CA1067462A - Measuring and dispensing apparatus - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An apparatus for automatically dispensing a mea-sured volume of liquid. The liquid is fed into a cylinder and displaces a piston which expels quantity of liquid pro-portional to the piston stroke. At the end of the stroke, the piston is made to abut a close a switch which actuates an electric motor driving a four-way rotary valve to reverse the liquid flow direction in the cylinder, whereby the piston moves in the opposite direction to discharge a measured amount of the liquid which was previously used to push the piston.
The piston, at the end of its second stroke, again strikes and causes the closing of a second electric switch which produces rotation of the four-way valve to again reverse the liquid flow to its original direction. The back-and-forth movement of the piston can be automatically repeated a predetermined number of times, being governed by an electric counter or any similar electri-cally-operated device. Means are provided to prevent the formation of air pockets in the clyinder, which would affect the measuring precision. The position of the electrical switches can be varied to vary the piston stroke and, therefore, the quantity of the liquid dispensed. As a modification, one or more additional cylinder and piston assemblies are provided with their pistons mechanically connected to the piston of the main cylinder and arranged to dispense two or more liquids in exact proportional amounts. Another embodiment shows a variable volume cylinder to adjust the amount of liquid being dispensed.
The four-way valve is leak-proof between the two liquid circuits because its valve member is frusto-conical and is pushed in seating position by a by-pass of the liquid under pressure. The apparatus can measure with great precision liquids of various viscosities and under very low or very high pressure.

Description

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-2-The prseent invention r~lates to an apparatus for dis-psn~ing measured volumes of liquid o~ the type including a aylinder ~il.ted with the liquld to be meq3ursd and hflving a pieton wh~ch 9ep-aratas the liquid in two portions~ the liquid on one ~lde of the picton i9 used to push the 12tter to exp01 a measured amount of the liquid on the other side o~ the piston~ the app~ratus includea a four-~ay valve ~hich reverses the liquld ~lo~ upon the pieton re~ching each ot it~

two limit positions.
Kno~n mea~uring apparatus of thi~ typs lack~ ln precisiDn, eapecially whsn the llquid is at high pressurs.
The maln ebJuct o~ th~ invsntion ie to provide an epparatus o~ the ch~ractar de~cr$b~d~ whlch h~ o uery high proo~ioa ir~eepectiv9 oP ths pr~ssure o~ the liquid to bs mea~ured and di~pensed in that the stroke of the mea~uring snd di~pensing pieton i5 praci4ely s~t beoeuss the piston strok~e 9t~p at the snds D~ i t~ strokes. Also, meens are provided to po~itively prevent leakage ~round th~ pieton und sround the v~lve ~mber o~ the ~Dur~ay ValV
Anoth~r ob~ect o~ the invention i3 to prouide ~witohin~
maans at the stops~ which ~re electrically inaulated ~rom the cylinde~
and piston ths~selve~ 90 that the apparatu~ con handl~ in~lammoble and other d~ngerouo liquids.
Another obJect of the invention is to provide e moro ~imple embodiment in which the piston and the 3top act e9 tho tw contaot~ oP an electrical switch. This e~bodiment i9 suitablo fo~
uee with non-in~la~mable liquids.
Another nbject i8 to provide an ~pp~ratus of th~ ch~racter de~cribed, which 8Ct8 as ~ propo~tionlng meter for di3pensing proportionate measured amounts of two or more liquid~.
Another obJqct of tho~invention i8 to provide an appar~-6~

tus of the character describ~d~ in which shock-absorbing msans are prouidsd at the 8top9 to dimini~h the~impact o~
the piston thereon and consequ~ntly reduce the noise meda by the spparatus.
The for~going and other ob~scts of the invention will bscome more apparent during the ~ollowing di~closure and by rsferring to the drswings~ in which~
Figure 1 is a longitudinal ~ection, tak~n along line 1-1 of Figure 2 o~ a ~irst embodiment o~ the 10. moasuring and dispsnsing apparatus of the invention;

