Note: Descriptions are shown in the official language in which they were submitted.
CA 02267882 1999-03-30
I
ATTAINS 'ROTOPORT' SYSTEMS
INTRODUCTION
What Is A 'Rotoport'?
Attains three proposed valve train systems are based on a new
component called "Rotoport". What is a "Rotoport'? It is a
composite word derived from a rotating port that delivers gas
under pressure to simplified poppet-valve mechanisms, which can
be opened by gas pressure and closed the same, or different ways.
How Does Rotoport Work ?
The 'rotoport' resembles a hollow-center camshaft with circular
ports attached to it; it rotates freely in plain bearings and
because it is not called on to overcome any mechanical
resistance, its movement is smooth, effortless and it doesn't
need much energy to perform its duty. Its operation does not
involve electronic, or electro-magnetic devices at all- and can
be driven by a toothed rubber belt at either 50~, or 25~ of the
engine's crankshaft speed. Consequently, the installation of a
'rotoport' valve system would be economical - and would require
modifications to the cylinder head only, leaving the engine's
short-block as is.
The 'rotoport' simply channels gas pressure to a cylinder with a
one, or two-way pistons, connected to a short-stem valve; it is
called a: "Piston-Valve Assembly."
. . . cont'd
CA 02267882 1999-03-30
II
introduction - cont'd
How Applicable Are The Rotoport Systems ?
Rotoport valve systems can be applied to all 4 stroke gasoline,
or Diesel-type engines, or 2-stroke-Diesels with exhaust valves,
as well as to 2-stroke engines with poppet valves. In all of
these engines - the number of cylinders and their end-use are
transparent to the innovations.
The new valve-train systems leave the present combustion process
as is, so the EPA regulations mandated to the auto-industry
remain intact. The same comments apply to the use of materials:
only existing grades of steel or alloys are needed, so the
investment into machinery and assembly methods also remain fully
protected.
The Main Benefits Of Rotoport Systems
Reduced engine weight through radically lower cylinder heads. A
lower engine that will promote better aerodynamics - and better
highway fuel consumption. Possibility of casting the cylinder
head with the engine block as one unit.
Superior engine performance on account of elevated RPM's -
that could be on par with pneumatic valves.
Extended durability and lower production costs/unit.
Rotoport Systems can take full advantage of variable valve
indexing as well as variable valve lifts.
. . . cont'd
CA 02267882 1999-03-30
III
the main benefits - cont'd
In all current combustion engines using poppet valves, their
opening/closing is entirely dependent on one, or more,
mechanical components. However, the valves in a rotoport system
are actuated by high-pressure gas (and its release, and/or
vacuum,) Consequently, there is a mechanical "disconnect" effect
that is evidenced in - at least three cylinder head design
areas:
a) valves - from 2 to 5/head - can be aimed at the combustion
chamber at any angle that optimizes combustion, or engine
performance; therefore, they can be asymmetrical.
b) radial valves, intake, exhaust, or both, can be used in any
desired disposition, or mixed, with item a) above
c) the distinction and /or, advantages of DOHC vs. SOHC engine-
types becomes blurred: a DOHC engine owes its mechanical
advantages to its very low valve-train reciprocating weight -
-(direct engagement) - when compared to an SOHC motor. In a
rotoport-type motor the advantage of a DOHC valve train does not
exist. All piston-valve assemblies (see below) are opened by gas
and an SOHC engine is just as effective as the DOHC motor.
The only mechanical component is a short valve, attached to a
piston and is extremely light and simple.
In all three systems presented - the valve-lash adjustment
mechanism has been eliminated - because - it is simply not
required.
CA 02267882 1999-03-30
IV
DESIGN OBJECTIVES OF THE ROTOPORT VALVE SYSTEMS
1. Create a lighter, smaller and lower engine of enhanced
performance with a simplified valve train and generate
attractive economies in production.
2. Reduce the engines' cylinder head heights by at least 50$ so
that future motors could be cast as one unit: engine block
with the cylinder head, which will further reduce the engine
weight.
3. Replace the camshaft with a lighter, more energy effficient
mechanical device and eliminate many components from the
present valve trains.
4. Increase engine's RPM potential in racing engines to exceed
today's level of 18,000 in Formula 1 motors and allow
'street motors' to run comfortably up to 10,000 RPM, if
needed, while taking advantage of the proposed technology.
5. Lower internal engine friction by reducing the 'Rotoport'
revolutions from 50~ to 25~ of the engine's crankshaft speed.
6. Carry forward and apply the 'variable indexing' technology
to the Rotoport applications - and amplify it through the
use of lower RPM's vis-a-vis the crankshaft speed, as per
point 5. above.
. . . cont'd
CA 02267882 1999-03-30
V
design objectives - cont'd
7. Expand the domain of 'engine management' by an additional
'dimension', which allows a variable valve lift along with a
continuous modulation of valve-timing.
