Sohc system with radial valves

A valve train mechanism for a multi-valve internal combustion engine having hemispherical combustion chambers and in which each chamber has a pair of radial exhaust valves located along one side of the longitudinal axis of the engine and has a pair of radial intake valves located along the other side of the aforementioned longitudinal axis and in which an inverted "L" shaped actuator is provided for actuating each of the exhaust and intake valves and the guide pins supporting the actuators associated with at least one pair of same-function valves are positioned relative to the valves so as to cause the actuators to reciprocate along and oscillate about the associated guide pins while the associated pair of same-function valves are moved between an open position and a closed position.

FIELD OF THE INVENTION 
This invention concerns internal combustion engines and, more particularly, 
relates to a single actuator system combined with radial or angulated 
intake valves and exhaust valves extending from a curved upper wall of the 
combustion chamber and in which each of the valves is operated through a 
rocker arm and an actuator system having inverted "U" shaped actuators. 
BACKGROUND OF THE INVENTION 
My copending patent application U.S. Ser. No. 08/629,161 entitled "Valve 
Train For An Internal Combustion Engine", filed on Apr. 8, 1996, discloses 
a valve train mechanism which serves to directly actuate radially disposed 
engine valves driven by an inverted bucket tappet through a spherical 
joint without any side thrust on the valve stem. Moreover, the mechanism 
shown in this patent application is designed to operate either one single 
valve per rocker arm or two. When two valves are operated, it is done by 
the use of a crosshead which can be guided or unguided. These mechanisms 
allow the valves to be operated without side thrust on the valve stem, and 
to do so they require inverted bucket tappets. In addition, these 
mechanisms combine sliding and rotating motions between the actuator, be 
it a finger follower, a rocker arm or cross member, and the inverted 
bucket tappet. In cases where rotating motion exits, it is provided by 
using spherical joints which take the form of a half-ball, a full ball or 
an encapsulated half-ball which at times is referred to as "an elephant 
foot". The sliding motion can be provided by a shoe associated with the 
ball portion of the spherical joint. As an alternative, the half-ball can 
have the flat surface thereof serve to provide the sliding connection with 
the actuator. All of the sliding motions have large surface areas between 
the contact members so as to minimize wear. Accordingly, high-wear "single 
point" or "line" contacts are eliminated. 
These mechanisms are particularly useful on engines in which the two sets 
of same-function valves (intake or exhaust) are disposed transversely to 
the engine centerline. This is the preferred disposition of the valves 
when swirl air flow is desired for combustion purposes because the port 
disposition enhances the swirling motion. Valve arrangements of this sort 
have been used for over thirty years on engines with conventional cylinder 
head layouts in which the valves are disposed with their stems in parallel 
to each other and to the axial centerline of the cylinder. Due to the fact 
that the maximum valve sizes achievable as well as the tortuous ports 
connecting them and opening to the outside of the engine are limited, the 
maximum air flow that the engine can process is rather limited. With the 
limited air flow and the relatively low injection pressures that have been 
used in the past, the necessary rapid mixing process of the fuel and air 
has not been easy to achieve. In order to avoid the slow combustion which 
results from such poor mixing process, swirl has been used to improve the 
mixing and combustion. (Swirl is defined as rapid rotational motion of the 
air about the axis of the cylinder). In more recent times, higher 
injection pressures have become available through more modern injection 
systems. Accordingly, the need for swirl has been reduced even with 
conventional four-valve engines. Since swirl is achieved by converting air 
pressure into air velocity, reducing it has increased the flow and the 
power output of the engine. For example, the new Detroit Diesel 
Corporation Series 60 engine with a 130 mm bore diameter realizes very 
good combustion by eliminating the swirl, increasing the air flow, and 
using extremely high injection pressures. The exchange of swirl for air 
flow has been obtained by placing the two sets of same-function valves 
side-by-side along each side of the engine rather than transversely as 
typically used in the smaller, high-speed truck engines. With the large 
increase in valve sizes and air flow provided by the radial disposition of 
the valves in the cylinder head, it is now possible to dispose of the 
swirl altogether and place the valves side-by-side in combination with 
short, direct, high-efficiency ports. Whereas on the larger engines, such 
as the above-mentioned Detroit Diesel engine, it is possible to use a 
valve train mechanism with longitudinally disposed conventional crossheads 
and parallel stems, on smaller engines it is impossible, as a practical 
matter, to downsize the mechanisms in a proportional scale because some of 
the components and critical dimensions cannot be scaled downward. For 
example, the mechanism would require extremely long and heavy rocker arms 
and a camshaft placed at a very large distance from the center of the 
cylinder, resulting in a very wide and heavy cylinder head. Therefore, if 
side-by-side ports are desired with all the inlets on one side of the 
engine and all the exhausts on the other side while utilizing radial 
valves, a new valve train mechanism is required. 