Figurs 2 is an end vi~w o~ ths same; .-Figure 3 i8 a cross-ssction o~ the ~our-way valve takan through line.3-3 o~ Figure 1;
Figure 4 i~ a p~rspective view o~ th~ s~al~ng gask~t used in the ~our-way valve;
Figur~ 5 i3 a longitudinal section o~ onc o~ ths stop rods and electrical switch used ln the smbodiment 3~ Figure 1;
Figure 6 is ~ partial longitudinal section o~ the mea-20. 5~ringchamba~ snd another:smbodiment~o~ ons o~ th~ stop~rod;

B ~ : Figure 7 i3 a view ~imilar to:that o~Figur~J~ but ~ ~ ~howing still anoth~r ~mbodiment o~ th~ stop rod and floating : pis~on;
Figur~ 8 Ls a longi~udin~l ssctlun of another embo~
diment o~ the measuring spparatu3 providing a ~ultiplicity uf mea~uring and dispen3ing ch~mb~rs; &nd figure 9 i8 a croa~- otion~ taken al~ng lLno 9-9 of Figure 8.

In the drawings~ like re~erence numeral~ indicat~
30~ like slemsnts throughout.

-` ~067~L~2 As shown in Figures 1 and 3, the apparatus of the flrs-t embodiment comprises an elongated tubular member in the form of a cylinder 1 in which is located a floa-ting piston 2, movable back and forth between stop rods 3. A liquid circuit for cylinder 1 includes a four-way valve 4 actuated in rotation by an electric motor 5 and a speed reducer 6 The mo-tor 5 is controlled through an electrical circuit, not shown, by a pair of switches 7 (see Figure 5) carried within the stop rods 3 and alternately closing upon abutment of the floa-ting piston 2 on a s-top piece 3, carried by the inner end of the stop rod.
Cylinder 1 is closed at both ends by head plates 9 ; with the in-termediary of sealing gaskets 10. Head plates 9 are secured -together by means of tie rods and nuts, as shown at 11 in Figure 2. The head plates 9 also support a plate 12 to which is secured the valve body 13 of four-way valve ~.
The floating piston 2 consists of a cylindrical block, to the opposite face of which is secured a sealing ring 14 held in position by a washer 15 and a bolt 16 screwed within the block 2.
The sealing ring 14 effectively prevents the liquid flowing past the piston from one side or the other.
Each stop rod 3 is carried by a respective head plate 9 in coaxial relationship with cylinder 1 and extends inwardly within the latter towards the floating piston 2. Each stop rod 3 is screwed in head plate 9 so as to be longitudinally adjustably positioned in cylinder 1. Once adjusted, it is fixed by a lock nut 17.
The head of the bolt 16 of the floating piston 2, on each side of the piston, is adapted to come in direct abutment with the s-top piece 8 of the associated stop rod 3 at the end of a stroke of the floating piston.
As shown in Figure 5, the stop piece 8 is carried by the inner end of the stop rod 3 through the intermediary of an elastic sleeve 18~ which holds the stop piece 8 in position bu-t allows limited longi-~ ~ ~ 4 ~5 2 tudinal displacement ~f the lattsr with respect to tha stop rod 3.
Inward displacement of the stop piece ~ causes closing of the switch conta~bs 19 and 20 af ths electrical switch 7. The contact 20 is eleckrically insulated by means of insulation 21. The two contacts 19, 2D are carried in opposite relationship by the two ends of a resilient U-shape element 22, normally ~aintaining the two con-tacts spaced apart. One of the legs is fixed in position within a cavity of the stop rod 3 by means of a bracket 23, while the leg carrying contact 19 abuts against stop piecs ~
Wires 24~ 25 are connected to U-shape member 22 and to contact 20 respectively. These wires ~reely extend through a central bore of the stop rod to ba connscted into the slectrical circuit uf the electric motor 5, The two stop rods 3 are identical in construction.
The switches 7 ars so connected to an internal switch~
indicated at 24, of the electric mDtor 7 so that each time one o~ the switchss 7 is closed9 the ele~tric motor will rotate in one direction to such an sxterlt that it will cause one-quarter rotation of the spindle 25a of the ~our-way rotary valve 40 Then the motor will stop and will start again upon closing of an alternate switch 7.
The valve stem 25a is rotated through one-quarter turn by its shaft 26 on which is secured a sprockst 27 driven in rotation by a chain 28 trained on the sprocket 27 and also on a sprDcket 29 secured to the output shaft 30 of the speed reducer 6, driven by motor S.
The valve body 13 consists of a block of square cross-section, as shown in Figure 3, provided with four bores 31, 32, 33, 34 respect-ively, disposed at the same level and right angles to each other.
rhe valve stam 25a is provided with two opposite grooves 35 and 36 at the level of the bores 31 to 34. The grooves 35 and 36 are transverse to the stem at the periphery thereof and are so shaped that they establish co~munication with any two adjacent bores 31 to 34.
For instance, i~ the position of the valve stem 25a, shown in figure 3, ~0~746;~

