US2250974A - Washing apparatus - Google Patents

Description

E. s. STODDARD WASHING APPARATUS July 29, 1941.

Filed Aug. 2, 1940 Fig. I.

Edgar S. Stoddard, b 7W 6. .19

H i-I s Attorney.

Patented July 29, 1941 WASHING APPARATUS Edgar S. Stoddard, Berwyn. 11L, assignor to Edison General Electric Appliance Company, Inc., a corporation of New York Application August 2, i940, Serial No. 349,670

8 Claims.

This invention relates to washing apparatus and particularly to dishwashing machines and has for its primary object the provision of new.

and improved means for preventing washing fluid within the tank of the washing machine from being drawn into or forced into the fluid supply piping 'and thereby causing contamination of the fluid supply system to which the supply piping is connected.

While this invention is to be particularly described as applied to a dishwashing machine, it-

is to be understood that it is not limited thereto since it has a more general application and may be used with other types of washing apparatus which are adapted to be connected to municipal water supply systems.

In most parts of the country health authorities have established specific regulations covering the connection of any washing apparatus to the main water supply system of the municipality. Many of these regulations'have been drafted with a view to preventing the contamination of the water supply system by the so-called back siphoning efl'ect. Such back siphoning can occur in those instances where the fluid inlet of a particular washing apparatus is or can be, by the stoppage of a drain, submerged by the wash water within the washing apparatus. With such fluid inlet arrangements, the occurrence 01' a partial vacuum in the water supply system as, for example, might be produced by a large suction pressure being placed on the system near the washing apparatus, causes the washwater in the apparatus to be drawn into the fluid supply-piping and into the system as a whole, thereby causing contamination of the system. The same result might also be produced it a sufllcient head pressure were built up in the washing apparatus so as to force some or the water back into the fluid supply.

In accordance with my invention, I have proapparatus due to either or these conditions. In accordance with the specific embodiment of my invention'more fully described hereinafter, I'have provided a fluid supply pipe which lies entirely outside of the washing tank. Provided in this mounted so that the end oi the fluid supp y 'vided improved means for preventing the possible j contamination of the fluid supply to a washing pipe can never be submerged by water backing up 'in the inlet casting. In order to prevent vapors which are formed upon the passage of the fluid through the air gap from accumulating in the casing of the washing apparatus and thereby causing rusting and deterioration or the parts enclosed in the casing, I have provided means for increasingthe velocity of the fluid as it passes through the air gap whereby any vapors formed will be drawn into the inlet casting and then into the tank of the washing apparatus.

For a more complete understanding of my invention reference should be had to the accompanying drawing in which Fig. 1 is a side elevation of a washing machine showing my improved fluid inlet means applied thereto; Fig. 2 is a rear elevation of the machine shownin Fig. 1 showing additional details of my improved fluid inlet construction; Fig. 3 is a vertical section taken on the line 33 of Fig. 2, looking in the direction of'the arrows, showing details 01' my newand improved fluid inlet means; Fig. 4 is a side view partly in section of the arrangement shown in Fig, 3; Fig. -5 is a sectional view taken Referring to the drawing and particularly Figs. 1 and 2, it will' be observed that I have shown my invention as applied to a dishwashing machine having a tank or tub III, a cover II, a fluid inlet connection I 2, a drain pipe l3 and motor means ll for operating the washing apparatus Ila mounted within the tank. All of these devices, except, of course, thecover, will be enclosed by a suitable casing: (not shown). As these devices per se form no part of this invention, no further description of them is deemed necessary. Moreover, it is to be understood that while my invention is to be specifically described as it is applied toa dishwashing apparatus it is not limited thereto since it may be applied to anyv permanently connected type 01' washing apparatus, such as clothes washing apparatus or sinks, wherein the problem oi back siphonage is preseat.

In and a control valve I! which may be of the for controlling the supply-oi,-

The control. valve may be operated by suitable means it;

hand operated type water to the washing apparatus.

mounted on the side of the tank 10 and I paratus flared opening a suitable knob ll which is adapted to lie outside the apparatus casing (not shown).

