close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2409178

код для вставки
0d. l5, 194.5.
A. H. ADAMS ETAL
2,409,175
HYDRAULIC SYSTEM
/
ATT RNEY
Patented Oct. 15, 1946
¿leans '
UNITED STATES `PATENT OFFICE
2,409,175
HYDRAULIC SYS TEM
Arben H. Adams and Theodore S. Tucker, North
Hollywood, Calif., assignors, by mesne assign
ments, to Bendix Aviation Corporation, South
Bend, Ind., a corporation of Delaware
Application October 19, 1942, Serial No. 462,614
12 Claims. (Cl. SII-54.5)
l
2
This invention relates to iiuid actuating sys
tems, and more particularly to fluid actuating
systems incorporating automatic means for com
pensating for fluid expansion or contraction, or
other factors añecting volume.
An object of the invention is to provide a fluid
actuating system wherein the driven member is
held in registration Within close limits.
Another object is to provide electrical means
Motor cylinder Illincludes a housing 36, a pis
ton 38 connected to a piston rod 40, and a ten
sion spring 42 connected to the housing 36 and
rod 4H, to urge piston 38 toward the left end
of cylinder 36.
<
.
In normal operation, clockwise movement of
lever 22 creates pressure on the fluid in the mas
ter cylinder I0 forcing it through conduit I2 into
motor cylinder I4. The fluid causes piston 38 to
for compensating a ñuid actuating system for
move the exact amount that piston I8 moves,
inasmuch as cylinders I6 and 36 are the same
changes and fluid volume.
Another object is to provide a fluid actuating
system having indicating means to show lack
of registration of driving and driven parts.
Another object of the invention is to provide
electrical contact means for compensating 'a
size.
This fluid actuating system is subject .to ther
mal expansion and contraction, however, which
increases or decreases the volume of the ñuid in
conduit I2 or in cylinders I6 and 36 causing a
fluid system.
lack of registry between the master and slave
pistons I8 and 38 respectively. For example, the
Another object is to provide a iiuid actuating
system having automatic indexing means when
the driving member reaches the extremes of its
actuating system may be used on an airplane,
whereby the pilot controls the throttle of an'en
gine placed in the wing of an airplane.. When
movement.
`
the airplane is flying in the higher cold altitudes
Another object is to provide automatic elec
the ñuid in conduit I2 contracts causing the pis
trical means for indexing a fluid system at the
ton 38 to move to the left, upsetting the throttle
extremes of movement of the driving member.
Other objects’ and advantages of the invention 25 setting. Or7 when the plane lands, the wing may
be exposed to the sun’s rays, heating up the fluid
will be apparent in the following description and
until the piston 38 moves to the right, giving a
claims.
change in throttle setting.
t. In the drawing forming a part of this specifica
ion:
‘
The invention includes means to compensate
for this iiuid expansion and contraction so that
Figure 1 is a schematic showing of a fluid ac
the motor cylinder 3B remains at the point to
tuating system having electrical compensating
which it was moved, within extremely close lim
means and a fluid indexing means; and
Figure 2' is a schematic showing of a fluid actu- \
ating system having electrical compensating
its. Formed on motor piston rod 40 is a pro
jection All. A slide member 46 sliding on a base
48 is adapted to be contacted by projection 44.
means as well as electrical indexing means.
In this specification the word “synchroniza
The clearance between projection ¿Il and slide 46
tion” will be used to denote a correspondence of
is made extremely small and may be .003 of an
inch on an end. vElectrical current is supplied to
position of driving and driven units while moving.
In other words, this relates to a dynamic condi
tion. The word “registration” will be used to de
projection M and a circuit is completed when it
contacts slide d5, sending current to a reversible
note a correspondence of position between driv
ing and driven units while both are stationary.
This word therefore refers to a static condition.
The word “indexing” will be used to describe the
act of registering driving and driven units at a 45
selected positionv of one unit, as at the ends of
the stroke of the driving unit.