groove 35 makes communication betwesn bores 31 and 34~ whil~ groove 36 makss communication between bores 32 and 33.
Rotation o~ the valve stem through one-quart~r turn clockwise ~rom the position o~ Figure 3 wIll make communication bstween bores 31 and 32 on the one hand, and 33 and 34 on the other hand.
Valve stem 25a is ~itted with a gasket 3~ shown in Figure 4 and al~o in Figures 1 and 3. This gasket includes upper and lower rings 38 and 39 transversely surrounding ths valve stem~ being positioned in grooves thereo~ above and below the bores 31 and 34, and langitu-dinally extending legs 40 connected to the rings 38 and 39 and diamstrically opposits to each other, beiag inserted within suitable longitudinal grooves of the valvs stem. The rings 38, 39 prevent leakage o~ the fluid at the owter ends o~ the ual~e stem while legs 40 prevent leakage from the high pressure to the low pressure side of valve stem 25a.
In urder to always prevent valve leakage despite its w0ar~ thsvalve stem is frusto conically shaped~ as shown in Figure 1~ and seats within a ~rusto-conical shape bore o~ the valve body 13. Moreover~ the stem is loaded into seating engagem~nt by liquid under pressure as hereinaftsr described and by a ball 41 pressed against the valve stem by pompression coil spring 42 bearing against the bottom of a recess 43 made in the plate 12.
The valve body 13 is rlgidly sscured underneath the plate 12 by meaas of tie bolts 44 passing through bores made in the ~alvs body 13, as shown in Figure 2. These tie bolts also assemble the valve 4 and the cylinder assembly 1 on top of a base plate 45~cserving also to carry the motor 5 and spsed reducer unit assembly 6.

The liquid to be measured comes ~rom a supply under pressure~
not shown, through a connection 46 into the bore 31. The liquid under

3~ pressure can either pass to bore 32 or to bore 34, depending on the angular position Df the value stem 25a. In the position shown in Figure 3 B

1067~6;~
. liquid under pressure enters bore 34, then bore 47 communicating therewith; then bore 48 extending through the plate 12; then bore 49 extending through the left-hand head plate 9. Bore 49 opens at the top portion of the cylinder 1 at one end thereof and the liquid is discharged within the chamber formed in cylinder on the left~hand side of the floating piston 2.
The liquid discharged within cylinder 1 must pa~s through an opening 50 of a cup-shaped annular member 51 surrounding stop rod 3 and secured between the end of cylinder 1 and head plate 9.
Opening 50 is disposed near the top of the cylinder 1 and, therefore, any gas which may accumulate in the cylinder will be expelled during the liquid discharge stroke of the piston 2.
The liquid discharged wibhin the cylinder 1 at the left-hand side of piston 2 will move this piston -to the right, causing discharge of the liquid at the right of the piston through right-hand side top opening 50 of cup-shaped member 51, then through bore 49 of the right-hand side head plate 9j then through bore 48 on the right-hand side of plate I2 and through bore 47' ma~ in valve body 13 and in communication with bore 32. The liquid then passes through groove 36 of the valve stem 25 and through bore 33 to be discharged to the exterior through elbow 52 and discharge tube 53. The pressure of the liquid in the discharge bore 33 is used to exert a further downward pressure on the valve stem 25 to maintain the same in fluid-tight engagement with the valve body. To this end, by-pass bore 54:connects with bore 33 and extends upwardly through the valve body 13 to open within a chamber 55 on top of the valve stem 25 (see Figures 2 and 3). When : no liquid is discharged through bore 33, there is no downward pressure on valve body 13 and the latter can rotate freely.
Bores 32 and 34 are plugged at their outer ends by threaded plugs 56. Similarly, the outer ends of bores 49 in the head plates 9 are plugged by means of threaded plugs 57.