SUMMARY OF THE INVENTION 
In this regard, the present invention disclosed in this patent 
specification provides such a new valve train mechanism. Moreover, the 
present invention has certain similarities to the valve train mechanism 
described in the above-mentioned patent application in that it utilizes 
spherical joints combined with actuators for operating radial exhaust 
valves and intake valves of an internal combustion engine. However, this 
invention differs structurally from the above-described valve train 
mechanism in that each of the valves is operated through a rocker arm and 
a piloted actuator supported by a guide pin. The actuator takes the form 
of an inverted "L" and comprises a leg portion and an arm portion. The leg 
portion is carried by the guide pin for reciprocating movement while the 
arm portion is connected to and maintains a force-applying connection with 
an inverted bucket tappet through a combined spherical joint and sliding 
connection. The latter mentioned connection as well as the design of the 
actuator allows the supporting guide pin to be positioned relative to the 
exhaust and intake valves at points which can permit the actuator not only 
to reciprocate along the guide pin but also simultaneously experience 
oscillation about the guide pin. Thus, by providing the actuator with the 
ability to have compound movement, an engine designer can have a great 
amount of flexibility in designing a valve train and port system for a 
multi-valve internal combustion engine and provide an optimum central 
location of the fuel injector or spark plug. 
Accordingly, one object of the present invention is to provide a new and 
improved actuator system for a valve train mechanism forming a part of an 
internal combustion engine and in which the actuator system is 
characterized in that individual inverted "L" shaped actuators are 
utilized for operating each of the exhaust valves and each of the intake 
valves. 
Another object of the present invention is to provide a new and improved 
valve train mechanism for an internal combustion engine that includes 
individual inverted "U" shaped actuators for each of the exhaust valves 
and each of the intake valves and in which each of the actuators is 
supported on a guide pin which allows the actuator to reciprocate along an 
axis parallel to the longitudinal center axis of the associated cylinder 
as the associated valve moves between the open and closed position. 
A further object of the present invention is to provide a new and improved 
actuator system for a valve train mechanism including angulated exhaust 
valves and intake valves incorporated in an internal combustion engine and 
in which the actuator system has an inverted "L" shaped actuator provided 
for each of the exhaust valves and each of the intake valves and each 
actuator is connected to its associated valve through a combined spherical 
joint and a sliding connection. 
A still further object of the present invention is to provide a new and 
improved actuator system for a valve train mechanism which forms a part of 
an internal combustion engine and in which the actuator system has an 
independent actuator provided for each of the exhaust valves and each of 
the intake valves and in which the actuator is capable of reciprocating 
along an axis parallel to the longitudinal center axis of the associated 
cylinder and is also capable of oscillating about the same axis during 
movement of the associated valve between a closed position and an open 
position. 
A still further object of the present invention is to provide a new and 
improved valve train mechanism for a multi-valve internal combustion 
engine in which each cylinder of the engine has at least a pair of 
angulated exhaust valves located along one side of the engine and a pair 
of angulated intake valves located along the other side of the engine and 
in which individual "L" shaped actuators are provided for actuating each 
of the intake valves and each of the exhaust valves. 