Referring to Figure 1, a master cylinder unit
Iû is connected by a conduit I2 to e, motor unit
electric motor 5l?. Motor 50 drives a reversible
pump 52 which is connected by a branch con
duit 5d to conduit I2. Pump 52 adds or sub
tracts fluid from conduit 54, removing or adding
it to a reservoir 56, all depending upon whether
there is expansion or contraction.
The electrical circuit is supplied by a, batteryäß
(near control lever 22) connected by a wire 60
to a switch SI. Switch SI is normally closed but
I4. The master unit includes a cylinder housing 50 is opened by depressing thumb lever 32. Lead
It, a piston I 3 movable therein connected to a
ing from switch SI isa Wire 62 which leads to
piston rod 2G. Piston rod 26 is actuated by a
projection 44. . Switches S2 and S3 connect the
manual lever 22 pivoted at 2liI and connected by
wire 62 to wires 64 or 68 respectively leading to
a link 26 to piston rod 2f). The lever 22 is main
reversible motor 56, causing it to rotate in one
tained in place by a brake shoe 23 contacting a 55 direction or another according to which wire de
braking surface 3E. Brake shoe 28 is Vlifted when
livers the current.
movement of the lever is desired and this is per
switchesare used for switches S2 and S3. In that
formed by manually depressing thumb lever 32
which lifts rod 32, shown largely in dotted out
line.
event, wire 62 is merely forked and connected
to wires 64 and- 66 through microA switches which
are normally open. Projection M then lmerely
ec
In actual practice micro
2,409,175
4
3
operate motor 5D inthe opposite direction to add
fluid to conduit I2 from reservoir 56 until the
motor piston 38 returns to its original position.
serves as a mechanical block for closing the
switches. Micro switches normally close on a
movement of .002' of an inch. Thus if a clear
ance of .003 of an inch is allowed at each end,
.002 of which is taken up by micro switch move
ment, there will be a. neutral free area of .G01 of
If the operator should now desire to move mo
tor piston 38 to the left, he moves lever 22 in a
counter-clockwise direction.
Master piston I8
thereupon moves to the left, relieving fluid pres
an inch.
sure momentarilyy allowing motor spring 42 to
Since it might possibly happen that the motor
move motor piston 38 to the left a corresponding
in spite of the compensating device, an indicator 10 amount. At the end of the movement, switch S2
will still be closed and the motor 50 will oper
is provided for this purpose. The indicator in
ate until motor piston 38 moves about .002 of an
cludes a battery G8 having parallel connections
inch to the right. Thereafter leakage and ther
through resistors 'I0 and ‘I2 from positive to
mal expansion and contraction will be compen
negative. Take oiTs 14 and 'I6 are provided for
and master cylinders will get out of registration
each resistance and are mechanically moved 15 sated for in the manner described above.
Since a continued series of operations of the
along their respective resistance by master pis
master cylinder in the same direction might re
ton rod 2B and motor piston rod 40 respectively.
sult in a lack of synchronisrn between master
The take-offs ‘I4 and 'I6 are connected to a polar
and motor units, galvanometer 'i8 is provided to
indicate this. Registration is important when it
galvanometer 18. Since the voltages at corre
sponding points on the resistances 'I9 and 'I2 are
equal, any lack of registration will be shown up
is desired to move the motor cylinder to a given
quantitatively and qualitatively on the galva
nometer 18.
Having been informed by galvanometer 18 of
a lack of synchronism, the operator may compen 25
sate for the same in two ways. He may move the
lever 22 in the direction to cause pump 52 to
position by moving lever 22 to a predetermined
position. The bridge system connected to gal
vanometer 'I8 indicates the direction and the
amount of lack of synchronism.
Lack of registration may be corrected by mov
ing lever 22 to close the proper switch S2 or S3 at
the same time keeping switch SIDI! closed. Thus
if there is too little fluid in the system, piston I8
correct the system and at the same time keep
a switch Slûil, in shunt to switch SI, closed.
