Note: Descriptions are shown in the official language in which they were submitted.
CA 02357794 2001-08-21
ATTAIN TECHNOLOGY INC.
ATTAINS NEW SPRING MEDIA
( A N S M )
SUBMITTED TO CIPO ON
AUGUST 18, 2001
DEVELOPED AND PREPARED BY
NICHOLAS M. OTTLYR
CA 02357794 2001-08-21
- Index, page 1 -
ATTAINS NEW SPRING MEDIA
I N D E X
Page
Ir~troducti~
Current Engine Technology a, b,
Attains Design Objectives c, d,
A. DLJC'S - D~t~rL aDIL SPRINGS
Introduction
a) External Actuation 1
b) Internal Actuation 5
c) External Extension 8
B. TANDEM SPRIrIGS
Introduction 11
1) OHV/SOHC/MVS Tandem Spring 12
2) SOHC/DOHC Tandem Spring - MODEL I 14
3) SOHC/DOHC Tandem Spring - MODEL II 18
C. THE "M" SPRING
Introduction 21
Component Description 22
Operating Principles Of M-Spring 23
. . . cont'd
CA 02357794 2001-08-21
- index, page 2 -
D. MJLTI VALVE SYS~ (MV5)
Introduction 25
a) Single Cam Actuates Two Valves
i) By intermediate Component 27
ii) Direct Actuation Of Above 32
bWta~o Cam-Lobes - One Spring 36
c) One Ca~rLobe - One Spring 39
di 2 Lobes Open - 1 Closes 2 Valves - No Springs 42
e) Combinations Of Above - In One Cylinder Head 47
CA 02357794 2001-08-21
- a -
IN~RO~K'1Z~N
Current Engine Technology
In the year of 2001, virtually all 4-stroke internal canbustion engines with
valves actuated by camshafts - and closed by springs - ~nploy co<npression-
type coil springs, which are c~anpressed externally by means of a valve-
cap and valve-lock assembly fastened to the top of the valve stem.
'I~neir reliability, long life and excellent service record date back to the
19th century; no wander, then, that they can be found in all types of valve-
trains, enjoying universal acceptance.
Hp~wever, the ubiquitous compression coil-spring has several key and inherent
disadvantages, acting as obstacles to any significant structural changes in
the cylinder head sub-assembly during the last 60 to 70 years; the key
disadvantages can be summed up as follows:
a) the most salient disadvantage of the long coil spring is its need for
ample overhead space, creating tall and bulky cylinder heads with a lot
of unnecessary height and weight
b) its method of actuation d~nands that the spring be depressed only fran
above, regardless of what type of valve train the engine uses, be it an
OEiV, SOHC or a DOHC
c) the compression coil calls also for a long ~~alve guide and a long valve
seem that must reach the spring almost to the top
. . 2
CA 02357794 2001-08-21
- b -
introduction - page 2
d) hence to access the valve (from the top), all related mechanisms must
also be placed very high in the cylinder head, amplifying the same
problem and creating an exceedingly tall cylinder head architecture.
A:~ a natural consequence of the above "givens" the present internal
combustion engine's cylinder head has remained essentially same for over
half a century; please refer to Exhibit A.
It follows, that if an engine designer wished to make the contemporary
cylinder head structure lighter, lower, or to save a substantial amount of
materials fran this sub-assembly - he/she would run into great obstacles.
CA 02357794 2001-08-21
F_'StHTRTT ~
THE VALVE/SPRING ASSEMBLY
1) IL-OHV ENGINE (Rockers & Pushrods)
Please note, that:
THE VALVE/SPRING ASSEMBLY
is identical to all three engine
types, in that it has very long
valve stems and guides and it also
shows a hefty cylinder-head mass
build-up below the spring seats
SOHC ENGINE (Rockers Only)
D(~~iC ENGINE ( Direct Attack )
CA 02357794 2001-08-21
- C -
ATrAIri ~ $ DF~SIC~1 ~JDCl'I'~F~S
It does appear that in the new Millenium engine producers around the world
would like to create a lighter, lower, more powerful engine with lower
e-nissions and higher performance. Above all, they would also like to
fabricate these motors at a lower-than-present costs.
While this is a tall order - facing seemingly insurmountable obstacles -
-it can be achieved in a very short period of time - and with a minimum of
disruption. How ?
Attains design objectives go hand-in-hand with the above 'wish-list',
b~rcause
a) the proposed Attain valve trains allow the lowering of the cyl. head
skructure by nearly 50$, or more, saving about 20~ to 25$ of its raw-
materials; in terms of dollars saved, it could mean a saving of $40 to
$50 in a small, 4 cylinder in-line engine and $75 to $100 in a V-8 motor
(with two cylinder heads.) - Much larger savings can be expected in large
cex~rcial, military, or marine engines
b,~ the reciprocating weight of the proposed valve-train mechanisms is
lowered by 20~ to 35$, enabling the engine to achieve higher RPM's and
dt~livering an improved terminal BHP, by a factor.of 10$ to 20~
c) most V-6 and V-8 engines with Attains cylinder heads are about 4" lower,
which creates two benefits:
1. intake runners can be lengthened up to 24"- 26", augmenting engine's
torque, AND
2. lower motors will lead to lower hood profiles, improving the aero-
dynamic drag and producing better highway mileage
CA 02357794 2001-08-21
-d-
design objectives - cont'd
d) when Attains valve train designs are applied to a cylinder head, its
main casting is reduced to a height of only about 50 to 70 mm, plus the
cam-stands. ~ doubt - it may verywell tgnpt the manufacturers to fabricate
the entire engine as a single unit, merging the engine block with the
cylinder head; such fabrication process could make the engine another 50
to 100 lbs. lighter and save a great deal of money, virtually doubling
the savings achieved in the application of valve trains alone.
O~~erall, Attains design objectives were formulated with two, over-riding
principles in mind:
1. _the engine's entire cc~nbustion process remains as is - at "status quo" -
- since the proposals are in the domain of structural & mechanical changes.
All elements of ignition, fuel delivery and camshaft timing are
unchanged; same applies to the combustion chamber shape, location of the
spark plugs, and so on
2. the proposed canponents are fabricated from current grade of materials,
In summary, Attains design have immediate application potential because
there is no need to wait for the advent of any new technologies or the
development of new scientific frontiers.
CA 02357794 2001-08-21
- 1 -
A. DUAL C~UIL SPRINGS
Introduction
While all present engines employ single, tall, compressions springs, that
can be only accessed from above, Attain proposes to employ two, smaller,
lower coil springs of equal strength (of the single one) flanking the valve
stem. Furthermore, these Dual Coil Springs - or 'DUCS' for short - can be
actuated in threw various ways, extending their application to OHV, SOHC,
DOHC and other valve-train types.
a) brternal. Actuation of Dual Coil Springs (DUOS)
Two short compression coil springs mounted on elevated pedestals and
straddling a short-stem valve are compressed externally from the top by
two sprint-caps which are either integral with a horizontal bar
attached to an extended valve-lock accessed by an intermediate valve
train component, or compressed directly by a cam-lobe bearing down on a
plain, or roller-topped bucket.
General Description
TWO half-length compression coil springs are placed on each side of a short-
stem valve, leaving a gap of about 12 to 14 mm between them to allow an
intermediate valve-train c~xnponent, like a rocker, or an arm, or a portion
of the cam-lobe to pass freely between them.
Tie bottoms of the coil springs are mounted in two, round seats or
pedestals, near the top of the valve's guide.
CA 02357794 2001-08-21
- 2 -
e:~t . actuation of DLICS - cont' d
A valve lock - fastened to the top of the valve-stem - forms an oblong
vertical opening, or a "window" - for a valve-train component to open the
valve; above this "window". a horizontal cross-bar joins two round, or
conical valve-caps that canpress both springs simultaneously.
Since the valve is closed by two smaller coil-springs - instead of one
larger and taller one - the component engaging the valve can be applied at a
much lower level as well; both factors are responsible for a reduction of
height of the cylinder head structure.
AD~though the two compression coils are smaller and reduced in height, their
cY~nbined strength, or closing force will have the same rating as the single
o:~e .
Wuile the two coil springs should offer adequate resistance against the
'cocking force' exerted against the valve's stun, a small roller tappet
should be used either in the rocker arm, or above the valve stem itself.