A still further object of the present invention is to provide a new and 
improved valve train mechanism for a multi-valve internal combustion 
engine having hemispherical combustion chambers and in which each chamber 
has at least a pair of radial exhaust valves located along one side of the 
longitudinal axis of the engine and has a pair of radial intake valves 
located along the other side of the aforementioned longitudinal axis and 
in which an inverted "L" shaped actuator is provided for actuating each of 
the exhaust and intake valves, and in which the guide pins supporting the 
actuators associated with at least one pair of same-function valves are 
positioned relative to the valves so as to cause the actuators to 
reciprocate along and oscillate about the associated guide pins while the 
associated pair of same-function valves are moved between an open position 
and a closed position.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to the drawings and more particularly to FIG. 1 thereof, a 
perspective view of a single cylinder of a multi-cylinder engine is shown 
having an engine block 10 on which is secured by fasteners (not shown) a 
lower head portion of a two-piece cylinder head assembly 12. The cylinder 
head assembly 12 serves to support a valve train mechanism 14 which 
includes an actuator system 15 in accordance with the present invention 
and seen in FIG. 2. 
Each of the cylinders of the engine houses a piston 16 which moves axially 
along the longitudinal center axis A of the associated cylinder and has 
the lower end thereof connected to the engine crankshaft (not shown) by a 
connecting rod 18. The lower base portion 19 of the cylinder head assembly 
12 is formed with a hemispherical surface 20 providing a recess which is 
aligned with the bore defining the associated cylinder 22 and together 
with the top of the piston 16 forms a combustion chamber 24 which varies 
in volume during the operation of the engine. In this instance, a diesel 
fuel injector 26 seen in FIG. 3 is secured in the cylinder head 12 
centrally of the hemispherical surface or recess 20 along the longitudinal 
axis "A" of each cylinder 22. The fuel injector 26 is secured in position 
by a clamp and a nut tightened on a stud threadably secured to the lower 
base portion 19 of the cylinder head 12. As will become apparent as the 
description of the present invention proceeds, the actuator system 15 
forming a part of the valve train mechanism 14 according to the present 
invention can also be used with a spark ignition internal combustion 
engine in which case a spark plug would be substituted for the injector 
26. 
As best seen in FIGS. 1 and 2, the cylinder head assembly 12 is provided 
with a pair of intake valves 28 and 30 and a pair of exhaust valves 32 and 
34 which are located in side-by-side relationship extending along the 
longitudinal axis of the engine. Each of the intake valves 28 and 30 has a 
valve stem 36 the lower end of which is formed with a round valve head 38. 
Similarly, each of the exhaust valves 32 and 34 has a valve stem 40 the 
lower end of which is formed with a round valve head 42. As is 
conventional, each of the intake valve heads 38 is normally seated in a 
valve seat formed in the cylinder head that defines a round opening or 
port 44 of an intake passage 46 formed in the lower base portion 19 of the 
cylinder head assembly 12 as seen in FIG. 2. Also, each of the exhaust 
valve heads 42 are normally seated in a valve seat formed in the cylinder 
head 12 that defines a round opening or port 48 of an exhaust passage 50 
also formed in the lower base portion 19 of the cylinder head assembly 12. 
It will be noted that the valve stems 36 of the intake valves 28 and 30 and 
the valve stems 40 of the exhaust valves 32 and 34 are disposed radially 
or angularly about the cylinder head 12 such that the intersection of 
their longitudinal center axes occurs at a point "B" located on the 
longitudinal center axis "A" of the cylinder 22 as seen in FIG. 1. As a 
result, the centers of the valve heads 38 of the intake valves 28 and 30 
and the centers of the valve heads 40 of the exhaust valves 32 and 34 are 
located on a common circle concentric with the periphery of the cylinder 
22. In addition, in this case, the centers of the valve heads 38 and 42 
are circumferentially equally spaced from each other. Also, each of the 
valve heads 38 and 42 is in an essentially tangential plane relative to 
the hemispherical recess 20. Thus, as seen in FIG. 1, the longitudinal 
centerline of each valve 28-34 is canted at an equal angle to both the 
longitudinal and transversal planes of the engine. This orientation not 
only allows for more room at the top of the cylinder 22 and lessensthe 
space requirements for valves, spark plugs, injectors, pre-combustion 
chambers or cooling water jackets, but also produces a far superior 
combustion chamber with optimum central location of the spark plug or 
injector. It will be understood that for practical considerations the 
valves 28-34 may be disposed with different angles on longitudinal and 
transversal planes so that the point "B" may not fall on the longitudinal 
center axis "A". 
Referring again to FIG. 2, it will be noted that this figure is an 
elevational sectional view of the cylinder head 12 taken along a plane 
extending transversely of the engine and shows the exhaust valve 34 and 
the intake valve 30 seen in FIG. 1 and the actuator system 15 employed by 
a valve train mechanism 14 for actuating the valves in accordance with the 
present invention. Inasmuch as the engine block 10 and the various 
operating components normally associated therewith are well known to those 
skilled in the art of engine design, a detailed showing and/or description 
of such parts and components is not being provided herein. Instead, the 
valve train mechanism 14 and the parts associated therewith will be 
described below in detail. In addition, it will be noted that in 
describing the structure of the cylinder head assembly 12 and the valve 
train mechanism 14, only the parts associated with one cylinder of the 
engine block 10 will be described in detail and it will be understood that 
similar and identical parts are associated with each of the other 
cylinders of the engine block 10. 
As seen in FIGS. 2-5, the cylinder head assembly 12 includes the lower base 
portion 19 which is generally rectilinear and preferably made of cast 
iron. The cylinder head assembly 12 also includes a tappet and camshaft 
carrier 52, preferably made in aluminum alloy, is secured to the base 
portion 19 by a plurality of bolts 54 and 142 and serves to support a 
camshaft 56, inverted bucket tappets 58, 60, 62, 64 for each valve, and 
rocker arms 66, 68 and 70 as will be more fully explained hereinafter, for 
each cylinder. The base portion 19, in turn, is fastened to the upper end 
of the engine block 10 by a plurality of head bolts 72 which extend 
through the body of the base portion 19 into threaded holes (not shown) 
formed in the engine block 10. Although not shown, a pair of laterally 
spaced and parallel side walls may be integrally formed with the base 
portion 19 and extend upwardly and, together with a valve cover (not 
shown) plus corresponding front and back walls, serve to enclose the 
carrier 52 and the valve train mechanism 14. As seen in FIG. 2, the air 
intake passage 46 and the exhaust passage 50 are provided in the base 
portion 19 and terminate respectively at the ports 44 and 48 which, in 
turn, communicate with the combustion chamber 24. 
As best seen in FIGS. 3 through 6, the carrier 52 for one cylinder of the 
engine is formed by fore and aft spaced bulkheads 74 and 76. The bulkheads 
74 and 76 are interconnected by a pair of laterally spaced expansion bars 
78 and 80 each of which has the midsection thereof formed with a "U" 
shaped loop portion 82. Each of the bars 78 and 80 are of relatively thin 
uniform cross section and are designed to flex in a limited region of 
stress and strain so that they act as an elastic portion of the carrier 52 
to compensate for the differential rate of thermal expansion between the 
aluminum alloy of the carrier 52 and the iron base portion 19 of the 
cylinder head assembly 12. 
