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Патент USA US2407879

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Patented Sept. 17, 1946
2,407,872
UNITED STATES PATENT OFFICE`
2,407,872
PISTON DEVICE
.
Sidney G. Down, Edgewood, Pa., assignor to The
Westinghouse Air Brake Company, Wilmerding,
Pa., a corporation of Pennsylvania
Application October 22, 1942, Serial No. 462,907‘
6 Claims.
(Cl. 184-18)
2
This invention relates to, automatically con
trolled lubricating means for periodically sup
plying lubricant to a plurality of cooperating
sliding surfaces such as those of a piston and a
cylinder Wall, and more particularly to the type
Periodic operation is assured since the emer
gency application of the valve device is rarely
used during the interva1 of a train trip and is
of lubricating means suitable for use in lubri- ì
road siding.
amount of lubricant to the friction surfaces.
eating the pistons and cylinder walls of brake
controlling devices for iiuid pressure brakes.
It is especially desirable with Vcontrolling de
vices for ñuid pressure brakes to maintain` a con
consistently used when the car is set on a rail
To effect the above objects an inertia or fluid
pressure controlled element may be used in com
bination with breather type lubrication means
10 to render the lubrication means operative only
sistent minimum of friction between the piston
during an emergency application of the train
and packing ring and the bushing in Which they
brakes. The piston of the brake controlling valve ,
are reciprocable in response to variations in the
device is provided with an additional or breather
pressure of fluid on opposite sides of the piston.
passage which is preferably arranged parallel
Limited andperiodic lubrication has been found 15 to the lubricant conducting passage between the
to be one of the best methods for maintaining
lubricant reservoir and the ring groove and which .
this minimum of friction over an extended period
by-passes the lubricant conducting passage and
of time and the provision of novel means whereby
renders it substantially ineffective during service
this is accomplished is one of the objects of this
applications.
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The piston is further provided with an inertia
20
One method for providing automatic lubrica
element in the form of a cylindrical valve adapted
Ítion over an extended period of time is by feed
to close on’ the breather passage when the pis
ing lubricant through capillary attraction means
ton is moved rap-idly and stopped abruptly as
to the cylinder Walls and the periphery of the
during an emergency application of the brakes.
piston at a slow continuous rate. This method 25 The continued reduction of the pressure of fluid
has a disadvantage in _that it is difficult to meter
outside the ring groove causes the ñuid in the
the supply of lubricant at a Slow enough rate
lubricant reservoir to now to the ring groove
to provide the desired lubrication. Also, the flow
through the lubricant conducting passage carry
continues at substantially the same rate regard
ing With it the lubricant that has collected in
less of the extent of active service the valve de ao the port by capillary attraction.
»
vice has experienced. Thus, a rate of ilow of
In the accompanying drawing Fig. 1 is a frag
lubricant that is barely suflicient for a valve de
mentary sectional view of an emergency portion
vice in highly active service would be excessive
of the type employed in the “AB” type of rail
and harmful in another in inactive service. An
way car `brake equipment; showing the inven
excess of lubricant has a tendency to collect dirt 35 tion embodied therein; Fig. 2 is a fragmentary
or get gummy thereby increasing the friction
sectional view showing a modiñcation of the in
between the piston and cylinder bushing to an
vention; and Fig. 3 is a sectional view similar to
abnormal degree. y
Fig. 2 but showing another modification of the
In other methods a breather port to` convey
invention.
the lubricant from a wick, capillary tube or the 40
As shown in Fig. l, the emergency portion of
like to the piston ring groove is employed. This
the equipment may comprise a brake controlling
invention.
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port acts, upon a reduction in pressure of the
valve device having a bushing I which is of the
usual tubular form and may be made of any suit
able material, such as brass or molded plastic
fluid in the brake pipe in a train brake system,
to direct the resulting flow of ñuid from a` lubri
cant reservoir in the piston to the ring groove 45 composition. This bushing is adapted» to be
across or through a lubricant collecting and dis
pressed into a suitable bore 2 inthe casing 3.
pensing element and in the direction of the ring
'I'he bushing is provided with a charging port 4
groove. These methods though they maintain a
relation between the rateV of feed of lubricant and
which connects with a passage 5 leading to a
valve chamber 6 and with the usual quick action
the activity of the valve device, too frequently
chamber not shown.
provide an undesirable excess of lubricant to the
friction surfaces.
