Note: Descriptions are shown in the official language in which they were submitted.
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MODULAR VALVE ASSEMBLY
This invention relates generally to valve mechanisms useful with either
intake or exhaust ports of internal combustion engines, pumps and the like
and more particularly is directed to a novel self-contained unitary valve
module.
In the typically familiar internal combustion engine, by way of general
example, intake and exhaust valves for controlling combustion and exhaust
cycles of the engine are mounted over intake and exhaust ports to control
the inflow of combustible fuel mixtures and the outflow of exhaust gases.
Frequently, such ports usually have annular permanent or insert valve seats
engageable with the head of an associated mushroom type valve heaving an
elongated valve stem and return spring coupled between the valve stem and
a fixed support for holding the valve head closed against it seat. A rotatably
driven cam commonly engages the lower end of the valve stem or an
intervening lift rod periodically to compress the return spring and lift the
valve head off its seat.
In the event of the valve failure, such as a warped or broken valve
head or stem, scored valve seat, defective return spring or like fault,
repairing the defective valve is not only time and labor intensive, but in
many
cases entails extensive tear down of the engine itself. In severe cases the
condition of the engine may dictate complete engine replacement.
It is an important object of this invention to provide a novel pre-
assembled valve mechanism adapted to be operable installed and removed as
a modular unit.
It is another important object of this invention to provide a modular
valve assembly useful for intake or exhaust valve functions in internal
combustion engines, pumps and like applications.
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Still another object of this invention is to provide a valve assembly in
the form of a readily replaceable module having particular use in valve
regulated mechanisms such as internal combustion engines and pumps, by
way of example.
A still further important object of this invention is to provide a novel
valve mechanism which promotes improved economies of production, repair
and installation.
The present invention provides a modular, pre-assembled valve
assembly designed to be installed and removed as a unit comprising: a
generally cylindrical housing having a lateral gas port and an adjacent valve
seat constructed to be removably and insertably secured completely within a
mating socket formed in an external support, of an engine block; a valve
having an elongated stem and a valve head cooperable with said valve seat;
a stationary valve guide insertable into and supported on an interior wall
portion within said housing to support said stem for coaxial movements there
within; an axially moveable cam follower slidably disposed within said
housing and engageable with a valve actuating cam located externally of said
housing, and a spring extending between an interior cylindrical blind socket
within said cam follower for slidably receiving a major portion of said spring
therein and one end of said guide for biasing said valve head against said
seat whereby, said cylindrical housing is easily inserted into and removed
from said engine block mating socket along with said valve guide, said
spring, said cam follower, said valve head, said valve seat and said valve
stem as a single unit simultaneously.
The present invention also provides a modular, preassembled, unitary
valve assembly actuated by an external valve cam, comprising in
combination: an elongated generally cylindrical housing having an axially
extending cylindrical interior with a frusto-conical valve seat at one end
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thereof; said housing having external threads at its other end for effecting
threaded assembling completely into and disassembling from a mating socket
formed in an external support of an engine block; an annular valve guide
insertable into and supported on a wall portion of said interior; a cam
follower slidably mounted within said interior in axially spaced relation with
said valve guide comprising a tail portion extending outwardly of said the
other end of said housing for operatively engaging the external valve cam; a
spring extending between and engaging one end of said guide and an interior
cylindrical blind socket within said cam follower for slidably receiving a
major
portion of said spring therein; and a valve comprising a head matingly
engageable with said valve seat and having an elongated stem extending
coaxially through said valve guide and said spring and detachably connected
with said cam follower whereby, said cylindrical housing is easily inserted
into and removed from said engine block mating socket along with said valve
guide, said spring, said cam follower, said valve head, said valve seat and
said valve stem as a single unit simultaneously.
IN THE DRAWING:
Fig. 1 is a partial elevational view with portions thereof in section of a
rotary engine embodying the improved valve assembly of this invention;
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Fig. 2 is an enlarged cross section of a portion of
the engine illustrated in Fig. Z showing the valve
mechanism of this invention in open position and
. indicating its relationship to related parts of the
engine;
Fig. 3 is a partial elevational view of the engine
similar to Fig. 1 with portions thereof in section,
showing the valve mechanism of this invention in closed
position;
Fig. 4 is an enlarged partial cross sectional view
of the engine illustrated in Fig. 3 and showing the
relationship of parts for the valve mechanism of this
invention in closed position;
Fig. 5 is an enlarged longitudinal cross sectional
view of the valve assembly of this invention divorced
from the engine of Figs. 1 and 3;
Fig. 6 is a longitudinal cross sectional view of the
valve body seen in Fig. 5;
Fig. 7 is a cross sectional view of the valve guide
shown in Fig. 5;
Fig. 8 is a side elevational view of the return
spring shown in cross section in Fig. 5;
Fig. 9 is a side elevational view of the valve shown
in section in Fig. 5;
Fig. 10 is a cross sectional view of the valve cam
follower taken substantially along vantage line 10-10 of
Fig. 11 and looking in the direction of the arrows
thereon;
Fig. 11 is a top plan view of the cam follower;
Fig. 12 is a right hand end elevational view of the
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valve cam follower shown in Fig. 11;
Fig. 13 is a schematic view showing the relationship
of valve and cylinder actuating cams of the engine
illustrated in Figs. 1 and 3;
Fig. 14 is an enlarged top plan view of the valve
cam shown in Fig. 13; and
Fig. 15 is a cross sectional view taken
substantially along vantage line 15-15 of Fig. 14 and
looking in the direction of the arrows thereon.