Each of the bulkheads 74 and 76 is integrally formed with a ring-shaped 
bearing portion 84 at one end thereof which is provided with a cylindrical 
opening 86 in which the journal portion 88 of the camshaft 56 is supported 
for rotation. As seen in FIG. 6, it will be noted that the cylindrical 
opening 86' in the bearing portion 84' of the bulkhead 76 has a smaller 
diameter than the cylindrical opening 86 of the bulkhead 74. Similarly, 
the journals 88 of the camshaft which are located in the cylindrical 
openings 86, 86' of the bulkheads 74 and 76 will have an outer diameter 
appropriately sized so that they fit into the accommodating cylindrical 
openings 86. This allows the camshaft 56 to be readily inserted axially 
into the cylindrical openings 86 of the carrier 52. The bulkheads (not 
shown) positioned adjacent the cylinders of the engine 10 to the rear of 
the bulkhead 76 will also have cylindrical openings which are 
progressively smaller so as to allow the camshaft 56 to be inserted 
axially into the bearing portions and retained axially by a thrust plate 
89 seen in FIG. 2 in combination with the camshaft gear or sprocket (not 
shown). This arrangement also facilitates the machining process by using 
stepped tooling. 
The bulkhead 74 is located at the front end of the engine and is integrally 
formed with a pair of laterally spaced and cylindrically shaped tappet 
guides 90 and 92. As seen in FIGS. 2 and 3, the tappet guide 90 supports 
the inverted bucket tappet 60 which is in contact with the upper end of 
the valve stem 40 of the exhaust valve 34 for movement along the 
longitudinal center axis of the associated valve stem 40. Similarly, the 
tappet-guide 92 supports the inverted bucket tappet 64, which is in 
contact with the upper end of the valve stem 36 of the intake valve 30, 
for movement along the longitudinal center axis of the associated valve 
stem 36. Both the exhaust valve 34 and the intake valve 30 are each biased 
into a closed position by a coil compression spring 94 the upper end of 
which abuts a retainer 96 secured to the valve stem by a conventional 
two-piece lock 98. The lower end of each of the springs 94 is located 
within a spot-faced recess on the top deck of a valve stem guide 100 which 
is integrally formed with the base portion 19 and supports the associated 
valve for reciprocal movement. 
As seen in FIGS. 3 and 4, the bulk-head 76 is integrally formed with a 
tappet guide 102 supporting the inverted bucket tappet 58 associated with 
the exhaust valve 32 for movement along the longitudinal center axis of 
the associated valve stem 40. In addition, a tappet guide 104 integrally 
formed with the bulkhead 76 supports the inverted bucket tappet 62 
associated with the intake valve 28 for movement along the longitudinal 
center axis of the associated valve stem 36. Similarly, the exhaust valve 
32 and the intake valve 28 are supported in the base portion 19 by parts 
corresponding to the parts supporting the exhaust valve 34 and intake 
valve 30 as seen in FIG. 2. In addition, although not shown, it will be 
understood that the bulkhead 76 has tappet guides such as tappet guides 90 
and 92 integrally formed on the side opposite the tappet guides 102 and 
104 for the intake and exhaust valves associated with the cylinder to the 
rear of cylinder 22. Similar bulkheads with two sets of tappet guides 
would be provided between the other cylinders and the last bulkhead would 
be a mirror image of the front bulkhead 74. 
As seen in FIGS. 1-5, opening of the exhaust valves 32, 34 and the intake 
valves 28, 30 against the bias of the associated springs 94 is controlled 
through the actuator system 15 which in this case, as shown, includes four 
identical "L" shaped actuators 106, 108, 110, and 112 each of which, as 
seen in FIG. 7, comprises an arm portion 114 integrally formed with a leg 
portion 116. The leg portion 116 of each of the actuators 106-112 is 
provided with a flat top surface 118 and is supported for reciprocal 
movement by a guide pin 120 the lower end of which is fixed to the top 
deck of the base portion 19. The longitudinal center axis of each guide 
pin 120 is positioned parallel to the axis "A" of the cylinder 22. 
