US2665700A - Liquid inlet and antiback-siphoning fixture - Google Patents

Description

Jan. 12, 1954 F, 0, ow

LIQUID INLET AND ANTIBACK-SIPHONING FIXTURE 5 Sheets-Sheet 1 Filed April 21, 1950 INVENTOR.

Frank D. Low

BY M OQM AH s..

Jan. 12, 1954 F. D. LOW

LIQUID INLET AND ANTIBACK-SIPHONING FIXTURE 3 Sheets-Sheet 2 Filed April 21, 1950 FIG. 3

INVENTOR.

. Frank D. Low

Attys.

Jan. 12, F. D. LOW LIQUID INLET AND ANTIBACK-SIPHONING FIXTURE Filed April 21, 1950 3 Sheets-Sheet 5 FIG. g

INVENTOR. Frank D. Low

@ZWZAMMM Patented Jan. 12, 1954 LIQUID INLET AND ANTIBACK-SIPHONING FIXTUR Frank D. Low, La Grange Park, 111., assignor to General Electric Company, a corporation of New York Application April 21, 1950, Serial No. 157,362

7 Claims.

The present invention relates to a vat and a combination liquid. inlet and anti-back-siphonmg fixture, and more particularly to the combination of a vat and a fixture of the character noted incorporated in dishwashing apparatus of the front opening type.

Dishwashin apparatus of the front opening type conventionally comprises an upstanding cabinet, an upstanding vat housed in the cabinet, a front door mounted for movements between open and closed positions with respect to aligned front openings respectively provided in the front of the cabinet and in the front of the vat, inlet valve mechanism for controlling the introduction of hot washing liquid into the upper portion of the vat, drain valve mechanism for controlling the drainage of the hot washing liquid from the lower portion of the vat, and impeller mechanism for circulating the hot washing liquid in the vat when the front door occupies its closed position. The inlet valve mechanism is connected to a suitable source of hot Washing liquid, such, for example, as a hot water tank that is normally connected to the public or city water mains; and the drain valve mechanism is connected to drain plumbing that is normally connected to the public or city sewerage system. Ordinarily in the dishwashing apparatus, the dishes, and the like, that are to be washed are supported upon an open wire-work racl: that is movable into and out of the vat through the aligned front openings when the front door occupies its open position. Usually in the dishwashing apparatus, the hot water is introduced into the upper portion of the vat and projected downwardly through the rack in the form of a spray by a spinner device mounted just below the top wall of the vat; While the impeller mechanism is mounted just above the bottom wall of the vat and directs the hot water upwardly in the form of a rotary swirl through the rack into bombarding relation with the dishes supported by the rack and toward the top wall of the vat, the hot water returning toward the bottom wall of the vat by the action of gravity. Finally, the dishwashing apparatus may comprise an electric heater, and an electric program control device that selectively governs the different elements thereof to provide an automatic timed cycle of operation including washing, rinsing and drying steps.

Occasionally, the supply of water from the city mains fails so that instead of the normal condition of a gauge pressure in the city water mains, the abnormal condition of a subatmospheric pressure appears in the city water mains, causin a back-suction or back-siphon action from the hot water tank into the city water mains and consequently from the inlet valve mechanism of the dishwashing apparatus into the hot water tank, whereby there is the possibility of back-siphoning from the upper portion of the vat of the dishwashing apparatus through the hot watertank into the city water mains, should it happen that the inlet valve mechanism occupies its open position at the time that the back-siphoning effect occurs in the city water mains. Should this happen, it is apparent that the supply of Water in the city water mains might be contaminated with the hot water that is being circulated in the vat of the dishwashing apparatus, which circulated hot water not only contains detergent but certain dissolved impurities and forei n matter that has been washed from the dishes that are undergoing the washing process in the vat of the operating dishwashing apparatus.

In order to safeguard the public health and to insure that the water in the city water mains is not contaminated in the manner described above, certain cities have adopted plumbing codes or regulations that require the installation into the plumbing connections between the hot water tank and the dishwashing apparatus of a vacuum breaking or anti-back-siphoning device.

These plumbing code requirements not only complicate the plumbing of the dishwashing apparatus, but they render it necessary for the plumber to stock or acquire the special antiback-siphoning device and to find some hidden place in the plumbing connections in which the device may be inserted. The latter requirement is often very diflicult when the kitchen space is rather small, as in the case of apartment buildings and the like.

Accordingly, it is a general object of the present invention to provide in dishwashing apparatus of the character described, a built-in combination liquid inlet and anti-back-siphoning fixture or device that fully satisfies the requirements of the plumbing codes mentioned, so that the installation of the dishwashing apparatus necessitates no special external device or apparatus.