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Thu apparatw oper~tes as ~o~lows~
The t~o stop rods 3 are longitudinallg ad~us~ed by unscrG~
the 8llme~ in their respective head plates 9, 90 a8 tio obtai~ the ~ BCt ~paCil~g B betw~en the stop pieC99 8 to obtain a desi~edJ_ :

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.
volume of discharged liquid ~or each stroke of the piston 2. Once the rods are threaded within the head plate, the lock nuts 17 are screwsd in position. At this start, the floabing piston 2 ls at either one of its limit strokes abutting either ons of stop piHces a.
Supposing floating piston~abuts le~t hand side stop piece 8~
then the valve stem is in ths position shown in Figure 3. The cylinder l is filled with liquid. Liquid under pressure discharged in tha left-hand sids chamber l will causs movement o~ the piston 2 towards the right and~ consequsntly~ discharge of the liquid in the right-hand side chamber -of the cylinder through ths discharge tuoe 53. This discharge will con- -tinus until piston 2 abuts right-hand side stop piece 8, thereby olosing the switch 7 associatsd with the latter. The supply~circuit of motor 5 is thus closed and immediately starts operating~ oausing rotation of the valve stem one-quarter turn, at which puint the motnr stops. Ths flow is now re~ersed~ that is the liquid supply is connscte~ with the right hend side chamber of the cylinder l~ while the left-hand slds chambsr is connected with the dischargs tube 53. The floating piston 2 ; movss towsrds ths 1eft thereby opening right-hand switoh 7, until ~; piston 2 abuts the left-hand side head piecs 8, closi~g ths switoh 7 - 20 associated therewith. The motor 5 starts again in the same directio~
of rotation, causing a further rotstion of the valvs stem through one-quarter turn thus again rever:ing ths liquid flow and the oycle is re-~ oeated. Thus, it will be appreciatad that at each stroke, a measured ; amount of liquid is discharged which is rigorously the same as the amount of liquid discharged in the previous ~troke, In the emoodime~t just described, the electrioal switches 7 are completely electrically insulated~from the liquid and, ther0fore, inflammable and otherwise dangerous liquids can be measured and dispensed fr~m the apparatus~ The apparatus can measure and :~

D

~ ~06~46:2 ~.g_ dispense a liquid which i9 at vsry high pressurs in a precise manner~ since there is no leakage around valve st0m 25 ~rom th~ supply circuit to the discharge circuit. Also, the apparatus csn moasure and disp~n~s liquids of various viscositi98~
Whenever a non-dang~rous liquid is ueed~ tha embodiments of Figure 6 or 7 can be used~ In the embodi~ent of ~igure 6, oylinder 1~ i8 made Or metal and i~ part D~ the eleotrical circuit~ baing conn0cted by wire 58 into said cir¢uit. The stop rod 3~ i9 electrically insulated ~rom oylinder 1~ and ha~
. a half-spherioal metallio stop piecu ~7 whi~h serves as one c~tact o~ tha elactrical switch as well as a stop member~ the other oontsct of the electrical switch being the bolt 16~ of the floating piston 2~
the latter having a metallic sealing gasket 14~ in contaot with the mstallio oylinder 1.
In ~igure 7, the stop piece 87~ of eleotrioally in~ulated stop rod 31~ and the piston 2~ alRo sarve a~ the two oontacts o~
tha electrical switch and; in addition~ the ~loating piston ~t7t is ~provided ~ith a sleeve~ ~ adapted to slidably ~it over the cylindrical stop piace 8~ at the~end o~ the p~ston stroke.

