A chain saw kit having a sub-frame assembly and a plurality of operating components, including at least a battery operated motor and battery. The sub-frame assembly is configured to define mount locations for the operating components so that the sub-frame assembly and operatively placed operating components make up at least a part of a main operating unit to which a chain bar and cutting chain can be assembled. A first outer housing assembly has at least a first outer housing part with a second outer housing assembly having at least a second outer housing part. The parts of the outer housing assemblies are interchangeably usable to allow selection of different overall size, shape, and/or appearance of chain saws based upon a common sub-frame assembly.

A chain saw kit having a sub-frame assembly and a plurality of operating components, including at least a battery operated motor and battery. The sub-frame assembly is configured to define mount locations for the operating components so that the sub-frame assembly and operatively placed operating components make up at least a part of a main operating unit to which a chain bar and cutting chain can be assembled. A first outer housing assembly has at least a first outer housing part with a second outer housing assembly having at least a second outer housing part. The parts of the outer housing assemblies are interchangeably usable to allow selection of different overall size, shape, and/or appearance of chain saws based upon a common sub-frame assembly.

A tool coupling device is configured to hold a machine tool cutting device. In particular, the tool coupling device is configured to hold a machine tool cutting device configured as a closed system, having at least one cutting train clamping unit for generating a cutting train clamping force and having at least one tool-holding unit comprising at least one movably mounted tool-holder element. The tool coupling device includes at least one movement-coupling unit by which the tool-holder element can be coupled with a clamping element for a movement of the clamping element of the cutting train clamping unit.

A tool coupling device is configured to hold a machine tool cutting device. In particular, the tool coupling device is configured to hold a machine tool cutting device configured as a closed system, having at least one cutting train clamping unit for generating a cutting train clamping force and having at least one tool-holding unit comprising at least one movably mounted tool-holder element. The tool coupling device includes at least one movement-coupling unit by which the tool-holder element can be coupled with a clamping element for a movement of the clamping element of the cutting train clamping unit.

An apparatus for automatically adjusting a chainsaw cutting element as the chainsaw cutting element lengthens during use due to thermal expansion includes an elongate flat bar circumscribed by the chainsaw cutting element, a motor for causing the chainsaw cutting element to rotate about the elongate flat bar, a motor housing for housing the motor and a cover housing secured to the motor housing for covering a proximal end of the elongate flat bar and a rotatably mounted sprocket gear that engages a proximal end of the chainsaw cutting element. The elongate flat bar has a first, fully retracted position, a second, fully extended position, and an infinite number of positions of adjustment therebetween. Bias members continuously urge the elongate flat bar to displace during saw operation in a proximal-to-distal direction from the first, fully retracted position to the second, fully extended position to maintain chain tension at all times.

An apparatus for automatically adjusting a chainsaw cutting element as the chainsaw cutting element lengthens during use due to thermal expansion includes an elongate flat bar circumscribed by the chainsaw cutting element, a motor for causing the chainsaw cutting element to rotate about the elongate flat bar, a motor housing for housing the motor and a cover housing secured to the motor housing for covering a proximal end of the elongate flat bar and a rotatably mounted sprocket gear that engages a proximal end of the chainsaw cutting element. The elongate flat bar has a first, fully retracted position, a second, fully extended position, and an infinite number of positions of adjustment therebetween. Bias members continuously urge the elongate flat bar to displace during saw operation in a proximal-to-distal direction from the first, fully retracted position to the second, fully extended position to maintain chain tension at all times.

To provide an operation lever including a first lever that has a base end portion swingably supported to a peripheral portion of a nut member for fastening a guide bar in a chain saw, and a second lever that is engaged with the first lever in a manner slidable in an axial direction. The operation lever can be placed in a receiving portion of the nut member with an axial length thereof shortened, and can be manipulated to rotate the nut member by being gripped on an outer end portion of the second lever in a state in which the operation lever is lifted out from the receiving portion and the axial length is lengthened. Thus, a sufficient fastening force for the guide bar can be obtained, and operability can be improved.

To provide an operation lever including a first lever that has a base end portion swingably supported to a peripheral portion of a nut member for fastening a guide bar in a chain saw, and a second lever that is engaged with the first lever in a manner slidable in an axial direction. The operation lever can be placed in a receiving portion of the nut member with an axial length thereof shortened, and can be manipulated to rotate the nut member by being gripped on an outer end portion of the second lever in a state in which the operation lever is lifted out from the receiving portion and the axial length is lengthened. Thus, a sufficient fastening force for the guide bar can be obtained, and operability can be improved.

A chain saw includes a wheel and a chain plate exposed to a saw casing, a chain trained over the wheel and the plate, and a driving device for driving the wheel. The plate is formed with an elongated slot. A chain tension adjustment mechanism includes a shielding cover disposed between the casing and the plate; a slide element disposed movably between the plate and the shielding cover, has a protrusion extending through the slot in the plate; and a biasing member biasing against the slide element and the shielding cover so as to push the slide element away from the wheel, wherein, movement of the plate toward the wheel against biasing action of the biasing member results in retraction of the biasing member from its initial shape and pressing the slide element toward the wheel, thereby releasing the chain from the plate and the wheel and vice versa.

A chain saw includes a wheel and a chain plate exposed to a saw casing, a chain trained over the wheel and the plate, and a driving device for driving the wheel. The plate is formed with an elongated slot. A chain tension adjustment mechanism includes a shielding cover disposed between the casing and the plate; a slide element disposed movably between the plate and the shielding cover, has a protrusion extending through the slot in the plate; and a biasing member biasing against the slide element and the shielding cover so as to push the slide element away from the wheel, wherein, movement of the plate toward the wheel against biasing action of the biasing member results in retraction of the biasing member from its initial shape and pressing the slide element toward the wheel, thereby releasing the chain from the plate and the wheel and vice versa.