Another object of the invention is to provide the combination of a vat, or the like, and a combination liquid inlet and anti-back-siphoning fixture that is so constructed and arranged that the posibility of back-siphoning from the vat into the liquid supply system preceding the fixture is positively eliminated.

A further object of the invention is to provide a combination liquid inlet and anti-back-siphoning fixture of improved and simplified construction and arrangement.

Further features of the invention pertain to the particular arrangement of the elements of the dishwashing apparatus and the combination liquid inlet and anti-back-siphoning fixture, whereby the above-outlined and additional oper ating features thereof are attained.

The invention, both as to its organization and method of ope-ration, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which Figure l is a fragmentary side elevational view, partly broken away, of dishwashing apparatus comprising a vat and a combination liquid inlet and anti-back-siphoning fixture, and embodying the "present invention; Fig. 2 is a plan view, partly in section, of the dishwashing apparatus, the section being taken in the direction of the arrows along the offset line 22 in Fig. 1; Fig. 3 is an enlarged fragmentary plan View, partly broken away, of the top wall of the vat and the fixture incorporated in the dishwashing apparatus shown in Figs. 1 and 2; Fig. l is an enlarged side elevational view, partly in section, of the fixture shown in Fig. 3, the section being taken in the direction of the arrows along the offset line it 6 in Fig. 3; Fig. ,5 is an enlarged fragmentary vertical sectional view of the partition and the combination nozzle and baffle element incorporated in the casing of the fixture shown in Figs. 3 and i; Fig. 6 is an enlarged vertical sectional view of the top wall of the vat and a modified form of the combination liquid inlet and anti-back-siphoning fixture, and embodying the present invention; Fig. 7 is an enlarged plan view, partly in section, of the fixture shown in Fig. 6, the section being taken in the direction of the arrows along the line 1-1 in Fig. 6'; Fig. 8 is an enlarged fragmentary bottom view of the fixture shown in Figs. 6 and '7; Fig. 9 is an enlarged vertical sectional view of the top wall of the vat and another modified form of the combination liquid inlet and anti-back-siphoning fixture, the section being taken in the direction of the arrows along the line 9-9 in Fig. 10, and embodying the present invention; and Fig. 10 is an enlarged plan view of the fixture shown in Fig. 9. In the drawings, the fixture shown in Figs. 3 to 5, inclusive, and the fixture shown in Figs. 6 to 8, inclusive, are drawn at an enlarged scale, while the fixture shown in Figs. 9 and 10 is drawn at approximately actual scale.

Referring now to Figs. 1 and 2 of the drawings, the dishwashing apparatus ii there illustrated, and embodying the features of the present invention, is of the general character of that disclosed in the copendin application of Edgar S. Stoddard, Serial No. 185,618, filed July 19, 1949, and comprises an upstanding outer cabinet l2, housing an upstanding vat IS. The cabinet I2 includes top and bottom walls 14 and I5, front and rear walls i5 and H, and opposed side walls l8 and is. The front wall It is provided with a laterally extending and rearwardly offset toereceiving recess 28 adjacent to the lower portion thereof and a front opening 2! that is laterally offset toward the righthand wall it. The vat I3 comprises top and bottom walls 22 and 23, a

rear wall 24, and opposed wide walls and 26. The bottom wall 23 has a substantial centrally disposed sump 2'! formed therein, and the top wall 22, the bottom wall 23, and the side walls 25 and 26 terminate in an outwardly directed front doorway or opening 28 that is aligned with respect to the front opening 2| formed in the front wall l6.

Further, a front door 29 is mounted upon the lower portion of the doorway 28 for movements between closed and open positions with respect to the front opening 2| and into and out of the doorway 28. The front door 29 carries a handle 3% adjacent to the upper end thereof in order .to faciliate the movements thereof, and is provided with structure 3| in the upper edge thereof that accommodates ventilation of the interior of the vat I3 through the doorway 28 and the front opening 2| adjacent to the top of the front wall Iii. Also vapor directing structure 32 is carried upon the upper portion of the front wall it for the purpose of guiding and projecting the vapor out of the top of the doorway 28 and to the exterior, as disclosed in the Stoddard application mentioned. The front door 29 is of the gasketless type and cooperates with the front doorway 23 and the wall structure of the vat [3 in order to prevent the escape of the washing liquid from the vat l3 during the operation of the dishwashing apparatus H.