Frcxn an application's point-of-view, the Dual Ccxnpression Coil Spring
assembly is suitable for the following valve train types:
a) OHV-Pushrod engines
b) SOHC engines with intermediate ca~ponents
c) SOHC/DOHC engines engaging the valve directly
d) Multi-Valve Systems (please see below)
CA 02357794 2001-08-21
d~acs - cont-d 3
FIGURE 1
Front View
1. Two, short compression coils are used as a closing media for the valve;
their c~nbined force equals one, long compression coil spring.
2. Two pedestals, with circumference of aprrox. 320° to 330°
degrees
support both springs, allowing sufficient gap between thin for the
actuation of the valve by an intermediate valve train c~nponent.
3. TWiO hat, or cone-shaped spring-cad combine with vertical braces and a
valve-lock to canpress both coil springs externally and to lift the
valve back into its seat at the end of the open-valve event.
4. A short-stun valve, with a proportionately short valve guide is
positioned in the middle of the two compression coil springs.
5. Tip of the rocker-arm with a roller accessess the top of the valve stun
through an opening in the dual spring-cap component.
Zbp View
6. Off-set rocker-arm moves inside the valve lock's opening to actuate the
valve mechanism.
FIGURE 2
Side View
1. Assembly shown in a side view with the valve, one of the springs and a
spring-cap; the side "A" showing the actuation by a rocker arm (OHV-
Pushrod engines) and "B", by a roller-finger-arm, used in SOHC and sane
DDHC motors.
. . . cont'd
CA 02357794 2001-08-21
ducs - cont'd
FIGURE 3
Frost View
1. Dual compression-coil springs in an SOHC engine
2. Dual spring-caps, valve-lock integral with a ball-tappet
Side View
3 , Actuation by. a curved arm, bearing down on a valve stem, topped with a
ball-tip tappet.
View
4, Curved~arm with groove for a ball tappet.
5. Trailing arms mounted in a Hydraulic valve-lash adjuster.
FI(~JRE 4
FYaet View
1. Two coil springs in an DOHC valve-train. Roller-top tappet, two spring
caps and a valve-lock are integral - and guided in two vertical columns.
Side View
2. Support of coil-springs is integral with a lower valve-guide
3. Valve operates in 2 valve guides: an upper and a lower one.
4. Vertical guides serve the ass~nbly as the upper valve guide; with the
lrywer valve guide, the valve receives complete .upport.
CA 02357794 2001-08-21
- 5 -
dual coil springs - cont'd
b ) Internal Actuation Of Dual. Ga~ression Coil ings
Two short compression coil springs mounted on elevated hollow-center
p'destals and straddling a short-stem valve are compressed internally
by two flared-out top tubular components that are attached at their
b~~ttoms to a cross-bar which is fastened to a valve lock which in turn
is pushed down either by an intermediate valve-train component, or
compressed directly by a Gam-lobe bearing down on a plain, or roller-
topped bucket.
General Component Description
Two ccxnpression-coil springs, with a gap of about 14 mm between them, are
placed on each side of a short-stem valve. The coil springs are seated in
doughnut-shaped pedestals with an opening in their center, which allow a
hollow, tube-like vertical canponent to access the springs internally; at
the top, the vertical component flares out, forming a 'tulip', so that when
it is pulled down, it is able to compress the valve; the bottoms of these
pall-down components are fastened to a horizontal. cross-bar, which is an
integral part of the valve-lock sub-assembly.
When an intermediate valve-train component, such as a rocker arm, or the end
of a roller-finger arm reaches the top of the valve, it pushes the valve
dawn to open it
CA 02357794 2001-08-21
dual coil springs - cont'd
internal actuation - cont'd
- 6 -
In the case of OHV, or SOHO valve train mechanisms described above, the
v:ilve-lock sub-assembly provides either an opening for the arms, or the
siring to open the valve from the top; in applications whexe the cam-lobe
bt=ars down on the sub-ass~nbly directly, the cross-bar is located below the
top end of the valve.
Just as in case a) above, the internal ccenpression of DUCS delivers a much
reduced height of the cylinder head and its entire sub-assembly.
Figures For Internal Aatuatiocn of DUOS
zTrrlmr
~,~ ~m a_,
1. ~ saaall. diameter "straight-cut" coil springs flank a short-stem valve.
2. The bottcans of the springs are placed in circular pedestals, covexing
about 300° to 330° of a circle, to allow more room around the
valve's
stem. Centers of the pedestals are hollow for insertion of spring
depression devices. The pedestals are mounted on solid portions of the
c3~linder head to assure the spring's stability.
3. An elongated spring-cap, is fastened in the middle to the valve-stem by a
valve-lock, has two round openings at each end for the insertion of
spring compression devices that must be inserted frcxn the bottom and
sacured by a small cap and lock.
4, Springs are cornpresse~d internally by small tubes with flared-out tops,
resembling the shape of a funnel, or a 'tr~unpet.' They are inserted from
tjie top and secured at the bottom to the elongated spring-cap.
S.The space between the springs permits an intermediate canponent, such as a
rocker(OHV), or a roller-finger-arm (SOHC engines) to compress both valves.
. . cont'd
CA 02357794 2001-08-21
dual coil springs -cont'd
figure 10 - cont'd
6. For reduced friction between the intermediate device and the valve-
lock, a roller may be placed either above the valve-lock, or, directly
in the intermediate device.
- VleW
7. The dual, elongated, eye-shaped spring-cap shows its circular opening
for the insertion of the 'trumpets.'
8. Gap, or space between the coil springs - for the engag~nent of the
pull-down elenuent.
Side View
1. Assembly viewed from the side. showing its alternate method of actuation.
2. Detail of pull-down el~nent (trtu~et) with its flared-out top, tube and
p~~rtion of the valve-cap and its locking device.
FIGURE 12
Front View
1. Camshaft bears down directly on a -
2. Roller-Tappet, supported by an oblong guide.
3. Pair of internally ccxnpressed coil-springs.
4_ Spring cap with two 'trumpets.'
5. Lower valve guide suppl~nents support of the valve with the upper one.
View
6. Oblong, upper valve guide with a roller-top tappet.
7. Rounded, vertical walls allow the roller-top tappet to move up-and-
down - and also as an upper valve guide.
CA 02357794 2001-08-21
-
dual coil springs - cont'd
c) bcternal Vision Of Dual Coil Springs
Trle top ends of two extension coil springs are solidly attached to an
overhead structure, or ceiling, leaving a gap between thin to allow
the top of a valve to be opened either directly by a cam-lobe, or an
intermediate valve-train component, which actuates a cross-bar with two
spring caps attached to the bottoms of the said springs causing these to
extend.
General Component Description
extension coil-springs are suspended above a short-stem valve from a
rigid, overhead structure, which may be called a 'ceiling'; the coil-springs
are turned, or screwed-in into special anchors that prevent their rotation.
When this valve-train is used in OHV, or SOHC engine types, the two coil
springs must be about 14 mm apart, to allow either a portion of the cam-
lobe, or an intermediate valve train component to reach the top of the valve
and its valve-lock sub-assembly. When the valve-train is used in a DOHC
engine, the gap between the two coil springs may be narrower.
CA 02357794 2001-08-21
- g -
dual coil springs - cont'd
extension coils - cont'd
4~hen the valve is being opened, a cross-bar that is fastened to the valve
stem is provided with two special valve-caps, capable to engage both
springs, so they can be extended. Of note is the fact, that extension coil-
springs can be made more canpact and be shorter than their copression-
type counterparts, so that less space is needed to accommodate them.
A further advantage of extension coils is their reduced exposure to heat. In
the case of the above mechanisms the known effect of "heat soaking' is
virtually eliminated, since the ' ceilings' frcm frcxn the coil springs are
s:~spended from is far removed fran direct heat of canbustion.
Figures For E~~:wal. F~cte~sion Of
Dual Coil Springs
Figure 20
Front View
1~. -~. structural support, called a ' ceiling' is on top of the mechanism and
provides dual, round seats for two extension coil springs, which are
screwed-in, into special receptacles, firmly holding the springs. Four
vertical braces are anchored to a solid portion of the cylinder head.
2. Placed in the middle of the two circular supports is a tubular, upper
valve guide, which stabilizes the valve -stem-valve-cap assembly and
prevents the valve stun from a side-thrust, or coking.
3. Valve-cap and Valve-lock assembly has two lateral arms, which pull the
c~~il-spring's down at the springs' bottoms; this component also locks
. .. cont'd
CA 02357794 2001-08-21
- 10 -
ducs cont'd
figure 20 - cont'd
onto the valve's stem.
4. Opening above the valve lock permits an intermediate valve train
c~ponent to actuate the valve
5. Tubular extension of the valve-cap/valve/lock assembly.
6. Lower valve-guide, which together with it~n No. 5 above, give the valve
stem and the valve complete stability.
Top View
7. Ceiling, or top support for the two coil springs.
8. Upper ends of vertical supports, through which the assembly can be
attached to the cylinder head.
9. Upper valve guide.
CA 02357794 2001-08-21
- i1 -
'.~AND~i SPRINGS
IIltrOduCtlOI1
Tandem Springs are - just like the Dual Coil Springs - a set of two springs
but they are not actuated simultaneously; instead, they operate in a
sequential fashion. First, a primary spring is compressed and its energy is
transmitted to a secondary spring by means of a flex-ring, which is a
static, light and drum-like canponent with two rims on its opposite ends:
one is facing inward - the second one outward. - The three basic types of
the Tandem Spring can be applied to virtually all known valve-train types is
use today; its variants are also proposed for the "Multi-Valve Systems" to
b. reviewed below. The three basic Tandem Spring types are:
1. OHV/SOHC Type: an intermediate valve-train canponent, such as a rocker,
or a roller-finger, pushes down on a valve-lock with an appropriate opening
to pull the Tand~n Spring ccxnponents down
2. SOHC/DOHC Type, Model I; the cam-lobe bears down on the top of a roller-
top assembly, simultaneously opening the valve, whose stem is attached to
this assembly; it compresses first a small, primary spring, whose 'flex-
ring' transmits is motion and energy to a large, secondary spring
3. SOHC/DOHC Type, Model II; here, the cam-lobe bears down on the roller-
top assembly and opens the valve - but compresses a large-diameter, primary
spring first, whose flex-ring transmits its energy to a small, secondary
spring, which is anchored near the valve's guide.
Again, the main objective of the Tandem Spring' is to reduce the height of
the engines' cylinder heads sub-assembly and to economize its manifacturing
costs.
CA 02357794 2001-08-21
- 12 -
tandem springs - con't
1) OHV/90HC/MV5 Tandem Sp~in9
A :short valve-stgn is topped with a valve-lock assembly that forms
first a "window" allowing a valve train component to depress the said
valve and continues to form an extension with a flared top, capable to
c~~cnpress a small primary coil spring whose bottom is supported by an
inward lip of a flex-ring that reaches up and in turn engages a
secondary spring with its outward lip, so that it can be compressed
against its circular, ring-type seat at its bottom.
C~nponent Description
A valve with a short stem is fastened to valve lock assembly that forms
first an opening, or a "window", which allow access for an intermediate
v:~lve train component, which will push the valve with the entire assembly
down.
A; vertical extension - in the form of a hollow tube - rises upward and
flares out at its top and a~mpresses a small diameter primary spring.
'I'tie bottcm of the primary spring is supported by an inward lip of a flex
ring, that is slightly larger than the primary spring and rises upward to
form and outer lip, that in turn engages a larger diameter secondary spring.
The secondary spring is supported at its bottom by a ring, which allows free
travel downward for the primary spring with the flex ring, since its center
is void.
CA 02357794 2001-08-21
- 13 -
tand~n springs - cont'd
FIGURE 30
Tandan Spri-n9 For OHV/SOHC Engines
Front View
1. The bottom of a short-stem valve is supported by short lower valve guide
a~-~d the top of its stem is inserted into a valve cap and valve lock.
2. The valve-lock & valve-cap combination forms a "window" above the
valve's stem, so that an intermediate valve train component, such as a
rocker-arm (OHV), or a roller-finger (SOHC) engines, can access the
v:~lve assembly to push it down.
3. An u~naard, tubular extension fastens to item no. 2 above and becomes the
u~~per-valve-guide - as well as a compression element, or 'trwnpet' that
compresses the primary spring.
4. When the primary spring is compressed, it transmits its motion to a
lower rim of a "flex ring".
5. The upper portion of the "flex'ring" - an outward shaped ring - in turn
c~xnpresses the secondary spring.
6. The secondary spring, which is firmly seated in its pedestal, is
axnpressesd against its seat - absorbing about 50~ of force transmitted
to it by the primary spring.
7. The upper valve guide & stabilizer assembly is attached to the secondary
spring housing - and consists of -
8. A lid, or brace, that holds its center - and of a guide, which aligns a
tube, so that it can serve as a stabilizer.
CA 02357794 2001-08-21
- 14 -
tand~n springs - cont'd
2) SOHC/DOHC Tandem :ring
MODEL I
p, plain, or roller-topped circular bucket with matching support walls
and hollowed cavities enabling a free passage of the cam-lobe, has below
its center a valve-lock for the attachment of the valve's stun and also
fozms a seat for a small diameter primary coil spring, whose bott~n
rssts on the inward rim of a flex-ring, which rises upward so that its
t.~p, outward-facing rim can engage the top of a larger, secondary coil
spring which is c~npressed against a circular pedestal with a void
center.
Canponent Description
A circular-shaped bucket is provided with roller, which rotates around an
axle inserted from one side of the bucket.
Tue center has cavities - running north and south on its surface, which
allow the lobe of the camshaft to turn freely inside it. The bucket itself
is supported matching walls; to counter-act the side thrust of the rotating
camshaft, the leading edge of the supporting wall is slightly higher, while
the trailing edge is lower. At its bottom, the bucket has also an irregular
s:zape: the leading edge is longer - the trailing edge, or rim is higher, in
order to clear the rising engine port.
. . . cont'd
CA 02357794 2001-08-21
tandem springs - cont'd
- 15 -
The center of the ' bucket' - below the toller-axle - has a short neck with
a~ opening, which serves as an attachment for a short-stem valve. The valve
is attached to the bucket by a standard valve lock, which also allows the
rotation of the valve.
A small diameter spring - calla~ primary - is seated under the bucket and
terminates in a supporting inside rim of a c~nponent called "flex-ring." The
flex ring is a short, inflexible piece of tube, or a drum, with two rims, or
lips: the one at the bottom is curved inward - and the top one curves
outward .
Wnen the primary (small diameter) spring is pushed down, it engages the flex-
ring, which in turns starts compressing the larger-diameter, secondary
spring with it. The secondary spring is firnlly seated inside the bucket on a
circular pedestal, which is integral with a short lower valve guide.
T-tie operating principle of the tandem spring device is, that each of the
scorings, i.e. the primary and the secondary, shares about 50~ of the load,
or force, needed to close the valve. Therefore, assuming that the load
between the springs is a venly divided, their motion will also be about 50~
o~ travel, which reduces the overall height of the entire assgnbly as well.
WI-lile the Tandem Spring assembly can also use a plain-top bucket, which may
further reduce its overall height, the friction between the ~;am-lobe and the
bucket will be considerable. Therefore, the roller-top bucket should deliver
superior performance in terms of reduced mechanical friction.
T« prevent the rotation of the bucket in its circular fence, rather than to
uae a 'key', the side through which the axle is inserted into the bucket may
made into a section of a flat wall - its enclosure matching this shape.
't'~e stability of the short-stern valve is assured by two valve guides : the
lower one - and the upper valve guide which is the center of the bucket
itself, where the valve stem inserted.
CA 02357794 2001-08-21
- 16 -
tandem springs - cont' d
FIGURE 31
Model I Tandgn Springs For 90HC/DOHC Engines
Side View
1. Roller-Top Bucket with 'cavities', or voids, to allay free passage of
cam's lobe.
2. Neck, or tubular extension of bucket for the valve's lock and for the
i~zsertion of the valve' s stun.
3. Seat of PRIMARY - small diameter spring
4. 'Flex-Ring' and its inward, lower rim, or lip
5> 'Flex-Ring' and its outward, upper rim
6. Large SECONDARY coil spring, which is pushed-down by the outward rim of
the FLEX Ring.
7. Lower valve guide and pedestal for the SECONDARY spring.
8. The rising, lower lip of the bucket.
9. Outward guides for the bucket.
FIGURE 32
Component Details Far Model I
A. Roller-Top Bucket - Top View
1. Roller with axle and its lock
2. Axle inserted fran 'flat side' of bucket
. . . cont'd
CA 02357794 2001-08-21
- 17 -
tandem springs - cont'd
figure 32 - cont'd
3. 'Cavities', or scalloped areas in the bucket for free passage of the cam-
lobe
4. Round, cylindrical walls guiding the bucket
5. Flat portion of the (round) guide, acting as a 'key' which prevents the
bscket fr~n turning.
B: Flex-Ring - Top View
n~ Inward facing rim of the Flex-Ring - for the primary spring
7. Vertical wall of the flex-ring
8. Outward facing rim of the flex-ring, supporting the secondary; larger
spring.
CA 02357794 2001-08-21
- 18 -
tandem springs - cont'd
3 ) SO~C/DOHC Tarx~n Spring
I~EL II
A Main, roller-topped
or circular
bucket. with
matching
support walls
has hollowedcavities enabling the passage the cam-lobe, has below
of
its center valve-lock the attachment the valve's stun and
a for of also
forms a diameter, primarycoil-spring whose bottom
seat for
a large
rusts on outward rim a flex-ring whichrises upward, so that
the of its
top with inward-facingrim can compresssmaller, secondary
an a coil
spring resting support above
on a circular the said valve's
guide.
Canponent Description
The functioning of the Model II Tandem Spring is virtually the same as that
in Model I, except there is a reversal of roles in the springs;
* the larger-diameter spring beccmes the primary spring - and is depressed
first - and acts on the flex-ring, which in turn
* compresses a smaller diamter spring, which is inside it and its lower end
is supported by a pedestal near the valve's lower guide.
Ttie 'flex-ring' in Model II is slightly smaller and the roller-top bucket is
more cc~pact, allowing the engine ports to assume a steeper angle.
. . . cont'd
CA 02357794 2001-08-21
- 19 -
tandem springs - cont'd
TT/.f717T
TaIIdeSI1 lng M(7del 1l. - S~~lneS
Side View
1. Large primary spring is compressed from the top by the roller-top
b~icket, pushing the flex-ring down.
2. Flex-ring, rises to the top, to engage a
3. Small, secondary spring, which is compressed against its seat that
s~irrounds the valve's lower valve guide.
FIGURE 34
Z'andem ing Model II - .Gom~onent Detail
Fret View
1. The flat side of a roller-top bucket, which allows the insertion of axle
for the roller
2. Seat of the large, primary spring
3. Valve lock with top of valve's stem
TTl~7TT 7C
Side View
A flat-top bucket version of a Tandem Spring - Model II
CA 02357794 2001-08-21
the "m" spring - cont-d - 20 -
FIGURE 36
TAD~F1~I SPRINGS 1~JDEL II
INS~LLED IN AN
J~ ~c v-8~oRn r..naoorrmGn~
Side View
1. A Model II Tandgn Spring Assembly is installed in a Jaguar XK V-8/Ford
Lincoln Engine to demonstrate its cylinder head height reduction
capability. The Attain rendition shows an 80 mm reduction in height of
the cam-box: 194 mm vs. 114 for the Attain assembly:
2. The centers of the camshafts reveal a corresponding reduction: in the
Jaguar engine the centers are @ 130 mm vs. 88 mm in the Attain model.
3. The main cylinder head casting height in the Attain engine profile could
b~ lowered to about 70 mm, or even less than that, creating in all cases
a substantial potential for savings in material usage and assembly line
time.
**
FIGURE 37
A complete cross section of a Jaguar KX V-.8 engine - frcdn the canpany's
sales literature.
T-tie figures shown in 'mm' are interpolated to actual size.
** Caparison Of Cyl. Heads In Inches:
Original Jag Attain Cyl. Head
MCH 7 . 5 ~~ - 4 . 5 rl ( red. 3 . 0" )
CS C 5 1/8" -3.5~~(1.5" +)
CHCH As Above - 2.5" +Flanges
CA 02357794 2001-08-21
- 21 -
the "M" spring
C. Tf~ "M" SPRn~IG
Introduction
Tree "M" Spring is also a dual, two-cc~nponent spring, with a primary and
secondary coil springs, which act upon each other in a sequential fashion.
W,~zat sets the "M" Spring apart from the above mentioned Tandem Spring is its
o~~erating principle, which combines an extension spring that is coupled by
means of a 'flex-ring' to compression coil spring. The main advantage is its
canpact size - a result of an inter-active arrang~nent, which can reduce' the
height of a spring by nearly 50~ in height.- The 'flex-ring' employed in the
"1~I" Spring is also more c~npact - adding to its reduced size.
T]~ie only disadvantage of the "M" Spring is the fact, that it is not suited
for (DOHC) valve-trains that operate without an intermediate components; the
"M" Spring must be pulled-down, rather than being canpressed fr~n above.
Tie name "M" steins from its image: when viewed from a side it resembles a
capital letter M.
Tne top inside rim of a larger compression-coil spring resting on a
center-void elevated pedestal is canpressed by a flex-ring, whose
c~..nter is fastened to a smaller extension spring which in turn is
anchored at its bottom to a tip of a valve stun with an integrated
cent'd
CA 02357794 2001-08-21
- 22 -
tie "m" spring - cont' d
abstract - cont'd
valve-lock and an opening device in the form of a collar, or a slot,
e;~gaging an intermediate valve-train component that pulls the said
valve open.
Component Description
A compression-coil spring, whose dia~ter is about equal to the 'foot-
print' of a valve, is seated in a ring-shaped, or center-void, elevated
pedestal. This higher position is mandated by the fact, that it must allow
an intermediate valve-train component to reach the tip of a short-stem valve.
A flex-ring, resembling a disc, slightly larger than the above coil spring,
compresses it; its center has a circular collar, to which a smaller,
secondary, extension spring is fastened; in turn, the bottom of the
extension coil spring is attached to a c~nbintation of a valve-lock and
m~xlified valve-cap, which fulfills three functions: it secures the tip of
the valve stgn, it provides a means, by which the valve is opened - and it
locks itself onto a the bottom of the extension coil spring.
The motion of the short-stem valve is secured by a proportionately shorter
valve guide and side thrust of the intermediate valve-train c~nponent on the
valve stein is minimized by a roller; however, additional stability - if
needed - may be obtained by employing an upper valve guide, which could be
inserted in the center of the flex-ring, fran the top.
hz operation, during a valve-open event, the valve-lock pulls on the smaller
coil spring first, extending it - and the flex-ring begins to ccxnpress the
larger, outer spring. Depending on design requirement both, or either
springs may be cone-shaped.
. . . cont'd
CA 02357794 2001-08-21
- 23 -
the "m" spring - cont'd
FIGURE 40
THE "M" SPRING AND OPERATING .PRINCIPLE
Note: for clarity's sake the image in this figure is ap~~imately double its
normal size.
Side View
1. A center-void pedestal solidly attached to a cyl. head body supports a
2. canpression coil springs, which is depressed fr~n above by a -
3. disc-shaped 'flex-ring'.
4. Two deep grooves, or threads on the underside of the 'flex-ring' permit
an extension spring to threaded-in, or other',vise fastened to it from
blow.
5. The extension spring is closely wound - because it will be extended.
6. Lower, upward facing grooves, to which the extension spring (No. 5) is
fastened - are part of a -
7. canbination of a valve-lock, a window-like opening to allow the opening
of the valve - and an upper stabilizer, or valve guide - should one be
needed
8. Tube-shaped stabilizer, or upper valve guide, whose top is attached to a
stable wall of the cylinder head; its bottom is inserted in the top eng
of part N~. 7.
9. I~ltermediat~. valve-train ccxnponent - actuation the valve.
10. Valve-stem and valve guide.
~rrrov w 7
A;z "M" Spring shown with the valve - in a reduced size. Intake valve size is
44 mm in diameter, 62 mm long.
CA 02357794 2001-08-21
- 24 -
the 'm' spring - cont'd
FIGURE 42
Side View - Of Enlarged Details
1. Center-void, elevated pedestal with a large diameter secondary spring.
2. Flex-plate pushes No.l down - but its inner rim has tabs that are
crimped to secure the primary spring fr~n underneath.
3. Primary, extension spring is secured fran below by No.2 - and from below
by a -
4. Round plate with tabs crimped around the lower end of the extension
spring pulling the spring down.
5. A hollow, vertical extension of the valve lock with a collet - attached
to the valve stem
6. Lower valve-guide and valve stun.
7. Fork-type end of a rocker, or a roller-finger arm.
8. Upper end of the hollow extension - which acts also as an upper valve
guide.