8. To save weight and cost, make the 'rotoport systems'
applicable to paired valve configurations, in which one
mechanism operates two valves.
9. Make full use of Attains Parallel-Flow Ports in the
Rotoport applications.
10. To save cost and improve reliability, minimize the use of
electronic and electro-magnetic devices in the Rotoport
applications.
11. Allow the individual valves - and their immediate mechanism-
to be arranged at any desirable angle toward the combustion
chamber.
12. Make all valve trains completely independent of the
intermediate mechanical devices that operate them.
CA 02267882 1999-03-30
VI
ATTAINS THREE ROTOPORT VALVE SYSTEMS
1. Pressure-Open & Pressure-Close System
G~3s pressure opens and closes the valve. The rotoport directing
gas over-and-below a piston in a dual-chamber cylinder;
pressure from opposite sides are also released by the rotoport.
System is applicable to single and paired valves, as well as to
Parallel-Flow Ports.
2. Pressure-Open - Vacuum-Close System
Gas pressures and their release from a valve-actuating cylinder
are directed by a rotoport but the closing of the valve is
accomplished by a separate vacuum cylinder, with a constant
negative pressure. This System is best suited for 'paired-
valves', which favour the disposition of the gas-pressure and
gas-vacuum cylinders.
3. Spring-Return - Gas Open System (SRGO)
Valves are opened by gas pressure fed into the cylinder,
overcoming the resistance of a pull-spring (Attain), or other
type of spring. Once the gas pressure is released by the
rotoport, the spring takes over and brings the valve into a
closed position. - This System is intended for 'street engines',
where a maximum speed of about 10,000 RPM's is more than
adequate.
The latter two Systems are adaptable to variable
valve-timing (indexing) as well as variable valve-lift systems.
CA 02267882 1999-03-30
- 2 -
rotoport - cont'd
Rotoport's Outer Shell
Tine Rotoport turns inside an outer shell, being separated from
it by sealing rings described below.
The outer shell is a two-component, air-tight vessel, or casing,
firmly bolted together and then fastened to a solid portion of
the cylinder head. The periphery of the outer shell contains
openings that align themselves to pressure and pressure-relief
ports, leading to the valve-actuation mechanisms.
Rotoport's Sealing Rings
Since the outer shell - consisting of two, nearly indentical
halves - will have two seams, the sealing ring is seamless and
slips over the rotoport, which assures its smooth passage and
prevents the rotoport from premature wear and loss of pressure.
The sealing ring will have as many openings in its body as they
are ports in the outer shell, with which it must align itself
perfectly. A notch on the outside of the ring fits into a
opening in the outer shell, which prevents its rotation.
Near its left and right edges, the sealing ring is provided with
a groove, that accommodates a circular seal, or an expandable
ring, similar in appearance to a piston ring. The function of
these is to prevent leakage of high-pressure gases to the outer
shell.
. . . cont'd
CA 02267882 1999-03-30
- 3 -
rotoport - cont'd
The Rotoport - The Inner Component
Tne hollow shaft of the rotoport is fed with high-pressure gas
(nitrogen) through one end of the shaft, or tube. Holes in the
shaft itself travel through the port passages of the rotoport
component, from where they go through the sealing ring, the
outer tube - and then into the pressure port of a valve
actuation mechanism. The gas pressure opens the valve.
Toward the 'valve-open-event', the turning rotoport begins to
open a pressure relief port - and the gases are now exhausted by
an exit port, back through the sealing ring - and are evacuated
through a relief port into the outer tube.
So that the released gases can travel from one rotoport to
another - and eventually be collected at one end of the outer
shell - each rotoport has transfer passages drilled into it, to
facilitate the movement of gases in a longitudinal way. The
exhausted gases are then fed to the suction-side of a gas
pressure pump.
The pump compresses the gas and feeds it under pressure into the
hollow shaft of the rotoport - thus completing the operating
cycle.
The number of openings in the rotoport is determined by the type
of system (i.e. 1, 2, or 3), the number of valves being operated
by the rotoport - and the speed of the rotoport rotation.
. . . cont'd
CA 02267882 1999-03-30
- 4
rotoport - cont'd
To actuate one valve in System 1, for example, there must be two
pressure and two relief ports for each 360° of rotoport
rotation - if the device is turning over at 50~ of the
crankshaft speed. Should the device rotate only at 25~ of the
engine speed, twice as many openings will be required.
In Systems 2 and 3, only half of the ports, or opening are
needed, because the valves are closed by different means. -
Additional functional details will be enumerated in the
description of the individual Systems.
Lubrication Of The Rotoport
As the rotoport closely resembles today's camshaft, its
lubrication will be similar as well: oil under pressure is fed
to the sealing rings, from where it will feed the surfaces of
the rotoport proper.
Since the rotoport does not need to overcome any mechanical
resistance - like spring pressure and built-up friction -
the functioning of the rotoport should be marked with longevity
and durability.
