US3026046A

US3026046A - Dish washing machine spray impeller head

Info

Publication number: US3026046A
Application number: US810883A
Authority: US
Inventors: Wickham Alfred Henry; Gilson Robert John
Original assignee: Charles Colston Ltd
Current assignee: Charles Colston Ltd
Priority date: 1955-12-23
Filing date: 1959-05-04
Publication date: 1962-03-20
Anticipated expiration: 1979-03-20
Also published as: NL213019A; BE553453A; GB832756A; CH349044A; NL99641C; DE1114011B

Description

March 20, 1962 A. H. WICKHAM ETAL 3,026,046

DISH WASHING MACHINE SPRAY IMPELLER HEAD Filed May 4, 1959 3 Sheets-Sheet 1 22 f A a Q :2 w /7 i i'iiv i' "'W 23 W 1) 2/ 5 I P am FIG. 6.

March 20,1962 w M AL 3,026,046

DISH WASHING MACHINE SPRAY IMPELLER HEAD 3 Sheets-Sheet 2 ddwm Filed May 4, 1959 March 20, 1962 H, WICKHAM TAL 3,026,046

DISH WASHING MACHINE SPRAY IMPELLEZR HEAD 3 Sheets-Sheet 5 Filed May 4 1959 nited States atent @fifice 3,026,046 Patented Mar. 20,1982

3,026,046 DISH WASHING MACHINE SPRAY IMPELLER HEAD Alfred Henry Wickham, Pontyclnn, Glamorgan, Wales,

and Robert John Gilson, New Malden, England, assignors to Charles Colston Limited, London, England,

a corporation of Great Britain Filed May 4, 1959, Ser. No. 810,883

Claims priority, application Great Britain Dec. 23, 1955 4 Claims. (Cl. 239-223) This invention relates to liquid impelling apparatus for dish washing machines comprising a washing chamber having a rotating Water impeller arranged to spray washing liquid over soiled dishes etc., placed in racks in the chamber. This application is a continuation-in-part of our co-pending US. application Serial No. 629,124, filed December 18, 1956, now abandoned.

It is known to use a rotating horizontal impeller in the form of a cylinder provided with blades or paddles adapted to scoop or receive water out of a sump at the bottom of the washing chamber and to throw it in an upward direction to impinge on the soiled dishes, but in such an arrangement it is found that an undesirably large proportion of the driving motor energy is dissipated in churning or threshing the water in the sump, and furthermore some of the available kinetic energy in the useful water discharge from the impeller is dissipated in overcoming the force of gravity before reaching the soiled dishes. A further disadvantage is the difficulty of separating e.g. by filtration any solid particles from the soil removed from the dishes, with the result that such particles tend to be redeposited on the washed dishes.

t is also known to use a rotatable horizontal spray tube mounted approximately central of the washing chamber and supplied with water under pressure from a separate pump, but in this arrangement it is usual to use the reaction of some of the issuing water spray jets to impart rotation to the spray tube and thus distribute said spray uniformly over the soiled dishes etc. A disadvantage of this arrangement is that some of the kinetic energy imparted to the water by the pump is dissipated in rotating the spray tube and consequently the washing action is correspondingly reduced. It is also found that solid particles of soil tend to be re-deposited on the washed dishes.

It is an object of the present invention to provide a liquid spraying system or apparatus in which undesirable energy losses are avoided so that the greatest possible proportion of the mechanical energy supplied by the driving motor is converted into kinetic energy in the jets of liquid striking the soiled dishes etc.

It is a further object of the invention to provide an improved design of impeller capable of discharging jets of liquid all around its swept periphery at an angle other than radial and in the direction of rotation.

The liquid impelling apparatus of this invention is characterised in that it comprises a revolving spray impeller head having jet orifices for the discharge of the washing liquid, which jet orifices are at an angle other than radial and face in the direction of rotation of the impeller or spray impeller head, means being provided within the interior of the impeller to constrain the mass of liquid therein to revolve bodily with it whereby the effective velocity of the jets will be equal to the vector sum of the emergent velocity due to impressed centrifugal head plus-the bodily rotational velocity of the nozzles.

