US2895548A - Apparatus for handling fluid materials - Google Patents

Description

July 21, 1959 sfF. sTAFFoRD 2,395,548

APPARATUS vFoR HANDLING FLUID MATERIALS Filed June 6, 1956 I v, 2 Sheets-Sheet 1 ATTORNEY July 2l, 1959 s. F. STAFFORD 2,895,548

APPARATUS FOR HANDLING FLUID MATERIALS Filed June s, 195s 2 sheets-sheet e zsec. (995er. ZI 5*.rec. 3

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\ x INVENToR. E. (1% x BY x W l United States Patent APPARATUS FRH-ANDLINGFLUID.

Ei'tephen-y Stalford; lRoosevel-NY.

Application June 6,.19S6,.Serial.Nof 589,615.

Z ('Jlains; (Cl. -16-1``f7),"

This invention4 relates, in:..generalr to. an. apparatus. fory handling uid materials and, more particularly, thevinven-J tion.` is concerned with a. fluid circulating apparatusfor use in a. dishwashing-machine. Theapparatus of. the-im vention accomplishes an intermittent type Huid. handling operation as distinguished. from continuous type operations commonly employed in. dishwashers.. Y

In one embodiment., the invention isexemplied by a 'uidcircul'ating apparatus. for useina typeof. dishwashing. machine which. is employed. in. railroad. cars and restaurants.

In many such types of dishwashing. machines .there arey several limitingfactors bearing. on. the. manner.. in .which such machines may be designed. A- principal. factor to be dealtwith. is aPublic Health'.requirementlmakingil.

mandatory that a certain number of. gallons; of, wash water per minutel be circulated.. This factortisfurther. complicated by space limitations necessarily present in railroad cars andi restaurants. `Freqi 1ent1`y,.the washer must be built within a 2'2"' x 22"v spacev allowance. third'consideration is proper maintenance ofthe pH factor, that is, the correct alkalinity or amount of soapv present in the wash water during the washing operation.. In addition, cost of the. metal construction and other equipment conventionally employed isa-highly important consideration.

To deal withthesevarious limitations.V it is. customary inypresently used equipmenttoy employ amotor-.driven pump which operates to continuously circulate a rela.-Y

In hospitals, motor-driven pumpsare' objectionable vfrom-- the standpoint ofV noise aswellA as the.A need' for special housings to avoid hazard to personnel'.

It is. a general object of the present invention to devise a simplified apparatus for handling.fluid.`materials. and especially to provide a method in which the use of' a motor-driven pump is eliminated. A further object of" the invention is to provide 4a fluid circulatinglf apparatus -which maybe used in adishwashing'` machine' andwhich' will avoid-diiiicul'ties` now encountered indi'sh'washingr machines used in railroad cars.,restaurants;hospitalsand` St-ill'another object is to. design a compact,`

the like. elcient apparatus for ,intermittently handlinguidmate.

rials, which apparatus may, have-applicationgenerally in.v a wide range. of..operations involving atransfer of uids.

from one point to another.

From a study of the problems noted` andhavingin mind the objectives above set forth, I have conceivedof" an apparatus for producing a. flow of iiuidl material i'n which the ilow of liuid may be periodically-- interrupted" 2,895,548 Patented July 21.,- 1959-A in.a,-.uniqpe-.n1anner to-providefor a cyclicuidhandling. operation. Int this method-of-'cyclic handling,y a bodyr of.

uidvis. periodicallyexpelled. from afreservoir. station. and, duringa.- shortinterval immediatelyy following they emptyf ingo-.the reservoir, the reservoiris refilled..

In.. carrying out invention in connection with a.-

disliwasrhing operation, the emptyingv of fluid" from its reservoir; takesplaceand. immediately thereafter 'the exa pelledruidis returned to thereservoir.- In other-- appli` cations,l the refilling may proceed with-` successive fluid portionsl from another source being introducedintotheY reservoirs In..thus.producing.a-periodicow of-uid-l tnd that-- I: may. selectiyelyI exert a-gaspressure internally of a body of uid. while-maintaining. the uid reservoir asa-sub stantially closed chamber.: whichv can be opened at thepointes/here. the reservoir. ofuid is emptied.

Asone. suitable means-.for carrying out the methodofexerting.. gas pressureinternally of aA body of huid-in the'- reservoir,.,lfhave.deviseda reciprocatinggas actuateduid ejector mechanism. With this fluii1ejector` mechanism, I Acombineanovel7 iluid reservoir compartment. The

ejector.. mechanism..i s.mounted in-.the compartment and-- the-latter member is provided with outlets andan inletpassageway.

