Patent EP0495260A2 successfully refreshed from Google Patents.
EP0495260A2
Expired / Lapsed
EP
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Apparatus for operating engine valve
Assignee: Motors Liquidation Co
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Filing: 1991-12-02
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Granted: —
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Expires: 2011-12-02
Abstract
Abstract A camshaft (18) has, for each valve lifter (32), a high-lift cam (26) between two low-lift cams (24), the high-lift cam (26) fitting within the envelope of the low-lift cams (24). The lifter (32) comprises an outer tappet (36) elongated in the direction of the camshaft (18) and slidably mounted in an elongated bore (30) in a cam carrier (10). The outer tappet (36) is contacted by both low-lift cams (24) and operates two valves (40) simultaneously. An elongated bore (54) extending transverse of the outer tappet (36) carries an elongated inner tappet (38) which is contacted by the high-lift cam (26). A hydraulically actuated locking mechanism (74) couples the tappets (36,38) for movement together for high-lift operation and unlocks for low-lift operation to allow the inner tappet (38) to idle in the outer tappet (36). <IMAGE>
Inventors
- 👤 Michael Edward Mc Carroll
- 👤 Mark Anthony Shost
- 👤 Mark James Spath
- 👤 Timothy Wilton Kunz
- 👤 Guy Ernest Giannone
- 👤 John Castellana
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 07:01
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/12; F01L1/14; F01L1/143; F01L1/26; F01L1/267; F01L13/00; F01L13/0015; F01L13/0036; F02; F02B; F02B2275/00; F02B2275/18
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
196 words
Apparatus for operating one or more valves in an internal combustion engine comprising a camshaft (18) including first cam means (24) adapted to provide a first, lower amount of movement and second cam means (26) adapted to provide a second, higher amount of movement; a two-step valve lifter (32) supported adjacent the camshaft by a support (10) and selectively operable by the first and second cam means (24,26); the valve lifter including a first lifter element (36) comprising a bore (54) therein and movable by one of the first and second cam means so as to slide reciprocably on the support, and a second lifter element (38) reciprocably movable in the bore of the first lifter element by the other of the first and second cam means; and locking means (70) adapted selectively to lock the second lifter element (38) to the first lifter element (36), whereby when the locking means is in a locked condition the first and second lifter elements are movable by the second cam means (26), and when the locking means is in an unlocked condition one of the first and second lifter elements is movable by the first cam means (24).
Claim 2
Dependent Claim
39 words
Apparatus according to claim 1, wherein the first lifter element (36) is adapted to be moved by the first cam means (24) and the second lifter element (38) is adapted to be moved by the second cam means (26).
Claim 3
Dependent Claim
91 words
Apparatus according to claim 1 or 2, wherein the first lifter element (36) has an oblong shape and comprises spaced cam contact portions (90) disposed on opposite sides of the first lifter element relative to the bore (54); the second cam means (26) comprises a single second cam (26) adapted to abut the second lifter element (38); and the first cam means (36) comprises a pair of first cams (36) disposed on respective sides of the second cam and adapted to abut the cam contact portions of the first lifter element.
Claim 4
Dependent Claim
83 words
Apparatus according to claim 3, wherein the profile of each of the first cams (24) comprises a first circular portion, the profile of the second cam is disposed within the profile of the first cam and comprises a second circular portion having a smaller diameter than the first circular portions; wherein, when the first and second lifter elements are in contact with the circular portions of their respective cams, the second lifter element extends beyond the contact portions of the first lifter element.
Claim 5
Dependent Claim
53 words
Apparatus according to claim 4, wherein the second lifter element (38) comprises a cam contact portion (92); the contact portion of the second lifter element extending beyond the contact portions of the first lifter element when the first and second lifter elements are in contact with the circular portions of their respective cams.
Claim 6
Dependent Claim
134 words
Apparatus according to any preceding claim, wherein the locking means includes a first sleeve (140) movable with the second lifter element (118); a second sleeve (116) secured to the first lifter element (110) and telescopically slidable within the first sleeve, the second sleeve comprising an aperture (134), the first sleeve comprising a pocket (144) adapted to be aligned with the aperture (134) when the first and second lifter elements (110,118) are in abutment with the circular portions or with circular portions of their respective cam means; a locking member (136) adapted to reside partially within the aperture; and an actuator (127) disposed within the second sleeve and adapted to move the locking member into the pocket to lock the first and second sleeves together, thereby locking the second lifter element to the first element.