The Bearings Supporting The Rotoport
In a typical V-8 engine, a rotoport serving both the intake and
exhaust valves would require 5 bearings. It would, in fact,
resemble an SOHC camshaft. The end-bearing would be a thrust
bearing, which could combine with a coupling for high-pressure
gas.
. . cont'd
CA 02267882 1999-03-30
- 5 -
rotoport - bearings - cont'd
Should each row of valves require a separate rotoport, then the
installation would parallel a disposition of a DOHC
configuration.
How Is The Rotoport Driven ?
One, two, or several rotoports can be driven by toothed rubber
belts off the crankshaft main pulley. An alternate arrangement
could be a chain drive. Both of these methods are purely
mechanical and do not require any elecronic devices.
Variable Indexing Of The Rotoport
Variable valve timing, or indexing of the camshaft, which is
very popular and effective - is equally available to the
rotoport and similar devices, whose slip-angle is governed by
hydraulic mechanisms - can be employed here as well.
When the rotoport is turning over only at 250 of the
crankshaft's speed, the variable indexing would be twice as
effective; therefore, the angle has to bereduced by 50~, which
may reduce the cost of such devices.
Variable Valve Lift
Certain rotoport Systems offer also variable valve lift. They
will be detailed below.
Application Of Rotoport
With minor modifications, the 'rotoport' is used in all 3
Systems proposed by Attain.
. . cont'd
CA 02267882 1999-03-30
- 6 -
application of rotoport - cont'd
As well, the rotoport valve systems can be applied to to single
and paired valves.
Furthermore, they can be used in Attains Parallel-Flow ports,
either in single, or dual-valve applications.
Gas Pump, Tank & Auxiliary Equipment
Tize nitrogen gas - most-likely substance to be used in the
proposed systems - is compressed by a pump and maintained at a
predetermined level at all times.
The pressurized gas is fed into the hollow shaft of the rotoport.
Gases exhausted from the piston-valve assemblies into the outer
tube of the rotoport are returned to the suction side of the
pump.
High- and low-pressure valves are needed to maintained the
desired pressure level in the system, along with a tank, or
reservoir.
CA 02267882 1999-03-30
FIGURES FOR 'ROTOPORT'
Figure 1 - Schematic Of Rotoport Valve Operation
Pump, Item 1., delivers gas (nitrogen) under pressure through a
circular seal into the hollow shaft of the 'rotoport', Item 2.,
to which four, rotating ports, are attached, delivering
pressurized gas to four piston-valve assemblies, Items: 3, 4, 5,
and 6.
To illustrate the functioning of the device the four 'rotoports'
have various ports, namely: Item 3. is open for pressurized gas
to enter the cylinder of the piston-valve assembly, while No. 4.
and item 6., are letting the gases to be exhausted into the
outer tube, Item No. 7. Port No. 5. is closed but the rotoport
shows a "transfer port", which lets the exhausted gas to travel
laterally in the tube, from where they are collected and
delivered by a return tube, Item 8., to the gas pump, Item 1.
Item No. 9., shows the 'blind-end' of the rotoport, its seal,
bearing and the wheel pulley, which is engine driven by Item No.
10, which could be either a toothed rubber belt, or a chain,
leading to the engine's crankshaft.
The 'rotoport' may be provided with a variable-index device,
similar to those used on variable valve-opening mechanisms in
today's car; these would be incorporated in Item 9., but are not
shown
Please note, that the 'rotoport' can be driven either at 50~, or
25~ of the crankshaft's RPM's.
. . . cont'd
CA 02267882 1999-03-30
_ g -
rotoport figures - cont-d
Figure 2 - Elements Of Piston-Valve Assembly
A short-stem valve is attached to a piston, and is called the
Piston-Valve Assembly, Item 1., and moves in a cylinder, Item 2.
The 'rotoport', Item 3., rotates in its outer enclosure, Item
4., and opens/closes ports Item 5., as required to move the
piston up and down in the cylinder.
Ttie piston, Item l., acts also as an upper valve-guide and
stabilizes the assembly in its upper region, while a lower valve
guide, Item No. 6, has an oil seal and stabilizes the assembly
's lower end.
Lubrication for the piston is provided by a channel in the
cylinder, Item No. 7.
It should be noted, that the functioning and mechanical details
of the piston- valve assembly will vary from system-to-system in
the 3 proposed models by Attain; additional details will be
provided in the appropriate places.
Figure No. 2, should be considered a generic illustration of
the valve-actuation principle proposed in the 'rotoport system.'
. . . cont'd
CA 02267882 1999-03-30
- g -
rotoport figures - cont'd
Figure 3 - 'Rotoport's' Outer Shell
Tne upper Image A, provides a side-view of the rotoport's outer
shell, as it is split along its vertical lines, Item No.l. The
right-hand side, Item 2., is fastened to the piston-valve
assembly, Item 3., and is connected to it by matching ports, so
that the valve can be opened, or closed. The outer shell is a
low-pressure type of vessel, since it handles only the gases
that have been expelled from the cylinders - and are on their
way to the suction-side of the gas pump. Otherwise, the outer
shell provides the rotoport with its outer bearings and carries
the end-seals.
