1 A poppet valve actuation system in which the poppet valve is operated, via a cam follower, by a cam which is joined by 2 pivoted links to a connecting rod, driven by a crankshaft, the first link, referred to as the "cam link", being rotatably connected at one end of the link to the cam, whilst the other end of the first link connects rotatably to one end of the second link, this second link, referred to as "control link" being rotatably connected, along its length, to the small end of the said connecting rod, the other end of this second link, termed the "free" end, being connected, via an appropriate mechanical joint, to an actuator that may apply a displacement to this free end of the control link, such that the control link's angularity relative to the first link and therefore the angular displacement of the cam can be adjustably controlled by the said displacement of the free end of the control link causing rotation about the connection of the control link with the small-end of the said connecting rod, the big end of which being free to rotate on the said crankshaft, the said crankshaft being driven in appropriate phase with the main engine crankshaft.
2 A poppet valve actuation system, as in Claim 1, in which the said valve actuation crankshaft is driven at half the rotational speed of the main engine crankshaft.
3 A poppet valve actuation system, as in Claim 1, in which the said valve actuation crankshaft is driven at the same rotational speed as the main engine crankshaft.
4 A poppet valve actuation system, as in Claim 1, in which the said valve actuation crankshaft is driven at any selected speed relative to the rotational speed of the main engine crankshaft.
5 A poppet valve actuation system, as in Claim 1, in which the said valve actuation camshaft is connected via a phase change mechanism to the main engine camshaft.
6 A poppet valve actuation system, as in Claim 5, in which the phase change mechanism is of the vane type.
7 A poppet valve actuation system, as in Claim 5, in which the phase change mechanism is of the helical spline type.
8 A poppet valve actuation system, as in Claims 1-7, in which the cam actuates the valve via a bucket tappet.
9 A poppet valve actuation system, as in Claims 1-7, in which the cam actuates the valve via a pivoted lever system.
10 A poppet valve actuation system, as in Claim 9, in which the cam actuates the valve via an end pivoted lever system.
A poppet valve actuation system, as in Claim 9, in which the cam actuates the valve via a centre pivoted lever system. A poppet valve actuation system, as in Claims 9-11, in which the cam actuates the lever via a sliding contact. A poppet valve actuation system, as in Claims 9-11, in which the cam actuates the lever via a rolling contact. A poppet valve actuation system, as in Claim 10, in which the pivot is a fixed post. A poppet valve actuation system, as in Claim 10, in which the pivot is a hydraulic tappet. A poppet valve actuation system, as in Claim 11, in which the pivot is a shaft. A poppet valve actuation system, as in Claim 16, in which the pivot is a continuous shaft for all the levers which actuate the valves. A poppet valve actuation system, as in Claim 11, in which the lever has a hydraulic tappet. A poppet valve actuation system, as in all previous Claims, in which the said valve actuating crankshaft is located in the cylinder head. A poppet valve actuation system, as in Claims 1-18, in which the said valve actuating crankshaft is located in the cylinder block. A poppet valve actuation system, as in Claims 1-18, in which the said valve actuating crankshaft is located in a carrier attached to the cylinder head. A poppet valve actuation system, as in Claims 1-18, in which the said valve actuating crankshaft is located in a carrier attached to the cylinder block. A poppet valve actuation system, as in Claims 1-18, in which the said valve actuating crankshaft is located between the cylinder head and the cylinder block. A poppet valve actuation system, as in Claims 1-18, in which the said valve actuating crankshaft is located between the cylinder head and the cam carrier. A poppet valve actuation system, as in Claims 1-18, in which the supporting bearings of said valve actuating crankshaft are located on the same split line as the supporting bearings of the valve actuating cam. A poppet valve actuation system, as in all previous Claims, in which the said valve actuating crankshaft is a continuous monolithic shaft with supporting journals.
