Note: Descriptions are shown in the official language in which they were submitted.
~J ~073
--2-
ThlS invent.ion relates to variable diaphragm type
meter~ng pumps, ahd more particularly, to an adjusta~le
pump which is well adapted or accurately and adjustably
supplying metered quant.ities of a two-component product.
ackyround of the Invention
One comrnon usage oE metering pumps is in the
measuring o~ components of multl-component products, such
as paints, resins, and floor coverings, and also in adding
small quantities of concentrate to water as in fertilizi.ng
and sprayin~ herbic.ides onto crop fields.
It i.s readily apparent that with such widely
different usages, numerous ~equirements ar~ encoulltered
as to maJce very suhstantial demands upon the capability
of the pump.
Al~hough a two-componen~. metering pump has been
known previously, inherent construction features clearly
limit the usefulness in certain situations. Metering
capability has been provi.ded by mechani.cal.l.y limiting the
return st.roke of the piston. See UOS. Patent 3 7 612,727O
In limitin~ the rekurn s~rolce o the pi.s~on, the piston
encounte.rs a mechani.ccll stop which sudd~nly absoxbs the
inertia o~ the piston, any assemblies connec~ed w.ith it,
and the diaphragm-operatin~ hydraul.ic fluid or oil.
The revolviny cam will ini~ially lif~ o~f the stopped
piston and then imp~ct the piston again to suddenly
start it into motion. Vepending upon the shape of the
cam and the time in each cycle at which the cam reengages
the piStvn, the repeated impact of the cam ayainst the
piston and the repeated impact of the pis~.on ayains~ the
.~ stop can create subs-tantial vihration in the pump~
Other single component ~iaphragm type metering
~umps have usea other types of mechanisms ~ox varying~the
pumping rate. For instance, one pump has a poxt .in the
,~.
073
-3-
piston for suddenly releasing pressure in the cylinder at
the end of the pressure stroke, as the piston port passes by
the end of a stationary and adjustable rod, see U.S. Patent
3,285,182. Another pump varies the length of stroke of the
piston by varying the eccentricity of the driver for the
piston, see U.S. Patent 3,374,750. Such varying of
eccentricity involves complicated mechanisms; and relying
upon relief of developed pressure at the end of the pressure
stroke requires a rather complicated mechanism and the
developing of vacuum pressures on the return stroke which
cause related complicating problems.
Still other diaphragm type pumps show the basic
separation between the hydraulic fluid pumped by the
reciprocating piston and the other liquid pumped by the
diaphragm. Excess pressure under certain circumstances is
relieved in various ways in these pumps and of course
refilling of the cylinder after such relief is necessary.
See U.S. Patents 2,578,746; 3,075,468; 3,254,845; and
3,680,981.
Brief Summary of the Invention
.
An object of the invention is to provide an
improved two-component diaphragm pump to simply and
effectively vary, over a wide range, the quantities of
`components pumped.
7 3
The variable diaphragm pump has as an adjustmen~
control and proportion-varying apparatus facilitatiny
extremely accurate adjustments of the quantities pumped,
these adjustments being accurately repeatable.
In a preferred embod.iment of the invention the
two-component proportioning diaphragm pump provides for
relief of the pressure of the pumping hydraulic fluid when
flow of the pumpage is suddenly stopped, and prevents relief
of any of the pressure of the hydraulic fluid during normal
operation and flow of the pumpage to the dispensing nozzle.
In another preferred embodiment of the present
invention the two-component proportioning pump has tandem
diaphragm pumps each operated by a separate piston pump with
a common drive and an adjustable sleeve forming the
cylindrical wall of one of the piston pumps in order to
obtain the desired proportioning at the diaphragm pumps.
In another preferred embodiment o~ th~ invention
the two-component proportioning pump utilizes tandem
diaphragm pumps and piston pumps to operate the diaphragm
`` pumps, one of the pistons operating in an adjustable sleeve
with a refill port therein communicating directly with the
common reservoir of pumping oil, the sleeve extending well
into the reservoir with its exterior exposed to the
reservoir while ~he piston extends into the interior
' thereof.
Another feature of a preferred embodiment of the
present invention is the provision of a variable speed
,~
s`-~ characteristic in the two-component proportioning pump for
1 ~6B073
-5
controlling the quantity of pumping by both of the diaphragm
pumps and with control apparatus for changlng the relative
pumping capabilities of the two diaphragm pumps to obtain
correct proportioning of the pumped liquid.
