US3875911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic tappet
Assignee: Individual
•
Filing: 1973-08-06
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Granted: 1975-04-08
•
Expires: 1993-08-06
Abstract
Abstract A hydraulic tappet is so constructed that the socket for the hollow pushrod is of two diameters, the lower portion being of smaller diameter and thereby providing a clearance space of increased radial width and bounding an intermediate reservoir space with the body wall between the larger oil entry reservoir and the radially narrower clearance space about the upper part of the socket of larger diameter. The clearance space about the upper part of the socket immediately above the lower part of reduced diameter leads to a collecting groove, the axial height of such clearance varying throughout the cycle. The central bore of the socket leading from the pushrod seat extends a considerable distance below the transverse bore leading from the collecting groove to provide an oil reservoir which supplies the hollow pushrod immediately upon start of the engine. The central bore stops short of the bottom of the socket, and the tappet is devoid of a disc valve at said socket bottom.
Inventors
- 👤 Charles Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:02
CPC Classifications
F; F01; F01M; F01M9/00; F01M9/10; F01M9/104; F01L; F01L1/00; F01L1/20; F01L1/22; F01L1/24; F01L1/245
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
273 words
A hydraulic tappet comprising a hollow cylindrical body, a hollow plunger within the body, a socket having a seat for a hollow push rod and supported on said plunger for reciprocatory movement therewith in said body, a central axial bore in the socket debouching into the seat, a transverse bore in the socket leading to the axial bore and opening in the outer surface of the socket, there being an annular collector groove in the interior wall of the body in communication with the transverse bore through-out the movement of the socket, a port in the body for the reception of lubricating oil, and an annular groove on the inside surface of the body communicating with said port and forming with the outer surface of the plunger an oil reservoir, said socket being of reduced diameter at its lower end opposite an unbroken inner surface of the body above the second-mentioned groove when the socket is in its upper position relative to the body, the clearance between the socket portion of larger diameter and the inner wall of the body being sufficient for the passage of oil into the first-mentioned groove, the region of the socket of reduced diameter providing an annular space for a body of oil immediately below said clearance, the axial length of the socket portion of reduced diameter being of such extent that for a substantial portion of the travel of the socket, the overlap between the inner wall of the body and the unreduced portion of the socket below the transverse bore and hence the length or axial height of the clearance about said unreduced portion, is variable.
Claim 2
Dependent Claim
273 words
A hydraulic tappet comprising a hollow cylindrical body, a hollow plunger within the body, a socket having a seat for a hollow push rod and supported on said plunger for reciprocatory movement therewith in said body, a central axial bore in the socket debouching into the seat, a transverse bore in the socket leading to the axial bore and opening in the outer surface of the socket, there being an annular collector groove in the interior wall of the body in communication with the transverse bore through-out the movement of the socket, a port in the body for the reception of lubricating oil, and an annular groove on the inside surface of the body communicating with said port and forming with the outer surface of the plunger an oil reservoir, said socket being of reduced diameter at its lower end opposite an unbroken inner surface of the body above the second-mentioned groove when the socket is in its upper position relative to the body, the clearance between the socket portion of larger diameter and the inner wall of the body being sufficient for the passage of oil into the first-mentioned groove, the region of the socket of reduced diameter providing an annular space for a body of oil immediately below said clearance, the axial length of the socket portion of reduced diameter being of such extent that for a substantial portion of the travel of the socket, the overlap between the inner wall of the body and the unreduced portion of the socket below the transverse bore and hence the length or axial height of the clearance about said unreduced portion, is variable.
Claim 3
Dependent Claim
41 words
A tappet according to claim 1, wherein the bottom edge of the lower part of the socket of reduced diameter is approximately on a level with the upper edge of the second-mentioned groove when the socket is in its uppermost position.
Claim 4
Dependent Claim
33 words
A tappet according to claim 1, wherein the radial clearance about the reduced bottom portion of the socket is at least 0.005 inch greater than that about the upper portion of the socket.
Claim 5
Dependent Claim
26 words
A tappet according to claim 3, wherein the height of the bottom portion of the socket of reduced diameter is of the order of 0.060 inch.
Claim 6
Dependent Claim
28 words
A tappet according to claim 1, wherein the clearance about the upper portion of the socket of larger diameter ranges between 0.0008 inch and 0.0015 inch measured radially.
Claim 7
Dependent Claim
34 words
A tappet according to claim 5, wherein the radial clearance between the bottom portion of the socket of reduced diameter and the opposing wall of the body is between 0.0058 inch and 0.0090 inch.
Claim 8
Dependent Claim
56 words
A tappet according to claim 1, wherein the radial clearance about the upper portion of the socket of larger diameter ranges between 0.0008 inch and 0.0015 inch, and wherein the radial clearance between the bottom portion of the socket of reduced diameter and the opposing wall of the body is between 0.0058 inch and 0.0090 inch.
Claim 9
Dependent Claim
32 words
A tappet according to claim 1, wherein the cylindrical portion of the central bore of the socket extends for about 0.093 inch to 0.115 inch below the bottom of the transverse bore.
Claim 10
Dependent Claim
79 words
A tappet according to claim 1, wherein the clearance about the reduced bottom end of the socket had a radial width in the range of 0.0058 inch to 0.0090 inch, while the clearance about the upper part of the socket above the reduced bottom end is in the range of 0.0008 inch to 0.0015 inch measured radially, and the axial height of the reduced bottom end of the socket is in the range of 0.05 inch to 0.08 inch.
Claim 11
Dependent Claim
31 words
A tappet according to claim 9, wherein the cylindrical portion of the central bore of the socket extends below the transverse bore for a distance of 0.093 inch to 0.115 inch.
Claim 12
Dependent Claim
39 words
A tappet according to claim 1, wherein the oil entry port in the body extends at a downwardly directed angle into the said oil reservoir to limit drainage of oil from the tappet when the engine is not running.
Claim 13
Dependent Claim
162 words
A hydraulic tappet having a body and a socket providing a seat for a hollow pushrod and having a transverse bore, said socket having also a central axial bore leading from the pushrod seat and extending below the transverse bore, said central bore communicating with the transverse bore, a hollow plunger on which the socket rests for conjoint movement therewith, an oil entry port in the body communicating with an oil entry port in the plunger, means for reducing the resistance to the flow of oil about the socket comprising a rabbet at the lower end of the socket and extending for a portion of the distance between the bottom of the socket and the transverse bore, said central bore terminating short of the bottom of the socket, the rabbeted portion being of such axial height that it comes into overlapping relation with an unbroken portion of the wall of the body to increasing extents during the upward stroke of the socket.
Claim 14
Dependent Claim
162 words
A hydraulic tappet having a body and a socket providing a seat for a hollow pushrod and having a transverse bore, said socket having also a central axial bore leading from the pushrod seat and extending below the transverse bore, said central bore communicating with the transverse bore, a hollow plunger on which the socket rests for conjoint movement therewith, an oil entry port in the body communicating with an oil entry port in the plunger, means for reducing the resistance to the flow of oil about the socket comprising a rabbet at the lower end of the socket and extending for a portion of the distance between the bottom of the socket and the transverse bore, said central bore terminating short of the bottom of the socket, the rabbeted portion being of such axial height that it comes into overlapping relation with an unbroken portion of the wall of the body to increasing extents during the upward stroke of the socket.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |