Automatic compression relief mechanism

Claim 2

An engine having a combustion chamber with a port therein, and having a camshaft with a gear thereon, and a compression relief member carried by the camshaft to normally effect momentary unseating of a valve and opening of said port for the relief of compression in the combustion chamber once each revolution of the camshaft, characterized by: A. means mounting the compression relief member on the exterior of the camshaft for guided motion lengthwise of the camshaft axis, between a normally operative valve unseating position and an inoperative position at which it has no effect upon said valve; B. a centrifugally responsive control member mounted on said gear for back and forth motion between defined limits, along a path substantially normal to the camshaft axis; C. spring means to hold the control member in one of said limits whenever the camshaft is rotated at less than a normal enginerunning speed, said spring means being yieldable to permit movement of the control member toward the other of said limits in response to centrifugal force thereon during acceleration of the camshaft to engine-running speeds; D. and cam means for translating movement of the control member toward said other limit of motion thereof into movement of the relief member toward its inoperative position, comprising 1. an abutment on said relief member, 2. and a fin on the control member extending crosswise of the camshaft and lengthwise alongside said abutment.

Claim 3

and a fin on the control member extending crosswise of the camshaft and lengthwise alongside said abutment.

Claim 4

and a fin on the control member extending crosswise of the camshaft and lengthwise alongside said abutment.

Claim 5

The engine of claim 1, wherein: A. a notch in the relief member, opening away from the camshaft, defines a pair of opposing abutments spaced apart in the direction of the camshaft axis, B. and said fin being engaged in said notch and being cooperable with each of said abutments to move the relief member back and forth between its operative and inoperative positions in consequence of back and forth movement of the control member.

Claim 6

and an elongated part on the control member which extends across the camshaft and over the valve-actuating member, said part having a surface thereon which is skewed out of normal with respect to the camshaft axis and which engages with said abutment to effect motion of the valve actuating member out of its operative position in consequence of movement of the control member in said one direction.

Claim 7

and an elongated part on the control member which extends across the camshaft and over the valve-actuating member, said part having a surface thereon which is skewed out of normal with respect to the camshaft axis and which engages with said abutment to effect motion of the valve actuating member out of its operative position in consequence of movement of the control member in said one direction.

Claim 8

The engine of claim 2, further characterized by: A. pivot means mounting the control member on the camshaft gear for back-and-forth swinging movement about an axis parallel to that of the camshaft and at the side thereof remote from the relief member; B. a stop member on the camshaft gear engageable by the control member to Define said one of its limits, said stop member being located at the opposite side of the camshaft and alongside said fin; C. and cooperating surfaces on the stop member and the camshaft gear, between which a portion of the fin is engaged to guide the movement of that part of the control member which is remote from the pivot means.

Claim 9

An engine having a combustion chamber with a valve controlled port therein, and having compression relief means on its camshaft operable during each revolution thereof at engine starting speeds to effect momentary unseating of said valve and opening of said port for the relief of compression in the combustion chamber so as to thereby facilitate cranking of the engine, said compression relief means being characterized by: A. a centrifugally responsive control member which is caused to move in one direction relative to the camshaft in consequence of acceleration of the camshaft to engine-running speeds; B. a valve-actuating member which is supported for bodily motion relative to the camshaft toward and from an operative valve unseating position along a path extending lengthwise of the camshaft axis; C. and cooperating cam means on said members operable to translate centrifugally produced movement of the control member into motion of the valve-actuating member out of its operative position, comprising

Claim 10

An engine having a combustion chamber with a valve controlled port therein, and having compression relief means on its camshaft operable during each revolution thereof at engine starting speeds to effect momentary unseating of said valve and opening of said port for the relief of compression in the combustion chamber so as to thereby facilitate cranking of the engine, said compression relief means being characterized by: A. a centrifugally responsive control member which is caused to move in one direction relative to the camshaft in consequence of acceleration of the camshaft to engine-running speeds; B. a valve-actuating member which is supported for bodily motion relative to the camshaft toward and from an operative valve unseating position along a path extending lengthwise of the camshaft axis; C. and cooperating cam means on said members operable to translate centrifugally produced movement of the control member into motion of the valve-actuating member out of its operative position, comprising