20~ The stop piece 81~ has a central bore 8a opening at th~

~ree end o~ the stop piece and in communioation with a oide pas~aga 8b. This arPangement ~orms a shoLk ab~orber to gradually 810w dow~ the piQton at the end o~ ~t~ stroke~ the liquid ` ~ emprisoned within the slseve by the stop piece 8~ ~lowly di charging through the bor0 8a nnd passag~8b. This ~rr3ng~-ment i8 naturally p~ovided on both side~ o~ the oylinder~

The mea~uring and dispensing apparatu~ o~ ths last embo~

dimantç shown in Figures 8 and 9, 30.

showS a modified main cylinder and also additional cylinders -~ur dis-pensing two or mnre separate liquids in exactly proportional volumes.
The msasuring cylinder 1l is similar to cylinder 1 o~ the first embodiment~ being provided with head plates 9l and a transverse plate 12~. Thess plates have a similar liquid cir~uit provided by the bores 49, 48. These bores are in communication with the bor~s 47, 47~' of the valve body 13 o~ the four-way value 4 of the first embodiment, this ~our-way valve being the same as the first embodiment and being actuated by an electric motor 5 and transmission 6 and the sprockets 29, 27 and chain 28.
Instead of a free piston~ a piston 60 is secured to a piston rod 61 freely slidable through bores oP the head plates 91. Each end o~ the piston rod is pro~ided with a stop finger 62~adapted to abut against a stop piece B at the sxterior of the cylinder. This stop piece is adapted to actuate an elsctrical switch 7 within stop rod 3 and similar to switoh 7 of Flgure 5. This stop rod 3 is held in adjusted position by a bracket 65, in turn held by a support 64 secured to the respectivs head plates g~. The two switches 7, one at each end of the cylinder~ are actuated upon alternate contact of the finger 62 with the r~spective stop pieces 8, so that the measuring and disp~nsing apparatus ` operates in the same way as in the first embodiment~ except that the ~::
switches are sxternal to the cylinder and are therefore more easily accessible for repair or the like.
;: In accDrdance with the main feature of Figure 8, one or more measuring and dispensing cylindsr assemblies can be mechanically con-nected to piston rod 61 to measure and dispense proportionate amounts of a like number of additional liquids. These cylinders may be of the same construction as the main cylinder and piston 1l' and 60, 61 with ; their piston rod 61 secured to one another by a connecting member 61S.
B

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:~674~2 ~ inders and pistons of different diameters can be provided to dispense different amounts of the separate liquids for the same piston stroke.
In accordance with a further embodiment, as shown in Figure 8, the auxiliary cylinders can be of variable volume, so as to dispense an adjusted amoun-t of liquid for the same stroke of the piston. The cylinder 65 (see Figures 8 and 9) has a wall of U-shape cross-section, being closed at its upper end by a top plate 66.
Both ends of the cylinder 65 are closed by head plates 67 with the 10. intermediary of a sealing gasket 68. The head plates 67 are secured to the head plates 9' of the main cylinder by means of a dovetailed tongue and groove arrangement 69. An adjustable partition plate 70 is fitted within the chamber 65 and can be ad~usted up or down to vary the volume of the chamber by being provi-ded with threaded studs 71 secured to the partition 70 at both ends and freely extending through the top plate 66. Compression coil spring 72 surrounds the studs 71 between the plate 66 and partition 70 so as to urge the plate downwardly. Nuts 73 are screwed on the studs and bear against the top of plate 66 to ~20. retain the partition 70 in precisely adjusted position within the cylinder 65.
A piston 74, of flexible material, is secured to j a piston rod 75 which extends at both ends freely through bores of the head plates 67. The two ends of the piston rod 75 are respectively secured by the connecting member 61' to the respective ends of the main piston rod 61. Thus, the piston 74 will move back and forth along with main piston 60 and accomplish the same stroke. Piston 74 i of flexible material, such as rubber, and when seen in end view, has a Y shape, as shown in Figure 8, with diverging legs 76, 30. which maintain a sweeping contact with the partition plate 70. The piston in cross-section, conforms to the cross-sectional shape of a chamber formed by the cylinder 65 and closing partition 7b.