Further, the dishwashing apparatus comprises inlet valve mechanism 33 that is connected by way of an inlet pipe as to a suitable source of hot water, such for example, as a hot water tank, the hot water tank, not shown, being normally connected to the city water mains so that hot water may be supplied under gauge pressure to the inlet valve mechanism 23. Further, the inlet valve mechanism 33 is connected by an inlet conduit 35 extending between the side walls It and 25 and between the top walls Iii and 22, to a combination liquid inlet and anti-backeiphoning fixture 36, the fixture 36 being arranged between the top walls i l and 22 and carried by an upwardly directed substantially centrally disposed square boss 22a provided in the top wall 22, and communicating with the upper portion of the vat I3 in a manner more fully explained hereinafter. It will be understood that the inlet valve mechanism 33 is of the solenoid-controlled type and is operative between closed and open positions so that the hot water may be introduced into the upper portion of the vat 13 by the fixture 36, when the inlet valve mechanism 33 occupies its open position. Preferably the inlet valve mechanism 33 is of the fast-opening and slow-closing type in order to elminate water hammer in the connected plumbing extending back to the hot water tank. Further, the dishwashing apparatus H comprises drain valve mechanism, not shown, that is operatively connected between the sump 21 of the vat l3 and the drain plumbing extending back to the city sewerage system. Preferably this drain valve mechanism, not shown, is of the solenoid-controlled type including open and closed positions so that the washing liquid may be selectively retained in the sump 2? when the drain valve mechanism occupies its closed position.

Further the dishwashing apparatus it com prises liquid circulating mechanism that may take the form of a motor-driven impeller 31? mounted for rotation adjacent to the bottom wall 23 within the sump 27. Finally, the dishwashing apparatus l i may comprise an electric heating element 38 of the sheathed electric resistance conductor type arranged in the lower portion of upon the front wall I 6 and disposedbetween the side walls 18 and 25.

In view of the foregoing general description of the dishwashing apparatus l I, it will be understood that the program selector switch 39 is controllable to produce an automatic timed operating cycle including washing, rinsing and drying steps. In the operation of the dishwashing apparatus i i, when the inlet valve mechanism 33 occupies its open position, hot water is supplied to the fixture 3S and introduced into the upper portion of the vat It, the hot water being directed downwardly therethrough and accumulating in the sump 2? when the associated drain valve mechanism, not shown, occupies its closed posi tion. On the other hand, when the drain valve mechanism, not shown, occupies its open position, the hot water accumulating in the sump 2'! is drained therefrom into the associated drain plumbing. During the normal operation of the dishwashing apparatus H, a motor, not shown, drives the impeller 3? so that the hot water accumulating in the sump 21 is thrown upwardly with a swirl toward the upper portion of the vat i3. Normally the dishes and other utensils that are to be washed are supported within the vat it upon a rack of open wire-work construction, not shown, the rack being movable into and out of the vat I3 through the front doorway 28 when the front door 29 occupies its open posi tion. During the drying step of the dishwashing apparatus H, the drain valve mechanism, not shown, is operated into its open position while the inlet valve mechanism 33 occupies its closed position, and an electric circuit, not shown, is completed for supplying energy to the electric heater 38, while the impeller 31 is operated; whereby heated air is blown upwardly through the rack, not shown, and circulated in the vat 3 for the purpose of drying the dishes supported by the rack.

Referring now to Figs. 3 to 5, inclusive, the construction and arrangement of the fixture 36, embodying the features of the present invention, is disclosed in detail and comprises an upstanding substantially cylindrical casing 40 terminating adjacent to the lower portion thereof in a substantially cylindrical downwardly extending projection 4!. The projection 4! is arranged in an opening 221) formed in the central portion of the boss 22a provided in the top wall 22 of the vat l3; and a liquid-tight connection is made between the casing 49 and the adjacent portion of the boss 22a by an arrangement including upper and lower resilient gaskets 42 and 43 surrounding the opening 22b and respectively arranged above and below the boss 22a. Also a metallic pressure ring 44 engages the gasket 43; and the assembly is retained in place by a nut 45 that is threaded upon the exterior surface of the projection 4!. Thus the lower end of the projection M, as well as the nut 45, the pressure ring 44, and the gasket 43 are disposed below the top wall 22 and within the upper portion of the vat I 3.