9, Stabilizer rod - anchored to a solid portion of a cylinder head to
achieve desired stability.
CA 02357794 2001-08-21
- 25 -
D. MULTI-VALVE SYSTEM
(MVS)
Introduction
By current definition, an engine with more than two valves/head is called a
"Multi-Valve Nbtor~~, Engines with 3, 4, or even 5 valves/head belong into
this family.
Wlzy are these multi-valve engines so popular ? The expense of additional
valves is justified by increased performance, i.e. more horsepower, or more
torque per unit of displacement; it is achieved by admitting more air
(oxygen) into the combustion chamber and increasing its ability to deliver
more power.
Additional valves in the cylinder usually means a doubling of valve-train
costs; if there 2 'valve on one side of the cylinder head instead of two
their cost doubles. The same applies for the exhaust-side.
Although some multi-valve engines employ different profiles for each of its
paired valves, the majority of motors use the same cam-profile for both
valves; this feature still allows them vary the valve timing for both valves
simultaneously, a system, which is very popular these days.
. . . cont'd
CA 02357794 2001-08-21
- 26 -
mvs - cont'd
Attain' a ProQo6ed Multi Valve S~staas
MVS proposals intend to reduce the cost of engine building by offering
designs in which either one cam-lobe, or one intermediate valve-train
component actuates both valves, or, in which one spring can close both valves -
or going even further - one mechanical element replaces the springs
altogether.
A~tain's Multi-Valve-Syst~ns are intended for the operation of two adjacent
valves in a 'multi-valve cylinder head', where both valves use identical
timing, i.e., their closings and openings occur simultaneously; they will
n~~t work in valve systems, where the neighbouring valves employ different
timing.
MV5 SYSr~-OC~1BIL~TIOIdS PROP06F~ BY ATTAai
a. one cam-lobe opens two valves - two springs close them
b. two cam-lobes two valves - one spring closes them
c. a single cam-lobe and spring - actuate both valves
d : two cam-lobes open two valves - one cam lobe closes them by means of a
three-prong fork; there is no main spring.
e. ccrnbination of single/dual cam-lobes and various springs.
. . cont'd
CA 02357794 2001-08-21
- 27 -
M V S S Y S T E M S
A SINGLE CAM-IpBE ACI~rTFS TiAO
VALVE/SPRING ASSEMBLIES
i ) BY IIJrF.fN~IATE OL~OI~
During a valve-open event, a tip of a roller-finger arm bears down on
an opening in a cross-bar connecting two adjacent valves, whose valve-
locks have vertical extensions leading to overhead springs which are
a~npressed internally, so that they can lift the said valves up into
their seats to close then.
Ca~o~~t Descripti~
A ;single cam-lobe, placed between 2 side-by-side valves, operates a roller-
finger-arm, anchored in a hydraulic adjuster seat. The roller-finger-arm has
t~ao arms, in a shape of wide fork, allowing the lobe of the cam to pass
between them; in front, however, the two arm join together to form a finger
that rides on a roller, which is imbedded in a cross-bar's center opening,
which could be called a "window."
The horizontal cross-bar has two, vertical and tubular portions, both on the
left and right sides.
~~e lower ends allow the insertion of a valves, which are fastened to the
c~_oss-bar by means of regular locks, while permitting the valves' rotation.
Tne upper vertical extensions are hollow tubes, that in turn lock onto
various spring c~npression components capable to pull-down and compress the
sr~rings internally.
Tree straight, or slightly tapered coil springs are each supported by a
circular pedestal - in turn fastened to a solid portion of the cylinder head.
. . . cont'd
CA 02357794 2001-08-21
- 28 -
mvs syst~ns - cont-d
c~nponent description - cont'd
Above the center of the cross-bar, immediately above the "window" is a
vertical extension in a form of a rod, that slides up-and-down in a tube,
which in turn is supported by the circular pedestals of the two adjacent
strings. This vertical rod is the assembly's upper valve guide and
stabilizer, which prevents the cross-bar to be twisted by the side-forces
that might imparted to the assembly by the roller-finger arm. Hence, the
c~_oss-bar is fully stabilized by the central upper guide and the two lower
valve guides. Further more, the pull of the springs on the valves' stem is
cxnpletely linear and vertical.
A:~ stated above, the roller-finger arm is seated on a. hydraulic valve-
lash adjuster, fully capable to compensate for any tolerance arising in the
assembly.
Ir_ should be noted, that there may be several methods of attachment of the
c~~oss-bar to the valves - but the one shown below is probably the simplest
and the most effective one.
The advantage of the mechanisms shown here is, that the camshafts can be
located on either side of the valves; this way, cylinder heads with a narrow
IVA° (Included Valve Angle) can place the camshafts on the outer side
of the
valves - as exemplified by the Jaguar/Lincon engine - or, when the IVA°
is
around 40°, or more, they can be placed near the center of the cylinder
head.
Ir_ follows, that the design offers flexibility that can accommodate a
variety of design needs.
CA 02357794 2001-08-21
- 29 -
mss - cont'd
MV'S a ) - i ) intermediate oa~onent
FIGURE 50
Side View
1. A roller-finger supported on a base, formed by a hydraulic valve-lash
adjuster, reaches an opening in a cross-bar, called a
2. window - through which both adjacent valves are opened simultaneously.
3. vertical extensions of the valve-lock is a hollow stern, which is coupled
to one of several types of Attain springs, such a Tandem, M, or a DUCS
spring, which pull the valves closed
4. Tip of the roller-finger arm, in which the two, separate arms join
together to bear-down on the "window" in the cross bar. The main body of
the roller-finger-arm has two parallel arms, letting the cam-lobe to
pass through between them.
Front View
5. Cross-Bar, showing the roller, which is imbedded in the bottom of the
' window" . The picture shows only the left side with one valve fastened
to the valve-lock formed by the cross-bar.
6. Upper valve guide and stabilizer of the cross-bar. The stabilizer is a
hollow tube - and its guide is supported by the spring pedestal
structure, which, itself is fastened to the cylinder head.
7. One of the 2 valve-guides
8. Tip of the roller-finger-azm.
CA 02357794 2001-08-21
- 30 -
m~~s - cont' d
FIGURE 51
Ft~tt View - Enlarged
1. "Window" of the cross-bar, with the roller-tappet and tip of the roller-
finger-arm
2~ Upper Valve Guide and stabilizer, showing integration with the the
pt~lestals supporting the springs.
3. Valve-locks and their extensions into w:~ich a variety of
spring-compression components can be attached.
4. Lav~er valve guides - which together with the 'stabilizer', or upper
valve guide (item 2, above) assure the assembly's complete stability.
View
5. Cross-bar, with its 'window'.
6. Left & right valve-locks and their tubular extensions
7. Roller=finger-arm, showing its tip, that is inserted into the cross-
bar's "window".
8. Dual arms of the roller-finger, through which the cam-lobe can pass
freely through.
CA 02357794 2001-08-21
- 31 -
mss - cont' d
FIGURE 52
AN MVS a) VALVE TRAIN INSPAI~ IN A
JAGC1AR/LINODLN ENGINE ( INrERN~IATE OQ~~'OI~ TYPE
Side View (In Actual Size)
1. The narrow angle IVA° (24°) allow the camshafts to be placed
over the
saort-block's shoulders, leaving the center of the cylinder head free.
2. The valve-lash adjusters for the roller-fingers operate in the space
between the individual (straight) runners of the intake and exhaust ports.
3. Cross-bar's "window", with rollers and upper 'stabilizers'.
4. Overhead springs - multiple choice.
5. Valve sizes - intake valves 35.5 mm diameter, about 50 to 52 mm long.
6. Design objectives of a much reduced cylinder head structure (and weight
reduction) are achieved, when ccmpared to the original Jaguar XK V-
8 engine dimensions that appear on Figure 53.
Measuring vertically up fr~n the deck-line the key el~nents of
a~mparison are: MCH - max. cyl.head height, C/S G - cmashaft center and
CHCH - cyl head casting height:
Item Jaguar Attain
MCH 194 (all in mm) 93 (- 101)
C/SG 130 70 (- 6~ )
CHCH 130 57 (low point)
Please Refer back 2b - FIGURE 37
Side view of a Jaguar X'K V-8 engine in reduced size; actual dimensions are
interpolated.