This may be continued until the galvanometer 30 should be moved to the left, closing switch S2,
which in turn actuates motor 5D, causing pump
reads zero. Ory he may use the hydraulic in
52 to add to the system. By moving piston I8
dexing or registering means which will now be
slowly to the left, this adding action may be con
explained. Mounted on master cylinder I8 is a
tinued until the desired amount of iluid is added,
valve housing 80 having conduit 82’connected
as indicated by meter 18. If there is too much
from it to conduit I2. Also connected to the
liquid in the system, piston I8 may be moved to
housing is a pressure conduit 84 and an exhaust
the right until switch S3 is closed. This causes
conduit 86. A valve slide member 88 is con
pump 56 to subtract liquid to the system, and
nected `to lever 22 by rods 90 and SZand rocker
by moving piston I8 to the right at the same rate
arm 94. When valve slide 88 is at the right end
of housing 88 conduit I2 is connected to exhaust 40 of speed, this action may be continued until the
desired amount is subtracted.
and when valve slide 88 is to the left, conduit I2
Or, alternatively, the lever 22 may he moved
is connected to pressure.
to one extreme or the other with switch SIUG in
The operation of the system of Figure 1 is as
open position. If moved to the left, valve 8B will
follows: The operator grasps lever 22, depressing
. move to the right connecting conduit I2 to ex
thumb lever 32, lifting brake shoe 38 and open
haust, relieving any excess fluid since spring 42
ing switch Sl. To move motor piston 38 to the
moves motor piston 38 to the extreme left. If
right, the lever is moved clockwise and the pres
sure created by piston I8 is transmitted through i lever 22 is moved to the extreme right and the
brake> is set, pressure ñuid flows through valve
conduit I2 to piston 38, causing it to move a
corresponding amount. When the motor piston 50 88 to conduit I2 to supply any deñciency until
motor piston 38 moves to the extreme right of its
moves to the desired amount the thumb lever 3?.
cylinder. If extremely high pressures are used
is released, lever 22 is locked in position and
they will merely force master piston I8 to the
switch SI closed. The movement of motor pis
left also, closing valve 88 through lever 22.
ton rod 48 also moves slide 46 with it, closing
From the foregoing description of Figure l,
switch S3. When switch S3 is closed current
it will be apparent that there are three cooper
ñows through wire 65 to motor 58, causing pump
ating parts of the invention, all necessary for the
52 to subtract or withdraw ñuid from conduit
single result of a registered and compensated
I2. This action continues until motor piston 38
fluid actuating system. Thus, the compensating
moves .002 of an inch to the left, opening switch
system counteracts expansion, contraction and
S3 and breaking the circuit to motor 50. Thus,
leakage. The indicating system shows whether
the motor piston moves a slight amount after
or not there is registration between the driving
being set by the master unit, but this movement
and driven parts. The compensation system, or
is so slight that it does not interfere with prac
tical operations.
If the fluid in conduit I2 should expand due
to heat or otherwise, the switch S3 will close after
piston 38 has moved .002 or .003 of an inch. This
starts motor 50 to act on pump 52 to subtract
fluid from conduit I2 until motor piston 38 re
turns to its original position and again opens
switch S3. If the ñuid should thermally contract
in conduit I2 or elsewhere, or become less because
of leakage, the spring 42 will force piston 38 tothe left. When this movement exceeds .003 of
an inch, projection 44 will close Switch S2 and
the separate hydraulic indexer, valve 88, may be
used to restore registration as previously ex
plained.
The device of Figure 2 will now be described.
It is essentially the same as Figure 1 except that
the hydraulic indexer (valve 88) is replaced by
an electrical indexer or means to register the
driving and motor units at the extremes of the
strokes. A lever |22 is connected by a link l26
to a piston rod |28 connected to a piston H8.
Piston IIS reciprocates in a cylinder IIB and
7.5 forms a master cylinder unit H0 with the same.