Connected to the valve I5 is an inlet manifold I! which is secured to the bottom of the tub ll by means of the blanked-off flanged T-connection i9. This inlet manifold l8 has a portion projecting beyond the support I9 and directly connected to this portion by means of a coupling 20 is a suitable length of supply tubing which extends outwardly to the back of the washing apand then upwardly as shown in Fig. 2. This inlet tubing 2| is preferably of brass so that it can be readily bent into the U-shaped.

form shown in Fig. 2.

' The tubing 2| is, of course, adapted to be connected to a suitable inlet opening 2la provided in the tub It. In the particular apparatus illustrated, the inlet opening is located in the rear wall of the tub near the bottom thereof. Any washing apparatus in which the overflow level of the apparatus lies above the water inlet to the tub or lies above any portion of the inlet piping lying within the tub is considered by the health authorities as a submerged inlet type of apparatus. Since in the construction illustrated the tub It) has no openings of adequate size below the top rim thereof to take care of overflow in the event of stoppage of the drain I 3, the top rim of the tank is considered the overflow level. Since the inlet opening 2la lies below this level, the apparatus is considered a submerged inlet type of apparatus even though in the normal operation of the apparatus the inlet 2|u lies above the normal water level within the tub or I tank. If the fluid inlet tube 2i were directly connected to the fluid inlet opening 2la in the tub and this opening became submerged through the stoppage of the drain, then during the time that the fluid supply valve is actually open or in a leaking condition it would be possible to have some of the wash water drawn or forced into the fluid supply pipe in the event that a partial vacuum were created in the supply line or a positive pressure applied to the washing water. within the tank. This forcing of wash water back into the fluid supply line would, of course, cause a contamination of .the supply system as a whole. In order to prevent contamination of the fluid supply system from such a source I have provided, in accordance with my invention, improved means for connecting the fluid inlet tube 2| to an adequate air gap between the two portions of the supply line to the tub Ill and also to insure that the discharge opening will lie above the overflow level of the flared opening 25 so that it cannot be submerged in the event that wash water backs up in the inlet casting 22 due to an abnormal rise in the level of the water in the tub III, as through the stoppage of the drain opening it.

In order to insure the proper positioning of the discharge end of the tubing 2| relative to the flared opening 25 of the inlet casting, a spacing and supporting bracket is provided at the upper end of the casting 22. As shown in Figs. 3 and 4, this bracket comprises a flange 25, a pair of upwardly extending leg members 21 and a discharge block 28 all formed as an integral unit and preferably cast on the upper end of the inlet casting as shown. Provided at the upper end of the discharge block 28 is a threaded portion 29 to which thetubing 2| is adapted to be connected by means of a suitable coupling 80. Centrally located in the block 28'is a vertically extending discharge passageway 3|. The legs 21 are sufficiently long to prevent submersion of the discharge end of the passageway 3| under the conditions previously described and the space between the legs 21 insures the formation of a proper air gap between the tubing 2| and the flared opening 25.

Due to the fact that some expansion takes place when the water issues from the discharge passageway into the air gap, some steam or water vapor frequently is formed at this point. As previously described, the entire apparatus shown in Figs. 1 and 2, except for the cover, is adapted to be enclosed by a suitable casing (not shown). The collection of such steam or water vapor in the apparatus casing would, of course, have a deleterious effect on all of the apparatus mounted in the casing. I have therefore provided in accordance with my invention improved means for the inlet opening 2|a of the tub l0. By my improved means an air gap is formed in the fluid insure a fluid-tight connection. This inlet casting is mounted so that it extends substantially vertically upward at the rear of the tub. III and formed in the upper end thereof is a flared opening 25. The inlet tubing 2i, as previously described, also extends up the back wall of the tub ill and it is given a U-shape so that the discharge end thereof lies above the flared opening 25 of the inlet casting. The discharge end of the supply tubing 2| is spaced sufficiently far above the 25 of the inlet casting to insure in: undue insuring that substantially all steam '01" water... vapor formed at the air gap will be drawn into.