Claim 7
Dependent Claim
93 words
Apparatus according to claim 6, wherein the actuator (127) comprises a spool axially slidable in the second sleeve (116) which is biased towards an unlocked position in which the first and second sleeves are unlocked and is hydraulically movable to a locked position in which the first and second sleeves are locked together, and comprises a recess for partially receiving the locking member and a surface (132) adapted to slope towards the pocket (144) so as to urge the locking member into the pocket on movement of the spool to the locked position.
Claim 8
Dependent Claim
174 words
Apparatus according to any one of claims 1 to 5, wherein the locking means comprises a cylinder (206) supported by the first lifter element (190) and located within the second lifter element (194) and which includes a closed end and an open end facing into the second lifter element; a piston (208) slidably mounted in the cylinder (206) and adapted to bear on the second lifter element, a chamber (209) being formed between the closed end of the cylinder and the piston; and a hydraulic actuator which includes a first valve (214) for filling the chamber with hydraulic fluid so as to hold the piston against the second lifter element, thereby locking the first and second lifter elements together; a second valve (220) coupled to the cylinder and adapted to allow fluid to leave the chamber, thereby unlocking the first and second lifter elements from one another; and means adapted to open and close the second valve (220) so as to unlock or lock the first and second lifter elements relative to one another.
Claim 9
Dependent Claim
133 words
Apparatus according to claim 8, comprising a cylindrical passage (200) adapted to feed hydraulic fluid to the chamber (209) through a first end thereof and to exhaust fluid from the chamber through a second end thereof; a drain (216) extending from the chamber to the second end of the passage; the second valve comprising a shuttle valve which includes a pin (220) in the cylindrical passage movable by hydraulic pressure to a first position which closes the drain and allows flow to the chamber and in the absence of hydraulic pressure movable by spring biasing means (222) to a second position which opens the drain and allows fluid to flow from the chamber, the first and second lifter elements thereby being lockable and unlockable relative to one another by means of hydraulic pressure.
Claim 10
Dependent Claim
69 words
Apparatus according to any one of claims 1 to 5, wherein the locking means comprises a pin (248;282) slidably mounted in the first lifter element (230;270) and adapted to extend into the second lifter element (234;274), the second lifter element comprising a stop (238;276) adapted to abut the pin so as to lock the first and second lifter elements together when the pin extends into the second lifter element.
Claim 11
Dependent Claim
49 words
Apparatus according to any preceding claim, wherein the second lifter element comprises means (292) for adjusting lash comprising a wear pad (274) on the surface of the second lifter element for abutment with the second cam means, the thickness of the wear pad being selected to compensate for lash.
Claim 12
Dependent Claim
70 words
Apparatus according to any preceding claim, wherein the first lifter element (36) has an oblong shape, the support (10) comprises an oblong aperture (31) within which the first lifter element is slidably received; the bore (54) of the first lifter element (36) having an oblong shape, the longitudinal axis thereof being substantially perpendicular to the longitudinal axis of the first lifter element; the second lifter element being oblong in shape.
Claim 13
Dependent Claim
48 words
Apparatus according to claim 12, wherein the support comprises one or more cylindrical bores aligned with and connected to the elongated bores (344) extending from the oblong aperture (31), a substantially cylindrical tappet (340) operatively engaging the first lifter element being provided in the or each cylindrical bore.
Claim 14
Dependent Claim
20 words
Apparatus according to claim 13, comprising two cylindrical bores (344) substantially equally spaced from respective ends of the oblong aperture.
Claim 15
Dependent Claim
50 words
Apparatus according to claim 12, 13 or 14, wherein the oblong aperture (31) and the first lifter element (36) comprises mating semi-cylindrical ends (30,36) adapted to bear slidably against one another when urged together and to guide the movement of the first and second lifter elements relative to the support.
Claim 16
Dependent Claim
67 words
Apparatus according to any preceding claim, wherein in a surface of the first lifter element on the opposite side of the valve lifter (32) relative to the camshaft (18) there is provided one or more threaded apertures (294), a lash adjuster (272) comprising a threaded stem being secured in the or each threaded aperture, the or each lash adjuster being adjustable by rotation of the stem thereof.
Claim 17
Dependent Claim
42 words
Apparatus according to claim 16, wherein the threaded stem of the or each lash adjuster comprises a tool engaging portion for adjustment thereof and the first lifter element comprises one or more tool access openings substantially aligned with the tool engaging portion.
References Cited (Backward Citations)
No citation records indexed.
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