2,409,175
"5
A conduit ||2 connects cylinder ||6 .to a motor
cylinder |35` having a piston |38 reciprocable
therein and urged to the left by a compression
spring |42. Connected to piston |38 iS a DÍSÈOII
rod |40 having a projection |134 engaging a slide
member |45 slideable on a base |58. The motor
unit is H4.
Branching from conduit || 2 is a conduit |54
controlled by a solenoid operated poppet |52 con
trolling the flow of fluid under pressure. A sec
ond branch |82 is controlled by a solenoid oper
y
6
nected to a wire 2|4 leading toward themotor
unit to a, normally closed switch S2 |, which in turn
is connected to pressure solenoid wire |56. When
there is too little iiuid for registration and lever
|22 is moved toward the extreme right, it will
close switch S29 while switch S2I is closed, pass
ing pressure fluid into the system. When reg
istration is achieved, motor piston |38 will open
switch S2 |, stopping the flow of ñuid.
The indicator device of Figure 2 is the same
as that of Figure l, and includes a battery |68,
ated poppet |55 controlling the ñow of iiuid to
exhaust.
The compensatingY circuit includes a battery
parallel resistances |70 and |72, and wipers |14
in turn is connected by a wire |52 to projection
which in turn, through fluid compression or the
and |15, as well as a galvanometer l '53.
The operation of the system of Figure 2 is as
|58 connected by a wire |66 to a switch S| l which 15 follows: Movement of lever |22 moves piston H8,
|54. Switches S|2 and S53 are placed on either
side of projection |44 and are connected ‘to wires
|64 and |65` respectively, wire |65 leading to pres
sure solenoid |80 and wire |66 leading to exhaust
solenoid |28. The operation is much the same
as in Figure l, fluid being added or subtracted
from conduit H2 .by valves |52 and |55 respec
tively.
tension of spring |42, moves motor piston |38 a
corresponding amount and direction. Motor
piston rod Idil moves slide |525 with it, then pro
jection |54. After the initial correction as de
scribed with reference to Figure l, switches SI2
and S|3 open the pressure and exhaust valves
|52 and |56 respectively, depending upon whether
there is contraction or expansion.
'
The electrical indexer of Figure 2 will >now be 25
Lack of registration is indicated by galva
described. Branching from battery |58 is a wire
nometer |58, in which case lever |22 may be
250 passing near the motor unit H4 where it is
moved to one extreme or the other to index or
connected to a. normally open switch SI4. Lead
synchronize the master and slave units. If there
ing from switch SIG is a wire 252 leading to a
is too much fluid in the connections, movement
normally closed switch Si 5. Switch Sie is in 30 of lever |22 to the right 'will close switch Sill,
turn connected to exhaust solenoid wire |55.
opening exhaust valve |56 until lever |22 reaches
Thus, if master piston rod |29 is moved toward
the extreme right position, at Which time switch
the extreme right, and there is more fluid in con
S|5 is opened. Likewise, movement of lever |22
duit |42 than normally prevails, motor piston
to the left closes switch SIB, opening exhaust
|38 will be “ahead” of master piston H8. For 35 valve |55 until motor piston |38 reaches the ex
this reason, motor piston |38 will reach the end
treme left, opening switch SH.
of its stroke and switch SM will be closed by an
Too little fluid for registration results in
actuator lêûl movable with the rod |55 before
switch S25 closing on clockwise movement of
switch SI5 is opened by an actuator |202 on rod
lever |22, opening pressure valve §52 until mo
|20, exhausting the excess ñuid by valve 156 until 40 tor piston |38 opens switch S2|. Leftward move
the master piston also reaches the end of its
ment of lever |22 closes switch SIB adding fluid
stroke, at which time switch Si 5 is opened, break
until lever |22 can go to the extreme left and
ing the circuit, and closing the connection to ex
open switch S | 9.
haust.