A poppet valve actuation system, as in all previous Claims, in which the said valve actuating crankshaft is a shaft with eccentric cylindrical sections that act as the crank throws of the crankshaft. A poppet valve actuation system, as in Claim 27, in which the valve actuating ςrankshaft is indented on one side of the shaft in the plane of each eccentric. A poppet valve actuation system, as in Claims 27-28, in which the said valve actuating crankshaft has lubrication conduits to the supporting bearings and eccentrics. A poppet valve actuation system, as in Claims 26-29, in which the said valve actuating crankshaft is of a cast-iron material type. A poppet valve actuation system, as in Claims 26-29, in which the said valve actuating crankshaft is of a forged steel material type. A poppet valve actuation system, as in Claims 30-31, in which the said valve actuating crankshaft has local hardening. A poppet valve actuation system, as in Claim 32, in which the said valve actuating crankshaft journals and eccentrics are surface hardened. A poppet valve actuation system, as in Claims 1-25, in which the said valve actuating crankshaft is of a built-up construction. A poppet valve actuation system, as in Claim 34, in which the built-up shaft has a steel mainshaft. A poppet valve actuation system, as in Claim 34, in which the built-up shaft has rigidly attached co-axial cylinders for the journals. A poppet valve actuation system, as in Claim 34, in which the built-up shaft has rigidly attached, eccentrically mounted solids of revolution for the crankthrows. A poppet valve actuation system, as in all previous Claims, in which the said connecting rods are monolithic parts. A poppet valve actuation system, as in Claim 38, in which the said connecting rods are of sintered metal material. A poppet valve actuation system, as in Claim 38, in which the said connecting rods are of cast iron material type. A poppet valve actuation system, as in Claim 38, in which the said connecting rods are of a forged aluminium material type.
A poppet valve actuation system, as in Claim 38, in which the said connecting rods are of a forged steel material. A poppet valve actuation system, as in Claim 38, in which the said connecting rods are of a metal matrix composite material. A poppet valve actuation system, as in Claim 43, in which the metal matrix composite material is alumina reinforced aluminium. A poppet valve actuation system, as in all previous Claims, in which the cam has a forked boss with internal bores for connection to the cam link. A poppet valve actuation system, as in all previous Claims, in which the cam has a blade for connection to the cam link. A poppet valve actuation system, as in all previous Claims, in which the adjustable link has a forked boss with bores for connection to the cam link. A poppet valve actuation system, as in all previous Claims, in which the cross section of the control link is U shaped A poppet valve actuation system, as in all previous Claims, in which the cross section of the cam link is U shaped
A poppet valve actuation system, as in all previous Claims, in which the cam link connection is situated in any region of the cam. A poppet valve actuation system, as in all previous Claims, in which the control link has forked boss with bores for connection to the small end of the said valve actuating connecting rod. A poppet valve actuation system, as in all previous Claims, in which the cam and cam link are joined by a pin which has interference with at least one of the interconnecting bores. A poppet valve actuation system, as in all previous Claims, in which the cam link and control link are joined by a pin which has interference with at least one of the interconnecting bores. A poppet valve actuation system, as in all previous Claims, in which the control link and connecting rod are joined by a pin which has interference with at least one of the interconnecting bores. A poppet valve actuation system, as in all previous Claims, in which each cam has supporting journals. A poppet valve actuation system, as in all previous Claims in which the locus of the path of the free end of the control link may be a circular arc.
A poppet valve actuation system, as in Claims 1-55, in which the locus of the path of the free end of the control link may be a straight line. A poppet valve actuation system, as in Claims 1-55, in which the locus of the path of the free end of the control link may be a path of varying curvature. A poppet valve actuation system, as in all previous Claims, in which the actuator shaft is a monolithic shaft with crank arms A poppet valve actuation system, as in Claim 59, in which the actuator crank arms are forked. A poppet valve actuation system, as in Claim 60, in which the said actuator shaft is of a built-up construction. A poppet valve actuation system, as in Claim 61, in which the built-up shaft has a steel mainshaft. A poppet valve actuation system, as in Claim 61, in which the built-up shaft has rigidly attached co-axial cylinders for the journals. A poppet valve actuation system, as in Claim 61, in which the built-up shaft has rigidly attached crank arms. A poppet valve actuation system, as in Claim 61, in which the journals are press fitted sintered parts. A poppet valve actuation system, as in Claims 59-61, in which the crank are press fitted sintered parts. A poppet valve actuation system, as in all previous Claims, in which the actuator shaft position is controlled by an electric motor. A poppet valve actuation system, as in Claim 67, in which the electric motor is a stepper motor. A poppet valve actuation system, as in all previous Claims, in which the valve actuating crankshaft receives lubricating oil. A poppet valve actuation system, as in all previous Claims, in which the valve actuating crankshaft distributes lubricating oil. A poppet valve actuation system, as in Claim 70, in which the valve actuating crankshaft distributes lubricating oil via internal drillings. A poppet valve actuation system, as in Claim 70, in which the connecting rods receive lubricating oil. A poppet valve actuation system, as in Claims 1-68, in which the control link pins receive lubricating oil.