I'l'rhave. further devised. a. valve structure which is: actuated by the reciprocating ejector mechanism .to open. and close the-.inletpassagewayin the lluid-f. reservoir compartment.. in. predetermined. timed relationship. to. displace'- mentofllid through the discharge outlets.-

YIlliave. still. further provided` electrical circuit.. control means. fon operating the. reciprocating-ejector mechanism. onatiine schedulewhich, having reg-ard. for the volume offthe fluid reservoir, .will .provide for allow in gal-lonsu perminute adequate. tomeet Pfublic Health requirements.-

rlhese vandfother objectsandnovel` features of thein.-` vention willbemore fully understood and. appreciated. from the following description-ofV preferredembodiments oftheinvention selected. for purposesV of illustration., and shown in the-.accompanying draw-ings, in. which.

Fig. 1"y isafcross-sectional view of. a-.dishwashing.ma. chine sho-wing the uid handling. apparatus of-4 the invenI tion in one positiong.,

Fig., 2' is a-schernatic-wiringgdi'agram for use in. operating the huid-handling apparatus;

Figs. 3" and'4. are diagrammatic views illustrating.v the` timing cams off Fig. 2' in .developed relationship;

Fig.. 5 is a plan crossfsectional view taken on theline.-

5"-5 of Fi'g'; l; and v Y Fig., 6 is-aY detail cross-sectionalV View of. a modified form of'reciprocating-.valve and ejector mechanism.

Theprincipalparts offthe invent-ion are best shown. in..

Fig.. 1` l-ndiinclude the huid-'reservoir compartment the fluid ejector. device mountedin the compartment for ex, 1:elling`uid4 therefrom anda wash chamber in whicha basket of'dishesmay be received and-washed.

Invr the, structure shown in Fig. 1,v A denotes an enf closure body preferably. consisting of a` bottom frame section 2' anda top chamber` section 4. This topA cham.-

ber,` section 4,..in one preferredformgmay be fabricated-- from stainless steel'andI constructed as a-substantiallyl closed` casing. of rectangular cross-sectiomas suggested in Fig. 5'.'v This structure is intendedto berepresentativeof4 a formoff dishwashing housing Vsuch as is used in railroad cars, hospitals andlrestaurants wherev a minim-uniof space is available.

I't will b'e understood. thatvv the upper' chamber section' 4` of" the. enclosure 'body' is intended Yto' comprise a' dish? washingstation `inwhich'may be located av dish rack. or" tray'of some Standardtyp'e. No attempt has' beenmade' to showsuch a basket as it forms no p'a'rt of the' present' invention; However,` numeralsv S and 7 denote` wash arms and numerals 9 and 11 indicate rinse arms, both of these units being of well known construction.

In accordance with the invention, I provide in the adjacent annular part 16 of the upper chamber section 4.V

Mounted on the annular part 16 and also secured by the fastenings 12 and 14 is a ring-shaped valve seat member 18 inclined inwardly and having mounted around its inner neck portion a sealing gasket 20. Arranged in close proximity to the valve seat 18 at the underside'thereof is a valve element 22 which may be of some desirable shape such as that shown in Fig. 1.

The valve element 22 is supported in the uidreservoir compartment in a position to be movedinto sealing relationship with the valve seat 20 and forms a part of a special fluid ejector mechanism constituting a basic component of the invention.

The uid ejector mechanism includes a tubular melmber 24 which is welded or otherwise secured to the bottom of the compartment 6, as shown in Fig. 1. 'Connected into the bottom of the tubular member 24-is 'a gas conduit 26 which is, in turn, connected to a supply line 52 leading to a source of compressed air.

Slidably disposed in the tubular member 24"is a piston structure 28, 28' which includes upper vand lower spaced-apart sections as shown in Fig. l. Section 28 is arranged to lie in the path of flow of compressed air entering the tubular member 24. Located' through the piston section 28, 28 is a pipe 30 open at its lower end and at its upper portion communicating with transversely disposed passageways 32 formed through the piston section 28. The valve element 22 may be detachably or solidly secured at the upper end of the piston section 28, as illustrated in Fig. 1. Y

It will be observed that when compressed air is admitted at the lower end of the cylinder 24; the piston structure is forced upwardly for a short distance until the valve 22 becomes rmly seated against the valve seat gasket 20. It is also pointed out that, in this extended position of the piston structure, the piston section 28 will project beyond the top of the cylinder 24 a distance sutnciently for the outlet ports 32 to communicate with the interior of the compartment 6. 'This is clearly apparent from the dotted line position of the valve element shown in Fig. 1.