The head end of each arm portion 114 of the actuators 106-112 is provided 
with a combination spherical and sliding joint. Thus, as seen in FIG. 4, a 
combination spherical and sliding joint is positioned between the actuator 
106 and the inverted bucket tappet 60, between the actuator 108 and the 
inverted bucket tappet 58, between the inverted 110 and the inverted 
bucket tappet 64, and between the actuator 112 and the inverted bucket 
tappet 62. As seen in FIGS. 5 and 7, the combination spherical and sliding 
joint, in each instance, is the same in construction and includes a 
half-ball member 122 having an integral upwardly extending tongue 124 
defined by a pair of spaced flat and parallel side walls 126 and 128 and a 
flat top wall 130 which is located in a plane normal to the associated 
side walls 126 and 128. The half-ball member 122 also includes a spherical 
lower surface 132. The top portion of the tongue 124 of the half-ball 
member 122 is slidably received by a slot 134 formed in the head end of 
the arm portion 114. The slot 134 is "U" shaped and of uniform cross 
section and extends along the longitudinal axis of the associated arm 
portion. The lower spherical surface 132 of the half-ball member 122 is 
located within a spherical recess 136 centrally formed in a socket member 
138 which is formed as a separate disc member centrally positioned within 
a circular recess 140 in the top of the associated inverted bucket tappet. 
As an alternative, the socket member 136 can be made integral with the top 
of the associated inverted bucket tappet. 
The actuators 106-112 are operated by the rocker arms 66-70 which are 
supported for oscillation by a rocker shaft 141 secured to one shoulder of 
the bearing portion 84 of each of the bulkheads 74 and 76 by a bolt 142 
which extends through a cap 144, through the rocker shaft 141, and through 
the corresponding hole 143 in each bulkhead 74, 76 into a threaded opening 
(not shown) in the base portion 19. The rocker arms 66 and 70 are mirror 
images of each other with the tail end portion of each being provided with 
a spherical joint 146 of the type frequently referred to as an "elephant 
foot". On the other hand, the rocker arm 68 is somewhat shorter in length 
than the rocker arms 66 and 70 and has the tail end thereof provided with 
a dual-end arrangement supporting a pair of spherical joints 148 which are 
identical in construction to the spherical joint 146 of the rocker arms 66 
and 70. In this regard and as seen in FIG. 2, each of the spherical joints 
146 and 148 includes an adjusting screw 150 the shank portion of which is 
threaded into the tail end of the associated rocker arm and is secured 
thereto by a locknut 152. The lower end of the adjusting screw 150 is 
integrally formed with a ball portion 154 captured within a spherical 
recess of a socket member 156 having a flat lower contact surface in 
relative slidable engagement with the flat top surface 118 of the 
associated actuator. 
Thus, as seen in FIGS. 4 and 5, the spherical joint 146 of the rocker arm 
66 rests on the flat top surface 118 of the leg portion 116 of the 
actuator 106 while the spherical joint 146 of the rocker arm 70 rests on 
the flat top surface 118 of the leg portion 116 of actuator 108. Also, the 
two spherical joints 148 of the rocker arm 68 rests on the flat top 
surface 118 of the actuators 110 and 112. The screws 150 serve to 
individually set the lash-adjustment for each valve actuating mechanism. 
The head-end portion of each rocker arm 66, 68, and 70 is provided with a 
roller 160 supported for rotation by a shaft 162 fixed to the associated 
rocker arm. As seen in FIGS. 2 and 3, the rollers 160 of the rocker arms 
66, 68, and 70 are in rolling contact with cam lobes 164, 166, and 168, 
respectively, formed on the overhead camshaft 56. Both the camshaft 56 and 
the rollers 162 are each supported for rotation about an axis which is 
substantially parallel to the rotational axis of the engine crankshaft. 
Also, the longitudinal center axis of the rocker shaft 141 about which the 
rocker arms 66-70 oscillate is parallel to the rotational axes of the 
rollers 160 and the camshaft 56. 
It will be noted that each of the guide pins 120 associated with the 
actuators 106-112 and the valves 28-34 are strategically located so as to 
realize an efficient operation of the valve train mechanism 14 and provide 
sufficient space for the spark plug in the case of a spark ignition engine 
and for the fuel injector in the case of a compression ignition engine. 