Another embodiment of the invention has a double
thread adjusting arrangement on an adjustable sleeve forming
the cylinder of a piston pump operating the diaphragm pump.
In the two-component proportioning pump embodiment
of this invention utilizing tandem diaphragm pumps, the
diaphragms are of a sandwich construction of Buna-N rubber
C at the oil side of the diaphragm and Teflon at the pumping
side of the diaphragm to resist deteriorating effects of
liquids being pumped and the sandwiched diaphragm has
annular inner and outer sealing beads confined in grooves in
the housing and the piston-operated stem attachment. The
diaphragm pumps, can be driven by either a rotary eccentric
or by another fast acting reclprocating drive/ such as a
piston type pneumatic motor.
A principal advantage obtained by the present
invention is the accurate metering of a quantity of liquid
being pumped and permitting the quantity of liquid to be
varied considerably and without allowing any undesired
vibrations to be set up in the pumping assembly, regardless
of the pressure and speed involved.
I
3a ~`T~ k
. i
~ ~6B07 3
-- 6 --
Brief Description of Drawings
Figure 1 is a diagrammatic plan view illustrating khe
invention.
Figure 2 is a longitudinal section view taken on an up-
right plane as indicated approximately at ~-2 in Figure 3.
Figure 3 is a longitudinal section view taken approxi-
- mately at 3-3 in Figure 2.
Figure 4, which appears on the first sheet of drawings,
is an enlarged detail section view taken approximately at 4-4
in Figure 3.
Figure 5, which appears on the first sheet of drawings,
is a diagrammatic plan view showing a modified Eorm of the
invention.
Figure 6 is an elevation view, partly in section, of a
modified form of proportioning pump.
Detailed Specification
The varia}:)lc two-component pump i5 indicated in
~eneral by numeral 10 an~ i6 illus~ra~ecl in Figure 1 to be
' typicL~lly used to supply thc pumpacJe to a mixer 11 from
- 20 which the mixed,components are conveyed by a long hose 1
- , to an airless sprayer 13. It should be recognized that
supplemental equipment may be employed be~ween the pump 10
and ~he mixer 11, for accomplishing such functions as
heating and filteLing the pumpage. In one typical usage,
resin is supplied f'rom one source 14, and ca~alyst ls
supplied from ano-ther source t.allk 15.
.~ rotor 16 provides a rotary source of power for
the pUIilp 10 and is connecte-l through a variable speed
pull~y 17, bclt 1.3, ar!d pull~y 19 to th~ input shaft 20
of ~he pump.
J
'~,S~ .
-7--
In the form of pump lll.ustrated in E'igures 2 and
3, ~he pump l0 has` a hcusing 21 which defines a central
chamber 22 de~i.nincJ a reservoi.r for hyclraulic ~luido
The shaft 20 is mountecl on bearings 23 and 24, and clefines
an eccentri.c 25 whi.ch includes an eccentric portlon 26 or'
the shaft 2U which .is embrace~ by a ball beari.ng 27, the
outer annular periphera~ surface 27a o~ which gyrates as
an eccentric around the ro~ation ax~.s of the shaft 20.
The pump 10 includes a pair of diaphragm pumps ,~8
and 29, and a pair of piston pumps 40 and 4].
The two cliaphragm pumps ~8 and 29 are essentially
identical to each other r and iclentic,al reerenc,e numerals
are used for bothO The housing 21 has recesses 21.1 and
21~2 receiving the frame blocks 30 of the di.aphragm pumps.
End covers 31 a~e affixed to the housing ~.l as by cap
screws Eox capturing and clampiny the frame blocks 30 in
stationary position~
The diaphracJm pumps ~8 ~ncl 29 have pum~age chambers
32 ancl hydrauli,c ~luid pumping chambers 33 on opposite
20 sides o:E diaphra~ms 34.
di.ap~lragm s~em 35 is attached b~ clampincJ -to the
c,e~:er OI the alnu:lar ~llaphrclgm 34, and ext~nds irli'~O the
SUppl'i' duct 36 ;.Il fralnc-, blo~.k 30 which col~nuni~ates w~ h
t:he hydraulic flu:i.d c~hclmber 33. A comE)ressio~l spring 3'~
, 25 has one end b~arincJ a~ainst a shoulder in the frame blocls
30, and the other end bearing against a washer 38 an~hored
to the free end of ~he diaphragm stem 35 as by a refaining
screw~ The diaphragm stem 35 is guided by a statioIIary
bearing sleeve 35.1 in the supply duct 36 and spaced from
the ~rame block 30 by a spider-like moullting.