The casing ta is hollow and is provided with a substantially annular flange 46 adjacent to the upper end thereof that is employed for the purpose of securing in place an associated cap 47 that is provided with a substantially annular flange 48 adjacent to the lower portion thereof. The cap 47 is of hollow construction and is secured in liquid-tight relation to the upper end of the casing 45 by an arrangement including a partition or diaphragm 49 and an associated gasket 55, as well as a plurality of screws 5f extending through openings provided in the flange 48 and threaded into aligned openings provided in the flange 45. More particularly the upper end of the casing 40 provides a substantially flat annular surface 52 that engages and supports the adjacent annular portion of the partition 49; and the lower end of the cap 4"! is provided with a substantially annular shoulder 53 that engages the adjacent gasket 55. Thus it will be understood that the partition 49 divides the interior of the casing and the cap 4! into an upper chamber 54 and a lower chamber 55, the chambers 54 and 55 being disposed primarily respectively within the cap 47 and within the casing 40.

The central portion of partition 45 is upwardly offset, as indicated at 56, and is provided with a centrally disposed hole 51 in which there is located and rigidly secured in place a substantially cylindrical element 58. The element 58 is of one-piece construction and includes an upper nozzle part 5e disposed within the chamber 54 and a lower baflle part as disposed within the chamber 55, the parts 55 and at being secured together by a pair of bridging lugs 61 formed integrally therewith and extending therebetween, whereby the parts 59 and 60 are separated from each other by two opposed slots 62. The nozzle part 59 is hollow and provided with a predetermined internal diameter; and likewise, the baflie part 59 is hollow and provided with a predetermined internal diameter. The internal diameter of the baffle part 60 is somewhat larger than that of the nozzle part 59, for a purpose more fully explained hereinafter.

Also the central portion of the cap 41 comprises a downwardly projecting hollow stud 63 extending into the nozzle part 59 and cooperating therewith to define a substantially cylindrical nozzle passage '64 therebetween that communicates directly with the chamber 54. Further the interior surface of the cap 47 is provided with an annular recess 65 in order to aiford a direct and free communication between the chamber 54 and the nozzle passage 64. A substantially cylindrical hole 66 is formed in the projection 4| and communicates directly between the lower portion of the chamber 55 and the upper portion of the vat I3; and a substantially vertically disposed shaft '6'! is arranged within the casing 40 and projects through the hole 66 into the upper portion of the vat I3. Specifically the upper end of the shaft 6'! is threaded, as indicated at 63, and engages the threaded interior of the hollow stud 63 carried by the cap 41. Thus the shaft 51 is disposed centrally in the cap 41 and the casing 4|) and projects downwardly from the stud 63 through the baffle part '60 in spaced relation therewith and thence through the chamber 55 and the hole 65. The lower end of the shaft 67 is arranged within the upper portion of the vat l3, as previously noted, and has mounted thereupon, a spinner member 69 formed of molded rubber, or the like. The spinner 69 is mounted for rotation on the extreme lower end of the shaft 6'! and comprises a substantially annular body portion 1'0 carrying a plurality of substantially radially disposed and curved blades 7!.

Also the cap 47 is provided with a substantially tubular inlet connection 12 communicating with the chamber 54 and into which one end of the inlet conduit 35 is secured in liquid-tight relation. In a similar manner, the casing 40 is provided with a tubular vent connection 13 communicating with the chamber 55 and supporting the inner end of a vent conduit 14, the outer end of the vent conduit 14 extending laterally over the top wall 22 of the vat l3 and being turned downwardly, as indicated at 15, between the sidewalls i8 and 25 in the dishwashing apparatus ii. The outer downwardly turned end 15 of the vent conduit l4 terminates just below the top wall 22 and communicates directly with the atmosphere. Thus the vent connection 13 provides a vent passage it extending through the vent conduit i l and communicating between the chamber 55 and the atmosphere. The cylindrical nozzle passage 64 is arranged above and in vertical. alignment with the cylindricad opening through the baiiie part 66 through which the shaft ti extends; and also the cylindrical nozzle passage tie is arranged above and in alignment with the hole 6'5 provided in the projection 4|; and the spinner 69 is located directly below the hole 55 and in alignment with the nozzle passage fi l.

