Valve actuating apparatus utilizing a multi-profiled cam unit for controlling internal combustion engines

Claim 2

Apparatus for operating a reciprocable valve member for opening and closing a valve port in communication with a combustion chamber of an internal combustion engine comprising a first rocker arm, means mounting one end of said first rocker arm for pivotal movement about one axis so that a portion of said first rocker arm is engageable with said valve member, a second rocker arm, means mounting one end of said second rocker arm for pivotal movement about a second axis relatively movable with respect to said first axis, a portion of said second rocker arm being engageable with longitudinal portions of said first rocker arm, a camshaft, first and second cam means on said camshaft, said second rocker arm having a first longitudinal portion engageable by said first cam means and a second longitudinal portion engageable by said second cam means, said first and second longitudinal portions being fixedly related with respect to each other, said first and second cam means having respective profiles and said first and second longitudinal portions having respective follower configurations so that said first cam means coacts with points along said first longitudinal portion to provide a first operating mode of said valve member, in which said valve member remains closed, and said second cam means coacts with points along said second longitudinal portion to provide a second operating mode of said valve member, in which said valve member is opened and closed, the distance between said pivotal axes causing said modes to vary in relation to each other.

Claim 3

Apparatus for operating a reciprocable valve member in accordance with claim 1 in which said first pivotal axis is fixed and said second pivotal axis is shiftable relative to said first axis.

Claim 4

Apparatus for operating a reciprocable valve member in accordance with claim 2 in which said first cam means includes a base circle portion and an eccentric portion, and in which said first longitudinal portion constitutes a linear or straight line section.

Claim 5

Apparatus for operating a reciprocable valve member in accordance with claim 3 in which said second cam means has a base circle portion and a lobe portion, said lobe portion projecting radially beyond said eccentric portion, and in which said second longitudinal portion engageable by said second cam means includes a substantially straight section and a curved section, said curved section being nearer said second pivotal axis.

Claim 6

Apparatus for operating a reciprocable valve member in accordance with claim 4 including third cam means having a base circle portion and a lobe portion, the lobe portion of said third cam means extending radially to a greater extent than the lobe portion of said second cam means, and said second rocker arm having a third longitudinal portion engageable at points therealong by said third cam means, said third longitudinal portion having a straight section and a curved section, the curved section of said third longitudinal portion being spaced nearer said second pivotal axis than the curved portion of said second longitudinal portion.

Claim 7

Apparatus for operating a reciprocable valve member in accordance with claim 5 in which said first, second and third cam means constitute a single cam unit.

Claim 8

Apparatus for operating a rciprocable valve member in accordance with claim 6 in which the center of said eccentric portion and said lobe portions are angularly aligned with each other.

Claim 9

Apparatus for operating a reciprocable valve member in accordance with claim 7 including pivotal arm means and shaft means carried on said pivotal arm means, said shaft means providing said second pivotal axis.

Claim 10

Apparatus for operating a reciprocable valve member in accordance with claim 8 in which said first rocker arm has a curved ramp portion, the free end of said second rocker arm being engageable with the curved ramp portion of said first rocker arm.

Claim 11

Apparatus for operating a reciprocable valve member for opening and closing a valve port in communication with a combustion chamber of an internal combustion engine comprising movable means engageable with said valve member, said means having a non-linear ramp surface, a rocker arm engageable with said non-linear ramp surface, means mounting said rocker arm for pivotal movement about one end thereof, said mounting means bing shiftable so that the free end of said rocker arm engages selected portions of said non-linear ramp surface, and means forming a plurality of cam follower surfaces on said rocker arm, one of said follower surfaces constituting a straight line section, a second of said follower surfaces including a straight line section and a curved section, and a third of said follower surfaces including a straight section and a curved section, said last-mentioned curved section being nearer said mounting means than said first-mentioned curved section, a first cam member engageable with said one follower surface and having a base circle portion and an eccentric portion, said eccentric portion having a slightly larger radius than said base circle portion, a second cam engageable with said second follower surface and having a base circle portion and a lobe portion, said lobe portion projecting radially beyond the eccentric portion of said first cam member, and a third cam member engageable with said third follower surface and having a base circle portion and a lobe portion, the lobe portion of said third cam projecting radially beyond the lobe portion of said second cam.

Claim 12

Apparatus for operating a reciprocable valve member for opening and closing a valve port in communication with a combustion chamber of an internal combustion engine comprising movable means engageable with said valve member, said means having a non-linear ramp surface, a rocker arm engageable with said non-linear ramp surface, means mounting said rocker arm for pivotal movement about one end thereof, said mounting means bing shiftable so that the free end of said rocker arm engages selected portions of said non-linear ramp surface, and means forming a plurality of cam follower surfaces on said rocker arm, one of said follower surfaces constituting a straight line section, a second of said follower surfaces including a straight line section and a curved section, and a third of said follower surfaces including a straight section and a curved section, said last-mentioned curved section being nearer said mounting means than said first-mentioned curved section, a first cam member engageable with said one follower surface and having a base circle portion and an eccentric portion, said eccentric portion having a slightly larger radius than said base circle portion, a second cam engageable with said second follower surface and having a base circle portion and a lobe portion, said lobe portion projecting radially beyond the eccentric portion of said first cam member, and a third cam member engageable with said third follower surface and having a base circle portion and a lobe portion, the lobe portion of said third cam projecting radially beyond the lobe portion of said second cam.

Claim 13

Apparatus for operating a reciprocable valve member in accordance with claim 10 in which said first means constitutes a second rocker arm, said second rocker arm being pivotal about a fixed axis, and said mounting means for said first rocker arm providing a shiftable axis.

Claim 14

Apparatus for operating a reciprocable valve member in accordance with claim 11 including pivotal arm means, said first rocker arm being pivotally mounted at one end to said arm means, pivotal movement of said arm means providing said shiftable axis.