The Lower Image B, shows the outer shell in its longitudinal
disposition, Item 4., and shows only a pair (of the several)
opening required to keep both halves together: Items 5 below and
above.
The vertical grooves, Item 6, are for the seals of the inner,
rotoport shaft.
Figure 4 - Sealing Rings & Seals
The ports of the rotoport must cross over the grooves, or seams
of the vertically split outer shell; to minimize wear and assure
batter sealing, a sealing-ring is proposed, that would make the
rotoport's ports glide over these spots smoothly.
Each sealing ring carries with it also two end-seals and is
. . . . cont'd
CA 02267882 1999-03-30
- 10 -
rotoport figures - cont'd
lodged firmly against the outer shell. To assure perfect
alignment of the ring with the rotoport and the ports of the
piston-valve assembly, the sealing ring is provided with a
protrusion that falls readily into a oavity of the outer shell.
Item Z., in the upper Image A, is a sealing ring, with left and
right seals, Items 2 and 3 flanking it. Item 4 shows a
protrusion, which locks itself into the outer shell, Item 5.
Item 6 delineates the position of the rotoport No.6, but does
not show its ports.
Image B, below, shows the rotoport in Item 7, and the sealing
ring is Item 8. The 2, left and right seals, are shown as Items
9 and 10, respectively.
Figure 5 - Rotoport's Inner Components
Image A is an axial view of the 3 types of ports, that are used
in the rotoport's disk, or collar, which serves the device also
as its own bearing. Item 1., is the rotoport's disk, item 2 -
(upper and lower one) are the pressurized gas ports, for the
shaft has to have openings. Items 3., and 4. are exhaust ports,
by which the gases are released into the outer shell - and
items 5 and 6 are the lateral transfer ports, by which the
expelled gases can travel from left to right - to be returned to
the suction-side of the gas pump. Item 7 shows how the device is
lubricated.
In Image B, Item 8 is a gas-pressure port, 9 is an exhaust port
and Item 10 is a lateral transfer port.
. . . cont'd
CA 02267882 1999-03-30
- 11 -
rotoport figures - cont'd
Figure 6 - Top View Of The Rotoport
Item 1., represents the inner, hollow portion of the rotoport,
which is fed by pressurized gas. As its rotates, its opening, or
ports, shown in Item 2., line up at predetermined intervals
against similar openings (ports) in the cylinder of the piston-
valve assembly, item 3, which actuates the valve. Item 4., is a
a transfer port, allowing the gases to travel laterally in the
rotoport. The outer shell, item 5, has suction, or return
channel, item 6, through which all gases return to the gas pump.
Figure 7 - Enlarged Cross-Section Of The Rotoport
This Figure aims to show the disposition of the 3 types of ports
present in a single rotoport, with their approximate timing
and/or overlap.
Item l., is the rotoport, in which a pressure delivery port,
item 2, delivers gas into the cylinder of the piston-valve
assembly. Item 3. , is an exhaust port, still open but about to
be closed. Item 4. is a transfer port. -
The vertical split of the outer shell can be seen in item 5, and
the rotoport's interface with the engine's cylinder head is
shown in item 6. - Item 7., is the 'locating-pin'for the sealing
ring, to keep in alignment. Item 8 shows a passage of
lubrication oil to the rotoport.
CA 02267882 1999-03-30
- 12 -
ATTAINS ROTOPORT SYSTEMS
SYSTEM 1
ABSTRACT
A piston attached to a short valve-stem actuates 1, or 2
valves by moving in a 2-way cylinder to which gas under
pressure is admitted, or released, through appropriate
passages opened and closed by a rotoport, which delivers
gas under pressure through its hollow shaft either to an
above, or below, portion of the said piston and releases
the said gases from the opposite portion of the said
cylinder just prior to pressure application, to let them
escape to the outer tube of the said rotoport, from where
they travel to the suction-side of the gas pump supplying
the system with constant pressure.
Valve Actuation In System 1
The upper portion of an Attain ~ Stem Valve is connected to a
piston moving in ,a 2-way cylinder. To open the valve, residual
gas pressure is first released from below the said piston -
and then applied above it. Moving freely down, the valve
piston assembly comes to stop when it reaches a "bumper", that
blocks its further travel.
At the end of the 'open-valve-event', the pressure is first
released from above the piston - and new gas pressure is
directed to the lower portion of the cylinder, below the piston.
The valve travels up and comes to a stop when the valve fully
closes the engine port.
. . . cont'd
CA 02267882 1999-03-30
- 13 -
sysrtem 1 - cont'd
Rotoport Function In System 1
~ihile rotating - over at 50~ of the crankshaft speed, each
collar, or port of the Rotoport will have 4 openings: two will
deliver gas under pressure to open and to close the valve -
and two relief, or exhaust ports. While gas under pressure
comes to the valve mechanism from the hallow center of the
rotoport shaft, the gases released by the 'exhaust ports' will
escape into the outer shell, from where they will be fed back to
the suction side of the gas-pressure pump.
If the rotoport turns over only at 25~ of the engine speed, the
number of ports will double, and will be 8, instead of 4.
Applications Of System 1
The above mechanism can be applied to single, or paired valves.
Additional Features Available In System 1
System 1 may be provided with a variable cam-phasing, or valve
indexing feature, by applying to present technology to the
rotoport. In fact, if the rotoport turns over at 25~, the cam-
phasing feature may be enhanced.
The downward travel of valve may be 'regulated' by employing a
movable stop, or 'bumper', by extending, or limiting its lift.
CA 02267882 1999-03-30
- 14 -
FIGURES FOR SYSTEM 1
Figure 10 - Piston-Valve Assembly
The piston-valve assembly, Item 1., moves in its cylinder,
Item 2. Because pressure is applied to both above and below the
piston, the latter must be fully enclosed. The travel of the
valve is limited in its down-ward stroke by a stop, Item 3.
The System 1 employs a (power) cylinder with four ports. To open
the valve, the rotoport opens first the exhaust channel 4, while
opening the power port, Item 5., which brings the piston down.
To close the valve, the upper exhaust port, Item 6. opens first
and the rotoport opens simultaneously the power port Item 7.,
which brings the valve into a closed position.
Tne piston-valve assembly is stabilized internally by two valve
guides: the piston acts as an upper valve guide and a short
valve guide at the bottom, Item 8, with an oil seal, stabilizes
the valve in the lower region. - The lower portion of the
cylinder is also provided with a pressure seal, Item 9.
Figure 11 - Actuation Of Piston-Valve Assembly
To illustrate the functioning of the pressure and exhaust ports,
this figure shows four images with the positions of the piston
in items A, B, C & D, going from left to right in a clok-
wise fashion.
. . . cont'd
CA 02267882 1999-03-30
- 15 -
Figure 11 - cont'd
ACTUATION OF PISTON-VALVE ASSEMBLY
IN SYSTEM 1
Image A
a) pressure is released from the lower cylinder, below the
piston, by exhaust port EX l, Item 1.
b) at the same time, pressure port P1. Item 2., opens and feeds
pressurized gas above the piston, forcing it down, all the
way to a stop, or bumper, Item 3.
Image B
* pressure port P1 remains either open, or maintains sufficient
pressure in the cylinder to keep valve open
Image C
c) exhaust port EX 2, Item 4., begins to open, relieving gas
pressure in the cylinder above the the piston
d) simultaneously, pressure port P ~2, Item 5., feeds pressurized
gas into the cylinder below the piston, forcing the valve up
and into its seat.
Image D
* pressure port P 2., Item 5., remains either open, or
maintains enough pressure in the lower cylinder portion to
keep the valve sealed.
The sequence of each complete cycle is as follows:
EX1 (gas out) - P1 gas in - forces the piston down, and
EX2 (gas out) - P2 gas in - forces the piston up
CA 02267882 1999-03-30
- 16 -
figures for system 1 - cont'd
Figure 12 A - Positions Of Pistons
Here, the piston is shown again in its extreme positions: item 1
shows it in top, while item 2, shows it in its extreme bottom
position; the four ports, previously described are also shown.
Figure 12 B - Four Openings In Rotoport
To illustrate the alignment of ports in the cylinder with the 4
openings in the rotoport, this figure shows that they are both in
the exact positions.
The pressurized gas ports are in the center, Items 1 and 2,
while the exhaust ports, Items 3. and 4 are on the outer sides
of the rotoport.
Figure 1'3 - Single Valve In System 1
Image A, is a cross-section of piston-valve assembly, Item l,
being actuated by a rotoport, Item 2. Only two ports are shown
but 4 are required to operate the valve.
Image B, is a top view of the piston-valve assembly, Item 3.,
shows the outer enclosure of the rotoport, Item 2.. the rotoport
itself, Item 4 and its 4 ports, '
. . . cont'd
CA 02267882 1999-03-30
- 17 -
figures for system 1 - cont'd
Figure 14 - Paired Valves - Single Rotoport
Image A shows two valves, side-by-side, called paired valves
in,a side view. They are actuated by a single rotoport.
In Image B, item 1, is a rotoport, and items 2 and 3 are the
piston-valve assemblies belonging to two valves. - Four
channels, or ports of the rotoport, Item 4 actuate both valves
but must be interconnected to perform the double duties.
Figure 15 - Valves In Attain' Parallel-Flow Ports
Single, or dual valves, placed in Attains Parallel-Flow Ports,
can also be actuated by the rotoport device.