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catory motion relative thereto is a piston l hav
ing a groove 8 formed in the periphery thereof,
in which groove is mounted the usual packing
It is the object of my invention, to correlate
the rate of feed of lubricant` with a periodic
function which occurs at less frequent intervals
by nullifying the` breather action and therebythe
lubrication of the partsV during serviceqapplica
tions of the valve device and rendering it leiiîec
l
Slidably mounted in the bushing for recipro
55 ring 9 which may be of'any suitable material such
tive onlyduring emergency applications. In this
manner it will be 'possible to ’supply a smaller 60
as brass, and which, due to its inherent resiliency,
is pressed outwardly into close frictional engage
ment with the inner friction surface of the bush
ing
l.
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The piston is'provided with a stem l0 which is
2,407,872
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adapted to operate the usual emergency slide_
valve I I, and is provided on its face with a bead
I2 which> is adaptedto engageagasket i3 at the
end of the` cylinder. "jïïhe- piston
„
until the charging port 4 is uncovered to the
chamber 2B at the face of the piston. Fluid Will
flow. by way ofthe charging port 4 and the pas
sage 5 to the valve chamber Sbehindthe piston.
also provided
with a centrally located lubricant storage reser
Voir Iâ in which a suitable amount of lubricant.
At the same time fluid will flow at a slow rate
mally closed by means of a plug Iößhaving ,an air
_the ringpgrooveâ‘and‘from thence flows through l
ypast the periphery of the piston and through the
necessary clearance space between the packing
is carried, which lubricant is supplied to the i
ringland the piston to the open space defined by
. chamberV through an opening provided inthe 1 ;
the inner surface o_f the ring and the bottom of
front face of the piston, the, opening being no1'
the passage 23 and. bore 2I to the lubricant reser
tight screw-threaded connection with the, piston.,
voir I4', thus slowly increasing the pressure of
>fluid in theîreservoir to substantially the same
The piston is further provided with a lubri
cant conducting passage Iiià extending radiallyV
pressure as that acting on the face of the piston.
From this space, fluid under pressure may also
upward from the reservoir I4 to the bottnm of the>
ring groove 8. This passage is for the purpose of“
flow by Way of the passage i'ö to the reservoir iii
permitting the Aflow of lubricant to the groove B
but due tothe 'resistance‘oíîered by the element
’i-‘I Ato such flow the'lmajorY portion‘o'f' the flow» will
under certain conditions to ‘be moreV fully de-`
scribed.
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be; by way of passage'l23.
Contained inthe reservoir 'it and"v covering the
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To effect an emergency application of: 'the
inner end ofthe passage I6 is a lubricant collect
ing and storage element Il to which lubricant is ,l brakes in a train of railway cars the pressure _of
fluid inthe train brake pipe and in piston cham
supplied by a Wick I8.A ,_ _The lubricant collecting
ber 28 at the face ofr the piston is rapidly reduced
and storage element il’comprises a disc of com-_
t0 preferably atmospheric pressure. Upon such
pressible _Inaterialsuch as'felt'and is engaged by
aï'reduction inbrake pipe pressure the fluid pres
sure in the chamber ßf'located to the left of the
a...s_pring` t9 vwhich serves two purposes; first, to
' maintain the element in its proper relation to the "
piston, propels the piston forwardly rapidly until
passage I5. and second, to compress the element
theamount necessary to ylimit itsïl‘ubricant col
lecting ` and storage,_„capacity to _the requisite
it» strikes the> gasket I31at the right hand end of
the chamber 28„_ thus bringing the `piston to an
amount. The upper fend ,2S of the spring Iii-is
abrupt stop. The slide valve II,` which is actu
turned upwardly sc_tl'rat it extends through the î»
storage“elementr and intothe >passage IE5, thus
atedby the piston, comes to a stop with the piston
in a position wherein,` 'in the> emergency portion
of a fluid pressure brake equipment of the “AB”
positioning thejelement I‘Ij with relation to the
type. connections are established by which the
passage. The lower end- of this spring is seated
on the bottom of the reservoir le.