DESCRIPTT_ON OF THE PREFERRED EMBODIMENT,
Turning now to the preferred embodiment of this
invention, illustrated in the drawings, initial reference
is made to Fig. 1 wherein a partial showing of a rotary
cam plate type engine is indicated generally at 20
comprising a plurality of cylinders 21 carried radially
of a rotor 22 for movement with the rotor and a central,
generally cylindrical combustion chamber member 23 that
is supported on a main bearing 24 concentrically
surrounding a stationary main shaft 25. (See Fig. 2) Two
parallel, stationary cam plates (not shown) having
recessed cam tracks 27 (See Fig. 13) are disposed
adjacent opposite axial ends of the rotor 22 to engage
cam followers 28, rotatably mounted on pintles 29
extending coaxially from opposite sides of a generally
cylindrical saddle means 30. The saddle is movable over
the exterior of cylinder 21 and is connected to a related
piston 31 by means of a wrist pin 32 whereby the piston
may be reciprocated in response to movement of the rotor
and saddle in accordance with the configuration of the
cam tracks 27.
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A rotary engine having the general features and
characteristics of engine 20 hereof is described more
fully in my U.S. Patent No. 4,653,438 issued March 31,
1987. It is to be understood, however, that the
particulars of engine 20 are not pertinent to the present
invention other than to provide a context in which the
novel valve assembly 34 hereof finds useful application.
As seen in Figs. 1-4, the embodiment of valve assembly 34
is employed as an exhaust valve in engine 20.
With reference now to Figs. 1-4 of the drawings, the
features of vale assembly 34 will be described more
fully.
As seen in Figs. 1 and 2, valve assembly 34 is
mounted in a cylindrical bore 35 extending inwardly of
one axial end of the combustion chamber member 23 and in
opposing alignment with a stationary annular valve cam 36
carried in one end section 37 of a two piece engine
housing, (partially shown in Figs. I and 3). It will be
noted that bore 35 has a reduced diameter portion 38 at
its inner end forming an annular shoulder which is
abutted by a mating annular stop shoulder 39 at~the
operationally inner end of the valve assembly 34 for
reasons to appear presently. Bore 38 openly communicates
with a combustion chamber 40 within member 23 that in
turn openly communicates with the inner radial end of a
combustion cylinder 21 individually associated with
chamber 40; there being several such chambers 40 in
member 23 corresponding to the number of engine
cylinders. Each combustion chamber 40 is invaded on one
side by a spark plug 41 and on its opposite side by a
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valve assembly 34. In this instance, the valve assembly
serves to control the flow of exhaust gases from the
combustion chamber 40 via communicating ports 42a, 42b
and 42c and passageway 43 of shaft 25 leading to exhaust
outlet 44 extending coaxially of such shaft.
As shown in Fig. 5 valve assembly 34 is generally
cylindrical with it's various component parts coaxially
arranged within a unitary cylindrical housing 50. It
will be recognized from sectional view Fig. 6 that
housing 50 has a cylindrical body 51 with exterior
threads 52 adjacent one outer end 53 thereof. A
cylindrical bore 54 extends axially inwardly of end 53
and is provided with a pair of diametrically opposed
slots 55, 55 receptive of a spanner wrench for rotatably
engaging threads 52 with the internal threads formed in
bore 35 of the combustion chamber member 23 whereby to
mount the assembly 34 in the engine 20 (Figs. 1 and 4).
In this regard, engagement of shoulder 39 adjacent
the inner and of body 51, with the opposing shoulder
formed by the reduced diameter portion 38 and bore 35,
serves to limit threading advance of body 51 into bore
35. This limit defined by stop shoulder 39 also assures
proper alignment of port 42a with port 42b of the exhaust
ports and passageway.
Bore 54 intersects a smaller diameter coaxial bore
56 extending inwardly of the opposite or operationally
inner end 57 of the assembly body 51; the junction
between the two bores 54 and 56 forming an internal
annular shoulder 58 in body 51, the purpose of which will
be explained more fully hereinafter. Port opening 42a is
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formed through the side wall of bore 56 for passage of
exhaust gases through ports 42b in chamber member 23 and
42c in the main bearing 24 to passageway 43 communicating
with the shaft exhaust outlet 44 as previously mentioned.
The inner end 57 of the body 51 is distinguished by a
frustro-conical annular valve seat 59 which cooperates
with valve 60.
