Clearance compensating mechanism, especially for valve drives of internal combustion engines

Claim 2

A clearance compensating mechanism for reciprocating drive linkages, especially for valve drives of internal combustion engines, comprising a cylinder; a piston movably mounted in said cylinder; a pressure chamber adapted to be filled with a liquid medium disposed immediately ahead of said piston; said piston and said cylinder defining a gap therebetween for permitting a minor amount of said medium to leak therethrough; reservoir means adapted to be filled at least partially with said medium; passage means including relief valve means disposed below an inlet to said gap for connecting said reservoir to said pressure chamber; and biasing means for biasing said piston in an outwardly direction with respect to said cylinder; characterized in that the pressure chamber exhibits a continuously increasing throughflow cross-section in an approximately funnel-like manner from the inlet to the gap downward to the passage means and in that the walls of said pressure chamber immediately adjacent the inlet to the gap form a maximum angle of approximately 20* with respect to one another, wherein said biasing means comprises a compression spring supported at a spacing from a wall surface of said piston on pin means extending approximately radially outward from said wall surface.

Claim 3

A mechanism according to claim 1, wherein said relief valve means includes a valve body and cage means for holding said valve body.

Claim 4

A clearance compensating mechanism for reciprocating drive linkages, especially for valve drives of internal combustion engines, comprising a cylinder; a piston movably mounted in said cylinder; a pressure chamber adapted to be filled with a liquid medium disposed immediately ahead of said piston; said piston and said cylinder defining a gap therebetween for permitting a minor amount of said medium to leak therethrough; reservoir means adapted to be filled at least partially with said medium; passage means including relief valve means disposed below an inlet to said gap for connecting said reservoir to said pressure chamber; and biasing means for biasing said piston in an outwardly direction with respect to said cylinder; characterized in that the pressure chamber exhibits a continuously increasing throughflow cross-section in an approximately funnel-like manner from the inlet to the gap downward to the passage means and in that the walls of said pressure chamber immediately adjacent the inlet to the gap form a maximum angle of approximately 20* with respect to one another, characterized in that the cylinder has a substantially constant circular cross-section along its axial direction and in that said piston extends downwardly into said cylinder, the surface of said piston having an uppermost portion of substantially circular cylinder shape which merges into an intermediate portion shaped as a frustrum of a first downwardly pointing cone having a conical angle of between 20* and 40* and said intermediate portion merges into a lowermost portion shaped as a second downwardly pointing cone having a conical angle of between 90* and 120*.

Claim 5

A clearance compensating mechanism for reciprocating drive linkages, especially for valve drives of internal combustion engines, comprising a cylinder; a piston movably mounted in said cylinder; a pressure chamber adapted to be filled with a liquid medium disposed immediately ahead of said piston; said piston and said cylinder defining a gap therebetween for permitting a minor amount of said medium to leak therethrough; reservoir means adapted to be filled at least partially with said medium; passage means including relief valve means disposed below an inlet to said gap for connecting said reservoir to said pressure chamber; and biasing means for biasing said piston in an outwardly direction with respect to said cylinder; characterized in that the pressure chamber exhibits a continuously increasing throughflow cross-section in an approximately funnel-like manner from the inlet to the gap downward to the passage means and in that the walls of said pressure chamber immediately adjacent the inlet to the gap form a maximum angle of approximately 20* with respect to one another, characterized in that the cylinder has a substantially constant circular cross-section along its axial direction and in that said piston extends downwardly into said cylinder, the surface of said piston having an uppermost portion of substantially circular cylinder shape which merges into an intermediate portion shaped as a frustrum of a first downwardly pointing cone having a conical angle of between 20* and 40* and said intermediate portion merges into a lowermost portion shaped as a second downwardly pointing cone having a conical angle of between 90* and 120*.

Claim 6

A mechaniSm according to claim 3, characterized in that the conical angle of said first downwardly pointing cone is approximately 30*.

Claim 7

A mechanism according to claim 3, characterized in that said relief valve comprises a check valve having a movable valve body and a cage for holding the valve body, said cage including a narrow leaf spring extending radially under the valve body.

Claim 8

A mechanism according to claim 3, characterized in that the biasing means includes a compression spring positioned between the bottom of the inside of the cylinder and the piston, said spring being supported at the piston by pins extending radially outwardly from the lowermost portion of the piston.

Claim 9

A mechanism according to claim 3, characterized in that the difference between the maximum and minimum radii of the frustrum of the cone forming the intermediate portion of said piston is approximately 1mm.

Claim 10

A clearance compensating mechanism for reciprocating drive linkages, especially for valve drives of internal combustion engines, comprising a cylinder; a piston movably mounted in said cylinder; a pressure chamber adapted to be filled with a liquid medium disposed immediately ahead of said piston, said piston and said cylinder defining a gap therebetween for permitting a minor amount of said medium to leak therethrough; reservoir means adapted to be filled at least partially with said medium; passage means including relief valve means disposed below an inlet to said gap for connecting said reservoir to said pressure chamber; and biasing means for biasing said piston in an outwardly direction with respect to said cylinder; characterized in that the pressure chamber exhibits a continuously increasing throughflow cross-section in an approximately funnel-like manner from the inlet to the gap downward to the passage means and in that the walls of said pressure chamber immediately adjacent the inlet to the gap form a maximum angle of approximately 20* with respect to one another, characterized in that there is a maximum distance of approximately 1mm between the pressure chamber walls in the area immediately adjacent the inlet to the gap where the maximum angle of 20* between said walls exists.

Claim 11

A clearance compensating mechanism for reciprocating drive linkages, especially for valve drives of internal combustion engines, comprising a cylinder; a piston movably mounted in said cylinder; a pressure chamber adapted to be filled with a liquid medium disposed immediately ahead of said piston, said piston and said cylinder defining a gap therebetween for permitting a minor amount of said medium to leak therethrough; reservoir means adapted to be filled at least partially with said medium; passage means including relief valve means disposed below an inlet to said gap for connecting said reservoir to said pressure chamber; and biasing means for biasing said piston in an outwardly direction with respect to said cylinder; characterized in that the pressure chamber exhibits a continuously increasing throughflow cross-section in an approximately funnel-like manner from the inlet to the gap downward to the passage means and in that the walls of said pressure chamber immediately adjacent the inlet to the gap form a maximum angle of approximately 20* with respect to one another, characterized in that there is a maximum distance of approximately 1mm between the pressure chamber walls in the area immediately adjacent the inlet to the gap where the maximum angle of 20* between said walls exists.