A chain saw unit has a sub-frame defining a plurality of mount locations and a plurality of operating components amongst which are at least: a) a battery operated motor; and b) a battery for operating the motor. The plurality of operating components is each operatively placed and maintained at one of the mount locations such that the sub-frame assembly and operatively placed operating components together make up at least part of a main operating unit to which a chain bar and cutting chain can be operatively assembled. The main operating unit has an exposed surface area. An outer housing assembly overlies the exposed surface area and defines an outermost exposed surface. The plurality of operating components are operatively maintained on the sub-frame assembly independently of the outer housing assembly.

A chain saw kit having a sub-frame assembly and a plurality of operating components, among which are 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, among which are 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 saw apparatus includes a guide bar, a chain driver, and an endless cutting chain trained about the guide bar and the chain driver. A hydraulic chain tensioning apparatus has a hydraulic actuator configured to be driven by a hydraulic power source to act against the guide bar to maintain tension in the cutting chain. A tension release valve is provided between the hydraulic power source and the hydraulic actuator. The tension release valve has a check valve, and a manual override press-button configured to maintain the check valve in an open condition while depressed. The tension release valve has a spring detent configured to maintain the manual override press-button in a depressed condition until selectively released.

A saw apparatus includes a guide bar, a chain driver, and an endless cutting chain trained about the guide bar and the chain driver. A hydraulic chain tensioning apparatus has a hydraulic actuator configured to be driven by a hydraulic power source to act against the guide bar to maintain tension in the cutting chain. A tension release valve is provided between the hydraulic power source and the hydraulic actuator. The tension release valve has a check valve, and a manual override press-button configured to maintain the check valve in an open condition while depressed. The tension release valve has a spring detent configured to maintain the manual override press-button in a depressed condition until selectively released.

A power tool has a sprocket wheel cover mounted on a housing and a guide bar secured between housing and sprocket wheel cover and having a guide groove for a saw chain. The guide bar has a guide slot extending in a longitudinal direction of the guide bar and guiding the guide bar on a guide element for longitudinal movement relative to the housing. The guide bar has a first exterior side extending in a first plane and facing the housing and a second exterior side extending in a second plane and facing the sprocket wheel cover. The guide bar has an oil supply opening extending from the second exterior side into the guide groove and connected by an oil supply channel with an oil supply device. The oil supply channel has a channel section separate from the guide bar and extending from the first to the second plane.

A power tool has a sprocket wheel cover mounted on a housing and a guide bar secured between housing and sprocket wheel cover and having a guide groove for a saw chain. The guide bar has a guide slot extending in a longitudinal direction of the guide bar and guiding the guide bar on a guide element for longitudinal movement relative to the housing. The guide bar has a first exterior side extending in a first plane and facing the housing and a second exterior side extending in a second plane and facing the sprocket wheel cover. The guide bar has an oil supply opening extending from the second exterior side into the guide groove and connected by an oil supply channel with an oil supply device. The oil supply channel has a channel section separate from the guide bar and extending from the first to the second plane.

A handheld work apparatus has a guide bar having a periphery along which a chain runs. The work apparatus has a housing and a fastening arrangement for fixing the guide bar to the housing. The fastening arrangement has an actuating device which can be actuated in a fastening direction in order to fix the guide bar. The work apparatus has a tensioning device to tension the chain. The tensioning device includes a tensioning spring. When the fastening arrangement is loosened, the tensioning spring exerts a force in a tensioning direction of the chain on the guide bar. Simple operation and a simple construction are achieved if the tensioning spring is in operative connection with the actuating device and is tensioned during actuation of the actuating device in the fastening direction.

A handheld work apparatus has a guide bar having a periphery along which a chain runs. The work apparatus has a housing and a fastening arrangement for fixing the guide bar to the housing. The fastening arrangement has an actuating device which can be actuated in a fastening direction in order to fix the guide bar. The work apparatus has a tensioning device to tension the chain. The tensioning device includes a tensioning spring. When the fastening arrangement is loosened, the tensioning spring exerts a force in a tensioning direction of the chain on the guide bar. Simple operation and a simple construction are achieved if the tensioning spring is in operative connection with the actuating device and is tensioned during actuation of the actuating device in the fastening direction.

A chain saw unit has a sub-frame defining a plurality of mount locations and a plurality of operating components including at least: a) a battery operated motor; and b) a battery for operating the motor. The plurality of operating components is each operatively placed and maintained at one of the mount locations such that the sub-frame assembly and operatively placed operating components together make up at least part of a main operating unit to which a chain bar and cutting chain can be operatively assembled. The main operating unit has an exposed surface area. An outer housing assembly overlies the exposed surface area and defines an outermost exposed surface. The plurality of operating, components are operatively maintained on the sub-frame assembly independently of the outer housing assembly.