fluid under pressure in the chamber 6' is vented
to atmosphere at a certain slow rate. e
' When the piston isA stoppedV abruptly as just
`
` -The'` wick I8 is preferably‘integrally attached
tothe element I7 and preferably extends from
described, the linertiaI element 22 continues to
move forwardly in itsbcre ZI relative to theenow
stationary piston and against the opposing -pres
theY element to the bottom of the lubricant reser
voir-I4. This wick conducts the'lubricant from
the main4 supply .to> the ~element ,by >capillary
attraction;`
`
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_ sure of the spring îßlandcovers the mouth of the
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by-pass passage 23. Since the fluidA in the lubri
The piston is furtherV provided with an axial
cant reservoir I4` is ata higher pressure than that i
bore `2l in which _is .carriedy a cylindrical inertia
element 22. This bore, 2l joins the posterior of
outside of the piston ring,»1f`luid"willñow from' the
reservoir through the lubricant saturated element
the- lubricant reservoir ,I4 and is also in lcom
munication Withfthe ring groove.l 8 by means of a' by-pass passage 23.
jI‘I and the'lubricantV conducting passage I6 tothe
ring vgroovegand fromv thence -willnow past the
packing -ring to the periphery ofthe piston and
to chamber 6, the flow to brake pipe having been
¿The by-pass passage ZBveXtends radially up~
ward Ifrom the axial bore 21| tothe groove 8 and
Vfor Athe *greatery portionv of yits length is parallel
blocked off at this time by the bead I2 of the
passage „23 joins the K.axial bore ZI at a» point a
short distance to the left of the iuncture of fthe
boreV and the reservoir ttl-,- where it maybe _sealed
_off by the inertia element 22 upon Vits movement
gasket I3;
to, the lubricant conducting passage Ij6. This »l piston-making a sealing engagement with the
outof normal position toward the front of' the
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The fluid as'lit passes through the lubricant
saturated element I'I, picks up a portion of the
lubricant and carries or forces it through the pas
55» sage 'I6 to the piston packing ring groove 8 and
against the rear and side surfaces'cf `the packing
piston, thus the element serves as a valve for
controlling communication between the passage _
Lubricant thus supplied tothe groove ß Will flow
23v and the bore 2I.
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The inertia lelement 2v2 is normally held against 60 within the groove'A along thepiston so as to supply
lubricant throughout the entire circumference of
rmg.
the backend of the bore 2i by means of a light
spring 24,_ which is seated ina central> recess 25
provided inthe element. The right hand end
the piston.
26'4 ofthe vspring 24 _is doubled back so that it
shown.
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The piston' packing ring' 9V fits the ring groove
8 closely, hence lubricant deposited on the ring
will ñow byY capillary vattraction to the outer fric
extends along the axis'of the' springI to itsVV oppo
site end Where it passes through a hole >ZÍI in the "
inertia element and .thenA into a recess formed
in the .pistonwhereit isanchored in thepiston as
>
tion' surface Vof the'ring and tothe friction sur- » `
faceA of bushing I. As therpi'ston is reciprocated
during subsequent service operations thev` lubri
V fcant will be spread“ evenly over `the _cooperating
’
v,Vlïhen the.v brake.„controlling1 valvedevice is
placed inservice, the pressure offiiuid supplied by '
Way. ofÑ the> usual brakev pipe,__not shown, and
acting cnthe. face of the piston 'i will be in
creased and will move the piston'in the direc.
ytionthoward,the leftf-handasviewed. in Fig. 1 7,5
sur-facesof the ring anri'bushir'ig.VV
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" „It Will beÍl noted;tl'ljatA during v_service Íapplicaf
tions o_f the brake4 thereductionsinthe; pressure
-of thefluid in the` brake: pipe are not‘at~ such
a'rapid rate, nor rto nsuch'wanuamouniçías those
Gf` emergency. applications; .Thèrefvre'ihe @were
2,407,872
gency piston 'I will not ystrike the gasket I3 and
the inertia element 22 Will‘not be moved out of
its normal position, consequently the by-pass
passage 23 will be open. Fluctuations in pressure
of the fluid on the face of piston will not create
any substantial pressure differential across‘the
lubricant storage `element I'I.`since the pressure
of ñuid in the lubricant reservoir and pressure
of ñuid in the ring groove will be equalized by a
less restricted ñow through passage I‘S.