In operation the water delivered by a feed pump emerges from a feed pipe at a rate suflicient to maintain the interior of the impeller full or nearly full. This contained mass of water inside the impeller is forced to rotate bodily with it by means of non-circular surfaces or axially extending ribs on its interior surface and is, therefore, subject to centrifugal force which causes it to issue from the orifices in the form of jets.

The volume of Water thus discharged by the revolving impeller is determined by its peripheral velocity, the total nozzle area and the radial depth of the mass of contained water and in practice these are so adjusted that the rate of discharge from the impeller is equal to the rate at which water is supplied by the feed pump.

The impeller is preferably of substantially tubular form and has an axial length several times greater than its diameter and approximating to one of the internal dimensions of the washing chamber and may conveniently have its axis horizontal and parallel to the side walls of the washing chamber. The inside of the impeller is provided with axially extending ribs, lobes or like non-circular features forming passages for the liquid, which terminate in jet orifices so spaced as to cover substantially the whole axial length of the impeller. Alternatively the internal liquid passages may be so shaped as to form converging nozzles adapted to discharge liquid jets in the direction of rotation of the impeller and approximately tangentially to its swept periphery.

The impeller is preferably mounted to rotate on bearings carried by a stationary support tube having perforated walls through which liquid is supplied to the inside of the impeller by operation of the feed pump. The impeller may be driven by a spindle passing through the support tube and having a pulley attached to its outer end, this pulley being driven by a driving belt which also engages a pulley on the pump spindle.

A heater may be fitted in the sump to heat the washing liquid, and ancillary control devices such as valves, timing gear and additive dispensers may be fitted so as to provide a fully automatic cycle of operation.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a diagrammatic sectional elevation showing a washing machine fitted with an impeller in accordance with the invention.

FIGURE 2 is a cross sectional view of the impeller or spray impeller head.

FIGURE 3 is a longitudinal sectional view on the line III-III of FIGURE 2.

FIGURE 4 is an end elevation in the direction of the arrow A in FIGURE 5 of a further embodiment of the impeller made, for example of pressed sheet steel.

FIGURE 5 is a longitudinal part sectional view of the impeller of FIGURE 4.

FIGURE 6 is a diagram showing the arrangement of the drive for the pump and impeller.

FIGURE 7 is a sectional end elevation showing a modified impeller.

Referring to FIGURES 1 and'2 there is metal cabinet of a washing machine having a washing chamber, which is approximately cubical in shapeand includes side walls I, an end or rear wall 2 and a top wall 3, access to the interior or washing chamber indicated at 4 being by means of a full Width front opening door 5 which is mounted to hinge, preferably as shown, about a horizontal axis 6, so that when open it assumes a horizontal position thus providing a convenient shelf for supporting crockery or the like.

A cylindrical impeller or spray impeller head 10, which in the embodiment shown in FIGURES 2 and 3 may consist of a plastic moulding, is mounted to rotate about a horizontal axis being supported at'one end upon hearing 11 carried by a tube 12, the tube 12 in turn being secured by means of a flange 13 at one end thereof to the rear outer wall of the dish washing machine casing.

It will be seen that the tube 12 serves a double purpose since it also provides the means for supply of liquid e.g.

shown the water to the interior of the impeller 10, the water feed being through an inlet opening in the end wall 2 and an elongated slot 15A in the supply tube (see FIGURE 2). Within the tube wall 12 is a driving spindle 16, this spindle 16 being journalled to rotate in bearing 17 in a manifold 18, the manifold 18 having offset flanges 20 by which it is secured to the end wall 2 and also providing a passage 21 for the feed water. Tue drive spindle 16 extends through a bearing '22 in the outer end of tube 12 and has a shouldered end 23 for engagement with a non-circular hole in the outer end of the impeller tube 10, the latter being detachably secured thereto by means of a fixing nut 24.

It will be seen that the impeller 10 is mounted within the chamber 4 in a substantially central position so as to provide washing space both above and below it for dishes and other articles to be washed.