In view of the foregoing description of the construction and arrangement of the fixture 36, it will be understood that when the inlet valve mechanism 33 in the dishwashing apparatus l I is operated into its open position that hot water is supplied from the inlet pipe 34 into the inlet conduit 35 under gauge pressure and thence into the communicating chamber 54. The hot water in the chamber 54 passes upwardly and thence downwardly into the cylindrical nozzle passage 64 between the nozzle part 59 and the stud 63; whereby a substantially annular stream of hot water is formed and projected downwardly around the shaft til. The defined stream of hot water passes from the cylindrical nozzle 64 downwardly through the bafile part 60, the chamber 55 and the hole 6'6 into the upper portion of the vat i3, whereupon it impinges upon the spinner 69 causing the spinner 69 to be rotated rapidly. The rotating spinner 69 breaks-up the stream of hot water and spreads it out and projects it in the form of a downwardly and outwardly directed whirling spray into the upper portion of the vat l3 and through the rack arranged in the vat l3 and supporting the dishes that are to be washed. The defined hot water stream projected through the chamber 55 around the shaft passes well inwardly with respect to the inner end of the vent passage '16 in order to prevent the escape of hot water from the chamber 55 through the vent passage 16 and consequently through the vent conduit 14 to the exerior. Also, it will be understood that the defined stream of hot water surrounding the shaft 8? and projected through the hole 66 is efiective substantially to prevent vapor or steam in the vat l3 from escaping upwardly into the chamber 55 and thence into the vent passage 16. Moreover the arrangement of the spinner 69 upon the lower end of the shaft til is useful in limiting the amount of vapor or steam that can escape from the vat [3 into the chamber 55 and thence into the vent passage when the inlet valve mechanism 33 occupies its closed position.

In the operation of the fixture 36, it will be understood that the pressure head in the chamber is converted into a velocity head in the nozzle passage St in a well-known manner, whereby the stream of hot water passing through the baffie part til is well-defined; however, the bairle part he surrounding the stream of hot water intercepts any spread of the stream and prevents the hot water from escaping from the chamber 8 55 into the inner end of the vent passage 16 and consequently into the vent conduit 14.

Further considering the operation of the fixture and assuming that the abnormal condition of the subatmospheric pressure appears in the inlet conduit 35, the subatmospheric pressure appears in the chamber 54 causing a backsuction through the nozzle passage 64 from the chamber 55. However, no substantial vacuum is drawn in the chamber 55 since the vent passage 56 is of ample cross-section and communicates directly via the vent conduit 14 with the atmosphere, whereby air is drawn into the vent conduit M and passes via the vent passage 16 into the chamber 55. The air thus delivered into the chamber 55 passes both through the space between the bafile part 60 and the shaft 81 and through the slots 32 directly into the nozzle passage 64 and thence into the chamber 54 and consequently into the inlet conduit 35, thereby substantially relieving the subatmospheric pressure therein. In any case, this venting of the chamber 55 via the vent passage 18 prevents any material back-siphoning through the hole 66, thereby positively eliminating the possibility of back-siphoning of hot water from the upper portion of the vat it into the inlet conduit 35 and thence through the connected hot water tank into the city water mains.

In the construction of the fixture 36, the vertical distance between the lower end of the nozzle part tit and the lower portion of the vent passage it at the inner end Of the vent conduit i4 must be at least 1 in order to comply with the usual city plumbing code requirements. Since the vertical distance between the top walls i l and Z2 is quite limited, the fixture 36 must be of compact construction, and in order to obtain the vertical distance of 1 previously noted, the partition 49 is upwardly directed, as indicated at b6, adjacent to the central portion thereof, as previously noted; and the slots 62 are provided between the nozzle part 59 and the baffle part 60.

In view of the foregoing description of the construction of the fixture 36, it will be understood that the cap H may be readily placed and removed with respect to the casing by proper manipulation of the screws 5|, the inlet conduit 525 being formed of copper or other flexible material to permit the relative movements required. Also the casing it may be readily placed and removed with respect to the opening 22?; formed in the top wall 22 by proper manipulation of the nut and the spinner 69 may be readily placed and removed with respect to the lower end of the shaft 61. Ai'ter the cap l has been removed irom the casing it, the partition or diaphragm it may be readily placed and removed with respect to the upper end 52 of the casing 46. Preferably the metal parts of the fixture 36, including the casing it, the cap 4?, the nut 45, the vent conduit 74, the partition 19, the element and the screws 5! are formed of copper or brass or other copper alloys; while the shaft 6 may be formed of a noncorrosive alloy of steel.

Referring now to Figs. 6 to 8, inclusive, the modified form of the fixture I36 there illustrated, and embodying the features of the present invention, comprises an upstanding substantially cylindrical casing Mil terminating adjacent to the lower portion thereof in a substantially cylindrical downwardly extending projection MI. The projection l li is arranged in the opening formed in the central portion or the boss 22a provided in the top wall 22 of the vat I3; and a liquid-tight connection is made between the casing I46 and the adjacent portion of the boss 22a by an arrangement including upper and lower resilient gaskets I42 and I43 surrounding the opening 221; and respectively arranged above and below the boss 22a. Also a metallic pressure ring I44 engages the gasket I43; and the assembly is retained in place by a nut I45 that is threaded upon the exterior surface of the projection I4 I. Thus the lower end of the projection I4I, as well as the nut I45, the pressure ring I44 and the gasket I43 are disposed below the top wall 22 and within the upper portion of the vat I 3.