The figure shows a single valve, which is actuated by a
rotoport, Item 1., its System 1 piston-valve assembly, Item 2.,
being completely concealed in the streamlined parallel-flow
port, Item 3.
CA 02267882 1999-03-30
- 18 -
cvcmz~a ~
T D C mD T !'m
A set of two adjacent valves connected by a cross-
bar is provided with two valve-actuation devices
comprising two pistons placed inside two cylinders,
which are connected to the ports of a rotoport, and one
centrally located vacuum cylinder with a piston attached
to the said cross-bar keeping both valves closed till
gas under pressure is admitted to both said cylinders
and overcomes the pulling force of vacuum cylinder for
the duration of the open-valve event, after which it is
released and both valves are closed.
Valve Actuation In System 2
System 2 is intended for 'paired-valves', where two adjacent
valves operate in unison, so to speak. The two valves are
connected (mechanically) by a cross-bar; in its center - is a
vacuum cylinder, which lifts up both valves into a closed
position.
Above each stem of the valves is a one-way cylinder with a
piston. To open the valves, gas pressure is applied to both
cylinders - and both valves are opened. It should be noted that
the gas pressure must by higher than the pulling force of the
central vacuum cylinder.
At the end of the 'open-valve-event' the gas pressure from the
two cylinders is released - and the constant vacuum force of the
central cylinder takes over, and closes both valves.
. . . cont'd
CA 02267882 1999-03-30
- 19 -
system 2 - cont'd
System 2 employs two pneumatic systems: to open the valves a gas
pressure is employed - and to close the valves, a secondary,
vacuum system is needed. The latter is a passive system,
unregulated, in that the force of the vacuum is applied
constantly to the vacuum cylinder in the middle of the two
adjacent valves.
Rotoport Function In System 2
The rotating collar of the rotoport has only two ports: one
delivers gas pressure to open the valve, the other releases it,
to allow the vacuum system to take over and to close the valves.
As in System 1, gas under pressure is delivered through the
hollow shaft - and the released, or exhausted gases are let to
escape into the outer shell. - The rotoport in System 2 can
turn over either @ 50~, or 25$ of the crankshaft speeds.
Additional Features Available In System 2
Both the variable cam-phasing and the variable valve-lift
features are available in System 2; In fact, the latter could
figure prominently here, because a 'bumper' , or a stop for the
valve-lift can be conveniently located below the vacuum cylinder
thus controlling the travel of 2 valves with one device.
...... cont'd
CA 02267882 1999-03-30
- 20 -
FIGURES FOR SYSTEM 2
Figure 20 - Piston-Valve Assembly
In System 2, the piston-valve assembly is simplified by the fact
that only two ports are need in the rotoport and in the cylinder
housing the piston. Gas pressure opens the valve and the
pressure is released by an exhaust port but the closing is
accomplished by a vacuum cylinder. For best performance, System
2 should be used only in paired-valve configurations, with 2
valves being connected by a cross-bar.
Item 1., is the cylinder, the gas pressure and exhaust ports are
items 2 and 3. The piston, Item 5 is open at the bottom; the
cross-bar, item 6 connects two valves. Item 7. is the lower
valve guide with an oil seal. Optional piston ring - Item 4.
The variable valve-lift is possible in System 2, and is placed
under the cross-bar. Please see Figure 21.
Figure 21 - Paired-Valve Operation
Image A shows the centrally located vacuum cylinder, Item 1.,
which returns both valves into their seats by means of a cross-
bar, Item 2. Both valves are opened by gas pressure from the
rotoport; the 2 valves are Items 3., and 4. - Item 5., is a
stabilizer, which includes a movable stop, Item 6., which when
moved hydraulically could either shorten or lengthten the travel
of both valves. Details of this mechanism are not shown here.
. . . cont'd
CA 02267882 1999-03-30
- 21 -
figure 21 - cont'd
Image B, shows the rotoport, Item 7, how it operates the 2
valves, Items 8., and 9. Item 10., is the vacuum cylinder.
Figure 22 - Paired Valves In Attains Parallel-Flow Port
The vacuum cylinder in between a couple of valves, operating in
Attains Parallel Flow Ports, brings back both valves to a
closed position by the force of a vacuum.
Item 1., shows the vacuum cylinder, Item 2 is the cross bar.
Both valves, Items 3 and 4, are provided with their own piston-
valve assemblies, under the control of a rotoport.
Item 5 shows a cross-section of piston-valve assembly in the
left-hand valve only.
The details of the rotoport and the vacuum lines, or pumps are
not included in this image.
CA 02267882 1999-03-30
- 22 -
~~~m~~
ABSTRACT
A valve-actuation mechanism comprising a piston attached
to an Attain ~ Stem Valve and fastened either to a pull-
or a compression-type spring, is moving in a cylinder
into which gas pressure is first admitted by the rotoport
and maintained there till the end of the valve-open
event, and subsequently exhausted through a relief port,
which allows the force of the extended, or compressed
spring, to bring the valve into its seat and to close it.
