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Патент USA US2131507

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Sept. 27, 1938.
w. M‘ GOODWIN
2,131,507
VALVE OPERATING MECHANISM
Filed March 25, 1935
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Patented Sept. 27, 1938
2,131,507
UNITED STATES PATENT OFFICE
2,131,507
VALVE OPERATING MECHANISM
William M. Goodwin, Central Square, N. Y.
Application March 23, 1935, Serial No. 12,641
9 Claims‘.
This invention relates to a valve operating
mechanism and pertains more particularly to
the actuating means for the usual spring closed
poppet valve of an internal combustion engine
5 of the class set forth in my Patent No. 1,609,711
dated December 7th, 1926.
In a'valve operating mechanism of the above
mentioned class, it is a well known fact that con
siderable di?iculty is experienced in preventing
10 lost motion between the actuating means as a
cam and the valve actuated thereby when said
.Valve is in the closed position in engagement
with its seat. This is due to variations in‘the
over-all length of the connecting parts intro
15 duced therein by temperature changes and it is
dif?cult, therefore, to prevent tappet noises inci
dent to such lost motion. The applicant is ac
quainted with many different devices which have
been introduced in an endeavor to overcome this
20 defect in the construction of internal combus
tion engines but in so far as'he is aware, these
devices have either been impractical due to- de
fects in mechanical construction or have been
so expensive to construct as to render them com,
25 mercially impractical.
,
It is one of the main objects of this invention
to produce an improved valve operating mech
anism for an internal combustion engine that
will prevent lost motion between the operating
30 cam and the valve actuated thereby and at the
same time allow the valve to properly engage
its seat over all working conditions.
Another object of the invention is to provide
a valve operating mechanism adapted to take
35 up any lost motion which may occur therein
that is simple, durable and economical in con
struction and which is positive, automatic and
'eflicient in operation.
In carrying out the above mentioned objects
40 I have provided a motion‘ transmitting mecha
nism incorporated in the valve operating mech
anism which has relatively movable members
for taking up lost motion between the operating
cam‘ and the valve stem and at the same time is
45 self-acting to permit variations in the length of
the associated parts, particularly the valve stem,
(01. 123-90)
movement of the members to compensate for
any variation in the length of the connections
introduced by temperature changes or by other
reasons. A still further object resides in pro
viding a self-adjusting mechanism for trans
mitting motion from a cam to a poppet valve
which will remain in the adjusted position dur
ing the opening and closing operation of the valve
as long as there is no variation introduced in the
length of the associated parts and thereby con
having a relative movement.
Other objects and uses relating to speci?c parts
of the mechanism will more fully appear in the 15
following description taken in connection with
the accompanying drawing in which:
Figure 1 is a vertical sectional view partly in
elevation of a poppet valve, the adjacent por
tions of an internal combustion engine and my
novel mechanism for transmitting motion from '
the operating cam to the valve.
Figure 2 is a detail horizontal sectional view
on an enlarged scale taken on line 2—2, Figure 1.
Figure 3 is a fragmentary sidev elevation part
ly in section of the adjacent end portions of the
valve stem and my novel motion transmitting
and take-up mechanism as viewed from line
3-3, Figure 1.
Figure 4 is a vertical sectional view of the 1
upper end portion of the motion transmitting
and take-up mechanism partly in elevation as
shown in Figure 1 but on an enlarged scale.
Figure 5 is a vertical sectional view partly in
elevation of the lower end of my novel motion
transmission and take-up mechanism and the
operating cam therefor taken at right angles to
the views shown in Figure 1.