The casing I40 is hollow and provided with a substantially annular flange I46 adjacent to the upper end thereof that is employed for the purpose of securing in place an associated cap I 41 that is provided with a substantially annular flange I48 adjacent to the lower portion thereof.

The cap I41 is of hollow construction and is secured in liquid-tight relation to the upper end of the casing I46 by an arrangement including a partition or diaphragm I49 and an associated gasket I50, as well as a plurality of screws I extending through openings provided in the flange I46 and threaded into aligned openings provided in the flange I46. More particularly, the upper end of the casing I46 provides a substantially fiat annular surface I52 that directly engages and supports the adjacent annular portion of the partition I49; and the gasket I56 is arranged directly between the annular portion of the partition I43 and the marginal flange I48 provided on the cap I41. Thus it will be understood that the partition I49 divides the interior of the casing I46 and the cap I41 into an upper chamber I54 and a lower chamber I55, the chambers I54 and I 55 being disposed primarily respectively within the cap H41 and within the casing I46. The central portion of the partition I43 is upwardly offset, as indicated at I56, and terminates in an upwardly directed tube I51 extending well into the chamber I54 and disposed in vertical alignment with respect to a hole 58 formed in the projection MI and communieating between the chamber I55 and the upper portion of the vat I3. A stream-forming element 559 is arranged in the tube I51 and provides a communication between the chambers I54 and I55.

The cap I 41 is provided with an inlet connection terminating the inlet conduit 35; and the casing I46 is provided with a vent connection I66 affording a vent pasage IBI and supporting a vent conduit I62 so that the vent passage I6I communicates between the chamber I55 and the atmosphere. Finally the nut I45 carries a substantially annular deflector I63 disposed therebelow and connected thereto by a pair of spacedapart arms I64. Preferably the nut I45, the deflector I66 and the arms I64 are formed of one-piece construction, whereby a pair of oppositely directed exit slots I65 are provided adjacent to the opposite sides of the deflector I63.

The operation of the fixture I36 is substantially identical to that of the fixture 36, previously described; and it will be understood that the hot water that is supplied via the inlet conduit 35 into the chamber I54 is projected by the stream-forming element I56 through the tube 571 in a well-defined stream and thence through the chamber I55 and the hole I58 into the upper portion of the vat I3. The defined stream of hot water impinges on the deflector I63 and is spread or broken up and delivered into the upper portion of the vat I3 through the exit slots I65. The defined stream of hot water that is projected through the central portion of the chamber I55 is spaced well inwardly with respect to the inner end of the vent passage I6I in order to prevent the escape of hot water from the chamber I55 through the vent passage I6I. In this construction of the fixture I36, the deflector I63 not only spreads the stream of hot water and delivers it into the upper portion of the vat I3 through the exit slots I65, but it also assists in partially blocking the lower end of the hole I58 in order to prevent the entrance of vapor or steam from the vat I3 back into the chamber I55 and consequently into the vent passage I6I and thence to the atmosphere.

In this form of the fixture I36, it will be understood that in the event of a subatmospheric pressure in the inlet conduit 35, a back-suction will take place through tube I51 between the chambers I55 and I54; however, air is supplied into the chamber I55 via the vent passage I6I and the vent conduit I62 so as to prevent any material back-siphoning of the wash liquid from the upper portion of the vat I3 through. the exit slots I65 defined between the nut I45 and the deflector I63; all for the purpose previously explained.

Referring now to Figs. 9 and 10, the other modified form of the fixture 236 there illustrated, and embodying the features of the present invention, comprises an upstanding substantially cylindrical casing 24!! terminating adjacent to the lower portion thereof in a substantially cylindrical downwardly extending projection 24 I. The projection MI is arranged in thev opening 22b formed in the central portion of the boss 22a provided in the top wall 22 of the vat I3; and a liquid-tight connection is made between the casing 246 and the adjacent portion of the boss 22a by an arrangement including upper and lower resilient gaskets 242 and 243 surrounding the opening 22b and respectivel arranged above and below the boss 22a. Also a metallic pressure ring 244 engages the gasket 243; end the assembly is retained in place by a nut 245 that is threaded upon the exterior surface of the projection 24I. Thus the lower end of the projection 2 4I, as well as the nut 245, the pressure ring 244 and the gasket 243 are disposed below the top wall 22 and within the upper portion of the vat I 3.