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‘It has been found in practice that it is not
diiiîcult to conduct an over-supply of lubricant to
and storage element I1 and ‘permits the equal
ization of the fluid pressures in the lubricant car
rying passage I6 and the lubricant reservoir I4.
The valve 3l is preferably of the disc type having
a guiding skirt II‘IIi and is carried in a cylindrical
chamber 38 in the piston body, into which cham
ber the ñlling plug 36 also extends. The valve
is provided with the necessary number'of ñow
restrictive openings 4I extending through that
10 portion of the disc which is outside the seating
area.
An annular‘seat rib 39 is provided at the
inner end of plug 33 for engaging the valve 31
the parts to be lubricated, the diñiculty being in
which is held out of engagement by a spring 42
limiting the supply to the small amount which
contained in a central recess 44 in the plug. The
it has been ascertained is suliicient to maintain 15 plug
36 is also provided with passages 43 extend
the frictional resistance offered by the cooperat
ing radially outward from the chamber 44 to con
ing parts substantially low and constant.
nect with an annular groove 45 in the piston
By limiting the lubricant supplying times to
body,
when the plug 36 is screwed tightly into
emergency operations of the emergency portion
of the equipment the amount of lubricant sup 20 the piston, the groove communicating with 'a by
pass passage 46 leading from theY lubricant car
plied to the cooperating surfaces will not be ex
rying passage I6. Thus, free communication is
cessive.
i
normally established between the ring groove 8
In Fig. 2 a modification of the inertia element
arrangement is illustrated. In this arrangement
relative movement between the piston 'I and the
inertia element is provided when the piston starts
suddenly or is brought to an abrupt stop.
As illustrated, the inertia element is indicated
by the reference numeral 29 and is located inter
and the lubricant reservoir I4 by way of the lu
bricant carrying passage I6 and also by Way of
openings 4I in valve 31 to chambers 36 and 44
which communicate by way of passages 43 ’in
plug 36, groove 45 in the piston body "I, and by
pass passage 46 to lubricant carrying passage I6.
During service brake applications, when the
mediate the ends of the axial bore 2l by means 30
pressure of ñuid in the train brake pipe is re‘
of light compression springs 36 and 3|. The ele
duced at a rate, to effect a service application of
ment is provided in the middle area of the pe
the brakes, valve 31 will remain in its normal un
riphery with an annular groove 32 from which a
seated position, since the openings 4I are of suf
series of passages 33 extend radially inward to
ñcient flow capacity to permit iiuid to flow at the
same rate from the chamber 38.` But when fluid
pressure in the train brake pipe is reduced rap
2I and lubricant reservoir I4. In normal posi
idly, as during an emergency application of the
tion of the inertia element the groove 32 regis
brakes, ñuid under pressure will be conducted
ters with the by-pass passage 35 in the body of
away from chamber 33 by way of chamber 44,
the piston.
40 passages 43, groove 45, by-pass passage 46 and
When the pressure of fluid in the brake pipe
lubricant conducting passage I6 to the ring>
is reduced at a moderate rate, as during a service
communicate with the central spring well 34 of
the element 29, which communicates with bore
application of the brakes, the piston will change
its position slowly and without sudden starting
and stopping. Thus, during service applications,
groove 8 more rapidly than it can flow through
the restrictive openings 4I in the valve 3l. Con
sequently pressure of iluid acting on the right
hand side of valve 3'! will be reduced to the extent
there will be no relative movement between the
that the pressure of fluid acting on the left hand
piston and element and as a result the pressures
side of valve 31 will overcome the opposing pres
in the lubricant reservoir I4 and the ring groove
sure of the spring 42 and the valve will _make
8 will be equalized, so that the lubricant passage
a sealing engagement with the seat rib 3S. This
I 6 is rendered ineffective.