74 A poppet valve actuation system, as in Claims 1-68, in which the cam link pins receive lubricating oil.
75 A poppet valve actuation system, as in Claims 1-68, in which the cam receives lubricating oil.
76 A poppet valve actuation system, as in all previous Claims, in which the poppet valve linear position is monitored by an inductive displacement transducer.
77 A poppet valve actuation system, as in Claims 1-75, in which the poppet valve linear position is monitored by a Hall effect transducer.
78 A poppet valve actuation system, as in all previous Claims, in which the actuating angular shaft position is monitored by a Hall effect transducer.
79 A poppet valve actuation system, as in Claims 1-77, in which the actuating angular shaft position is monitored by a potentiometer.
80 A poppet valve actuation system, as in all previous Claims, in which the actuating electric motor rotational position is controlled, using an electronic control circuit, in response to signals from the monitoring sensor.
81 A poppet valve actuation system, as in Claim 80, in which the actuating electric motor rotational position is controlled in a feedback mode in response to signals from the monitoring sensor.
82 A poppet valve actuation system, as in Claim 80, in which the actuating electric motor rotational position is controlled in a feedforward mode in response to signals from the monitoring sensor.
83 A poppet valve actuation system, as in Claim 80, in which the actuating electric motor rotational position is controlled in an open loop mode in response to signals from the monitoring sensor.
84 A poppet valve actuation system, as in Claim 80, in which the actuating electric motor rotational position is controlled in a combination of feedback, feedforward and open loop modes in response to signals from the monitoring sensor.
85 A poppet valve actuation system, as in all previous Claims, in which the pivots of the control links are a shaft.
86 A poppet valve actuation system, as in Claims 1-84, in which for all the pivots of several control links are on a common shaft.
87 A poppet valve actuation system, as in Claim 85-86 in which the control shaft is supported in more than one position along its length.
88 A poppet valve actuation system, as in Claim 57 in which support for the control shaft is provided by a guide rotatably connected to the control shaft and slideably connected to a cap which is fixed to the engine.
89 A poppet valve actuation system, as in Claims 57 and 85-87 in which the control shaft is actuated by angular displacement of a threaded shaft.
90 A poppet valve actuation system, as in Claims 1-85 in which the actuator is an hydraulic actuator.
91 A poppet valve actuation system, as in Claim 90 in which the hydraulic actuator is in an hydraulic control system.
92 A poppet valve actuation system, as in Claim 90-91 which includes a spool valve.
93 A poppet valve actuation system, as in Claims 90-92 which includes a differential lever.
94 A poppet valve actuation system, as in Claims 1-84 in which the actuator crank arm is slotted to guide a sliding member rotatably connected to the control shaft which is positioned by the angular displacement of the arm and the position of a coaxial rotatable sleeve in a track in a cam plate.
95 A poppet valve actuation system, as in Claim 44, in which the camplate is stationary.
96 A poppet valve actuation system, as in Claims 1-84 in which the camplate is stationary.
97 A poppet valve actuation system, as in Claim 94-96 where the said sleeve outer surface is profiled to reduce contact stress with the cam track.
98 A poppet valve actuation system, as in all previous Claims in which actuation of the control shaft is provided at more than one position along its length.
99 A poppet valve actuation system, as in all previous Claims in which a phase change mechanism is inserted between the main crankshaft and the valve actuating crankshaft.
100 A poppet valve actuation system, as in Claim 99, in which the phase change mechanism is of the epicyclic gear train type.
101 A poppet valve actuation system, as claimed in all previous Claims, in which the cam may have a primary profile and a secondary profile
102 A poppet valve actuation system, as claimed in Claim 101, in which the cam secondary profile may be on one or other side of the primary profile
103 A poppet valve actuation system, as claimed in all previous Claims, in which the cam may have a third profile.
104 A poppet valve actuation system, as claimed in Claim 103, in which the cam third profile may be on one or other side of the primary profile
105 A poppet valve actuation system, as claimed in Claims 101-104, in which the additional profiles may be selectively engaged by controlling the end position of the control link.