The casing 240 is hollow and is threaded adjacent to the upper end thereof in order to receive the threaded lower annular flange 246 of an associated hollow cap 241. The upper end of the casing 246 terminates in a substantially annular shoulder 248 that engages and supports the associated annular portion of a partition or diaphragm 249. Specifically the annular por-- tion of the partition 249 is clamped between the shoulder 248 on the casing 240 and an associated annular shoulder 256 provided on the cap 241, a resilient gasket 25I being disposed between the annular portion of the partition E49 and the shoulder 256. The partition 246 divides the interior of the casing 246 and the cap 241 into an upper chamber 254 and a lower chamber 255, the chambers 254 and 255 being disposed primarily respectively within the cap 24? and within the casing 246. The central portion of the partition 249 is upwardly offset into the chamber 254 and is provided with a hole 256 therein that is arranged in alignment with a hole 25'! formed in the lower end of the projection 2M, the hole communicating between the chambers 25!! and the hole 25! communicating between the chamber 255 and the upper portion of the Vet it.

A substantially centrally disposed hollow stud 25% is carried by the cap 25! and projects downwardly into the hole 256 in order to define a substantially annular nozzle passage 259 therebetween and communicrting between the chambers 25d and 255. Further the nut M5 carries a substantially annular deflector 263 disposed therebelow and connected thereto by a pair of spacedapart arms 26 i. Preferably the not 245, the defiector 263. and the arms 264 are formed of onepiece construction, whereby a pair of oppositely directed exit slots 265 are provided adjacent to the opposite sides of the deflector 253.

Further the fixture. 235 comprises a substantially annular upwardly and outwardly directe battle 265 surrounding the projection E li and engaging the slzet 242. Specifically the inner an nular portion of the bafile 256 is clamped between a shoulder provided on the lower end of the casing and the gasket 2 12, the compression being provided between the shoulder 25'! by the nut 245 threaded upon the lower end of the projection 24!. Also the fixture comprises a pair of concentric and nested baffles 2G6 and its secured to annular flange 2'68 provided on the lower end of the-cap M? by a plurality of screws Zl'l. The baffles 268 and are arranged in surrounding relation with the casing 24%! and extend downwardly into cooperative relation with respect to the beflle 256 in orde to provide two substantially concentric annular spaces 2'52 and 2'53 surrounding the casing 248. A plurality of radially spaced-apart vent passages 21s are formed in the body of the casing 2 3%! and communicatedirectly with the annular space 2'52. Accordingly the baiiles 265, 2d? and 26S cooperate with each other to define the annular spaces 2E2 and 213 surrounding the casing 243 and providing a protected communication between the vent passages 2M and the atmosphere. Finally upstanding substantially cylindrical reticulated screen 275 is arranged in the annular space 2'52 in surrounding relation with respect to the casing 212- 3, whereby the arrangement of the baffles 25%, 258 and 269 and the screen 215 positively protect the vent passages 2M against the entry of foreign material and dust into the chamber 255 in the event of the abnormal condition of a subatmospheric pressure within the chamber 254. Finally the cap 24? is provided with an inlet connection 215 that communicates with the inlet conduit so that hot water may be supplied to the chamber 25 5.

The operation of the fixture 23B is substantially identical to that of the fixture 35 previously described; and it will be understood that the hot wster that is supplied via the inlet conduit 35 into the chamber 254 is projected by the nozzle arrangement through the nozzle passage 259 in a we1l-defined stream and thence through the chamber 255 and the hole 25's into the upper portion of the vet IS. The defined stream or hot water impinges on the deflector 251i and is spread or broken-up and delivered into the upper portion of the vet is through the exit slots 255. The defined stream of hot water that is projected through the central portion of the chamber 255 is spaced well inwardly with respect to the inner ends of the vent passages 274 in order to prevent nor arrang ment.

the escape of the hot water from the chamber 255 and the vent passages 214 to the atmosphere. In this construction ofthe fixture 235, the defiector 263 not only spreads the stream of hot water and delivers it into the pper portion of the vat 13 through the exit slots 255, but it also assists in partially blocking the lower end of hole 25'! in order to prevent the entrance of vapor or steam from the vet it back into the chamber 255 and consequently into the vent passages 2'54 and thence to the atmosphere.

In this form ofthe fixture 235, it will be understood that in the event of a subatmospheric pressure in the inlet conduit 35, a back-suction will take place through the nozzl passage 25%! between the' chamber 25 and however, air is supplied into the chamber 255 via the vent passages 214 so as to prevent any material backsiphoning of the wash liquid from the upper portion of the vat it through the exit slots 265 defined between th nut 2&5 and the deflector 263, all for the purpose previously explained.