It will be apparent, therefore, that when this compartment is lled with water or other fluid, the compressed air which is discharged through the outlet ports 32 will immediately exert an internal pressure on the water operating to displace the water from the compartment. To facilitate such a displacement, I provide discharge conduits as 36 and 38 which are open at their lower ends and which extend vertically upward through the members 16 and 18 into the wash chamber of the upper section 4 where they communicate with a transverse conduit 40. The member 40 feeds ejected uid out through the wash arms 5 and 7. Y

It will be appreciated that, as soon as the level of the uid in the compartment 6 has been lowered to a point near the entrances to the discharge conduits 36 and 38, it is important to cut off flow of compressed air so yas to permit the pressure in the compartment 6 to be reduced to a point where the valve 22 may be opened and thus permit return of the expelled uid. As soon as all of the uid is expelled from the reservoir compartment, it is necessary, therefore, to move the valve out of sealing relationship, as well ascutting off the flow 4 of air so as to provide an open passageway through which expelled fluid may flow back into the reservoir in the quickest possible time in preparation for repeating the cycle.

To control these operations in a correctly timed relationship, I provide an air valve 50 which is adapted to open and close the supply line 52 for the compressed air which operates the ejector device. This valve is preferably actuated by a solenoid 54 which is included in the electrical control circuit shown in Fig. 2. Also included in this control circuit of Fig. 2 is another solenoid 56 which opens and closes a water supply line 58 through which water may be fed through the rinse arms 9 and 11.

Considering in detail the operation of the apparatus and its electrical control circuit, it may be assumed rst that the huid reservoir compartment 6 has been tilled with water which is passed down through the wash chamber and through the inlet passageway P. This water ordinarily reaches some level such as that indicated at L in Fig. l.

With dishes in the wash chamber, a periodic washing cycle and conventional rinse cycle is carried out. This involves a series of mechanical operations and a series of related circuitry functions which are, for purposes of convenience, discussed separately. Noting rst the mechanical operations, compressed air is introduced through the air supply line 52 into the lower end of the cylinder v24 where it exerts an upwardly directed pressure on the piston assembly 28, 28 as suggested by the, small arrows. This pressure forces the piston structure upwards into the position shown by the dotted lines in'Fig. 1 where the valve element 22 tightly seats against the gasket 20, thus sealing the reservoir compartment at its uppcr end.

Air under pressure continues to flow into the cylinder and` passes through the'tubular member 30 and out through the ports 32 in the upper piston section 28 and, thence,

into the uid reservoir compartment. There is thus almost instantly exerted an internal pressure which rapidly expels the fluid in the compartment out through the discharge conduits 36 and 38 and then out of the wash arms 5 and 7.

After this expelled water in the form of a spray has fallen upon the dishes in the wash chamber, it collects as a separate body of fluid which reaches some level L', as suggested in Fig. l. When this level is reached, any excess water drains away through an overow port O into a suitable drain pipe carrying with it grease and food particles which rise to the surface of the fluid collecting in the wash chamber.

When the reservoir compartment 6 has been emptied of wash water, air entering the supply line 52 is cut off and the pressure drops to atmospheric pressure. The piston'assembly 28, 28', then drops back to its original position, as shown in Fig. l, and the wash water quickly tlows down around the valve.

Immediately, a new supply of air is introduced and the described cycle is repeated as many times as is required to complete a full wash cycle. After the wash cycle period, the supply line to the rinse arms, is opened and maintained in effect for a predetermined period. At the completion of the rinse period, the timing means cuts out and the operation is ended.

In usual practice, the doors of the washing machine are now opened, the basket of dishes removed and another basket of dishes placed in position for washing. It is pointed out that, in many localities, Public Health Departments require that the wash-rinse cycle be out of the control of the operator so that once the cycle is started the period cannot be shortened by manual control. The` wash-rinse cycle in basket type dishwashing machines comprises a wash period which may vary from 60 seconds to seconds or more, during which time the wash solution is recirculated and sprayed over the dishes. Following the wash period, clean hot rinse water at F. or higher is sprayed through the rinse nozzles. The rinse period may vary from to 30 seconds. The volume of this rinse water is very important as it performs several functions. It replaces the heat absorbed from the Wash solution by colder dishes. The rinse water also heats the dishes to a point where no toweling is required. The rinse water also sterilizes the dishes, replaces a portion of wash solution which overflows and floats away grease.

To perform the mechanical steps set forth above and, having in mind the limiting factors just above listed, I have devised a special control circuit which includes means for intermittently actuating the valve and ejector mechanism for a predetermined number of times and means for immobilizing the ejector mechanism circuit while operating a rinse circuit.

Referring to the wiring diagram of Fig. 2, a main power supply line switch 60 is normally closed. The operator first closes the normally open switch 62 and holds it closed until the pilot light 64 remains lighted when switch 62 is released.

Energizing the pilot light 64 indicates that the timer arrangement 66 has closed a circuit through the relay coil 68 and through the normally open contacts of the cam controlled timer switch 70 operated by cam 72. If the operator releases the switch 62 before this normally open switch has been closed, the pilot light will go out. As soon as the operator closes the switch 62, the normally open contacts of the relay 68 complete the circuit to the coil of the solenoid air valve 54 which sets in operation the ejector mechanism already described. The operation of the ejector mechanism continues for a predetermined time controlled by the cam dwell of a second timing cam 76.