The cliaphragms 34 are of annular and laminar
construction, with a lamina 34.1 o~ neoprene rubber~
faclng the hydraulic fluid chamber 33~ ancl a lamina 34.2
of a substantially inert plastic such as a pla.stic known
3~ by it.s ~rademaxk M~LAR, or oE another plas~ known by its
~ ~66~73
trademark T~FI,ON, mo:re spe~c:i~i.cally polyfluorotetra-
e~hylene~
The cliaphragms 34 have annl1lar bead; 34.3 at
their inller peripheries~ and annular beads 3~.~ at their
outer periphexies.
The outer beads 3~.~ o the dilpllrac~ms fit into
annular grooves 3().1 in thc? frame hlocks 30; and the inner
beacls ~4~3 f;t :i.nt.o a;~IIular grooves 35.2 .formed in the
clc~mping head 35.~ Oll the e~ncl of the cliaphragm st:em 35O
The inner ~e~r:~phery of the diapll:ra~m 34 i5 ClalTlped aCtail~st
the head .~3 by a clampi.ll~ d~ c 3~ ret~lined onto the end
of ~he di.aphragm s~em by a screw 3'3.1.
'l'h~ pumpage chambers 32 of the ciia.phragm purnps 28
and 29 are connected throug}l ~i-tti.ngs ~2 ~nd 43 which are
~5 respectively prov.ided wi.t.h inf'low and outf 10~7 check valves
44 and 45 thxou~h ~hich the~ pumpa~e is directed into and
out of the pumpaqe chambers 32. The fitti.ncts 42 are
connected to supply flow l.ines 46 and ~7 from the two
sources of mat.erials to be mixed; and the discharge
fi-ttings 43 are connected to the discharge hoses ~8 and
; 49 which suppl~ the components -to the mixer 11.
~he diaphractrn purnps 28 ancl 29 are re.spectively
operated by hyclrauli.c Eluid pumped from the pi.slon pumps
40 and ~1. The piston pumps ~0 ancl 41 have reciprocatin~
pistons 50 and 51 which h;lve hearing heads 50.1 and 51.1
which bear arJainst the peripheral surface 27a of the
eccentric. Coil springs 52 and 53 bear a~ one end agai.nst
a shoulder o~ the hou~.;in~ 21',and bear against the heads
50.1 and 51~1r respectively, of pistons 50 and 51 to
continually urge the ~istons against the peripheral
surface of the eccelltric.
The cylinders 54 and 55 in ~lich the pi.stons 50
and 51 reciprocate are de:Eined by cyllnder wall sleeves
56 and 57, respectively. Cyl.inder wa:Ll 57 is stationa.ry
in the houslng 21'and is c~alnped ~y -the ad~acent frame
1 1~6~73
-9-
block 30 so that a shoulder 57.1 abuts agaillst an adjoining
shoulder .in the housing 2:Li. A sic3nlfi.cant lerltJth o: the
inne~r encl of the cYylinder wall sleeve 57 ex-tends into the
hydraulic fluid reservoi.r 22 whicll su:rrounds tile outer
per.iphery 57~2 of the inner portion of the cylinder wall
sleeve 57. ~ pai.r of ports 57~3 e~xtr~-3nd throut3h -the
cylinder wall sleeve 57 and communicate at their inner
ends with the pump chc~mbc3r or cylinder 55, and at tlleir
outer ends with the reservoir 22.
.It will be no-ted tha-t l~he spring 53 closely
embraces the outer peripht-3ry of the cylinder wall sleeve
57.
The inner encl 56.1 o~ the cylinder wall sleeve 56
also extt-~nds a sign.licant distance into ~he reservoir 22,
and ports 56.~ through the cyli.nder wall sleeve 56 provide
communication between the pu~ in~ chambex or cylinder 54
and the reservoir 22 at the outer periphery of the ~lee~e
; 56. Sieeve 56 is snu~ly mounted in a bore 21.1 of -the
housing and is long:itllc1ian]..ly slidable -therein. The
sle~ve 56 has a closed head portioII 5G.3 which has a
longituclinal ];e~way or groGv~.3 56.~ ~herein. ~`kt3yin-J pin
5~ is thr~.3aclc3d in the housing 21 and e.~.-kent~ls into the
keyt~7a~ 56.~ for gllid.i.ntJ the cylinder wall 56 in its
longitudinal movement withoul.: perlnltt:i.n(3 any rotation
of the sleeve.