Also in this form of the fixture 2'56, a groove 2% is formed the bottom of each of the vent passages 2M and communicating with the adjacent annular portion of the bathe so that any liquid that might accumulate in the dish-iii: bailie as a consequence of the condensation of vapor therein may b returned back into the vat 13 via the hole 25?. Also the central portion of the stud 258 depending from the cap 24'? is threaded, as indicated 253', so that the fixture 235 may be converted, if desired, from the arrangement including the deflector 253 to a spin- In other words, the deflector arrangement 2E3 employed in the fixture 23% is identical to the deflector arrangement its employed in the fixture 36; and for this arrangement, the spinner arrangement $5 of th fixture may be readily substituted. Thus the fixture 233 may comprise either the deflector arrangement of the fixture 136 or U118 spinner arrangement of the fixtur 355 for the purpose of breaking up and spreading out the defined stream in the upper portion of the vat 23.

In view of the foregoing, it is apparent that there ha been provided in dishwashlng apparatus, including a vat, an improved combination liquid inlet and anti-back-siphoning fixture, whereby hot water may be readily delivered into the upper portion of the vat without any danger of back-siphoning in the event of the abnormal condition of a subatmospheric pressure in the hot water inlet conduit.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in th appended claim all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In combination with a liquid receiving vat or the like provided with wall structure having an opening therein disposed above the normal liquid level in said vat, a liquid supply fixture comprising a hollow casing secured in liquid-tight relation with said wall structure about said opening, a partition arranged in said casing and defining first and second chambers therein, said casing having a first hole therein communicating with said second chamber and through said opening with the interior of said vat, said partition having a second hole therein communicating between said first and second chambers, said first and second holes being substantially aligned with respect to each other, a shaft carried by said casing and projecting through said first and secnd chambers and through said second and first holes and through said opening into said vat, an inlet conduit communicating with said first chamber for normally supplying liquid under gauge pressure thereinto, a substantially cylindrical nozzle arranged in said second hole and supported by said partition and surrounding said shaft for projecting liquid from said first chamher in a defined stream along said shaft through said second chamber and said first hole and said opening into the interior of said vat, said casing having a vent passage therein communicating between said second chamber and the atmosphere in order to supply air into said inlet conduit in the event of the abnormal condition of a subatmospheric pressure therein so as positively to prevent back-siphoning of liquid from the interior of said vat into said inlet conduit, said nozzle projecting the liquid stream along said shaft through said second chamber in spaced relation with respect to the inner end of said vent passage in order to prevent the escape of liquid from said second chamber into said vent passage, and a member carried by the inner end of said shaft and arranged within said vat and positioned in the path of the liquid stream for deflecting the liquid from the liquid stream and for spreading the liquid through the interior of said vat.

2. The combination set forth in claim 1, wherein said member is in the form of a spinner mounted for rotation on the inner end of said shaft and rotated by the force of the liquid stream impinging thereupon.

3. The combination set forth in claim 1, and further comprising a baflle arranged in said second chamber between the liquid stream and the inner end of said vent passage for positively pre- 14 venting the escape of liquid from said second chamber into said vent passage.

4. The combination set forth in claim 1, and further comprising a substantially cylindrical baiiie carried by said partition and dis-posed in said second chamber and aligned with said nozzle and surrounding the liquid stream for positively preventing the escape of liquid from said second chamber into said vent passage.

5. The combination set forth in claim 4, wherein said nozzle and said bafiile are formed of onepiece construction and the inner diameter of said bafiie is somewhat greater than the inner diameter of said nozzle, and wherein a slot is provided in said construction between said nozzle and said baflie to provide a communication with said second chamber between said nozzle and said battle.

6. The combination set forth in claim 1, wherein said hollow casing terminates in a projection arranged in said opening, and further comprises an element carried upon the inner end of said projection within said vat and engaging the adjacent portion of said wall structure for supporting said casing upon said wall structure and for securing said projection in liquid-tight relation with said wall structure.

'7. The combination set forth in claim 1, wherein the vertical distance between the lower end of said nozzle and the botom of said vent passage is at least 1".

FRANK D. LOW.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,469,625 Dodge Oct, 2, 1923 2,212,559 Ehret Aug. 27, 1940 2,250,974 Stoddard July 29, 1941 2,361,694 Langdon Oct. 31, 1944 2,405,639 Boosey Aug. 13, 1946

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