The word “ñuid” has been used in describing
Branching from the left end of wire 205 is a 45 the invention, since gas or liquid can be used
wire 264 leading to a normally open switch Sie.
as the operating medium. It will 'be appreciat
Switch S|6 is connected to a wire 255 leading to
ed, however, that for best results an incompres
a point near the motor cylinder to a normally
sible liquid is preferable.
closed switch SI1, the other end of which is con
Although this invention has been described
nected t0 exhaust wire |54. Thus, if there is too 50 with reference to particular embodiments thereof,
much fluid in the connections for registration
it is not limited to these embodiments nor other
and lever |22 is moved to the extreme left, switch
Wise except by the terms of the following claims:
S|5 will be closed by an actuator IZili on rod mi!
We claim:
before switch Sil is opened by an actuator |5ll2.
_ 1. A ñuid actuating system comprising driving
This opens exhaust valve |55 allowing the fluid 55 means, driven means, a fluid connection between
to escape to exhaust until motor piston |38 also
said means whereby said driven means moves in
reaches the end of its stroke. At this point switch
response to said driving means, movable means
S|l lwill be opened, -breaking the circuit and al- ` moved by said driven means, switch means ac
lowing valve |56 to close.
tuated by contact of said driven means with said
Branching from wire 25€) near the right end 60 movable means, a connection to exhaust, a valve
is a wire 268 leading to a normally open switch
to control the same, a connection to pressure
SIB. This switch is connected to a wire 229
and a valve to control the same, said valves be
leading toward the master cylinder to a nor
ing controlled vby said switch means whereby
mally closed switch Sië. Switch SiS is connect
fluid is removed or added to said driving, driven
ed to pressure solenoid wire ISE. Thus, when
and connection means depending upon the di
there is too little fluid in the connections, and
rection of contact of said driven means with said
lever |22 is moved toward the extreme left, mo
movable means.
tor switch S98 will close before master switch
2. A ñuid actuating system comprising driving
SIB opens. rì‘his opens pressure valve |52 until
means, driven means, a fluid connection between
sufficient :duid has entered the system so that To said means whereby said driven means moves in
lever |22 can be moved to the extreme left, at
response to said driving means, movable means
which point it opens switch S|9 breaking the cir
moved by said driven means, switch means ac
cuit.
tuated by contact of said driven means with
Branching from wire 255 near the left is a wire
said movable means, a connection to exhaust, a
2 I2 connected to a normally open switch S20 con
valve to control the saine, a connection to pres
2,409,175
7
ing> and 'said driven means.
ing controlled by said switches Awhereby fluid is
removed or added to saidv driving, driven and
connection means depending upon the direction
9. A fluid actuating system comprising driving
means, driven means, a iiuid connection between
the same, moveable means moved by said driven
means, ñrst switch means actuated by contact
of said driven means with said moveable means,
a fluid connection 'to exhaust, a valve to control
of contact of said driven means with said mov
able means, and means to render said'switches
inoperative when said driving means is operat
ing to move said driven means.
3. A fluid actuating VSystem comprising driv
ing means,'driven means, a fluid connection be
the same, a fluid connection to ñuid under pres
10 sure, a valve Áto control the same, a connection
to said valves` from the first switch means to
tween the same; means to compensate for vol
selectively actuate said valves depending upon
ume changes in thefluid, means to indicate the
state of registration of said drivingand driven
means, and indexing means comprising a valve
adapted to connect said system to exhaust at one
the direction of contact of said driven means
with said moveable means to add or subtract
fluid for compensating purposes, and a second
switch means operable at at least one point in
the stroke of the driving means, and ‘connected
to said valves for control of the same, to register
extreme of movement o_f _said driving means and
to` connect said system to pressure at the other
extreme of movement.
i
‘ «
said driven means with said driving means.