50 will interrupt any further now of fluid through
' However, when the pressure in the brake pipe
the openings 4I and enough differential in iluid
is reduced rapidly, as for instance during an
pressure `will be developed across the lubricant
emergency application, the piston will start to
storage element I'I to initiate a flow of fluid
move suddenly. As a result, the inertia element
therethrough carrying lubricant to the ring
29 will move to the left, covering by-pass passage
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35A vand interrupting any lnow of fluid there 55 groove 8.
From the foregoing description it will be ap
through. Lubricant will be carried to the ring
parent that with each form of the invention dis
groove 8 as previously described. When the pis
closed the piston will be lubricated only when an
ton` is stopped suddenly the function will be the
emergency application of the brakes is being ef
same as that described for Fig. 1. In passing from
the extreme left end of axial bore 2| to the ex 60 fected thereby avoiding the delivery of excessive
lubricant to the parts to be lubricated.
treme right end, groove 32 in the‘element‘ 29vwi1l
Having now described my invention, what I'
connect brieiiywith passage 35. Because'of the
claim as `new `and desire to `secure by > Letters
rapid movement, the interval of communication
between the groove 32 and the passage 35 will be
so short as to be negligible.
In Fig. 3 another modification of my invention
is shown wherein a pneumatically controlled
valve is provided which is operative only during
emergency applications of the brake.
In this form of my invention the iilling plug 3B
for the lubricant reservoir I4 is modified to make
a sealing engagement with a valve 3'! which is
interposed Ibetween the lubricant chamber and a
Patent, is :`
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‘1. In a lubricating apparatus for the cooperat
ing friction surfaces of two members, at least one
of which is movable relativeto the other, a fluid
pressure chamber to which a surface. of the mov~
able> member is exposed and in which the pres
sure of íiuid‘may be varied, a lubricant storage
reservoir formed in’- said movable member and
adapted to receive a lubricant, a passage leading
from ‘said reservoir to at least one of said surfaces
and to said chamber, said passage constituting a
passage which by-passes the lubricant collecting 75 communication through which ñuid under pres
,2,407,872
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,
sufre-»mayV flow- from :said lubricant’ storage reser-`
voir in- response to a reductionïin‘theîpressure `of
fluid in said chamber, m'eans'adapted to supply
lubricant from said lubricant storage reservoir
to the fluid which flows from the reservoir to said
passage, a` second vpassage leading from -said lu
bricantstorage reservoir to thesurface‘to be lu
bricated' and to said chamber, said second pas
'den change yin the speed-ofsaidfpiston-«inducedfby
aisudden‘reductionin the pressureof fluid-in said
chamber >to interrupt vthe flowofß fluid under pres'
sure from said reservoir to said second mentioned
passage.
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4. `1in apparatus for lubricating alf/ricti'on sur~
face of a movablefmember, in combinatiomfaflu
bricant storage reservoir formed in said movable
member -and adapted to containlubricantymeans
sage constituting a communication of less re
for maintaining saidrese-rvoir normally- charged
10
stricted flow capacity than the first mentionedA
with fluid under pressure, two passages »through
communication through which fluid under pres
whichfluid under pressure containedfin-saidsres
sureY may breathe into and out Vof said reservoir
ervoir may flow„means conducting lubricantein
in response to variation in the pressure of fluid
said reservoir to one of -said passageswhich pas'
in‘said chamber, and said second passage‘being
sage
adapted to carry lubricant from said
normally open so as to inhibit the flow of fluid 15
' andI thereby the lubricant through the 'ilrst men
tioned passage, and inertia means operative upon
means to saidl surface by fluideflowing- from .the
_ reservoir, the other passage ybeing normal-lyopen
so that when fluid flows’therethrough fromsaid
reservoir it will inhibit the flow of fluid through
said reservoir to said second passage, so that 20 said one passage, andy inertia'means responsive to
a sudden change- in the speed of the movable
fluid flows> from the reservoir to the first »men
member for closing communication betweenrsa-id
tioned passage.
