUM>. Once the projections <NUM> slide beyond the spring detents <NUM>, the spring detents <NUM> rebound and create a mechanical interference between the projections <NUM> and the spring detents <NUM> to inhibit the piper reamer attachment 90a from being removed from the drive wheel <NUM>. During a reaming operation, the drive wheel <NUM> is driven, for example, in a clockwise direction, while the pipe reamer attachment 90a is coupled to the drive wheel <NUM> by rotating the pipe reamer attachment 90a, for example, in a counterclockwise direction so as to inhibit the pipe reamer attachment 90a from disconnecting from the drive wheel <NUM> during operation. The pipe reamer attachment 90a includes an annular shroud 104a that accommodates pipe ranging from <NUM> (<NUM>/<NUM> inches) in diameter to <NUM> (<NUM> inch) in diameter. In other embodiments, the pipe reamer attachment 90a may accommodate pipe having a different diameter.

<FIG> illustrates another embodiment of a pipe reamer attachment 90b that is coupled to the drive wheel <NUM> via a helical thread pattern <NUM>. Specifically, the drive wheel <NUM> includes a helical thread pattern <NUM> that engages with a corresponding thread pattern <NUM> on the piper reamer attachment 90b. Again, the pipe reamer attachment 90b is rotatably coupled to the drive wheel <NUM> in an opposite direction of the direction of rotation of the drive wheel <NUM> to inhibit the pipe reamer attachment 90b from disconnecting from the drive wheel <NUM> during operation. The pipe reamer attachment 90b includes an annular shroud 104b that accommodates pipe ranging from <NUM> (<NUM>/<NUM> inches) in diameter to <NUM> (<NUM> inch) in diameter. In other embodiments, the pipe reamer attachment 90b may accommodate pipe having a different diameter.

<FIG> illustrates yet another embodiment of a pipe reamer attachment 90c that is integrated as part of the drive wheel <NUM>. In other words, the pipe reamer attachment 90c and the drive wheel <NUM> are formed as a single component that is directly coupled to the drive wheel spindle <NUM>. The pipe reamer attachment 90c may also be recessed within the drive wheel <NUM>, such that the pipe reamer attachment 90c does not extend or extends only slightly beyond the drive wheel <NUM>, as shown in <FIG>. Still, the pipe reamer attachment 90c includes an annular shroud 104c that accommodates pipe ranging from <NUM> (<NUM>/<NUM> inches) in diameter to <NUM> (<NUM> inch) in diameter. In other embodiments, the pipe reamer attachment 90c may accommodate pipe having a different diameter.

Each pipe reamer attachment 90a, 90b, 90c includes a blade <NUM> for engaging and removing a burr formed on the end of a pipe after the blade <NUM> has cut the pipe. The blade <NUM> is disposed within the annular shroud 104a, 104b, 104c to prevent the blade <NUM> from being exposed from the exterior of the shroud 104a, 104b, 104c. The blade <NUM> of the illustrated embodiment is a multi-tiered blade, where each tier is capable of engaging a different sized pipe, such as pipes ranging from <NUM> (<NUM>/<NUM> inches) in diameter to <NUM> (<NUM> inch) in diameter. In other embodiments, the blade <NUM> may alternatively be three separate blades.

With reference to <FIG> and <FIG>, the band saw <NUM> further includes a shoe <NUM> having a support surface <NUM> against which a workpiece is abutted during a cutting operation and a slot <NUM> through which the saw blade extends. The shoe <NUM> is adjacent the cut zone <NUM>. The shoe <NUM> is adjustable along a shoe axis <NUM> that extends substantially parallel with the saw blade <NUM>. By adjusting the shoe <NUM> along the shoe axis <NUM>, the support surface <NUM> is moveable to support and accommodate pipes of varying diameters. The shoe <NUM> includes a slide mechanism <NUM> with an actuator <NUM> that, when depressed, allows a user to move the shoe <NUM> between a retracted position and an extended position along the shoe axis <NUM>. The slide mechanism <NUM> maintains the shoe <NUM> in different predefined positions between the retracted and extended positions via a detent mechanism <NUM> (<FIG>). Specifically, the detent mechanism <NUM> includes a tooth <NUM> that is actuated via the actuator <NUM>, and a plurality of notches <NUM> that selectively receive the tooth <NUM> to maintain the shoe <NUM> in various predefined positions. When the tooth <NUM> is in an extended position (as shown in <FIG>), the tooth is received in one of the notches <NUM> and inhibits the shoe <NUM> from moving along the shoe axis <NUM>. In contrast, when the tooth <NUM> is in a retracted position, the tooth <NUM> is removed from one of the notches <NUM> thereby enabling the shoe <NUM> to move along the shoe axis <NUM>.

However, the detent mechanism <NUM> is designed in a cam-like manner such that the tooth <NUM> has a cam surface <NUM> shaped to permit the tooth <NUM> to be removed from the notch <NUM>, without depressing the actuator <NUM>, and moved to the retracted position when a sufficient upward force is exerted on the shoe <NUM> (from the frame of reference of <FIG> and <FIG>). In this case, the shoe <NUM> retracts to the retracted position in response to a sufficient force being exerted upon the shoe <NUM>. An impact force proportionate to dropping the band saw <NUM> from a distance greater than approximately <NUM> (two inches) above a ground surface is sufficient to cause the shoe <NUM> to retract to the retracted position when the impact force is exerted on the shoe <NUM>. The resulting impact force exerted upon the shoe <NUM> overcomes the biasing force of the detent mechanism <NUM>, allowing the shoe <NUM> to retract via the slide mechanism <NUM>. When the band saw <NUM> is dropped from a distance less than approximately <NUM> (two inches) above a ground surface, the shoe <NUM> remains in position without retracting to the retracted position because the impact force exerted on the shoe <NUM> is not sufficient to overcome the biasing force of the detent mechanism <NUM>. The slide mechanism <NUM> is designed to avoid causing damage to the shoe <NUM> when the band saw <NUM> is inadvertently dropped.

With reference to <FIG>, the drive wheel <NUM> further includes a recess <NUM> on the interior side adjacent the motor <NUM>. The recess <NUM> accommodates a portion of the drive assembly <NUM>, as shown in <FIG>. Also, a top rotor bearing <NUM> is accommodated within a recess <NUM> of a motor fan <NUM>, as shown in <FIG>, and mounted within a corresponding pocket <NUM> in the motor cover <NUM> (<FIG>). As such, the motor cover <NUM> and the motor fan <NUM> are spaced apart just enough to avoid mechanical interference, but the gap therebetween is otherwise negligible. The purpose of the recess <NUM> and the recess <NUM> is to consolidate the configuration of the motor <NUM>, the gearbox <NUM>, and the drive assembly <NUM> as much as possible so the motor cover <NUM> protrudes from the deck <NUM> as little as possible. By reducing the overall length L between the motor <NUM>, and the drive wheel assembly <NUM> measured along the rotational axis <NUM>, the band saw <NUM> is more ergonomic and reduces torque exerted on a user during a cutting and reaming operation. In some embodiments, the overall length L is between <NUM> (<NUM> inches) and <NUM> (<NUM> inches). And, in some embodiments, the overall length is no more than <NUM> (<NUM> inches).

Claim 1:
A handheld band saw (<NUM>) comprising:
a housing (<NUM>);
a handle (<NUM>) coupled to the housing and configured to be grasped by a user during a cutting operation;
a motor (<NUM>) supported by the housing;
a drive wheel assembly (<NUM>) rotationally driven by the motor, the drive wheel assembly at least partially disposed within the housing;
a saw blade (<NUM>) driven by the drive wheel assembly and configured to cut a workpiece during the cutting operation; and characterized by
a pipe reamer attachment (90a, 90b, 90c) coupled to the drive wheel assembly, wherein the pipe reamer attachment is configured to deburr the workpiece after completion of the cutting operation.