Although as will be readily understood, this in
vention is not limited in its application to an
internal combustion engine and particularly to
the valve mechanism therefor, I have illustrated
in Figure 1 my novel transmission ‘and take-up
mechanism as ‘I in connection with a poppet
valve of an internal combustion engine 9 in which
the valve 8 is opened and closed to and from
due to expansion or contraction thereof caused
its seat 10 by means of a cam II and a retract
by temperature changes.
ing spring I2 respectively. The valve 8 and re
tracting spring 12 may be of any well known
A further object of the invention is to provide
50 means for locking the relatively movable por
tions of the motion transmission mechanism to
each other to prevent relative movement there
of during the opening of the valve and to unlock
said portions as the valve approaches -or is in
55 the closed position to permit necessary relative
10
‘tribute to a maximum life of the device by re
ducing to a minimum the wear incident to parts
construction but as shown the valve stem as I3 50
isreciprocally mounted in a vertically disposed
guide 14 mounted in an extension I5 of the en
gine frame 9 while the'spring I2 is mounted on
the valve stem and guide between the engine
frame extension 15 adjacent the lower end of“
2
2,131,507
the guide opening and a retaining washer l6 on
the valve stem adjacent the lower end thereof.
The cam H‘ is secured to or made integral with
a cam shaft l‘! which is journaled in the usual
manner in the base iii of the engine. This cam
may be of any desirable form capable of lifting
the valve 3 from its seat l0 against the action
of the spring i2 once during each revolution
and as shown is of usual construction except that
10 it is provided with a peripheral cam groove 20
in the lower side thereof substantially mid-way
between the sides of the cam.
This cam groove
'20 is arranged diametrically opposite the high
side of the cam in symmetrical relation there
15 with and is of slightly more than 180° in length
for the purpose of effecting the operation of the
locking mechanism included in my novel motion
transmission and take-up mechanism for opera
tively connecting the cam with the valve stem
in a manner which will hereinafter be more ap
parent.
be rotated by the action of the spring l2.
It will thus be understoood that while the
spring 32 functions to produce relative rotation
of the tappet screw 29 and the plunger 24 in one '
direction to increase the over-all length thereof,
the axial pressure exerted on the tappet screw
by the valve spring l2 tends to produce relative 10
rotation of these members in the opposite direc
tion to shorten the over-all length-thereof. In
order, therefore, that the tappet screw and the
plunger may be maintained or locked against
relative rotation during the axial movement 15
thereof and particularly when said members are
being lifted by the action of the cam II to raise
the valve 8 from its seat Ill, I have provided a
novel locking mechanism which is controlled
by the cam II and cam groove 20 for accom 20
plishing thisresult.
The motion transmission and take-up mech
anism ‘I as illustrated in the drawing comprises‘
a vertically disposed tubular plunger 24 mounted
25 for reciprocative movement in a guide bearing
25 on the engine frame between the cam II and
the valve stem I3 with its axis of movement in
alignment with that of said valve stem. This
plunger 24 is of considerably less length than the
30 distance between the cam II and valve stem l3
and has ?xedly secured to the lower end there
of a foot or contact member 21 to form an in
tegral part of the plunger and adapted to contact with the cam ll.
range the threads 30 and 3| at an angle some
where between 30“ and 45° to the axis of the screw
so as to reduce the tendency of said screw to
‘
In the upper end of the plunger 24 is adjust
ably mounted a tappet screw 23 which has the
lower portion thereof provided with relatively
coarse external threads 30 in threaded engage
ment with similarly constructed internal threads
40 3| provided in the upper end portion of the
plunger 24. The upper end portion of the tap
pet screw 29 is reduced in diameter and is main
tained in constant engagement with the outer or
lower end of the valve stem l3 by a torsional
spring 32 coiled about the upper end of the tap
pet screw with one end connected as at 33, Fig—
ure 2, to the screw to rotate therewith and the
other end fixed to the upper end portion of the
plunger 24, as at 34, Figures 1 and 3, to rotate
with said plunger. The spring 32 is tensioned to
constantly urge relative rotation of the plunger
24 and screw 29 in a direction to cause separa
tion thereof by the screw threads 30 and 3i to
increase the over-all length of said plunger and
screw. In other words, the tappet screw isurged
by the spring 32 to be rotated in a direction to
move the screw axially toward the valve stem
l3 and to rotate the plunger 24 in the opposite
direction to effect the downward movement
thereof toward the cam shaft H for maintain
ing said members in constant contact with the
valve stem and cam I i respectively.
The angle of the screw threads 30 and 3| is
preferably as shown substantially 45° to the axis
thereof so that relative rotation of the tappet
screw and plunger to produce relative axial
movement thereof may be readily effected
whether axial pressure is exerted at the upper end
of the screw or at the lower end of the plunger.
While I have illustrated the threads extending
70
at an angle of substantially 45° it is to be un
derstood that this angle may be altered as desired
so as to interpose whatever frictional resistance
is required; that is, if the spring I2 is exception
ally highly tensioned, it may be desirable to ar
_
This locking mechanism consists of a pair of
screw members 38 and 39, one of which as 38 is
provided with external threads 40 and is mount
ed in a central bore 29' provided in the lower 25
end portion of the tappet screw 29 with the
threads 40 in meshing engagement with similarly
constructed internal threads 42 provided in said
bore.
The upper end of the screw member 38
normally terminates some distance below the in 30
ner end of the bore 29’ and an expansion spring
43 is mounted in said bore between the upper end
, of the member 38 and the bore 29' as shown in
Figure 4 for exerting a constant downward pres
sure on the member 38.
35
The other screw member 39 is mounted in a
central bore 21' provided in the contact member
21. The screw member 39 is provided with ex
ternal screw threads 45 which are in meshing en
gagement with similarly constructed internal 40
screw threads 46 provided in the bore 21’. The
pitch of the screw threads 40 and 45 as shown
in the drawing is substantially 60° so as to per
mit the ready relative rotation of the screw mem~
bers intheir associated elements when axial pres 45
sure is applied to either end thereof and to fric
~tionally resist relative rotation of these screw
members and the tappet screw 29 and plunger 24
during relative rotation of said screw and plunger
to vary the over-all length thereof affected by 60
the screw threads 30 and 3| in the manner here~
inbefore described. However, it is to be under
stood that the angle of the threads 40 and 45
may be ‘so selected as to interpose whatever fric
tional resistance is required. The screw members 55
38 and 39 are secured together by the tongue and
slot connection 49 as illustrated in Figure l to
cause said members to rotate in unison and at
the same'time permit relative axial movement
thereof. The lower end of the screw member 39 60
is somewhat reduced in diameter to form an ex
tension 39' projecting below the threads 45‘ for
engaging in the cam groove 20.
Operation
65
Assuming that the cam shaft I1 is moving in
the direction indicated by the arrow X, Figures
1 and-5, and that the high point of the cam is
positioned at substantially right angles to the
axis of the plunger 24 and valve stem I3 under 70
which condition the valve 8 will be in the closed
position in contact with the seat in. The lower
end 39' of the screw member 39 will be in regis
tration with the rear end portion of the cam
groove 20 and may or may not be extended into 75
3
2,131,507
v said cam groove in the manner illustrated in/ Fig
ures 1 and 5, Then as the cam H is rotated, if
the end 39’ is in the groove 20, the lower end of
the screw member 39 will be moved out of the
cam slot 20 and will be brought into and main
tained in the plane of the lower end of the foot
or contact member 21.
The engagement of the cam II with the con
tact member 21 will, of course, produce upward
10 axial movement of the plunger 24 and the screw
member 39 and at the same time the upper ver
tical movement of the plunger will be transmitted
' to the tappet screw 29 through screw threads 30
and‘ 3| and thence to the valve stem i3 to lift
the valve 8 from its seat l9.