Valve Actuation In System 3
An Attain-type valve - with a very short stem - referred to as a
"Z Stem Valve" - is attached to a piston that moves in a
cylinder. The valve-and-piston are named a "piston-valve-
assembly". Various types of Attain-type springs can be attached
to the piston either from above, or below it.
Whether the spring is placed above, or below the piston, the
prime design objective is to have a valve with a shortest stem
possible, to minimize the reciprocating weight of the piston-
valve assembly.
The type of springs employed in the system 3 could be: a pull-
coilspring, wafer pull-spring, or ypsilon (compression) spring,
a pyramid pull-down spring, etc. Some of the springs can be also
. . cont'd
CA 02267882 1999-03-30
- 23 -
system 3 - cont'd
mounted externally, outisde of the power cylinder.
Just like the two previous sytem, System 3 does not require any
valve-lash adjustment mechanism.
Rotoport Function In System 3
In System 3, the rotoport's function is almost identical to that
in System 2: it is limited to open the valve by delivering gas
under pressure - and then to release it.
The return spring pulls the valve shut,
Applications Of System 3
Due to the presence of a spring, the System 3 mechanism cannot
be expected to operate in engines turning over at 12,000 RPM's,
or higher. - However, its light weight and simplicity should
deliver adequate performance for 'street engines' operating up
to 10,000 RPM's. Both single and paired valves are eligible.
Additional Features Available In System 3
Variable cam-phasing and variable valve-lift may be easily
installed in System 3, enhancing its performance.
. . . cont'd
CA 02267882 1999-03-30
- 24 -
FIGURES FOR SYSTEM 3
Notes:
1) the piston-valve assembly in the System 3 is very similar to
the one used in System 2; please see Figure 20. - The
cylinder uses only two ports and the valve is returned to
its seat by an Attain-type spring, attached either below the
piston, or on the ceiling of the cylinder. These springs
were proposed in Attar s ANSA and DEM submissions.
2) for the sake of clarity, the majority of figures are
presented in the "double actual-size", or DAS format so that
by a 50~ reduction they represent real-life components,
while providing better definition of details. In particular,
the sizes of the valves should be noted, as they affect the
height of the cylinder heads.
Figure 30 - Ypsilon Compression Spring
An ypsilon compression spring is attached under the piston and
mounted in such a way, that its coils do not interfere with each
other in compression; the piston is Item l., the spring is Item
2. A two-channel rotoport, Item 3. actuates the valve by pushing
the piston down gas pressure. When the pressure is exhausted, or
released, the force of the spring returns the valve into its
seat. The actual valve size is 35 x 52 mm long.
. . . cont'd
CA 02267882 1999-03-30
- 25 -
figures for system 3 - cont'd
Figure 31 - Pyramid Compression Spring
In piston, Item 1., a pyramid compression spring, Item 2., is
mounted inside it. The rotoport. Item 3, actuates the valve in
a similar fashion as in Figure 30. - The valve size is 35 x 40L.
Figure 32 - Pull-Coil Spring
A pull-coil spring, Item 1., is suspended from the ceiling of
the cylinder by means of clamps, or attachments, Items 2 and 3.
The bottom of the spring is fastened to a center-piece of a
two-component piston, Item 4. The rotoport, Item 5., actuates
the valve by admitting gas under pressure into the cylinder and
then releasing it. In order to reduce the inside volume in the
cylinder, a cone-shaped cavity fills the center of the cylinder
and reaches down from its ceiling. The valve is 36 x 46mm long.
Item 6., is the cavity.
Figure 33 - Two Component Piston
The center piece of a two-component piston, Item 1., is provided
on its periphery by threads, Item 2, that can be screwed in into
the outer diameter of the piston, Item 3.
The center-piece also has a valve-lock, Item 4., to which the
valve, Item 5., is secured but is allowed to rotate, if so
desired.
The upper portion of the center-piece, Item 1., has also a
provision for a bolt-on clamp, Item 6., which secures the bottom
of the pull-coil spring, Item 7. to the center-piece, Item 1.
. . . cont'd
CA 02267882 1999-03-30
- 26 -
figures for system 3 - cont'd
Figure 34 - Wafer Pull-Spring
In Image A, an Attain z stem valve - 35 mm diameter, and only 40
mm long, Item l., is attached to a piston, Item 2. The crown of
the piston is provided with rising flanges, or ears, that are
pierced with a short rod, Item 3., to which the bottom of a
wafer Pull-Spring is looped. The expansion spring, Item 4., is
also secured to the ceiling of the spring dome, Item 5.,
containing four locks, Item 6, that are locked to the open-
end of the spring. Item 4. O~.zly a half of the spring is shown.