Claim 11

An internal combustion engine having a centrifugally responsive control member on its camshaft which is yieldingly urged toward a first position maintaining a compression relief member in an operative position effecting momentary unseating of an engine valve during each revolution of the camshaft at engine cranking speeds, and which control member is movable to a second position under the influence of centrifugal force thereon in consequence of rotation of the camshaft at higher speeds, to thereby render the relief member inoperative, characterized by: A. a gear on the camshaft by which the latter is driven from the engine crankshaft; B. means mounting the control member on said gear for back-and-forth motion along a path substantially normal to the camshaft axis; C. cooperating means on the gear and on the control member defining said first and second position of the control member; D. means mounting the compression relief member on the exterior of the camshaft for guided motion lengthwise of the camshaft axis, toward and from said operative position of the relief member; E. a notch in the relief member, opening outwardly away from the camshaft and defining opposing abutments with surfaces generally transverse to the camshaft axis; F. an elongated fin on the control member extending lengthwise of said path and in substantially tangential relation to the camshaft throughout the permitted range of control member movement, said fin being received in said notch and engaging the abutments defined thereby so as to provide cooperating cam means through which force is imposed upon the relief member to produce translatory motion thereof toward and from its operative position in consequence of movement of the centrifugally responsive control member between said first and second positions thereof; G. and said fin overlying the bottom of the notch in the relief member to hold the same against displacement from the exterior of the camshaft.

Claim 12

An internal combustion engine having a centrifugally responsive control member on its camshaft which is yieldingly urged toward a first position maintaining a compression relief member in an operative position effecting momentary unseating of an engine valve during each revolution of the camshaft at engine cranking speeds, and which control member is movable to a second position under the influence of centrifugal force thereon in consequence of rotation of the camshaft at higher speeds, to thereby render the relief member inoperative, characterized by: A. a gear on the camshaft by which the latter is driven from the engine crankshaft; B. means mounting the control member on said gear for back-and-forth motion along a path substantially normal to the camshaft axis; C. cooperating means on the gear and on the control member defining said first and second position of the control member; D. means mounting the compression relief member on the exterior of the camshaft for guided motion lengthwise of the camshaft axis, toward and from said operative position of the relief member; E. a notch in the relief member, opening outwardly away from the camshaft and defining opposing abutments with surfaces generally transverse to the camshaft axis; F. an elongated fin on the control member extending lengthwise of said path and in substantially tangential relation to the camshaft throughout the permitted range of control member movement, said fin being received in said notch and engaging the abutments defined thereby so as to provide cooperating cam means through which force is imposed upon the relief member to produce translatory motion thereof toward and from its operative position in consequence of movement of the centrifugally responsive control member between said first and second positions thereof; G. and said fin overlying the bottom of the notch in the relief member to hold the same against displacement from the exterior of the camshaft.

Claim 13

An engine having a combustion chamber with a valve-controlled port therein, and having compression relief means on its camshaft operable during each revolution thereof at engine starting speeds to effect momentary unseating of said valve and opening of said port for the relief of compression in the combustion chamber so as to thereby facilitate cranking of the engine, said compression relief means being characterized by: A. a centrifugally responsive control member; B. means supporting the control member from the camshaft for rotation therewith and for rocking motion relative thereto about an axis fixed with respect to the camshaft and parallel thereto, so as to provide for rocking of the control member in one direction as a consequence of acceleration of the camshaft to engine-running speeds; C. a valve-actuating member separate from but adjacent to the control member; D. means supporting the valve-actuating member on the exterior of the camshaft for guided bodily motion relative to the camshaft and to the control member, toward and from an operative valve unseating position along a path which is parallel to the camshaft axis; E. and cooperating cam means on said control and valve-actuating members operable to translate centrifugally produced motion of the control member in said direction into motion of the valve-actuating member out of its operative position.

Claim 14

An engine having a combustion chamber with a valve-controlled port therein, and having compression relief means on its camshaft operable during each revolution thereof at engine starting speeds to effect momentary unseating of said valve and opening of said port for the relief of compression in the combustion chamber so as to thereby facilitate cranking of the engine, said compression relief means being characterized by: A. a centrifugally responsive control member; B. means supporting the control member from the camshaft for rotation therewith and for rocking motion relative thereto about an axis fixed with respect to the camshaft and parallel thereto, so as to provide for rocking of the control member in one direction as a consequence of acceleration of the camshaft to engine-running speeds; C. a valve-actuating member separate from but adjacent to the control member; D. means supporting the valve-actuating member on the exterior of the camshaft for guided bodily motion relative to the camshaft and to the control member, toward and from an operative valve unseating position along a path which is parallel to the camshaft axis; E. and cooperating cam means on said control and valve-actuating members operable to translate centrifugally produced motion of the control member in said direction into motion of the valve-actuating member out of its operative position.