CA 02357794 2001-08-21
- 32 -
mvs - cont'd
MVS a) - ii) DIRF~T ANION
In a multi-valve engines two adjacent valves are opened by a single canr
lobe, which directly actuates a roller equiped cross-bar fastened to two
valve-locks with vertical extensions that circumvent the shaft of the
camshaft and rise to couple with spring caps, compressing two pedestal
mounted springs externally which close the said valves upon completion
o~ the valve-open event.
Introduction
T~iis subcategory does not employ an intermediate valve-train c~nponent;
instead, a single cam-lobe actuates a cross-bar directly, which opens both
valves simultaneously. Hence, a single cam-lobe actuates tcao valves-spring
assemblies.
~t Des~ipti~
A Single cam-lobe, installed over a camshaft with a slim mainshaft, actuates
a holler, that is imbedded in a cross-bar. The left and right ends of the
c~:oss-bar form t~ valve-locks, which hold the valves.
Ttie two valve locks have semi-circular extension that sweep upwards, so that
another set of straps can be attach~l - to the first set.
E~.ch valve is provided with a spring (several choices are available) that
closes the valve; however, the disposition of the pull-down elements is
such, that the slim mainshaft of the camshaft is allowed to move freely
between them.
Tree springs are seated on circular pedestals - and allow the vertical
straps to move freely as well.
. , cont'd
CA 02357794 2001-08-21
- 33 -
mvs - cont'd
component description cont'd
The cross-bar of this valve train requires special reinforcement to carry
the pressure exerted by the roller to the its ends - to open the valves -
without bending. To this end, a longer and stronger than normal axle is
employed by the roller - and is used as a structural element that prevents
the deflection of the cross-bar: two, right-angle components can "lean" with
their backs against the roller's axle, that ..cannot be compressed.
2b counteract the side-thrust -. imparted on the roller by the rotating cam-
lobe, two round thrust-plates could be installed on the leading edge of the
cross-bar - or a centrally located tubular stabilizer could be used below
the cross bar - space permitting.
T?lis valve-train mechanisms employs valves with very short valve stems,
ranging from 52 to 57 mm - in engines with 3 to 5 liter displac~nent - and
a:~out 33 to 55 mm in diameter.
Preliminary height projections of the MVS . mechanism installed in an engine
range from 95 to 105 mm, which is considerably lower, than existing types.
Orle of the main advantages of this valve train type is its complete
independence frem the cylinder heads' IVA° - included valve angle,
because
the syst~n is very slender.
Also of note is the extremely low center of the camshaft, which could be as
l~xa as 65 mm above the deck-line, which in turn will lower the overall
height of the cylinder head casting - and will save materials, thus making
the engine considerably lighter.
CA 02357794 2001-08-21
- 34 -
mvs - cont'd
r_vr~ma GG
MVS A) - Type a
~ «_ ._ _
1. A roller, centrally located on a cross-bar, is directly actuated by the
lobe of the camshaft.
2. Cross-bar, with a longer than needed roller-axle and its two, right-
angle braces reinforcing the bar - and two valve-locks at its ends.
3. Valve locks, with "U-shaped", vertical extensions, that engage the
sarings' pull-down tabs.
4. External c~npression spring and its round pedestal, fastened to the body
of the cylinder head; the pedestal has voids on its sides to clear the
pall-down tabs.
5. Valve's lower valve-guide; dimensions of the valves used in this image
are: 33 mm in diameter, the length is 55 mm.
Side View
6. "U-shaped", circular valve-lock extensions.
7. Springs' external, pull-dawn tabs, that lock into item 6.
8. Valve's lower valve-guide.
9. 'It~ao, semi-circular thrust guides for the cross-bar; its mating fences
are part of the cylinder head structure. An alternate stabilizer below
the roller m~3y also be used; it is shown in dotted lines.
View
lO.Valve's spring, its pedestal and its external pull-down tabs.
CA 02357794 2001-08-21
- 35 -
mas - cont'd
FIGURE 56
F~1IARGED VIF~nIS OF THE
CR06S-BAR.~& STABILIZERS
Front View
1. Elongated roller-axle acts as a structural support for the left and
right sides of of the cross-bar.
2/2. Left/right wings of the cross-bar with rectangular elbows and profiled
"ribs" that reinforce its structure and resistance to bending under
vertical loads.
3,~3. Valves' locks for tips of valve stems.
4/4. Vertical extensions for springs' pull-down tabs.
5. Camshaft with single lobe for two valves.
6. Tubular stabilizer, below the cross bar; in dotted lines - optional -
if the vertical thrust fences are not used.
Side View
7. Roller of the cross-bar.
8, Direction of camshaft's thrust.
9., Vertical guides behind the roller, absorbing the camshaft's thrust.
10. Matching vertical fences for the vertical guides.
CA 02357794 2001-08-21
- 36 -
mvs - cont'd
MV5 - b)
(~nlp CAS-hOBES - ONE SPRING)
Introducti~
In a multi-valve cylinder head, two adjacent valves are opened by separate
cam-lobes and two roller-fingers but are closed by a single spring pulling
on a cross-bar connecting both valves.
- 'h.NO cam-lobes open two adjacent valves by means of two roller-finger-
arms bearing down on the valve-stns above the valve-locks and above a
cross-bar, whose center is fastened to a spring, which closes both said
valves by lifting the cross-bar at the end of the valve-open event.
~pott~t Description
In a multi-valve cylinder head two adjacent valves are opened by two roller-
finger-arms that engage the valves above their valve locks and above a cross-
bar that connects both valves.
Each roller-finger-arm is seated in a hydraulic valve-adjuster stand for
individual adjustment of tolerances.
T~tie center of the cross-bar is attached to a spring, which could be either a
Tandem, "M", or DUCS type; the linear pulling action of the spring is
likely to forego the need for a central stabilizer, whicki together in
ccxnbination with the valves' locks and their lower valve-guides - may be
sufficient to counteract the 'cocking motion' of the two roller-finger-
arms.
Tne MVS pi valve train is very will suited for SOHC :engines and DOHC motors
. . . contd
CA 02357794 2001-08-21
- 37 -
mvs - cont'd
component description - cont'd
in which the included valve angle (IVA°) is at least 34°;
narrower angles
may force the cylinder head to become taller
The b) type is slim and canpact; the top of the cambox is about 100 mm (4")
tall and the center of the camshaft can be placed at about 80 m<n above the
motor's deck-line.
FIGURE 60
Side View
1. One of two cam-lobes actuating one of the two valves.
2. Roller-Finger-Arm bearing down on a -
3. Cross-bar that pulls both valves up.
4. Single spring attached to the cross-bar.
View
5/5. Cam-lobes opening two adjacent valves
6/6. Two adjacent valves.
7. Cross-bar - lifting both valves.
8. Spring that closes both valves.
.... cont'd
CA 02357794 2001-08-21
- 38 -
mvs - cont'd
TT/~1I1T C7
Front View
1. Cross-bar connecting two adjacent valves - is attached to two roller-
topped valve-locks; its function is only to return the two valves into
their seats upon completion of the valve-open event.
2. Two cam-lobes opening two valves by means of roller-finger arms.
3. A single spring closing both valves is attached to the cross bar; an
o~~tional stabilizer below the cross-bar is shown in dotted lines.
4. Spring's pedestal is attached to a solid portion of the cylinder head.
5. Lower valve-guides.
Side View
6. Enlarged details of the roller-finer-arm and its blade-like tip,
bt_aring down on the roller-topped valve lock.
cW
7. Enlarged details of the spool-shaped roller tappet and the tip of the
rs~ller-finger-arm.
Tfie shape of the roller keeps the finger aligned over its center.
CA 02357794 2001-08-21
- 39 -
mvs - cont'd
MV5 - c)
(Old C~-IrOBE - CJNE SPRING)
Introduction
Iln a multi-valve cylinder head - two adjacent valves are actuated by a
single cam-lobe, that bears down by means of a tip of a Roller-Finger-
Arm on a cross-bar, that both opens and closes the two valves.
A single cam-lobe bearing down through a roller-finger-arm on a cross-
bar opens two adjacent valves which are also closed by a single spring
supported by brackets to the cylindeer head body and attachewd to the
said cross-bar.
Qom De~iption
A cross-bar is firmly attached to two valve stems by means of valve locks,
above which there are openings, or "windows" that accommodate the tips of
roller-finger arms that open the valves.