'
reservoir and -said otherA passage» whereby fluid
2.» In a lubricating apparatus for the cooperat
under
pressure and thereby lubricant 4mayflow
ingfriction surfaces of two members, at least one
through said one passage only;
~
of which is movable relative to the other, a fluid
5. In a lubricating appa-ratusofV the typef'co'm-i
pressure chamber to which a surface of the mov
prising Aa movable member- having' a surface `to
ablermember is exposed and in which the pressure
be‘lubric‘ated, said member lbeing providedïwith a
of fluid may be varied, a lubricant storage reser-Y
lubricant storage reservoir and. a» lubricant con-'
voir formed in saidmovable member and adapted
avsudden change in the speed of said,V movable
member for inhibiting the flow of fluid from
to receive a lubricant, a passage leading from 30 ducting passage having associated therewitha
lubricant, carrying member and through which
lsaid reservior to at least one of saidfsurfaces and
fluid under pressure may'flow Yto thereby carry
to= said chamber, said passage constituting a com
lubricant from saidv reservoir to said surface; =in
munication through which fluid under pressure
combination, means for maintaining said reser
may flow from said lubricant reservoir in response
voir normally charged with’fluìd under pressure,
to a reduction in the pressure of fluid in said 35
another passage normally open to 'said reservoir
chamber, means adapted to supply lubricant from
and to said lubricant conducting lpassageV for
saidìlubricantstorage reservoir to the fluid which
flows from the reservoir to said passage, a passage
means for by-passing said passage and constitut
ing a communication through which fluid under
»pressure may breathe into and out of saidlubri
cant sto-rage reservoir in response to variation
in the pressure of ñuid in said chamber, the. lat
ter communication being normally open and- less
equalizing the pressure of fluid thereinso that 1no
effective amount `of fluid flows through thelubri
cant conducting passage, and means operative
upon a sudden change. inthestate of'moticn of
said member for-closing said otherfpassage:
6. In a fluid pressure brake controlling valve
device, of the type having a-piston subject :to
opposing fluid pressures and having“ a- lnormal
restrictive than theformer communication so as 45
to divert the flow or fluidv to the bly-pass passage
means, an inertia means operative upon a sud
brake release position and an emergency brake
application position, said pistonl upon a- sudden
reduction‘in the pressure of fluid acting‘on one
side thereof being operative from its normal
den change in the speed of said movable member
asv it is moved> in response to the sudden reduction
brake release position to-thefemergency .applica
in the pressure of fluid in said chamber to render 50
tion position, in combination, a lubricant'carry
said by-passpassage means ineffective, so that
ing reservoir formed in‘said pistonand normally
fluid flows from the reservoir to the first ‘men
charged wtih fluid under pressure, a passage
-tioned passage.
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formed in lsaid- piston through'which fluid under
3, Ina piston device, the combination of a cyl
inder, a piston mounted in said cylinder to form 55 pressure may Lflow and carry4 lubricant from-.said
reservoir- to the »friction surfaces-of theî pistoni,
a chamber at each side of said piston, said piston
means supplied with lubricant from said reservoir
being ,reciprocable «in response to variationsin the
and located in the pathof fl'owof fluidffromsaidy
pressure of fluid in one of said chambers, and a
reservoir to said passage for 'supplying-,lubricant
lubricating apparatus comprising a lubricant
to
fluid whichY may flow from thereservoi-r tothe
reservoir formed in said piston and adapted to 60
passage, another passage formed in said- piston
contain lubricant, a passage leading from said
leading from said reservoir to said flrst’passage
>reservoir to the periphery of said piston and to
through which fluid may flow to` equalize the
said chamber, means for conducting lubricant in
pressure of fluid acting on opposite sides oísaid,
said reservoir to said passage, said passage being
means, and valve means operative as-an incident
adapted to conduct fluid and lubricant supplied 65 to
the effecting of a middeny reduction Y‘inthe
thereto to the periphery of said piston upon are
pressure 'of fluid actingon one sideof said'zpiston
duction in the pressure of fluid in said chamber,
for preventing the flow of fluid from said reserà
asecond passage communicating with said reser
voir and said chamber adapted to conduct fluid
from said. reservoir more freely than the first said
passage, and valve means operative upon .a sud
voirby Wayio-f said other passage.
s'iDNEY
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