4. In a fluidactuating system including driv
ing means, driven means, a fluid connection be
8
saidcompensating means to register said driv
sure, a valve to control the same,’said valves be
20
10. In a fluid actuating system including driv
ing means and driven means movable through
corresponding ranges and a fluid connection be
tween said means whereby said driven means is
moved in response to movement of said driving
of movement of said driving means and connect
said system to exhaust at the other extreme of 25 means; indexing means responsive to movement
of said 'driving means into one end of its range
movement of said driving means.
tween the same; an indexing valve connected to
said system and actuated by saiddriving means
>to connect said system to pressure at one extreme
of movement for varying the volume of the fluid
5. In a iiuid actuating system including driving
in Ithe system in direction to move the driven
means, driven means, and a fluid connection be
means into its corresponding end position, and
tween the same; an electrical indexer comprising
interconnected switch means at both ends of the 30 means responsive to movement of said driven
means into its corresponding end position for dis
strokes of both'of said driving and said driven
abling said indexing means.
means, and fluid adding and’subtracting means
11. A fluid actuating system comprising driv
to index said driving and vdriven means, and op
ing means, driven means, a fluid connection be
erated by said switch means.
6. A fluid actuating system comprising driving 35 tween said means whereby said driven means
moves in response to said driving means, a first
member moved by said driven means, a second,
said means, electrical means compensating for
freely movable member in the path of said ñrst
fluid volume changes within close limits, means
member and adapted to be contacted by and
to index said driving and said driven means,
and means to inoicate the state of registration of 40 moved only by contact with said ñrstmem
ber and be frictionally retained in whatever po
said driving and said driven means, said indi
sition it is moved to by said driving means, means
cator means comprising a source of electrical po
to vary the volume of fluid in said system to
tential, two resistances connected to said source,
compensate for fluid volume changes, switch
a wiper on each said resistance, one moved by
means actuated by contact of said first member
the driving means and one moved by said driven
with said second member to actuate said volume
means, and a polar galvanometer connected to
means, driven means, a fluid connection between
said wipers.
7. A fluid actuating system comprising driving
varying means in such direction as to reverse
the movement of said driven means, and means
for disabling said volume-varying means during
means, driven means, a fluid connection between
the same whereby said driven means moves in 50 movement of said driving means.
12. A fluid actuating system comprising driv
response to said driving means volume compen
ing means, driven means, a fluid connection be
sating means to add and subtract iiuid to and
tween said means whereby said driven means
from said driving, driven, and connecting means,
moves in response to said driving means, a ñrst
a member moved by said driven means, switch
means actuated by contact of said member with 55 member coupled to said driven means for move
ment therewith and a second, freely movable
the driven means to actuate said volume com
member in the path of said ñrst member and
pensating means to add or subtract fluid de
adapted to be contacted by and moved only by
pending upon the direction of contact, and means
contact with said ñrst member and be friction
interlocked with said driving means to render
ally retained in whatever position it is moved
60
said ñrst-mentioned switch means inoperative
by said driving means, said ñrst member having
when said driving means is operating to move
a small range of movement with respect to said
said driven means.
second member, compensating means for vary
'81y A fluid actuating system comprising driving
ing the volume of fluid in said system to com
means, driven means, a ñuid connection between 65 pensate for fluid volume changes, switch means
said means >whereby said driven means moves in
selectively responsive to relative movement of
response to said driving means, moveable means
said first member in either direction with respect
moved by said driven means, switch means actu
to said second member for actuating said com
ated by contact of said driven means with said
pensating means to vary the volume of fluid in
movable means, compensating means to add and
such direction as to reverse the direction of move
ment of said driven means and said ñrst mem
subtract fluid from driving, driven and connect
ber, means for disabling said compensating means
ing means and controlled by said switch means,
during movement of said driving means.
and electrical indexing means connected to said
ARBEN H. ADAMS.
compensating means and operative at at least one
THEODORE S. TUCKER.
point of stroke of the driving means to actuate 75
Документ
Категория
Без категории
Просмотров
0
Размер файла
775 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа