Table saws with safety systems are disclosed. The safety systems detect and react to dangerous conditions, such as contact between the blade and a person. The table saws may include a switch, a first light that illuminates to indicate the safety system is operable, and a second light that illuminates to indicate that the safety system is inoperable. The switch may not power the saw when switched on if the second light is illuminated.

Table saws with safety systems are disclosed. The safety systems detect and react to dangerous conditions, such as contact between the blade and a person. The table saws may include a switch, a first light that illuminates to indicate the safety system is operable, and a second light that illuminates to indicate that the safety system is inoperable. The switch may not power the saw when switched on if the second light is illuminated.

An object detection system in a saw includes an electrically conductive plate positioned at a predetermined distance from the implement, a detection circuit comprising a transformer, and a single cable connecting first terminal and second terminals of the transformer. The single cable includes a first conductor electrically connected to the first terminal of the winding and to the electrically conductive plate, a second conductor electrically connected to the implement, and an electrical insulator positioned between the first conductor and the second conductor.

An object detection system in a saw includes an electrically conductive plate positioned at a predetermined distance from the implement, a detection circuit comprising a transformer, and a single cable connecting first terminal and second terminals of the transformer. The single cable includes a first conductor electrically connected to the first terminal of the winding and to the electrically conductive plate, a second conductor electrically connected to the implement, and an electrical insulator positioned between the first conductor and the second conductor.

An attachable and extendable saw and methods for cutting objects with the attachable and extendable saw are provided. The attachable and extendable saw can include a blade housing coupled to a main body. The blade housing at least partially covers a saw blade and the extendable member can be configured to move the saw blade with or without the blade housing between a retracted position and an extended position relative to the main body. The extendable saw can also include means to drive the saw blade, means to drive the extendable member, and means for attaching the attachable and extendable saw to the objects to be cut. Saw blade height adjustment means, handles for ease of use, and eyelets for tethering are provided. The saw blade is attached to the attachable and extendable saw via pins and fasteners.

A positioning device for a miter saw includes a working table, an elastic member, and a lever member. The elastic member has a movable portion adapted to be adjacent to a scale disc of the miter saw, and a protruding portion. The lever member is disposed in the working table, and has a linking portion connected to the movable portion, and a handle portion movable to convert the elastic member from a locking state for engaging the protruding portion with one of notches in a scale disc of the miter saw so that the working table is non-rotatable, to a releasing state for moving the movable portion away from the scale disc so that the protruding portion is disengaged from the one of the notches to permit rotation of the working table.

A positioning device for a miter saw includes a working table, an elastic member, and a lever member. The elastic member has a movable portion adapted to be adjacent to a scale disc of the miter saw, and a protruding portion. The lever member is disposed in the working table, and has a linking portion connected to the movable portion, and a handle portion movable to convert the elastic member from a locking state for engaging the protruding portion with one of notches in a scale disc of the miter saw so that the working table is non-rotatable, to a releasing state for moving the movable portion away from the scale disc so that the protruding portion is disengaged from the one of the notches to permit rotation of the working table.

A power tool assembly includes a drop arm frame with an opening configured to rotatably support an arbor shaft, a lower surface spaced apart from the opening, and a plurality of ribs extending between the lower surface and the opening. The plurality of ribs define a respective one of a plurality of axes, the plurality of axes intersect at a locus, and the locus is adjacent to, but spaced apart from, a center of gravity of the drop arm assembly. The power tool assembly further includes an actuating device configured to transfer a force to the drop arm assembly when the drop arm assembly is at the first drop arm assembly position, and a control system configured to control the actuating device to transfer the force to the drop arm assembly when an unsafe condition is sensed.

A power tool assembly includes a drop arm frame with an opening configured to rotatably support an arbor shaft, a lower surface spaced apart from the opening, and a plurality of ribs extending between the lower surface and the opening. The plurality of ribs define a respective one of a plurality of axes, the plurality of axes intersect at a locus, and the locus is adjacent to, but spaced apart from, a center of gravity of the drop arm assembly. The power tool assembly further includes an actuating device configured to transfer a force to the drop arm assembly when the drop arm assembly is at the first drop arm assembly position, and a control system configured to control the actuating device to transfer the force to the drop arm assembly when an unsafe condition is sensed.

A method for measuring brush wear in a motor of a saw includes generating, with a sensor connected to a brush in a motor of the saw, a first signal corresponding to a level of wear in the brush and identifying, with a controller, a level of wear for the brush with reference to the first signal. The method further includes generating, with the controller and a user interface device, an output requesting replacement of the brush in response to the identified level of wear exceeding a predetermined threshold.