US4083334A — Hydraulic valve lifter

Claim 1

Independent Claim 392 words

In an hydraulic valve lifter comprising a body having an external generally cylindrical shape and an interior wall defining a cylindrical cavity extending from an open end of the said body to a closed end thereof, and including a first cross port between the outer and inner surfaces of the body and leading into an oil reservoir within the body; a plunger assembled within said body for reciprocation therein and having an outer generally cylindrical shape which fits with a very small clearance within the inner surface of said body, the interior of the plunger defining an oil reservoir, a second cross port between the outer and inner surfaces of said plunger communicating with the first cross port; a check valve mounted within the bottom portion of said plunger so as to allow the flow of oil from the plunger reservoir to the reservoir in said body but prevents the opposite flow; the combination of a separately constructed pushrod socket which is force-fitted into said plunger, said socket being of cylindrical shape and having two diameters above the plunger, of which the larger upper one fits with a very small clearance against the inner surface of said body, and the smaller lower one defines with the inner surface of said body an annular zone; a first groove formed in the inner surface of said body which through the first said port communicates with the exterior of said body; a second groove formed in the outer surface of said plunger which through said second port communicates with the said plunger reservoir and is located at such a height that in any relative position of said plunger and body said second groove of the plunger always overlaps said first groove of said body; a transverse bore in said pushrod socket which communicates with a central axial hole of the socket but does not directly communicate with the plunger reservoir, said transverse bore communicating also with the said annular zone and allowing the free flow of oil from the said annular zone to the axial hole of the socket; there being an hydraulic connection between the first port of said body and the axial hole of the socket through said first groove, through said annular zone, and through said transverse bore of the socket, whereby the hydraulic resistance concentrates almost exclusively in said annular zone.

Claim 2

Dependent Claim 392 words

In an hydraulic valve lifter comprising a body having an external generally cylindrical shape and an interior wall defining a cylindrical cavity extending from an open end of the said body to a closed end thereof, and including a first cross port between the outer and inner surfaces of the body and leading into an oil reservoir within the body; a plunger assembled within said body for reciprocation therein and having an outer generally cylindrical shape which fits with a very small clearance within the inner surface of said body, the interior of the plunger defining an oil reservoir, a second cross port between the outer and inner surfaces of said plunger communicating with the first cross port; a check valve mounted within the bottom portion of said plunger so as to allow the flow of oil from the plunger reservoir to the reservoir in said body but prevents the opposite flow; the combination of a separately constructed pushrod socket which is force-fitted into said plunger, said socket being of cylindrical shape and having two diameters above the plunger, of which the larger upper one fits with a very small clearance against the inner surface of said body, and the smaller lower one defines with the inner surface of said body an annular zone; a first groove formed in the inner surface of said body which through the first said port communicates with the exterior of said body; a second groove formed in the outer surface of said plunger which through said second port communicates with the said plunger reservoir and is located at such a height that in any relative position of said plunger and body said second groove of the plunger always overlaps said first groove of said body; a transverse bore in said pushrod socket which communicates with a central axial hole of the socket but does not directly communicate with the plunger reservoir, said transverse bore communicating also with the said annular zone and allowing the free flow of oil from the said annular zone to the axial hole of the socket; there being an hydraulic connection between the first port of said body and the axial hole of the socket through said first groove, through said annular zone, and through said transverse bore of the socket, whereby the hydraulic resistance concentrates almost exclusively in said annular zone.

Claim 3

Dependent Claim 48 words

A valve lifter according to claim 1, wherein the socket is press-fitted in said plunger by way of its bottom section of smallest diameter in order to prevent the plunger from rotating against the body, whereby a constant average leakdown rate of said hydraulic valve lifter is provided.

Claim 4

Dependent Claim 46 words

A valve lifter according to claim 1, wherein the outer surfaces of the top portion of the socket of largest diameter and the outer surface of the plunger are concentric to such an extent as to prevent any material non-axial positioning between them and the body.

Claim 5

Dependent Claim 236 words

In a hydraulic valve lifter, the combination of a body having a cylindrical inner surface and closed at its bottom end, a plunger within the body having a valve-controlled lower end and an open upper end, a socket formed of three sections of progressively decreasing diameters from the top to the bottom thereof, said socket being force-fitted into the open end portion of the plunger by way of its lowest section, thereby providing an annular passageway for oil about its intermediate section, a transverse bore in the intermediate section of the socket communicating with the annular passageway, said socket having a seat for a hollow pushrod and provided with a central vertical hole communicating with the transverse bore, an oil inlet port through the body and a registering port in the plunger for charging oil into the interior of the plunger, the top section of the socket and the plunger being ground concentrically with respect to each other and to the inner surface of the body, the clearance between the plunger and body being about 6 to 9 microns and the clearance between the top socket section and the body being of the same order, whereby the socket and plunger on the one hand and the body on the other are maintained constantly in substantial axial alignment whereby the leakdown rate between the plunger and body is maintained substantially constant for all positions of the plunger.