'W a mechanism Toys two cam-lobes and a single spring, whose moving
el~nt is attached to the cross-bar, while its body is upheld by brackets,
leading to the closest solid portion of the cylinder head.
awhile ale fore-arm: of the roller-finger will create s~ thrust, or
cxking motion on the valves' stun - this force may be counter-acted by
roller-tappets (in the window.) and by the use of a stabilizer placed in the
center of the cross-bar, below the spring.
The MVS c) type may use several types of springs, a modified version of a
Tandem spring with a dual spring-cap (as shown) delivers the most compact
mechanism.
. . . cont'd
CA 02357794 2001-08-21
- 40 -
component description - cont'd
The Tandem Spring's dual spring cap is fastened to the center of the cross-
bar and exerts a straight, linear pull and counter-acts the cocking moment
created by the tip of the roller-finger arm.
Side View
1. Modified Tand~n Spring - with two coils compressed simultaneously.
2. Dual pedestal supporting the spring - attached to the cylinder head body.
3. Single cam-lobe.
4. Single roller-finger-arm engaging a roller in the cross-bar.
5. Hydraulic adjuster for the roller-finger arm.
FIQ1RE 71
Side View
1. Cross-bar with opening for the tip of the roller-finger arm.
2. Top of the cross-bar with a two-tier spring-cap for the Tandem Spring,
caressing two coils simultaneously.
3. Dual support collar of the Tandem Spring - shaving the left side only.
4. Two adjacent valves - with their valve-guides.
5.. Top of the cam-box - covering the Tandem Spring.
6. Center of the camshaft - the cam-lobe is not shown.
CA 02357794 2001-08-21
- 41 -
FIGURE 72
Front View
1. Camshaft - with its single lobe
2- Roller-top assembly - its outer shell
3-. Two adjacent valves attached to its valve-locks and to the outer shell
of the roller-top assembly; attachernent acts as the valve's upper valve-
guide.
4. Valve lash adjusters.
5. Tandem Spring, Model II; a large, outside primary coil, its bottom
nests on the flex-ring, which connects to the small, seconder spring in
the inside of the assembly.
6. Bottom support, or pedestal, for the small, secondary spring.
7. Valves' lower valve guides, which are attached to the port and the
cllinder head.
8. Upper valve guides, semi-circular in shape, stabilizing both valves and
the 'bucket', containing the larger Tand~n spring.
~r~ror 7Z
Side yiew
1. Roller-top assgnbly with the roller, interfacing the single cam-lobe.
2_ Walls, or supporting 'skirts' guiding the roller-top assembly. Note
their irregular shape, accom~dating the rising engine port.
3. Side openings in the supporting walls for the roller-top assembly, which
allow free movement of the valve locks.
4. Valves' lower valve guides - which together with the upper valve guides,
the attachments to the roller-top assembly, provide the ass~nbly with
s 'ability.
CA 02357794 2001-08-21
-41A-
fIQIRE 74
Top View
1. Main shaft of the camshaft.
2. Roller with its axle.
3. Outer 'travel' of the cac~lobe.
4. Outside casing of the 'bucket' - enclosing the Tandem Spring.
5. Valves' perimeter
6. Valve stem - and its valve lock
7. Valve's upper, semi-circular guide and stabilizer
CA 02357794 2001-08-21
mvs - cont'd
- 42 -
rws -a
( ZWO C~-I~F~S ~T, ~ CIrOf~S 2 ~ VALVES - NO SPRn~IG)
Introduction
This multi-valve system employs two cam-lobes that bear down directly on two
roller-topped tappets to open two adjacent valves but their closing is
accomplished without main springs by a three-prong closing fork that is only
partially loaded against a closing lobe that exerts just enough pressure to
seal the two valves. Therefore, its functioning is virtually friction free,
without the resistance of the springs - except the last phase of the valves'
closing - when they have reached their seats. A substantial gain in
mechanical efficiency and reduction of noise should be the main advantages
of the valve-train mechanism.
Two adjacent valves are opened by cam-lobes bearing down on roller-
topped tappets and are closed by means of a pivoting three-prong arnn,
whose center c~ponent rides on a closing cam that lifts the said arm
o:~ly during the last phase of the said valves' closing cycle to seal
them in their seats.
~onent Description
Tao roller-topped valve tappets enclosed in tvao round, or oblong carriers
a.re directly actuated by two cam-lobes. The carriers have an opening on the
trailing side, through which two, single element closing forks can lift theqn
up and seal the valves in their seats.
Etch valve has two valve guides: the upper one, which is the roller-carrier
itself and a short lower guide with a stgn seal.
. . . cont'd
CA 02357794 2001-08-21
mvs - cont'd
component description - cont'd
Since there is no main spring, or springs, the closing of the valves is
accc~nplished by means of a closing cam-lobe, that is positioned right in the
center, between the two opening cam-lobes; the closing cam-lobe actuates a
three-prong fork, that pivots freeley in two, or three bearings.
Wclen the valves are opened, the closing cam-lobe, releases the three-pn~ ng
fork, so that the valve-open event becomes freed fr~n any resistance fr~n
scorings; during the first phase of the valve-closing event the three-prong
fork begins to lift the valves by means of the two, single-arm forks below
the rollers and brings thin into the seats. At this particular moment the
valves' closing, the closing cam-lobes' profile begins to turn the three-
prong fork further - and since it is spring loaded against the two outside
lift-forks, sufficient pressure is generated to seal the valves in their
s:~ats. Thus, spring pressure is only applied to the mechanisms only when it
is needed - to seal the valves.
ZtNO types of valve-lash adjusters are envisaged for this mechanisms:
mechanical by shims, or an automatic, hydraulic type; both of these can be
incorporated into the lower portion of the roiler~-carriers, in the area of
the valve-locks.
Several types of springs may be used in the three-prong fork mechanism: a
flat spring, a coil-spring in torsion, or even a short torsion spring. The
effective range of spring application is restricted to about 25° to
35°.
The MVS d) type should allow an engine to employ an extended open-valve time
cycle, similar to a desmodromic type, with a 'radical' valve timing and a
substantially reduced mechanical friction -= both factors leading to. a ;ouch
improved performance.
CA 02357794 2001-08-21
mvs - cont'd - 44 -
FIGURE 80
Side View
1. Opening cam-lobe.
2. Closing cam-lobe.
3. Roller-topped valve-tappet with side slit on trailing side.
4. Valve-lock and valve-lash adjuster area; adjuster not shown.
5. Pivoting three-prong closing fork with a spring-loaded center arm.
6. Oval-shaped roller-guide shown here with --~ its curved underside serving
as a push-up contact for the valve. The body of the guide also serves as
an upper valve-guide for the assembly.
7. Outside walls, or guides, for the roller-top tappet.
8. Lower valve guide with a valve seam.
Zbp Views
9. One half of a return fork with a flat spring
1~. One half of a return fork with a short torsion spring.
FIGURE 81
Fit View
1. Two opening - plus one closing cam-lobes.
2. Axis of the three-prong return fork.
3. Center fork - spring-loaded against the closing cam-lobe.
4. Right valve shows a return fork inside the roller-topped valve-lock
assembly.
. . . cont'd
CA 02357794 2001-08-21
mvs - cont'd_ - 45 -
figure 81 - con't
Side Views
5. Valve is fully opened - and the closing arm is fully released; the
c~..nter arm rides on the closing cam's base circle.
6. Valve is fully closed - the center - arm rides on the high profile of
the closing cam - and is spring loaded, forcing both valves to be closed.
FIGURE 82
View
1. Enlarged view of the roller-top tappet shows its axle and the closing
arm below it.
2. Shaft, on which the single closing arm pivots. Engagement of spring is
not shown.
FIGURE 83
Side View
1. Enlarged view of the roller-top tappet assembly with its axle, the
roller and its vertical side supports - as well as the inside curved
surface by which the assembly is closed by the single-arm closing fork.
2. The single closing fork, or arm, exerting its upward pressure to close
the assgnbly.
3. Outer guide of roller-top assembly.
4. The area of the valve lock and valve-lash adjustment; adjusters are not
shown.
5. Flat spring - connects to center-arm.
CA 02357794 2001-08-21
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mvs - cont'd
FIGURE 84
Side view of an MVS - d) valve-train installed in a Jaguar XK V-8/Lincoln
engine shows substantial cylinder head, cam-box and cylinder-head casting
height reductions, when cccnpared to the original design.