The cylinder wall sleeve 56 is provided with a
stem 56.5 hâvi.ng threads 56.6 on its outer periphery.
The stem 56~5 is ~hreaded into a ro~ary control in the
.Eo~n oE a ~leeve 59 having a knurled head 60 a:Efixed
~hereon. ~he rotary control 59 has a threaded exterior
surace 59.1 which is threaded into a boss 61 formed
integrally o the housin~ 21~
The threads at both the inner peripherv and the
outer periphery of the annulax rotary control 59 are
both righthand threads, but they have a different pi.tch.
lL~6~;~73
--1.0--
At the oute.r pexiphery of the rotary control 59, the
threads by which ~he rotary control 59 .is connected to the
boss 61 of the housing has an 1~ pi-~ch in the forrn
illustrated. The threacls at the inner periphery o~ the
rotary control and on the stem 56.5 have a 24 pitcho
Accordi.n~l~, turniny the rotary control 59 and 60 th~ough
. a significar2t arc of rotat.ion, will produce only a ver~
l.imited endwise movement of the stem 56 5 and of the
cylinder wall sleeve 56.
he cylindex wall sleeve 56 has a plurality of
larcJe flow ports 62 thereth.rough for open con~unication
with ~he duc~ 36 which communicates w.lth the h~vd.raullc
fluid chamber 33 of the adjacent diaplhragm pump 28~
Pressure relief or bypass pas~ages 63 and 64 are
provided in the housing 21 to allow hydraulic ~luid to
` r.etllrn from the pump chambers 54 and 55 to the reservoir
3-~' ~ under certain condit.ions, such as when the spray
nozzle 13 is suddenly closecl so as to prevent any pumpage
from moving out of the pumpage chambers 32 of the
diaphragm pumps. Pressure rel.ief valves 65 are provided
in the bypass passages 63 and 6~ ancl are substantiall~
identical with each other~ Each of the p.res~ure relie~
valves has ~ valve elemen-t 66 urged by a spriny 67
against the valve seat 68 .so as to keep the pressure
rellef valve 65 closecl un~il pressure i,n the acljacent
pump chamber exceeds a predeterrninecl minimum. The tenslon
on the spring 67 is main~ained and adjus~,ed by an anchor
68 threaded into a mounki.ng pluy 69 which is ~hreadably
connected to the boss 70 of ~che housing 21.
Comrnunication is provicled from t~le pump chamber 54
into the pressure relief valve fi5 in the passage 63
through an annular manifold groove 71 in housing 21 and
extending entirely around the outer periphery of cylinder
wall sleeve 56 adjacent the ports 62. The manifold groove
71 also communicates with the d~ct 36 through which
.
.~
-- I 1 6 6 0 7 3
hydxaulic i.`luid is suppliec.1 to t.he hydratllic ~luid chamber
33 oE tlle diaph~agm pump 2~.
: Th~ cylindel wal.l sleeve 57 has similar ports 62.1
which provide flow communica-t.ion i.nto an annular man:ifold
groove 71.1 to allow the hyclraulic Elui.d to enter the
b~pass passage and pass by the relief ~al.ve 6S in the
event of eY~cessive pressures.
In operatioll, the motor 16 is operated ancl the
variable speed pulley 17 ls adjusted as to produce rotation
o.[ the shaft 20 at a speed withln the rancJe oE approxi
mately 200 to 1200 rpm. The quantity of pumpage from the
two diaphragm pumps 28 and 29 may be ~aried over a w.ide
range by changing the speed of the drive shaft 20.
Changing the speed will chan~e the pumping rate of -the two
diaphragm pumps in substantially direct relati.on to the
speed of the drive shaft. In add:ition, the pumping rate
of the diaphra~m pump 28 may ~e changed by adjusting the
hand control 60 as ~o procluce longi.tudi.nal reIocation of
the cyllnder wall s.1.eeve 56 and o~ the port 56.2~
~s ~he shaft~ 20 revo].ves, -the eccentric produces
reciprocation o~ -the pistons 5Q and 51. The pistons are
almost entirely confi.ned i.n the cantiliver end porti.olls
of the cyl.inder wal:L s:Leeves 56 ~nd 57 whi.ch project into
: the reservoir 22.