1 2 1~6746Z ~ ~

It will bs noted that the legs 76 can P]Lex more o~ less d~pending on the ad~ustsd vertical poQition o~ the partition 70 so aR to rsmain in sweeping andQ sealing contact ther~with, irrespective o~ the posi~ion oP partition 70, The ~lquid cirsuit Por the auxiliary cylinder iQ as follow~.
Liquid ~rom a supply under prsssure is odmitted through inlet opaning 77 of the top plate 66 into the chamber 78 de~insd by ths top plate 66 and the mouable partition 70. The latter i~R provided with a pair o~ check valves 79 at a greatsr distance from sach other than the maximum stroke. These valves 79 allow liquid Plow Prom the chamber 77 into the cyl~nder 65 but pravent rever~e ~lor.
The liquid is d~chsrged from either snd of the cylinder through a tube 80 having its inlet near ths partition 70 and conne~ ~d with an outlet bore 81 made in th~ head plate 67 and adapted ~
~or connection to a~discharge pipe~ ~ur~ny a ~troke oP the pi~ton 76 in one direotion~ th~ liquid i8 admitted to the cylinder through the check valvo behind the piston ahd i9 discharged through ths oUt~e~
81 fo~wardly oP the piston.

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Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed, are defined as follows:

1. An apparatus for dispensing a Measured volume of liquid comprising an elongated tubular body having an inside wall surface and end walls closing both ends of said body, a pair of stop rods extend-ing through the respective end walls inwardly within said tubular body, a free piston movable longitudinally within said body in fluid-tight contact with said body and inside wall and having an abutment surface at each side thereof adapted to abut the respective stop rods upon the free piston reaching one of two limit positions, said free piston defining two measuring chambers in said body, one chamber on each of the opposite sides of said piston and between said sides and the respective end walls, each chamber having at least one port, a source of liquid under pressure to be measured and dispensed, a liquid circuit including a control valve comprising a valve body having an inlet port connected to said source of liquid under pressure, an out-let port and two additional ports connected to said measuring chambers, respectively, said control valve further having a valve member movable within said valve body between a first position connecting said inlet port to one of said chambers and said outlet port to the other of said chambers, and a second position connecting said inlet port to said other chamber and said outlet port to said one chamber, an electric driving means to move said valve member between said two positions, and an electric circuit for controlling said electric driving means and including two electrical switches, one electrical contact of each electrical switch being formed by the respective abutment surface of said free piston, while the other electrical contact is formed by the inner end of the respective stop rods, the latter being electrically insulated from the end walls of said elongated tubular body, said free piston being in electrical contact with said body, the latter being electrically conductive and connected into said electric circuit, movement of said free piston between said two limit positions causing alternate operation of said electrical switches by alternate abutment of said free piston with the respective electrical switches, operation of either one of said electrical switches causing actuation of said electric driving means to move said valve member from one to the other of its two positions.

2. An apparatus as claimed in claim 1, wherein said stop rods are longitudinally adjustably secured to the respective end walls to adjust the stroke of said free piston.

3. An apparatus as claimed in claim 1, wherein said control valve is a four-way valve and said valves body has a tapered bore, said valve member consisting of a tapered valve stem fitted within said bore, said valve body having four passages at right angles to each other in the same plans and opening within said valve body bore, said valve member having opposite peripheral grooves for establishing communication between said passages two by two, said valve stem being fitted with an O-ring below and above said passages and further with longitudinally extending gasket members adapted to separate the high pressure feeding liquid circuit from the low pressure liquid discharging circuit and wherein said valve body has a closed chamber in which the larger end of said valve stem is exposed, and further including a by-pass passage in said valve body communicating said outlet port with said chamber, whereby liquid pressure in said outlet port is exerted on said valve stem to make the valve more liquid-tight and, when there is no liquid in said outlet port, the valve stem is not subjected to said liquid pressure and can rotate more freely.

4. An apparatus as claimed in claim 1, wherein the orifices of said liquid circuit within said measuring chambers are located at the top portion of said chambers, whereby any air entrapped within the liquid will be discharged through said orifices during the discharge stroke of said free piston.