The cam 76 and its dwell periods are shown in developed form in Fig. 4, together with a similarly developed form of the cam 72 in Fig. 3. As shown in these figures, the lirst dwell for the cam 76 during which water is being sprayed may run for 10 seconds, for example. At this point the timer cam 76 opens the circuit to the coil of the solenoid valve 54 for a brief period which may be, for example, 3 seconds, as indicated in Fig. 4. This permits the wash solution to flow into and refill the compartment 6, as already described.

The timing cam 76 continues to open and close the circuit to the solenoid air valve 54 until the total wash time cycle is completed, including, for example, a period of 88 seconds, as indicated in Fig. 4. Timing cam 76, at the end of this period, opens the circuit to the solenoid coil 54 and holds it open during the rinse period. During this part of the time cycle, shown as 30 seconds in Fig. 4, the circuit to the timer 66 and also to the coil of the relay 68 is completed through the normally closed contacts of the switch 80. This maintains the circuit to these two components which would otherwise be opened when cam 72 closed the circuit to the coil of the water solenoid 56 through the normally closed contacts of the timer switch 70.

At the end of the wash-rinse cycle noted as 120 seconds on the time diagram of Fig. 4, timer cam 76 opens the circuit to the coil of the relay 68. The contacts of the relay 68 return to their normally open position and the time circuit opens. The cycle is then completed and the contacts of the two timer switches 70 and 80 are returned to their original starting positions in readiness to repeat the cycle when the starting swich 62 is again closed. The normally closed switch 84 may be used to stop the operation at any point in the cycle. The normally open switch 86 may be closed when a separate rinse period is desired.

It will be understood that, while I have shown a preferred embodiment of the invention dealing specifically with a specialized type of washing machine, I may, nevertheless, desire to employ the invention in various types of fluid transfer operations, such as transferring successive quantities of fluid from one container to another. Similarly, I may desire to vary the details of construction of the washing machine forms of the invention. For example, I may desire to employ a plurality of injector units or I may desire to modify the manner in which the compressed air is employed to remove the fluid. In this connection, I may desire to include in the wash chamber a tubular outlet having a source of compressed air which is delivered through an aspirator tube 92 and this device may be used to exhaust hot steam and other gases from the wash chamber. In another form of modification, I may construct a valve element corresponding to the valve element 22 already described and mounted on a tubular member 102 telescopically supported in a cylinder 104. This structure, having outlet ports 106, may be used to perform the function of the cylinder 24 and piston structure 28, 28 already described.

It will be evident from the foregoing description that I have provided a novel intermittent type fluid handling method and operation, particularly suited to use in dish- Washing machines and characterized by simplicity and efficiency in operation with saving in space and materials and elimination of many diiliculties.

Having thus described my invention, what I claim is:

l. In a fluid circulating apparatus an enclosure body said enclosure body including a fluid reservoir compartment having discharge conduits connected thereto, said enclosure body further including a fluid receptacle for receiving iluid ejected from the said discharge conduits, said fluid receptacle having a passageway communicating with said fluid reservoir compartment, a valve member, reciprocating means for supporting said valve in the fluid reservoir compartment in `close proximity to the passageway, said reciprocating means consisting of a cylinder mounted in said fluid reservoir compartment, a compressed gas actuated piston assembly slidably rereceived in the cylinder and having the said valve secured at the upper end thereof, said piston structure being formed with gas outlet means communicating with the iluid reservoir compartment when the piston is extended into a position to -force the valve against the passageway, and means for intermittently exerting gas pressure on the said piston structure.

2. A fluid circulating apparatus including a fluid reservoir compartment having a discharge conduit communicating therewith, ejector means in said reservoir fluid compartment for exerting pressure and periodically ejecting predetermined volumes of iluid of the same magnitude from said compartment through said discharge conduit, a fluid receptacle constructed and arranged to receive and hold said predetermined volumes of ejected fluid, said fluid receptacle having a passageway connected with the fluid reservoir compartment and a valve mechanism responsive to drop of any pressure in the ejector means for opening the said passageway and releasing the said predetermined volumes of fluid during the time intervals corresponding to one another in each instance, said ejector means including a cylinder having a source of compressed gas connected at the lower end thereof and said valve mechanism consisting of a valve element having a tubular extension which is telescopically received in said cylinder and said tubular extension being formed with passageways which communicate with the reservoir when in an extended position and which passageways are normally sealed by the cylinder wall when not in an extended position.

References Cited in the file of this patent UNITED STATES PATENTS 603,580 Shaw May 3, 1898 1,358,507 Berford Nov. 9, 1920 2,551,379 LaRaus May l, 1951 2,570,021 Beach Oct. 2, 1951 2,734,520 AbreSch Feb. 14, 1956

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