Item Original Design Attain Gain
z
Cam Box 194 113 - 81
_ 130 90 - 40
C/
CHCH 130 72 - 58 ?
In the above, the "items" are:
Cam Box, or MCH - max. cylinder head height
C/S ~ Camshaft Center
CHCH - cylinder head casting height - the main body of the cylinder head
N.B.:
Measured in Inches the reductions in height are very close to those shown on
page 20-, for the Figure No..36, namely:
* height of the ca~box is 3.5" lager, the camshaft center at 3.5" and the
m~3in cylinder head casting is only about 2.5" tall, plus the flange, or
intake port lip.
CA 02357794 2001-08-21
-
MV5 e)
Introduction
Dual springs for single/dual valves can be canbined in this category in a
single cylinder head. - Such is the case of a 3 V/H Mercedes-Benz engine,
where only one valve serves the exhaust side, - while two adjacent valves
are used on the intake-side of the cylinder head.
The ccmbintation employs mechanisms and spring ccxnbinations which were
previously covered.
z~r~ror on
$lde VleW
1. A Mercedes-Benz SOHC motor, with a 3 V/H configuration; a single valve
for the exhaust side and paired valves for the intake side.
2. Exhaust valve is actuated by a roller-finger arm, its base rests on a
valve-lash adjuster. While the valve may be closed by 3 different types
of DUCS, the image shows two externally ccxnpressed coil springs.
3. Tvao intake valves of the MVS variety, with a choice of several springs.
A rocker with dual arms rides on two cam-lobes, contacts made via roller-
tappets. The roller of the rocker acts as a valve-lash adjuster.
In total, three cam-lobes and four - or more - springs actuate the
t~zree valves.
4. Vertical line for the V-6 and V-8 engines, @ 45° here
. . . cont'd
CA 02357794 2001-08-21
- 48 -
5. Applied to this engine, Attains valve trains show results listed below.
Figures in brackets are those of the original Mercedes-Benz engine; all
measureqnents are in MM, taken either vertically up from the deck-line,
or follow the 45° line of item No. 4:
C/S ' ø 82 (108) - gain of - 26
MCH 107 (190) - gain of 83 (all in mm)
C~iCH 55 - low, 75 @ flanges; (108) - gain 30
INgi 130 (210), gain of - 80.
In the above, the abbreviations are: cam-shaft center, max. cylinderhead
height, cylinder-head casting height, and intake manifold height.
The words "gain" are, in fact, reductions in the height.
FIGURE 91
Side view of the Mercedes-Benz V-6, or V-8 engine in a 50~ reduction.
Tree measured heightss of the Mercedes-Benz V-6, or V-8 engines taken fran
the actual-size drawing are as follows:
Max. Cylinder H. Height 190 mm
Center of the camshaft - and the height of the main cylinder head casting
are both 108 mm above the deck line.
T-rie height of the Intake manifold - which the maximum height of the engine
is 210 mm.
All measurements are taken from a "zero-level-reference-point", which is the
top inside circle of the cylinder bore.
CA 02357794 2001-08-21
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MVS, Type a ) - Oo~itinued
Recapitulation
The above category has been defined as a canbination of single/dual cam-
lobes - and one, or two springs actuation 2 adjacent valves.
Please refer to the introductiory comments for this category on page 26.
The MVS valve-trains are proposed for cylinders with more than 2 valves,
v~nich may imply 3, 4, or even 5 valves/head. However in this instance it is
a valve train thank may be applied only to DOHC (Dual Overhead Camshaft)
engine with 4 valves and a relative narrow IVA (included valve angle) of
same 26 to 40°.
A Single Cam-Lobe And Two Springs Valve Train
Component Description
l~ Two camshafts operate in a narrow angle cylinder head; during their
rotation, thw cam-lobes on the intake-side almost come into coma
with the exhaust side
2. a simple cam-lobe opens 2 valves by riding a roller-tappet imbedded in
an oval, or oblong shaped bucket;
3. a "tongue" or a hook protruding from the front of the bucket engages a
"cross-bar", whose left-and- right horizontal ends engage two adjacent
valves of of equal size; the "tongue" moves up and dc~m in a vertical
slot of the bucket.
. . . cont'd
CA 02357794 2001-08-21
- 50 -
component description - continued
4. the valves are of the ~ stem-type, (Attain's designation), since
their stem length is only adbout 50~ of the 'regular' length; e.g.:
55 mm, instead of 110 mm
5. each valve has a light, tubular extension, which is fastened to the
valve stem; the top of the said extension flares out at its top,
a:~suming a "funnel" shape, so that when the valve is depressed, or
p~zshed down by the cross-bar, it ccxnpresses the spring as well
6. Regular coil-compression springs are mounted on 'doughnut-shaped'
pedestals, allowing the thin, tubular extension to operate freely
through its center
7. At the end of the valves' open-event the vertical pull exerted by
the springs on the valves and their extensions, pull both valves
saut.
8. The above mechanism can be provided either with a mechanical, or
h~rdraulic valve lash adjustment mechanism
The mechanical/manual adjustment may be incorporated into the
roller' axle, or a fully automatic/hydraulic type could be built
into the bucket's tongue.
I~r_ should be noted, that in both instances the adjustments made
affect both valves through the 'cross-bar.'
. . . . cont'd
CA 02357794 2001-08-21
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mvs e) - cont'd
The Main Advantages Of This Mechanism
Tree main advantages of this valve train are its compact size, low
reciprocating mass and an extremely low friction, since only one roller_-
bucket actuates two valves.
Furthermore, its installation in a current Lincoln/Jaguar (2001 model)
e:~gines yields a 3.5" reduction in height of the cylinder heads' cam box, a
camshaft center that is lowered to about 3.5" - and above all - a main
cylinder head casting that is just sligthly over 2.5" tall.
T-ue last attribute is very important, because it may open the doors to a
"new" construction method, in which a compact and shallow cylinder head
could be cast as one unit with the engine block and deliver further
signicant weight and cost reductions for the manucturers -~and deliver
improved fuel econany to create a more environment-friendly motor.
~rnrroc ~ nn
MV5 a ) Type - Ttao Springs - One (~-Kobe
OR
DtICS - 1/L
Side View
Figure 100 shows the MVS mechanism with Dual Compression Springs (DL7CS) with
a single cam-lobe (1?L) in a Lincoln/Jaguar short block - in actual size;
the dimensions of this configuration are as follows:
1- X43/8" (-110 ~): 2. Camshaft Center is @ 3 3/8", or 85 mm; 3. the
hsight of the main cylinder head casting is 2.25", or only 58 mm.
Tie projected height of the intake manifold is not shave but is only 5. 0" ,
or 125 mm.
CA 02357794 2001-08-21
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mvs e) - cont'd
Side View - "O~1.S" (Double Actual Size)
1. Single cam-lobe of the MVS Assembly.
2. Roller in an asymmetrical bucket.
3. Front 'nose', or hook, engaging the horizontal cross-bar.
4. Horizontal cross-bar.
5. One of the DUOS Springs - an internally compressed coil spring. This
image shows a spring in conical shape - buck straight springs, or M-
Springs accomplish the same function.
6: Springs pedestal - with a center-void.
7. Spring's pull-down ca~onent.
8. Bucket guide.
9. Valve guide.
10. The canplete assanbly shown here in a vertical position is only 4" , or
101 mm tall, allowing significant cylinder height reductions, and/or the
casting of the cylinder head with the engine block.
FIC~JRE 102
Front Vlew - In "OAS"
1. Camshaft with a single cam-lobe
2. Roller
3. Roller's bucket
4. DUOS
5. Valves
6. Horizontal cross-bar.
CA 02357794 2001-08-21
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FIGURE 103
A. Zbp View - Assaobly
1. Cam, cam-lobe
2. Valves
3. Roller ~ front "nose"
4. Cross-bar
B. Roller ~ : Zb~p Views
1. Front "nose"
2. Roller, axle
3. Horizontal bar
~rrsro~ i -w
Cross Har d~ Its Attad~ment to tt~e Valve Assembly
1. Fron View - shows how the horizontal bar is inserted into the spring's
pull-down element of the valve.
2. Side View - shows the valve-keeper, lock and two vertical "stops" located
the horizontal bar, and assure its stability.