While this figure shows a dual Wafer Pull-Spring, the mechanism
could well operate with a single expansion spring.
Image B, shows the details of the spring attachment: Item 7,
shows the four spring terminations, that are secured in the
round cap, Item 8, of the power cylinder.
Item 9, shows the rising flanges,(two) - and the rod, Item 10,
that secures the two springs to the crown of the piston.
Figure 35 - External Pull-Coil
In this mechanism the rotoport, Item 1., is directly above the
piston-valve assembly, Item 2. A relatively long valve - 40 x 57
mm - Item 3. is locked-on to the piston and below this lock is a
modified spring-cap, Item 4, that reaches out beyond the
diameter of the cylinder, Item 5., to engage an external pull-
coil, Item 6.
. . . cont'd
CA 02267882 1999-03-30
- 27 -
figures for system 3 - cont'd
Figure 36 - System 3 In A Parallel-Flow Port
A nearly 'square' - 30 x 31 mm long valve, Item 1, is attached
to a piston-valve assembly, Item 2., completely enclosed by a
valve-shroud, Item 3.. in an Attain Parallel-Flow Port, Item 4.
A pull-coil spring, Item 5 is attached to the piston of the
piston-valve assembly and then to the ceiling of the valve
shroud, Item 3, as shown in Item 6.
The rotoport, Item 7., actuates the valve by means of 2 channels.
Figure 36 shows the operation of a single valve but a 'paired'
valve operation is also well feasible.
CA 02267882 1999-03-30
- 28 -
'PROFILES' OF COMPLETE ENGINES
At least five of the sated design objectives of the Rotoport
Valve Systems can be seen in the 'profiles of complete engines'
submitted in this section. - They are:
1. the ultra-low cylinder-head heights (referred to as MCH, i.e.
Maximum Cylinder-head Height)
2. anticipated reduction in engine weight
3. possibility of a Unicast/Unibloc construction method, in
which the cylinder-heads are cast with the engine block
4. ability to use valves at various, "asymmetrical" angles
5. possibility to use radial valves (with No. 4, above)
6. clear lack of any advantage by using DOHC valve trans vs.
SOHC types, due to a "mechanical disconnect" present in the
Rotoport Valve Systems. (SOHC is: single-overhead camshaft
and DOHC is Dual Overhead Camshaft.)
In previous Attain patent submission claims have been made to
the effect that the cylinder heads were at least 50~ lower than
their original counterparts. A true, A to B comparison can't be
made, because such enginesaren'tin existence. Since the Rotoport
Valve Systems are a 'novelty', such a comparison is not possible.
Therefore, the only point of reference is the engine's cylinder
bore, e.g. a diameter of 90 mm, etc. The MCH (see above, please)
can then be fererenced to the engine bore.
As a general rule the cylinder head height is considerably less
than the engine's bore, e.g. 70 mm of MCH vs. 90 mm of engine
bore.
. . . cont'd
CA 02267882 1999-03-30
- 29 -
Figures For Complete Engines
Figure 40. An SOHC type, with 2 to 4 V/H, suitable for Systems
1, 2, or 3. - Included Valve Angle (IVA°) is 26°, bore is 90 mm
but the MCH (Maximum Cylinder-head Height) is only 70 mm.
A single Rotoport actuates all valves.
Figure 41. Also an SOHC motor with an IVA° if 18; bore is 90 mm
and the MCH is only 60 mm. Suitable for Systems 1 and 3.
Figure 42 (lower image). An SOHC motor, with 2 to 3 valves at
22° IVA. Bore is 90 mm. It is suitable for System 3 only and
uses Wafer Pull-Springs. MCH is 75 mm.
Figure 43, represents a DOHC racing engine with Rotoports,
actuating 3 to 5 valves, at 36° IVA. Attains Parallel-Flow
Ports are used in both the intake and exhaust tracts; The
camshafts are located just above the 'shoulders' of the engine
block; their location is designated as DCIH (dual camshafts in
head.). The engine bore is 100 mm but the MCH is only 80 mm.
There does not appear to be a mechanical advantage to use two
Rotoports, except for reasons of exceptionally low MCH and
better engine cooling.
Figure 44. A high-performance engine with a single Rotoport,
actuating both the intake and exhaust valves. The intake tract
uses Attains Parallel-Flow Ports, while the exhaust tract is a
"regular" port; the valves are @ 34° and the engine bore is 94
mm. The engine is suitable for System 1 only.
The MCH is only 75 mm.
CA 02267882 1999-03-30
APPENDIX
Attains Rotoport Valve Systems make several references to
previously submitted innovations, included in patent
applications forwarded to CIPO at previous dates:
Item CIPO Reference
Attains ~ Stem Valves
Special Expansion ~Z 2,221,622
Compression Springs 2,222,979
PFP - Parallel-Flow Ports (all types)
T-Bar 2,225,048
New Camshaft Locations
(as applied to Rotoports) 2,227.025