Claim 6

Dependent Claim 236 words

In a hydraulic valve lifter, the combination of a body having a cylindrical inner surface and closed at its bottom end, a plunger within the body having a valve-controlled lower end and an open upper end, a socket formed of three sections of progressively decreasing diameters from the top to the bottom thereof, said socket being force-fitted into the open end portion of the plunger by way of its lowest section, thereby providing an annular passageway for oil about its intermediate section, a transverse bore in the intermediate section of the socket communicating with the annular passageway, said socket having a seat for a hollow pushrod and provided with a central vertical hole communicating with the transverse bore, an oil inlet port through the body and a registering port in the plunger for charging oil into the interior of the plunger, the top section of the socket and the plunger being ground concentrically with respect to each other and to the inner surface of the body, the clearance between the plunger and body being about 6 to 9 microns and the clearance between the top socket section and the body being of the same order, whereby the socket and plunger on the one hand and the body on the other are maintained constantly in substantial axial alignment whereby the leakdown rate between the plunger and body is maintained substantially constant for all positions of the plunger.

Claim 7

Dependent Claim 33 words

A hydraulic valve lifter according to claim 4, wherein the annular passageway about the intermediate section of the socket extends for a distance of about 11/2 to 4 mm. above the transverse bore.

Claim 8

Dependent Claim 56 words

A hydraulic valve lifter according to claim 4, wherein the shoulder formed between the intermediate and bottom sections of the socket extends below a shoulder on the inner surface of the body and defines the lower edge of the portion of the body surface forming with the intermediate section of the socket the aforementioned annular passageway.

Claim 9

Dependent Claim 25 words

A hydraulic valve lifter according to claim 6, wherein the annular passageway extends for a distance of 11/2 to 4 mm. above the transverse bore.

Claim 10

Dependent Claim 47 words

A hydraulic valve lifter according to claim 4, wherein the inner surface of the body facing the socket sections above the plunger is devoid of an annular collecting groove, whereby the oil flowing upwardly through the annular passageway flows directly into the transverse bore of the socket.

Claim 11

Dependent Claim 195 words

In a hydraulic valve tappet comprising a body having a port for entry of oil under pressure, and a socket and hollow plunger arranged for reciprocating movement relative to the body as the engine valve is opened and closed, the socket provided with a seat for supporting a hollow push rod having a port at its bottom which is in communication with a vertical bore in the socket, said socket having a transverse bore communicating with the vertical bore, the plunger having a port communicating with the first port for charging oil into the interior of the plunger, the provision of a socket having a lower section of reduced diameter compared to the diameter of the upper section of the socket, said reduced diameter extending at least to the said transverse bore, said reduced socket diameter forming with the facing wall of the body an annular passageway providing a clearance substantially greater than that about the upper socket section, both said body and said socket being devoid of an annular collecting groove in the vicinity of the transverse bore and communicating directly herewith, so that the oil flows directly from said passageway into said bore.

Claim 12

Dependent Claim 195 words

In a hydraulic valve tappet comprising a body having a port for entry of oil under pressure, and a socket and hollow plunger arranged for reciprocating movement relative to the body as the engine valve is opened and closed, the socket provided with a seat for supporting a hollow push rod having a port at its bottom which is in communication with a vertical bore in the socket, said socket having a transverse bore communicating with the vertical bore, the plunger having a port communicating with the first port for charging oil into the interior of the plunger, the provision of a socket having a lower section of reduced diameter compared to the diameter of the upper section of the socket, said reduced diameter extending at least to the said transverse bore, said reduced socket diameter forming with the facing wall of the body an annular passageway providing a clearance substantially greater than that about the upper socket section, both said body and said socket being devoid of an annular collecting groove in the vicinity of the transverse bore and communicating directly herewith, so that the oil flows directly from said passageway into said bore.

Claim 13

Dependent Claim 56 words

A hydraulic tappet according to claim 9, wherein the clearance about the upper section of the socket is of the order of 6 to 14 microns, while the clearance about the lower, reduced section of the socket is of the order of 50 to 60 microns, while that about the plunger is 6 to 9 microns.