~s the p;.ston 50 proyresses frGm the position
illustrated in Fi.cJures 2 and 3 in an outward directiorl
along the cylinder wa:Ll sleeve 56, the leading face of
the piston 50 will initlal:Ly move across and then close
the ports 56.2 in sleeve 56. Until the ports 56.2 are
entirely closed, the pumping stroke of the~ piston pump 40
does not commence. At the instant the piston 5q closes
the ports 56.2, pumpln~ act.ion commences, and the hydraulic
fluid commences to ~low through the ports 62 and duct 36
~; into the hydraulic fluid chamber 33 of diaphragm pump 28.
As the hydraulic fluid in chamber 33 moves the diaphragm
` ~ ~166~73
-12-
34~ pumping of the l.iqu:id in the pumpage chambe.r 32
commences~ and continues until the eccentric completes
the outward movement of the piston 50. As the piston 50
stops and ~hen starts returning inwardly under the
influence of spriny 52~ the spring 37 of diaphragm pump ~8
draws ~he diaphra~m -toward its rest position; and
simultaneously, the pumpaye chamber 32 i5 again refilled
with the licluid from -the source 15~
Simultaneously as the eccentric is dr.iving the
10 piston 50 outwarclly, and subsec~uently as the spring 52
returns khe piston 50 to the position sho~n in Fiyures 2
ancl 3, the other piston 51 i.s also being moved. InitialLy,
from the position illustrated in Figures 2 and 3~ -the
piston is moved under the influence of spr.ing 53 in an
inward cl.irection as the eccen-tric revo].ves to allow such
inward movement. The movement of piston 51 permits the
spriny 37 to draw the diaphragrn 34 toward the hydraulic
fluid chamber 33, and simultaneously the p~page chamber
32 is b~ing enlarged ~o draw liquld from the source 1.4
for the nex~ pumping stroke~ During the normal operation
of the pump wllile the nozzle~ 33 is open so tha~ botll of
the diaphragm pumps 28 and 29 are ~ull~ ope:ratiIIg~ there
will be no ~low whAteve~: throuyh the bypass passayes ~3
and 64, and the valves 65 remai.n entire:Ly closed.
In -this circumstance, there is essentially no flow through
the ports 57.3 of cylinder wall sleeve 57 and ports 56.2
of cyl.inder wall slee~Je 56~ because there has been no ~oss
of hydraulic fluid from the pump chamhers 54, 55 duriny
the normal operation of the piston pumps. If ~here i5 some
srnall loss of hydraulic fluid due to seepage along the
piston or otllerwise, the hydraulic fluid in the pump
_~ chambers S4, 55 will be replenished duriny each stroke of
the pistons ,hrough the poLts 56.2 and 5~l.30
The advantagesof extendiny the cylinder wall
~5 sleeves 56 and 57 well into the reservoir 22 are numerous.
~16~073
-:L3-
The refill passac3es or po:rts 56.2 and 57.3 axe extremely
shor-t, equaling tlle thickness oE the cylinder wall
sleeves 56 and 57. Therc is no neecl for purposes of the
refill to ut.ilize long and complic2ted passayes in the
housing 21. Construction of tne pi5ton pumps 40 and 41
is simple by virtue of the remo~able cylinde~- wall slee~es
so that in the event any mai.ntenance or adjustment as to
cylinder and piston size is desired, the cylinder wall
sleeves can be readily repl.aced. The proportions of the
1~ materials b~ing pumped may be very accura~ely con..rolled
by adju.s~ing the rotary control 59, 60O The slightly
di.fferent pitch on the threads at 56.6 and 59~1 allows
the rotary control. 6~ ~o be revolved -thro-lgh a significant.
arc for a small amount of lonc~itudinal mo~ement of the
sleeve. Because of the careful control of the longitudlnal
movement of sleeve 56~ the :rol:ary control 59, 60 can
allow the setti.n~ o:E the sl~eve to be repeated duriny
sequential pumplng oper:ations. As illustrate~ in Figure 2,
a scale may be provicled arollncl the peri.phery of the hand
wheel 60 and on -the boss 61 to produce a ve.~nier scale.
Somc mate.r:i.als be.i.llg pumpe~ may vary from bat~h
to batch or with the temperature cc~rld:ition.s and tlle
adjustment o:E cylincler wall sleeve 56 can minutely aEtect
the quantit~ of malexial pumped by the diaphragm pump 28.