the opening 25 of the drain casting 22 and thence into the tank III. To effect this result, I have provided an oriflce 32 in the lower end of the passageway 3|. In the specific embodiment of my invention illustrated the oriflce 32 has a diameter of about of an inch. As the supply fluid passes through this oriflce its velocity is increased and this increase in velocity causes the formation of a slightly reduced pressure at the air gap and particularly at the flared opening 25 of the casting 22. Through the formation of this reduced pressure area, any vapors formed upon the discharge of the supply fluid through the air gap will be'drawn into the drain casting and thence into the tank Ill so that the surrounding apparatus is maintained relatively free from condensate from this source.

The particular washing apparatus illustrated in Figs. 1 and 2 is of the impeller type, that is, the wash water brought in through the fluid inlet is sprayed on the articles to be washed by the motor driven fan-like impeller Ila mounted in the bottom of the tub. The eflectiveness of such a spray, of course, depends upon reaching all points in the washing chamber with a substantial spray. If the inlet casting 22 is large throughoutits vertical length, the impeller will tend to blow steam and spray out the opening 25. .In order to prevent this and also avoid creatfrictional resistance to the incoming water, the inlet casting 22 is provided with athroat 33 which is slightly larger than the. oriflce 32. This throat is large enough to permit the free entrance of supply water and the production of a slightly reduced pressure in the flared inlet 25 but is small enough and far enough from the tub entrance to prevent the exit of steam and spray through the throat-during the washing operation. Of course, if some other type of washing apparatus were employed, the throat 33 would be'eliminated and the casting 22 made in the form of a straight-sided pipe with no flare at the opening 25.

From the foregoing detailed description it is believed that the manner in which my improved supply means prevents the contamination of a fluid supply system is apparent. It is to be paring a washing fluid having a fluid inlet lying below the overflow level of said tank, a fluid inlet member connected to said fluid inlet and extending substantially vertically upward outside of said tank, a water inlet tube mounted on said tank so as to have the discharge .end thereof lie above said fluid inlet member, a discharge member secured to said discharge end of said tube, and a bracket formed on said discharge member having a pair of leg members secured to the upper end of said fluid inlet member for spacing the discharge end of said discharge member from the upper end of said fluid inlet member so that an air gap is formed therebetween and so that said discharge end lies above the overflow level of said inlet member.

I 3. In a washing apparatus, a washing tank, a fluid inlet in said tank, an inlet casting connected to said fluid inlet, a fluid inlet tube se- It is also to be particularly observed that I have provided improved means whereby the fluid supply iine for a dishwashing apparatus lies entirely outside of the washing tank. This is desirable in that the possibility of corrosion of supply pipes by the solutions in the tank is eliminated and another source of contamination through the leaking. of a corroded submerged supply pipe is removed. i

Moreover, it will be observed that my improved means is particularly constructed and arranged so as to insure that substantially all of the vapors forming at the atmospheric opening in the supply line will be drawn directly into the tub of the washing apparatus and to insure that all the vapors collecting in the tub are retained there, whereby mating and. deterioration of the remainder of the washing equipment by these vaporsisprevented.

While I have described and shown a particu lar embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made,

and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spiritand scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a washing apparatus, a tank for receiving a washing fluid having a fluid inletlying below the overflow level of said tank, a fluid inlet'member connected to saidfluid inlet and lying outside of said tank, a fluid inlet tube secured to the bottom of said tank and extending upwardly outside of said tank so as to lie above said member, means for spacing the discharge end of said tubing above said member so as to form an air gap in the fluid supply line of said tank so that back-siphoning offluid from said tank into said fluid inlet tubeupon the submergence of said fluid inlet and the formation of a partial vacuum in said fluid inlet .tube is prevented, and means in said fluid inlet member defining a throat section forsubstantially preventing the egress of steam or spray from said tank through said inlet member to said air gap during operation of said washing apparatus.

