Chain saw starting system

Claim 1

A chain saw operable to be hand held comprising: a cutter chain; an internal combustion engine operably connected to said cutter chain for driving said cutter chain including chain saw cylinder wall means, chain saw cylinder head means closing one end of said chain saw cylinder wall means, chain saw piston means reciprocably mounted in said chain saw cylinder wall means for reciprocation along an axis extending axially of said chain saw cylinder wall means, and a chain saw crankshaft; chain saw stationary hand grip means extending generally longitudinally of the axis of reciprocation of said chain saw piston means and displaced generally longitudinally of said chain saw engine in relation to said axis; chain saw control means including, a chain saw decompression port disposed in a longitudinally intermediate portion of said chain saw cylinder wall and operable, when open, to facilitate starting of said hand held chain saw by providing communication between the atmosphere and the interior of said saw cylinder wall, vent means extending from said chain saw decompression port to the atmosphere, a normally closed, chain saw compression relief valve operable to close said chain saw decompression port, chain saw engine starting conditions control means substantially contiguous with said chain saw hand grip means, and operable to control a starting condition of said chain saw engine, movable means substantially contiguous with said chain saw hand grip means and operable to permit releasable positioning of at least a portion of said chain saw engine starting condition control means in a selected position determining a starting condition of said chain saw engine, linkage means connecting said movable means with said chain saw compression relief valve to hold said chain saw compression relief valve in an open position when said movable means has positioned said portion of said chain saw engine starting condition control means in said chain saw engine starting condition determining position; chain saw throttle controlling trigger means, included in said chain saw starting condition control means, carried by said hand grip means, and mounted generally adjacent said movable means; said linkage means being supported adjacent said chain saw engine and operable to transmit chain saw compression relief valve opening and closing force from said movable means to said chain saw compression relief valve in said chain saw cylinder wall means, said linkage means including, an arm having a first end connected to an outer end portion of said compression relief valve and a second end connected to said movable means, and a pivot positioned between said first end and said second end; said arm being dimensioned with respect to said pivot such that a mechanical advantage is achieved by said second end connected to said movable means with respect to said first end connected to said compression relief valve whereby an opeRator may readily operatively manipulate said movable means and thus open and close said compression relief valve; said chain saw decompression port being spaced from said chain saw cylinder head means and operable to be covered by said chain saw piston means during reciprocating movement of said chain saw piston means toward said chain saw cylinder head mean; said chain saw hand grip means, engine starting condition control means, and movable means, at least in part, being generally mutually contiguous, located in generally longitudinally displaced relation from said chain saw crankshaft with respect to said axis of piston means reciprocation and operable to facilitate simultaneous manual holding and starting of said chain saw; said chain saw hand grip means being operable to permit manual support of said chain saw, with an operator engaging said movable means and concurrently positioning at least said portion of said chain saw engine starting condition control means in said starting condition determining position and said chain saw compression relief valve in said open position, and with said chain saw engine extending away from said operator along said axis of piston means reciprocation; and said movable means and said chain saw throttle controlling trigger means being positionally related on said stationary chain saw hand grip means so as to permit said operator, with one hand and without releasing said chain saw hand grip means, to grip and at least partially encircle a portion of said stationary hand grip means, to actuate said movable means, and to actuate said chain saw throttle controlling trigger means with a single digit member of said one hand; said chain saw engine being operable to be started with the interior of said chain saw cylinder wall means being cyclically and alternately, place in communication with said atmosphere through said vent means and isolated from said atmosphere in response to reciprocation of said chain saw piston means.

Claim 3

A method of starting and operating a portable chain saw of the type including a cutter chain, an internal combustion chain saw engine operatively connected to said cutter chain, and a stationary hand grip positioned generally longitudinally extending with respect to a cylinder of said chain saw engine, said method comprising: gripping a portion of said hand grip means of the portable chain saw with one hand; while gripping said portion of said chain saw hand grip means with said one hand, manipulating movable means mounted on said portion of said chain saw hand grip means to concurrently provide and maintain a starting condition in at least a portion of an engine of said chain saw, and reduce the compression level in a combustion chamber of said engine; effecting said reduction of pressure in response to said manipulating which conditions at least said portion of said chain saw engine for starting including the steps of, opening a compression relief valve positioned into said combustion chamber by, actuating a lever connected with a mechanical advantage through a fulcrum to the compression relief valve; while gripping said portion of said hand grip means of said chain saw, maintaining said reduced engine compression and starting said chain saw engine; and after said starting said chain saw engine, and while continuing to grip said portion of said hand grip means of said chain saw with said one hand, causing said movable means to move to a release position and concurrently terminating the maintenance of said chain saw engine starting condition, and increasing the compression in said combustion chamber of said chain saw engine; and with said one hand, operating a throttle of said chain saw on said hand grip means generally adjacent said movable means, while continuing to grip said portion of said chain saw hand grip means with said one hand.

Claim 4

A method of starting and operating a portable chain saw of the type including a cutter chain, an internal combustion chain saw engine operatively connected to said cutter chain, and a stationary hand grip positioned generally longitudinally extending with respect to a cylinder of said chain saw engine, said method comprising: gripping a portion of said hand grip means of the portable chain saw with one hand; while gripping said portion of said chain saw hand grip means with said one hand, manipulating movable means mounted on said portion of said chain saw hand grip means to concurrently provide and maintain a starting condition in at least a portion of an engine of said chain saw, and reduce the compression level in a combustion chamber of said engine; effecting said reduction of pressure in response to said manipulating which conditions at least said portion of said chain saw engine for starting including the steps of, opening a compression relief valve positioned into said combustion chamber by, actuating a lever connected with a mechanical advantage through a fulcrum to the compression relief valve; while gripping said portion of said hand grip means of said chain saw, maintaining said reduced engine compression and starting said chain saw engine; and after said starting said chain saw engine, and while continuing to grip said portion of said hand grip means of said chain saw with said one hand, causing said movable means to move to a release position and concurrently terminating the maintenance of said chain saw engine starting condition, and increasing the compression in said combustion chamber of said chain saw engine; and with said one hand, operating a throttle of said chain saw on said hand grip means generally adjacent said movable means, while continuing to grip said portion of said chain saw hand grip means with said one hand.