.~t.i.mply chany.incJ the ].ongitudinal posit.ion of the
cylinder wal.l s].eeve 56 causes the ports 56.2 to assume
a new position 50 as to cau~e the piston 50 to change the
phasing o~ closincJ of ~he port 56.2~ whereupon to actually
change the amount of hydraulic fluid moved in and out of
the hydraulic ~luid chamber 33 of ~he d.i.aphragm pump.
In the event that the dispensing nozzle 13 i5
suddenly closed to stop the flow of ~he pumpage ~roM ~he
two diaphragm pumps 28 and 29~ the hydraulic ~luid from
pump chamber~ 54 and 55 is no longer capable of moving
the diaphracJms 34, and accordlngly~ ~xcessi~e pre.ssures
1 1~6~73
.4-
are immec1iate1y created in the pump chalnbers ~4 ancl 55.
The exce~sive pr~ssllxe.s i~nedi.clte1y cause the relief valve~
65 to open to allow tlle hydraulic fluicl to f1.ow through
the bypa.ss p.~s~ages 63 an~l 6~ and return to th~ reservoi.r
22. The ecce~-tric wil:1. collti.nue to reciprocate t-he
pistons 50 and 51., anc~ a lclrrJe proporti.on of the hycl:Lau1ic
flu.icl in -the pump ch~mhers 54 and 55 will ~e eY~pel1ed
through the ~ypass passa~es.
As SOO~I ac~ the dispensiny nozz1e 13 is ar~ain
r~opened, ~low is permittecl :Erom the pumpage chamber~ 32
of the diaphragm pl~nps and h~rlraul.ic fluid wil:i be dra~n
into the purnp c,ha~ er~ 5~ ancl 55 throucJh the recill ports
56.2 ancl 57.3 so as to bring the pi~l:on pumps 40 and 4l
bac]c to fully operating condition wi.thin a few strokes.
Similarly~ the cliaphragm pumps 28 ancl 29 will be operatinq
at ~u11 capaci~y withi.n a E~w strokes aEter the r~openin~3
of the valved dispensi.n~ no~zle :L3.
In order to acco~nodate wide variance i.n the
quantity of p~npincJ cles:irecl ancl the proper proportioni.n~
of ~he components, the variabl.e speed pulley 17 Oll the
motor ~ha~t may be acljusl~ecl tv chancJe the speecl of the
sha~t 20 ancl ctf the eccentri.c a3ld o~ the pis~:on pl.llllp5.
Durin~ operation of the di.aphrac3m pumps, the :inne~
and ollter perip}leri~s of ~.he c11aphragms 34 are clan~pecl and
retainecl aCJclin~t unde,~.;ire~d Inoverllerlt throurJII the ef:~ec!ive
operation of the beads 34.3 and 34.4. The beacls provide
for extremely e:EEective sealing to prevent any migration
of puMpage ox hydraulic fluid past the diaphragm.
The chemically re~.istant laMina 3~o2 of each o
the diaph.rayn1s perrnits pumplng of an e~tremely wide range
of materia1s wi-~h this proportioning pump. The lamina 34,2
is relatively thi.n compared to the neoprene ruhber lamina
34~l, but ls efficient to resist the effec~ of the pumpage
liquids.
1 lB6073
Alt}loll(3h, in tl~e orrn .illustrélted, the eccentric
provides a cal~lning periphe:~el1. surface 27a to transmit -the
reciprocatirlc3 mot.ion to t-he piS-tOllS 50 a~d 51 which are
al:igned ~:ith e~lCh othe.r. i:n t1.- e cylinder wall sl.eeves 56
and 57 whi.ch are also alicJned with ~ach other, it is
readl:l.y under!>-..andable -that e,ach o-~ Ihe piston.s may be,
in an alternate form, connected by a piston roc1 directly
to the eccent:ric of the drive shaEt.