106 A poppet valve actuation system, as claimed in Claims 101-104, in which the additional profiles may be collectively engaged by controlling the end position of the control link.
107 A poppet valve actuation system, as claimed in all previous Claims, in which the actuator end of the control link is moved to a position relative to the cam link, such that always is an acute included angle between the cam link and the control link, as viewed from the actuating crankshaft side of the cam and control links.
108 A poppet valve actuation system, as claimed in all previous Claims, which uses a centre pivoted lever, or rocker, which makes contact with the cam of the variable valve timing mechanism via rolling element bearing, or a fixed contact pad, and the rocker actuates a pair of valves.
109 A poppet valve actuation system, as claimed in Claim 106, in which the valves are actuated via a bridge piece
110 A poppet valve actuation system, as claimed in Claims 108-109, in which the actuating crankshaft is located above the pivoted lever or rocker.
111 A poppet valve actuation system, as claimed in Claims 108-109, in which the actuating crankshaft is located below the pivoted lever or rocker.
112 A poppet valve actuation system, as claimed in Claims 108-109, in which the control actuator is located below the pivoted lever or rocker.
113 A poppet valve actuation system, as claimed in Claims 108-109, in which the control actuator is located above the pivoted lever or rocker.
114 A poppet valve actuation system, as claimed in Claims 108-113, in which the pivoted lever or rocker is cranked.
115 A poppet valve actuation system, as claimed in Claims 108-114, in which the plane of the variable valve timing mechanism is in the plane of the valves upon which it acts.
116 A poppet valve actuation system, as claimed in Claims 108-114, in which the plane of the variable valve timing mechanism is out of the plane of the valves upon which it acts.
117 A poppet valve actuation system, as claimed in all previous Claims, in which at least one joint of the connecting links is joined by a pin and bush.
118 A poppet valve actuation system, as claimed in Claims 1-116, in which at least one joint of the connecting links is joined by a pin and the rolling element bearing.
119 A poppet valve actuation system, as claimed in Claims 57-58, in which the locus of the path of the free end of the control link is modulated by an arrangement in which the end point of the control link is located off centred to a first cylindrical body, which itself is housed off centred, and with clearance, to the cylindrical hole of a second body, the second body having a cylindrical outer surface whose axis is parallel to the axis of its cylindrical hole, and having a separation between the two axes, the second body also being free to rotate about the axis of its external surface, in a housing which is rigidly fixed relative to actuating crankshaft.
120 A poppet valve actuation system, as claimed in Claim 119, in which a first cylindrical body may be rotated an electric motor.
121 A poppet valve actuation system, as claimed in Claim 120, in which the electric motor is a stepper motor.
122 A poppet valve actuation system, as claimed in Claim 119, in which the second cylindrical body may be rotated an electric motor.
123 A poppet valve actuation system, as claimed in Claim 122, in which the electric motor is a stepper motor.
124 A poppet valve actuation system, as claimed in claims 1-118, in which the free-end of the control link is actuated by a pair of electric motors, each having a ball screw drive and stirrup connection to the control link free end.
125 A poppet valve actuation system, as claimed in Claim 124, in which the electric motors and ball screw drives have screw drive axes that are parallel to each other.
126 A poppet valve actuation system, as claimed in Claim 124, in which the electric motors and ball screw drives have screw drive axes that are orthogonal to each other.
127 A poppet valve actuation system, as claimed in all previous claims, in which the cam has means for adjusting the clearance relative to the tappet or follower that is in contact with the valve tip.
128 A poppet valve actuation system, as claimed in Claim 127, in which the means for adjusting the clearance relative to the tappet or follower comprise a rotatable member mounted between an inner bore in the cam and the shaft
supporting the cam, the axis of the solid of revolution being off centred from the centre of the shaft.
129 A poppet valve actuation system, as claimed in claims 127-128, in which the rotatable member may be locked into a specific position.
130 A poppet valve actuation system, as claimed in Claim 129, in which the means of locking comprise a high friction thread between the inside bore of the cam and the outside surface of the rotatable member.
131 A poppet valve actuation system, as claimed in Claim 130, in which the high friction thread is deformable.
132 A poppet valve actuation system, as claimed in Claim 129, in which the means of locking comprise at least one locknut engaging with a thread which is on the rotatable member.