Thus, as seen in FIG. 3, the center of the guide pin 120 of the actuator 
106 is located along a line interconnecting the center of the half-ball 
member 122 of the actuator 106 and the center of the half-ball member 122 
of the actuator 110. Similarly, the center of the guide pin 120 of the 
actuator 108 is located along a line interconnecting the center of the 
half-ball member 122 of the actuator 108 and the center of the half-ball 
member 122 of the actuator 112. Also, as seen in FIG. 3, the center of the 
guide pin 120 of the actuator 110 is located along a line interconnecting 
the center "A" of the cylinder 22 and the center of the half-ball member 
122 of the actuator 110. In addition, the center of the guide pin 120 of 
the actuator 112 is located along a line interconnecting the center axis 
"A" of the cylinder 22 and the center of the half-ball member 122 of the 
actuator 112. This "folded back" motion arrangement of the rocker arm 68 
and actuators 110, 112 allows the proper rocker arm ratio and physical 
disposition of all of the valve train components including the injector 
within the limited space provided for each cylinder over the cylinder 
head. 
Accordingly, with the guide pins 120 of the actuators 106-112 being 
positioned as described above, and as the camshaft 56 rotates in timed 
sequence to the associated engine crankshaft, the tail end of the rocker 
arms 66 and 70 will be pivoted downwardly as seen in FIG. 2 when the 
rollers 160 are contacted by the lift portions of the cam lobes 164 and 
168 to open the exhaust valves 32 and 34 and provide communication between 
the combustion chamber 24 and the exhaust passage 50. Inasmuch as the 
center of the tappet moves radially towards the center of the cylinder, 
the tail end of each of the rocker arms 66 and 70 moves along an arc while 
each of the associated actuators 106 and 108 (under the urging of the 
rocker arms 66 and 70) moves downwardly along a straight line defined by 
the longitudinal center axis of the guide pin 120. During this motion, the 
socket member 156 of the spherical joint 146 of each rocker arm 66 and 70 
will slide in the transversal plane relative to the associated actuator. 
At the same time, as the actuators 106 and 108 are moved downwardly by the 
rocker arms 66 and 70, the combination spherical joint and sliding 
connection between each of the actuators 106, 108 and the associated 
inverted bucket tappets 58, 60 serves to compensate for the skewed 
movement of the tappets towards point "B" as seen in FIG. 1. Since each of 
the inverted bucket tappets 58, 60 experiences a compound movement during 
this time, the associated actuator also experiences a compound movement 
due to the position of the guide pin 120. In other words, each of the 
actuators 106 and 108 not only moves in a downward direction along the 
associated guide pin 120 but, in addition, the arm portion 114 of each of 
the actuators 106 and 108 pivots about the associated guide pin 120 as 
indicated by the arrows in FIG. 3. This movement occurs because, as seen 
in FIG. 3, each inverted bucket tappet 58 and 60 moves downwardly along 
the longitudinal axis of the associated valve stem, so it also moves 
towards the center axis "A". This movement, in turn, causes the half-ball 
member 122 to slide within the slot 134 relative to the associated arm 
portion 114 in a direction towards the guide pin 120 of the associated 
actuator while the latter pivots about the guide pin 120. At the same 
time, the half ball member 122 within the accommodating spherical recess 
136 compensates for the movement of the associated inverted bucket tappet 
along a path different from that followed by the downwardly moving arm 
portion 114 of each of the actuators 106 and 108, while it also rotates in 
relation to the socket member 138. 