Fur~hermore~ it should be reco~nlzed t}lat although
the ~orm of the inve~n-tion illustrated in Fi.~Jures 1. 4 has
only one acljustable piston pump 40, wherei.n l.he sylinder
wa11 sleeve 56 is longi.tudinally adjustable, in F.igure 5,
the pump lOol incorporates two separate variable piston
pumps 40.1 an~ ~0.?., both o~ which are identical with the
lS plston pump 40 illustrated in Figures 1 - 3. Each of the
variabl~ pi.ston pumps 40.1 and 40.2 operates a cor.responding
diaphrac3m p~lp 28.1 a.~d 2Y,~2, ea~h oE whi.ch i.5 identical
-to -the diapllr~Jtrl pump 28 ill.ustrated in Fiyures :L - 4 for
pumping the culllporlents of the mixtur. In Fi.cj~re 5 the
motor lG.l al50 ilaS ~ v,.lr.iable speed pul.:ley L7.:l. for
varying the operat:illcJ speed o~ the pumps. ~ccordingly, a
:ide variclti.on :in t;he~ proporti.orlin~ o:E ma.ter.ials beirll.3
p~?d c~clrJ 1~ O~te~ 'l t.:hrc~ Jl~ v~l.ryill{J ~ operal i.ol'l 0:~'
the piston pWTIpS throucJIl their controls Ç0.1 anc1 60.2 in
the manner previously described in collnectio~l with -the
piston pump L1 O o~ Fi.~ures 1 - 4.
11l F.igure 6 the proportioni.ng pump 10 . 2
incorpo.r:ates ~h~ two pis~on pumps 40.1 and 40O2 o~ Fic3ure 5,
and the diaphragm pun~ps 28.1 and 2R.2 thereof. In this
Eorm, the sQurce o.~ reciprocatinc3 po~ler is provided by a
double acting piston type air motor 75. It should be
obvious that the alr motor 75 could also be used with the
piston pumps 2~ and 2g OI ~iyure 1 and the correspondiny
diaphragrn pumps 28 ancl 29.
~'
1 16~073
.l. ~;--
T'.-le heads 50.1' o~ t~ns 50' of the pist~n pumps
~0.1 anc'l ao.2 are contlnuously urcJecl aqains-t the adjacerlt
encls o~ the piston rod 76 by springs 52'. Piston 77 on
rod 76 reciprocates in c,yli.nder 78, into which air under
pxessure i.s supplied alld e.Y~h.lusted througll ports 79 ancl 80
in the cylincler wallr Ai.r .is supplled -~o and exhausted E~om
th~ ports by a f'our-way valve 81 havincJ pilo-t operato~s 82
~,nd 83 for shiftillcJ the ~alve~ Piston poS:ition sensing
valves U4, 85 contro.l application o:E pressurized air to
the pilot operators ~2, 83 so as to synchronlze the
operati.on of' the four way valve 81. with the reciprocation
of pist.on 77 and rod 76.
Air moto.r 75 may be operated to reciprocclte
pistons 50' at the same rate ~nd with the s,~le effect as
in the other forms of the invention.
Hyclraulic flui.d reservoirs 22.1 are provided in
-the air ~otor housincJ ~la so as -to irnmerse -the pistolls 50 7 ~
spri.ngs 52' ancl the cylinder slee~es :f-'or supp].ying hydraulic
Eluid int-o the pump chambers as herein described in
connection wi-th Fi.gures 1 ~ ~. The reservoirs may be
in-~,erconnected with I~assacJeways or conc1u.its if desi.red.
In certain ins~.ances, it may be desi.rable to reduce
the capacity of one of the pis~.on pumps by ut:i.lizi.ng a
piston of smaller diamet0r, and a cylinder slee~e of
corresp~nd,i.ng sizeO In order to compensate or the varyinc3
loadin~ at the al.r rno-tor, the ai:r p:iston and the cyli.nder
wall th~refor may both be stepped so as to have effectively
different piston surface areas against which the pressuri~ed
air acts.
In another form of the inven-tion, the pressure
relief valves 65 may be entirely confined in a removable
cartridge ox cap~,ule r SO aS to facilitate effectively
eliminat~ J the pressure relief valve from the h~dra.ulic
circui-t durincJ prlmi.ng, and wi.thout los:ing a pre-established
settin~ of the relief valve~
~ ~66~3
-17~-
It w.ill be seen tll~t: tile inverlt3.0n provides a
two-component prOpOrtiOninCJ an~ t.andem di.apilracJm pul~p
wherein the cylinder wall of one of the piston pumps ma~
he lon~i.tudinally adjusted to chancJe the pumpin~ stroke
o -~he piston pump and there~y va.ry the qualltity oE
p~npage Erom the associated diaphrac~n pump~ The pump may
be operated as a single pump without requiring the use of
the t~o components, but ;.n mo.s~ instances two components
will bP consistently pumped at the desired relative rates
lQ to each other.