2. In a washing apparatus, a tank for receivcured to said tank and extending upwardly outside of said tank so that the discharge end thereof lies above said casting, a flared openingin the upper end of said casting, and a pair of leg members projecting upwardly from said flared opening and secured to said fluid inlet tube-for spacing the discharge end of said tube from the flared end of said casting so that an air gap is formed therebetween and so that said discharge end lies above the overflow levelof said flared end of said-casting.

4. In a washing apparatus, a tank for receiving the washing fluid having a fluid inlet lying below the overflow level of said tank, a fluid in let casting connected to said fluid inlet and extending substantially vertically upward outside of said tank, a flared opening in the upper end of said casting, a water inlet tube mounted on the .exterior of saidtank so as to have the discharge end thereof lie over said flared end of said casting, a discharge member secured to said discharge and 0f;said tube, bracket means supporting said discharge member-and secured to saidflared opening for spacing the end-of said discharge member from the flared end of said inlet casting so that an air gap is formed there-.

said fluid inlet casting deflning a throat section for substantially preventing the egress of steam oispray from said tank through said inlet casting to said air gap during, the operation of said washing apparatus.

,5. In a dishwashing machine, a tank for receiving a washing fluid, an inlet for said washing fluid lying below the overflow level of said tank when said tank is in use, fluid supply means connected to said inlet, means forming an air gap in. said fluid supply means, and nozzlemeans in said fluid supply means above said air gap for producing a reduced pressure at said air gap so that v pors formed by the passage of through d air gap are drawn into said 8 .-In a washing apparatus, a washing tank havging a submerged type 'fluid inlet, a supply casting having a flared open end secured to said fluid mlet, a fluid supply system, a tube connected to said fluid supply means and having its end terminating above said flared opening of said supply casting so that an air gap is formed in said supply line, and a nozzle in the end of said tube for increasing the velocity of the fluid as it issues from said tube into said drain casting, said increased velocity of water producing a reduced pressure at said air gap so that vapors released by the discharge of said fluid through said air gap will be drawn into said inlet casting and hence into said tank.

'7. In a dishwashing machine, a tank for receiving a washing fluid and the objects to be washed, an inlet for said washing fluid lying below the overflow level or washing fluid in said tank during a washing operation, an inlet casting secured to said fluid inlet so as to pro- :Iect upwardly outside of said tank, a flared opening at the upper end of said inlet casting, a fluid supply tube adapted to be connected to a fluid supply system, means for supporting said fluid supply-tube outside of said tank, said fluid supply tube having its discharge end spaced from said flared opening in said inlet casting so that an air gap is formed in the fluid supply line of said tank whereby the contamination or the fluid supplysystem to which said supply tube is connected due to the back siphoning of wash water in said tank through said fluid inlet is prevented, means for spacing said discharge end of said tubing from said flared end of said inlet casting so that said discharge end lies above the overflow level of said flared casting, and a nozzle in said discharge end 01- said tubing for increasing the velocity of said fluid as it isdischarged from said end into said flared end of said casting, said increased velocity producing a reduced pressure by which vapors released by the discharge of said fluid into said air gap are drawn into said casting and then into said tank.

8. In a dishwashing machine, a tank for receiving a washing fluid having a fluid inlet lying below the overflow level of said tank, a fluid inlet casting connected to said fluid inlet and lying outside of said tank, a fluid inlet tube secured to the bottom 0! said tank and extending upwardly outside of said tank so as to lie above said casting, means for spacing the discharge end of said tubing above said casting so as to iorm an air gap in the fluid supply line of said tank, means for increasing the velocity of said water as it is discharged from the discharge end of said supply tubing into said casting so that vapors released upon the passage of-said fluid through said air gap are drawn into said inlet casting and then into said .tank, and means in said fluid inlet casting defining a throat section for substantially preventing the egress of steam or spray from said tank through said inlet casting to said air gap when no fluid is being supplied to said tank and said machine is being operated for a washing operation. g

EDGAR S. BTODDARD.

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