Inasmuch as this
'upward movement of the valve will be effected
against the action of the spring H the resistance
thus produced to the upward axial movement of
the tappet screw 29 will tend to produce relative
rotation of the tappet screw and plunger 24
against the action of the spring 32 through the
medium of the screw threads 30 and 3| to shorten
the over-all length of the motion transmitting
mechanism 1 and improperly open the valve 8.
However, the plunger 24 and tappet screw 29
25
_ will be prevented from relative rotation during
the axial movement thereof by the screw threads
on the screw members 38 and 39 owing to the
frictional resistance o?ered thereby to such turn
30 ing movement by the difference in the pitch or
particular relative angular arrangement of the
screw threads 40-42 and 30--3l and also to the
fact that the screw member 39 is prevented from,
downward axial movement relative to the plunger
35 24.
This relative axial movement of the screw
member 391s prevented for the reason that the
end 39' of the screw member 39 is always in con—
tact with the high portion of the cam H during
the axial movement of the plunger 24 which holds
40 the screw member 39 against being screw thread
ed downwardly or toward the cam ll relatively
to the plunger 24 and tappet screw 29.
In other words, as looking members 38 and 39
are held by cam ll against rotation in the di
45 rection of rotation of tappet screw 29 when the
latter is being screw threaded into plunger 24,
bers 38 and 39 and will thus cause the lower end
39’-of the screw member 39 to enter the cam
groove 20 to a greater or less degree which action
is assisted by the spring 43. As the cam groove
20 again passes beyond the screw member 39 the
lower end of said member will again engage the
high portion of the cam H and be forced up
wardly relatively to the plunger 24 and thereby
effect a turning movement of the screw member
in the plunger and screw thread the screw mem 10
bers 38 and 39 upwardly into the plunger and
tappetscrew 29 respectively without affecting the
over-all length of the plunger and tappet screw.
If, on the other hand, the over-all length of the
plunger and tappet‘screw is insufficient to main 15
tain the tappet screw in contact with the valve
stem l3 when the valve engages the seat l0 and
the low portion of the cam II is in contact with
the member 21, the spring 32 will rotate the
tappet screw 29 in a direction to screw thread 20
the same outwardly or upwardly from the plunger
24 and thereby increase the-over-all length of
these members until the tappet screw again con
tacts the valve stem l3. As the over-all length
of the plunger and tappet screw is thus in 25
creased, the screw members 38 and 39 will re
main practically in their lower position due to
the action of the spring 43 as will be readily
understood, and when relative rotation of the
screw members is produced by the relative to 30
tation of the tappet screw and plunger any axial
relative movement of the screw members pro—
duced thereby will be permitted by the tongue
and slot connection 49 between said members.
It is to be understood that when there is an 35
easy sliding ?t between the screw members 38
and 39 and the tappet screw 29 and plunger 24
the spring 43 may be omitted, but when the
spring is incorporated in the structure this spring
is sufficiently light in structure so that when the 40
over-all length of the plunger and tappet screw
remains constant and any relative rotation of
these members occurs, the screw members 38 and
39 will remain in ?xed relation thereto during
each cycle of movement and will only move 45
downwardly when the lower end 39' of the mem
any normal tendency of the tappet screw to ro- ' ber 39 is in registration with the cam groove 20
tate in said direction will be prevented by the
upon relative rotation of the plunger and tappet
locking members for the reason threads 40 on
50 looking member 38 are of greater pitch than that
of threads 38 on tappet screw 29.
It will thus be seen that during the vertical
axial movements of the valve 8 produced by the
cam H and spring I2 the plunger 24 and tappet
55 screw 29 are locked against relative rotation and
the over-all length thereof will, therefore. re
main constant and will produce a uniform lifting
screw in a direction to shorten the over-all ‘length
’ of the valve 8 to open the same upon each revo
60
lution of the cam shaft l1.