A somewhat different movement of each of the actuators 110 and 112 occurs 
when the lift portion of the cam lobe 166 causes downward movement of the 
tail end of the rocker arm 68 to open the intake valves 28 and 30 against 
the bias of the associated springs 94. In this regard, it will first be 
noted that sliding movement of the two spherical joints 148 relative to 
the flat top surfaces 118 of the actuators 110 and 112 occurs similar to 
that as explained above in connection with the rocker arms 66 and 70 and 
the actuators 106 and 108. In this instance, however, inasmuch as the 
longitudinal center axis of each arm portion 114 of each of the actuators 
110 and 112 moves downwardly along a plane which passes through the 
longitudinal center axis of the valve stem 36 of the associated intake 
valve and axis "A", neither of the actuators 106 or 108 experience 
pivoting about their guide pin 120. The tongue 124 of the half-ball member 
122 associated with each the actuators 110 and 112, however, experiences a 
sliding movement within the accommodating slot 134 towards the guide pin 
120 of the associated actuator. In addition, the half-ball member 122 
within the spherical recess 136 of each inverted bucket tappets 62 and 64 
compensates for the different angle of motion of the actuator and the 
tappet. The actuators 110 and 112 move in a vertical plane while the 
tappet moves in a radial plane, that is, a combination of longitudinal and 
transversal planes. From a practical standpoint, the spherical joint 
allows simple and inexpensive manufacture of interchangeable parts which 
are not position-sensitive. In other words, the identical inverted bucket 
tappets 58-64, half-balls 122, socket members 138, and actuators can be 
installed in combination with any of the tappet guides 90, 92, 102, 104 at 
random, without matching. Furthermore, the ball and socket mechanisms also 
allow free rotation of the tappets 58-64 and sockets 138 about their own 
axis to minimize wear. 
With reference to FIG. 3, it will be noted that, if desired, one could 
reposition the guide pins 120 of the actuators 110 and 112 so they are 
located closer to the guide pins 120 of the adjacent actuators 106 and 
108. If this were done, the center of each guide pin of the actuators 110 
and 112 would no longer be in the aforementioned plane passing through the 
longitudinal center axis of the valve stem of the intake valve and the 
axis "A". As a consequence, each actuator 110 and 112 would experience a 
similar compound movement as enjoyed by the actuators 106 and 108 
associated with the exhaust valves 32 and 34. Namely, a downward movement 
along the associated guide pin 120 and the pivoting about the guide pin 
120 as the actuators 110 and 112 are being depressed by the rocker arm 68. 
Accordingly, it should be apparent that the different arrangements and 
positions of the guide pins 120 provide different degrees of oscillation 
of the actuators and sliding of the half-ball at the end of the actuator 
arm portions. With the arrangement typically shown for actuation of the 
exhaust valves, the actuator will have the maximum range of oscillation, 
but the half-ball at its end will have the minimum amount of sliding 
motion. With the arrangement as shown for the intake valves, there would 
be no oscillation, but the sliding movement would be at its maximum. 
As should be apparent from the above description, this invention provides a 
new and improved actuator system and, in effect, provides a new valve 
train mechanism. Moreover, as disclosed in the accompanying drawings (the 
cross sections and isometric views of which were taken from true 
engineering drawings), the valve train mechanism shown is incorporated in 
a rather small diesel engine of 98.4 mm bore diameter. In this regard, it 
will be noted that in spite of the use of radial valves and their larger 
spread between the valve stem tips, the width of the cylinder head is 
quite acceptable. In addition, the design of the cylinder head satisfies 
the requirements for short rocker arms with low mass and a very compact, 
light and narrow cylinder head while allowing high-flow radial valves, 
placed side-by-side with efficient intake and exhaust ports. 
Various changes and modifications can be made to the above-described valve 
train mechanism and the actuator system without departing from the spirit 
of the invention. For example, although the center of the guide pin 120 of 
each actuator 106, as seen in FIG. 3, is described as being located along 
the line interconnecting the centers of the half-ball members 122 
associated with the actuators 106 and 110, it will be understood that the 
center of such guide pin 120 could be moved slightly to one side or the 
other of such line (as could be required by packaging considerations) 
without effecting the operation of the valve train mechanism 14. The same 
applies to the location of the center of the guide pin 120 of the actuator 
108. Accordingly, such changes and modifications are contemplated by the 
inventor and he does not wish to be limited except by the scope of the 
appended claims.