As shown in Fig. 9, valve 60 comprises an elongated,
ground cylindrical stem 61, having a reduced exteriorly
threaded tail portion 62 at one end thereof, and an
enlarged mushroom head 63 at its opposite end. The valve
head 63 is provided with a frustro-conical seat 64 which
is matingly engageable with the valve seat 59 at the
outer end of the housing for the purpose of periodically
opening and closing the inner end 57 of the body 51.
An annular valve guide 65 is shown in Fig. 7 to
comprise a cylindrical sleeve body 66 having a reduced
diameter portion 67 at one end to form an annular
shoulder 68 about the body's exterior. The exterior
diameter of body 66 fits closely within bore 54 of the
housing 50 while the exterior diameter of portion 67
thereof fits closely within the smaller bore 56 of the
body with annular shoulder 68 thereabout engaging .
shoulder 58 of the housing body 51. A cylindrical bore
69 extends coaxially through body 66 and is dimensioned
to closely received the valve stem 61 therethrough for
guiding the valve during its movements coaxially of the
housing 50.
As shown in Fig. 8 a coil spring 70 surrounds the
valve stem 61 with one end 71 thereof abuttingly engaging
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an adjacently opposing end face 72 of the valve guide
(See Fig. 5). The major portion of spring 70 fits
closely within a cylindrical blind socket 73 extending
axially inwardly of an operationally inner end 74 of a
valve cam follower member 80 (See Figs. 10-12). It will
be noted that the other end 75 of spring 70 bottoms
against the end wall 76 of socket 73 and that a threaded
bore 77 extends coaxially beyond end wall 76.
Cam follower 80 has a generally cylindrical body 81
provided with a radially inset annular kerf 82 formed
adjacent its inner end 74 and is further distinguished by
an axially extending cam engageable tail portion 83 at it
opposite end. Portion 83 is formed with a pair of
arcuate top and bottom faces 84 and 85, respectively,
which are laterally intersected by angularly convergent
planner faces 86, 86 and a transversely related planar
outer end face 87 (See Figs. 11 and 12). The two angular
faces 86, 86 serve to engage risers 90 of the valve cam
36 while the end face 87 of the follower periodically
engages spaced lobes 91 of the valve cam in operation
(See Figs. 13-15).
With particular reference now to Fig. 5, the
organization of the several parts of the unified assembly
34 will be apparent. As there shown, the cylindrical
housing 50 is first fitted with the valve guide 65 by
inserting the same coaxially into bore 54 until shoulder
68 engages shoulder 58 at the junction of the two bores
54 and 56. This interengagement of the shoulders
provides a substantially gas-tight fit.
Once the guide 65 is in place, spring 70 is inserted
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into the blind bore chamber 73 of the cam follower 80.
It is to be noted that the kerf 82 of the cam follower is
fitted with an 0-ring seal 92, as shown in Fig. 5. The
sub-assembly of the cam follower, spring and 0-ring is
then inserted into bore 54 of the housing so that end 71
of spring 70 engages end wall 72 of the guide sleeve 65.
Next the valve 60 is inserted axially through bore 56,
the guide sleeve bore 69 and the open interior of spring
70 until the threaded tail portion 62 thereof engages the
threaded opening 77 in the cam follower. The valve is
then rotated to thread the tail portion 62 into the
threaded bore 77, slightly compressing spring 70 and
drawing the cam follower 80 into its Fig. 5 position to
complete assembly 34.
The unified assembly 34 is readily mounted in
operating position in an engine such as engine 20
illustrated, for example, by inserting the same into
combustion chamber bore 35 and engaging threads 52 on the
exterior of the assembly housing with the internal
threads, adjacent the outer end of bore 35 (See Figs. 2
and 4). The spanner wrench slots 55 are available to
tighten the valve assembly into its operating position
where at the abutment of stop shoulder 39 with the
shoulder formed by reduced diameter 38 of bore 35 effects
a substantially gas-tight seal, preventing hot exhaust
gasses from reaching threads 52 which could freeze
assembly 34 in bore 35. Rotational alignment of the
valve, particularly the valve cam follower, is
accomplished by two annular thrust bearings 93 and 94
mounted in housing 37 and disposed above and below the
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follower portion 83 to closely engage the arcuate
surfaces 84 and 85 thereon. In this latter respect,
surface 84 is convex while surface 85 is concave; such
surfaces being formed at different radii to fit the inner
radius of the larger or upper ring bearing 93 and the
outer radius of the smaller or inner ring bearing 94.
It will be appreciated from Figs. 14-15 that
movement of the valve follower 80 past or off of a lobe
91 of the. valve cam serves to expand spring 70 causing
the valve 60 to move axially from its open position of
Fig. 2 to its closed position as shown in Fig. 4.
Conversely, the valve returns to its open position when
the follower engages a riser 90 and raised cam lobe 91
(See Figs. 2 and 13-15).
._.T