Claim 15

Apparatus for operating a reciprocable valve member in accordance with claim 12 in which said pivotal arm means is actuated in accordance with a desired operating mode for said internal combustion engine, the position of said first rocker arm with respect to said second rocker arm determining the time at which said valve member opens and closes and also the amount of lift of said valve member.

Claim 16

Apparatus for operating a reciprocable valve means associated with the combustion chamber of an internal combustion engine, said valve means having at least a certain amount of lash, the apparatus comprising first rotatable cam means having a base circle portion and an eccentric portion, said eccentric portion sloping radially outward from said base circle portion a distance corresponding generally to said amount of lash, said base circle and eccentric portions successively engaging said valve means as said first cam means rotates, second rotatable cam means having a lobe portion projecting radially outward a greater distance than said eccentric portion, said lobe portion also engaging said valve means as said second cam means rotates, and follower means engageable by said first and second cam means for transmitting motion from said first and second cam means to said valve means, said follower means including a shiftable stepped rocker arm formed with a first longitudinal portion having a straight section engageable by said first rotatable cam means at various points therealong depending on the position of said rocker arm relative to said first cam means and said rocker arm being formed with a second longitudinal portion having a curved section engageable by said second cam means at various points therealong depending on the position of said rocker arm relative to said second cam means, said first and second longitudinal portions being fixedly disposed relative to each other and moved in unison when said rocker arm is shifted relative to said first and second cam means.

Claim 17

Apparatus for operating a reciprocable valve means associated with the combustion chamber of an internal combustion engine, said valve means having at least a certain amount of lash, the apparatus comprising first rotatable cam means having a base circle portion and an eccentric portion, said eccentric portion sloping radially outward from said base circle portion a distance corresponding generally to said amount of lash, said base circle and eccentric portions successively engaging said valve means as said first cam means rotates, second rotatable cam means having a lobe portion projecting radially outward a greater distance than said eccentric portion, said lobe portion also engaging said valve means as said second cam means rotates, and follower means engageable by said first and second cam means for transmitting motion from said first and second cam means to said valve means, said follower means including a shiftable stepped rocker arm formed with a first longitudinal portion having a straight section engageable by said first rotatable cam means at various points therealong depending on the position of said rocker arm relative to said first cam means and said rocker arm being formed with a second longitudinal portion having a curved section engageable by said second cam means at various points therealong depending on the position of said rocker arm relative to said second cam means, said first and second longitudinal portions being fixedly disposed relative to each other and moved in unison when said rocker arm is shifted relative to said first and second cam means.

Claim 18

Apparatus for operating a reciprocable valve member in accordance with claim 14 in which said second cam means also has a base circle portion having the same radius as the base circle portion of said first cam means.

Claim 19

Apparatus for operating a reciprocable valve member in accordance with claim 14 in which said valve means includes a lash cap.

Claim 20

Apparatus for operating reciprocable valve means in accordance with claim 14 in which said valve means includes a valve member and a spring member biasing said valve member in the direction of said follower means, said base circle portion and said eccentric portion on said first cam means acting on said follower means so that said valve member prevents gaseous flow to or from said combustion chamber, said lobe portion on said second cam means acting on said follower means to cause said valve member to open and thus permit gaseous flow to or from said combustion chamber.

Claim 21

Apparatus for operating reciprocable valve means associated with the combustion chamber of an internal combustion engine, said valve means having at least a certain amount of lash, the apparatus comprising a camshaft rotatable about a given axis, a cam unit on said camshaft, said cam unit including a first cam having a base circle portion and an eccentric portion and a second cam having a base circle portion and a lobe portion, said lobe portion projecting a greater radial distance from said camshaft axis than said base circle portion, a rocker arm having a first follower portion engageable by the base circle portion and the eccentric portion of said first cam and a second follower portion engageable by the base circle portion and the lobe portion of said second cam, the follower portion engageable by the portions of said first cam being generally linear and the follower portion engageable by the portions of said second cam including a linear section and a nonlinear section, means mounting said rocker arm for pivotal movement, and means for shifting said mounting means and said rocker arm with respect to said valve means and with respect to said camshaft axis so as to render said first cam effectual in one shifted position so that said valve means remains closed and to render said second cam means effectual in a second shifted position so that said valve means is opened by the lobe portion of said second cam.

Claim 22

Apparatus for operating reciprocable valve means associated with the combustion chamber of an internal combustion engine, said valve means having at least a certain amount of lash, the apparatus comprising a camshaft rotatable about a given axis, a cam unit on said camshaft, said cam unit including a first cam having a base circle portion and an eccentric portion and a second cam having a base circle portion and a lobe portion, said lobe portion projecting a greater radial distance from said camshaft axis than said base circle portion, a rocker arm having a first follower portion engageable by the base circle portion and the eccentric portion of said first cam and a second follower portion engageable by the base circle portion and the lobe portion of said second cam, the follower portion engageable by the portions of said first cam being generally linear and the follower portion engageable by the portions of said second cam including a linear section and a nonlinear section, means mounting said rocker arm for pivotal movement, and means for shifting said mounting means and said rocker arm with respect to said valve means and with respect to said camshaft axis so as to render said first cam effectual in one shifted position so that said valve means remains closed and to render said second cam means effectual in a second shifted position so that said valve means is opened by the lobe portion of said second cam.

Claim 23

Apparatus for operating reciprocable valve means in accordance with claim 18 in which said shifting means includes an accelerator pedal for shifting said rocker arm.

Claim 24

Apparatus for operating reciprocable valve means in accordance with claim 19 in which said shifting means additionally includes a hydraulic amplifier, said accelerator pedal controlling said hydraulic amplifier.