Now as the high portion of the cam H passes
beyond the contact member 21 and said member
engages the low portion of the cam, the cam
groove 20 is brought into registration with the
screw member 39 and if the valve stem l3 has
65 been lengthened during the axial movement
thereof due to expansion or other causes, the ac
tion of the spring l2 tends to force the tappet
screw 29 downwardly and produce relative ro
tation of the tappet screw and plunger 24 against
70 the action of the spring 32 to decrease the over
all length thereof until the valve has reached the
limit of its downward movement by the engage
ment thereof with the seat III. This relative ro~
tation of the tappet screw and plunger will pro
75 duce a corresponding rotation of the screw mem
of these members.
‘
It will now be understood that the over-all
50
length of the motion transmission mechanism 1
will be automatically adjusted to assure a con
tinuous connection between the cam l l and valve
stem l3 and thereby prevent lost motion and 55
noise incidental thereto and although I have
shown and particularly described the preferred
embodiment of my invention, I do not wish to
be limited to the exact construction shown as
various changes in the form and relation of the 60
parts thereof may readily be made without de
parting from the spirit of the invention as set
forth in the appended claims.
I claim:
1. A valve operating mechanism comprising a
plurality of valve operating members having
movement relative to each other to increase or
decrease the over-all length thereof, a con
tinuously operating cam for intermittently -re
ciprocating said members to open and close the
valve, means for locking said members against
said relative movement throughout the recipro
cating movement thereof including two holding
elements operatively connected to transmit mo
tion from one to the other, means for main
75
2,131,507
taining operative connection between each hold
ing element and a respective valve operating
ing one of the valve operating members for inter
member effective upon a decrease in the over
means for said valve operating members includ
ing a holding element, means maintaining oper
ative connection between the holding element
and two of the valve operating members whereby
all length of the valve operating members to
positively produce movement of the holding
elements relative to said members toward the
cam to bring one of said elements into operative
engagement with said cam, a second cam co
operating with said one of the holding elements
10 during the inoperative portion of the cycle of
movement of said ?rst mentioned cam for re
leasing said locking means, and means rendered
operative by the release of said locking means
for adjusting said valve operating members rela
tive to each other.
2. A valve operating mechanism comprising a
plurality of axially reciprocating valve operating
members, means for maintaining operative con
nection between the members so that upon rela
tive rotation of themembers their over-all length
will be increased or decreased, a cam for inter
mittently reciprocating the valve operating mem
bers to open and close the valve, co-acting look
ing elements arranged in co-axial relation with
each other and having'axial movement relative
to each other and to thegreciprocating mem
bers toward and from the cam, screw means be
tween each locking element and a respective one
of said members effective upon said relative rota
30 tion of the members to decrease the over-all
length thereof to positively move the elements
relative to said members toward the cam, said
cam having holding engagement with one of the
locking elements during said intermittent move
I ment only for maintaining said elements and
members against said relative axial movement,
a second cam for releasing said locking elements
at the end of the intermittent movement of the
members, and means rendered operative by the
40 release of said locking means for adjusting said
reciprocating members relative to each other.
3. In a valve operating mechanism, in com
bination, a plurality of axially reciprocating valve
operating members, means including screw
threads for maintaining operative connection
between the members so that upon relative rota
tion said‘ members will be moved axially to in
crease or decrease the overall length thereof, a
cam engaging one of the valve operating mem
mittently reciprocating said members, locking
relative rotation of said members to decrease the
overall length thereof will positively produce
movement of the holding element from a re
tracted position at one side of the cam to an 10
extended position into the path of movement of
said cam, a groove in the cam adapted to register
with the holding element for releasing the look
ing means at the end of the intermittent move
ment of the valve operating members, and means 15
rendered operative by the release of said locking
means for rotating the valve operating members
to increase the overall length thereof.
,
5. A valve operating mechanism comprising, in
combination, a plurality of valve operating mem 20
bers having movement relative to each other to
increase or decrease the overall length thereof,
means including a continuously operating cam
engaging one of the valve operating members for
intermittently reciprocating said members to 25
open and close the valve, said cam having a
peripheral groove in the lower side thereof, lock
ing means for said operating members including
a holding element mounted in said member en
gaged by the cam to be moved by said cam from 30
an extended position beyond the member and
within said cam groove to a retracted position
within the member engaged by the cam, means
maintaining operative connection between the
holding element and at least two of said valve 35
operating members effective during a decrease
in the overall length of the members to posi
tively produce movement of the holding element
from said retracted to said extended position,
and means yieldingly urging relative movement
of the valve operating members to increase the
overall length thereof.
_ 6. A valve operating mechanism comprising, in
combination, a plurality of valve operating mem
bers having movement relative to each other to
increase or decrease the overall length thereof,
means including a continuously operating cam
engaging one of the valve operating members
for intermittently reciprocating said members to
bers for intermittently reciprocating said mem
open and close the valve, said cam having a
bers, locking means for said valve operating , peripheral groove in the low side thereof, locking
members including two, holding elements opera
means for said valve operating members includ
tively connected to transmit rotary motion from ing two holding elements operatively' connected to
one to the other, means including screw threads
55 operatively connecting each of said elements with
a respective one of the valve operating members,
said latter screw threads being so constructed
transmit motion from one to the other, means
for maintaining operative . connection between
each holding element and a respective one of the
valve operating members eifective during a de
and arranged relative to the first mentioned crease ‘in the overall length of the members to
screw threads that a decrease in the over-all
positively produce movement of ‘the holding ele
length of the valve operating members will posi
ments relative to said members toward the cam,
tively produce axial movement of the holdingv one of said holding elements being mounted to
elements relative to said members to be engaged alternately register with the cam groove and. to
by the cam, a second cam for releasing said hold
be engaged by the cam whereby the valve oper
ing elements during the inoperative portion of ating members are free to move relative to each
the cycle of movement of the first cam, and other when the valve is closed and will be main
means rendered perative by the release of said tained against movement relative to each other 65
locking means f r adjusting said operating mem
during the opening and closing operation of the
bers relative to each other.
valve, and means yieldingly urging relative
4. In a valve operating mechanism, in combi
movement of the valve operating members to
70 nation, a plurality of axially reciprocating valve increase the overall length thereof.
70
operating members, means including‘ screw
7. A valve operating mechanism comprising a
threads for maintaining operative connection be
plurality of axially reciprocating valve operating
tween the members so that upon relative rotation members having screw-threaded connection with
said members will be moved axially to increase or each other whereby upon relative rotation the
decrease the overall length thereof, a cam engag
over-all length thereof may be increased or de~ 75
2,131,507
creased, a locking element having screw-thread
ed engagement with one of the valve operating
members, the pitch of the screw-threads of said
locking element being greater than the pitch of
the screw-threads between said valve operating
members, so that when the locking element is
held against rotation the valve operating mem
bers will be maintained thereby against rotation
with respect to each other, and means for recip
10 rocating the valve operating members and for
intermittently holding the locking element
against rotation.
‘
8. A device as in claim 7 having means ren
dered operative by the release of the locking ele
ment for producing relative rotation of the valve
operating members.
9. A valve operating mechanism comprising a
plurality of axially reciprocating valve operating
members having screw-threaded connection with
5
each other whereby upon relative rotation the
over-all length thereof may be increased or de
creased, a pair of locking elements splined to each
other to rotate in unison and to have axial move—
ment relative to each other, each of said locking
elements having screw-threaded engagement
with a respective one of said members, the pitch
of the screw-threads connecting said locking
elements to said valve operating members being
greater than the pitch of he screw-threads 10
connecting the valve operating members to each
other, so that when the locking elements are
held against rotation the valve operating mem
bers will be maintained thereby against rotation
with respect to each other, and means for recip
rocating the valve operating members and for
intermittently holding the locking elements
against rotation.
WILLIAM M. GOODWIN.
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