Claim 14

Dependent Claim 86 words

A hydraulic tappet according to claim 9, wherein the socket and plunger are force-fitted together and their outer surfaces ground concentrically whereby substantial coincidence of the central longitudinal axes of the inner wall of the body and of the socket; plunger member is maintained, and the oil flow through the annular passageway is continuously of tubular form and of substantially uniform radial thickness, while the median leakdown rate about the plunger is maintained substantially constant in all positions of the socket-plunger member relative to the body.

Claim 15

Dependent Claim 176 words

A hydraulic tappet comprising a cylindrical body and a socket and plunger assembled therein, said socket having a transverse bore and a seat for a hollow pushrod, said seat communicating through an axial hole with the transverse bore, said transverse bore, in all relative positions of the socket and body, facing at its ends a smooth unbroken surface of the inner wall of the body, the transverse bore being in communication with an annular passageway formed by a reduced section of the socket, the upper section of the socket being of larger diameter than the lower portion thereof, the clearance between the section of the socket above the transverse bore and the body being so much less than the clearance between the reduced lower section of the socket and the body, that flow of oil therethrough is impeded, whereas oil can flow relatively freely upwardly through the said annular passageway and directly into the transverse bore, the clearance between the plunger and body being of the order of that about the upper section of the socket.

Claim 16

Dependent Claim 176 words

A hydraulic tappet comprising a cylindrical body and a socket and plunger assembled therein, said socket having a transverse bore and a seat for a hollow pushrod, said seat communicating through an axial hole with the transverse bore, said transverse bore, in all relative positions of the socket and body, facing at its ends a smooth unbroken surface of the inner wall of the body, the transverse bore being in communication with an annular passageway formed by a reduced section of the socket, the upper section of the socket being of larger diameter than the lower portion thereof, the clearance between the section of the socket above the transverse bore and the body being so much less than the clearance between the reduced lower section of the socket and the body, that flow of oil therethrough is impeded, whereas oil can flow relatively freely upwardly through the said annular passageway and directly into the transverse bore, the clearance between the plunger and body being of the order of that about the upper section of the socket.

Claim 17

Dependent Claim 217 words

A hydraulic valve lifter comprising a body, a hollow plunger disposed in said body and a socket closing the upper end of the plunger, said socket having an upper section of larger diameter spaced from the cylindrical wall of the body by a clearance on the diameter of about 6 to 14 microns, a lower section of the socket being of reduced diameter to provide an oil passageway between itself and the wall of the body, said passageway having a considerably larger clearance between itself and the wall of the body to provide a path of lower resistance to oil flow than in the clearance about the upper section, a transverse bore in the socket opening into said annular passageway, a vertical hole in the socket communicating with said transverse bore and opening into a pushrod seat, a port in said body for the entry of oil, the inner surface of the body having a groove in the region of said port to provide a reservoir for the oil, there being a shoulder formed at the upper edge of said groove the lower section of the socket having a shoulder at its lower end which, in the lowermost position of the plunger, is disposed a substantial distance below the shoulder on the inner surface of the body.

Claim 18

Dependent Claim 217 words

A hydraulic valve lifter comprising a body, a hollow plunger disposed in said body and a socket closing the upper end of the plunger, said socket having an upper section of larger diameter spaced from the cylindrical wall of the body by a clearance on the diameter of about 6 to 14 microns, a lower section of the socket being of reduced diameter to provide an oil passageway between itself and the wall of the body, said passageway having a considerably larger clearance between itself and the wall of the body to provide a path of lower resistance to oil flow than in the clearance about the upper section, a transverse bore in the socket opening into said annular passageway, a vertical hole in the socket communicating with said transverse bore and opening into a pushrod seat, a port in said body for the entry of oil, the inner surface of the body having a groove in the region of said port to provide a reservoir for the oil, there being a shoulder formed at the upper edge of said groove the lower section of the socket having a shoulder at its lower end which, in the lowermost position of the plunger, is disposed a substantial distance below the shoulder on the inner surface of the body.

Claim 19

Dependent Claim 52 words

A hydraulic valve lifter according to claim 13, wherein the shoulder at the bottom of the lower section of the socket extends below the shoulder in the inner wall of the body when the plunger is in its lowermost position for a distance equal to approximately half the stroke of the plunger.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1981-04-10	1981-10-10	1982-04-11	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1985-04-10	1985-10-10	1986-04-11	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1989-04-10	1989-10-10	1990-04-11	$7700.00	Window Closed / Lapsed

Hydraulic valve lifter

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