The bottom wall to the chamber 4 is provided with a sump 25 leading to a port 26, which opens into the lower end of the passage 21. A removable fine mesh wire gauze disc or other screen 27 is provided to act as a filter for the return flow of liquid to the impeller to prevent particles from the dishes being washed passing into the sump and thence to the pump by means of which water is recirculated to the impeller. A heater H is located in the sump so as to heat water as desired before circulation through the impeller.

A pump indicated at 30 is mounted in the lower portion of the passage 21, the pump conveniently being of the centrifugal type but an axial or any other suitable form of pump may be used. The pump 34 is provided with a spindle 31 which is journalled to rotate in a bearing formed in the manifold 18. Pulleys 31A and 32, fast on

spindles

31 and 16 respectively, are driven by a common belt or chain B (see FIGURE 6) which also engages with a pulley P on the driving motor spindle M.

The discharge capacities of the pump 30 and impeller 10 are approximately balanced so that the impeller is just maintained completely full of water without excess pressure thus avoiding undesirable energy losses in the feed pump.

In operation the water delivered by the feed pump emerges from the perforated wall of the feed tube and builds up inside the hollow impeller. This contained body of water inside the chamber defined by the impeller wall is forced to rotate bodily with the impeller by virtue of the non-circular internal surfaces or ribs adjacent the impeller wall, and is, therefore, subject to centrifugal force which causes the liquid to be centrifugally forced outwardly against the impeller wall in a compact ringlike mass for being discharged by fluid pressure from the orifices in the form of high pressure jets. The volume of water thus discharged by the revolving impeller is determined by its peripheral velocity, the total nozzle area and the radial depth of the body of contained water, and in practice these are so adjusted that the rate of discharge from the impeller is equal to the rate at which water is supplied by the feed pump.

The total velocity of the jets discharged by the impeller will, of course, be the vector sum of the emergent velocity due to impressed centrifugal head, plus the bodily rotational velocity of the nozzles. In practice, it is found that convenient and eflicient operating conditions are secured when the dimensions and speed of the impeller are such that the peripheral velocity of the impeller at the nozzles is about equal to or greater than the emergent velocity of the jets relative to the nozzles.

In order to avoid undesirable energy losses in the feed pump, it is also convenient to so proportion the discharge capacities of the pump and impeller that the latter is not completely filled with water, ie the radial depth of water contained within the impeller is less than the radial gap between the nozzles and the outside of the feed tube. Under these conditions the energy losses in the feed pump are kept to a minimum, and in practice it is found that the power absorbed in driving the pump is substantially less than the power absorbed in driving the impeller. The impeller itself has relatively low energy losses and it follows, therefore, that the overall efficiency of energy conversion is higher than obtained in other systems where the whole of the water energy is derived from a pump developing sufficient pressure to force the washing jets out of stationary of non-energised spray nozzles.

In an alternative construction the impeller may consist of a plain cylinder 40 (see FIGURE 7) in which the discharge orifices are provided by apertures 41 positioned around its periphery, the apertures being arranged in staggered rows. That portion 42 the impeller adjacent each aperture 41 and in advance thereof when considered in relation to the direction of rotation as indicated by the arrow x is bent inwardly so that the axis of each aperture 41 is in a direction other than radial and does, in fact, approach a tangential position with regard to the cylindrical impeller. Thus spray jets issuing from the interior of the impeller through the apertures 41 will be in the direction of rotation of the impeller.

An internal rib 43 extending inwardly from the wall of the impeller is provided adjacent each row of apertures 41 and is located rearwardly thereof in relation to the direction of rotation of the impeller. These internal ribs ensure that the volume of water contained within the cylindrical impeller 49 rotates bodily with the impeller. Dot and dash line 44 indicates approximately :how water inside the impeller will build up against one rib.

Referring now to FIGURES 2 and 3 there is shown an impeller cylinder, for example, a plastic moulding, formed with a series of elongated slots 33 providing jet orifices arranged in three rows, one row being indicated at 34 and the other two rows at 34', 34". Each row of

orifices

34, 34 and 34" is formed in a separate lobe or nozzle head, one of which is indicated at 35.

In operation liquid is drawn from the sump 25 and delivered to the inside of the supply tube 12 by means of the pump 30 whence it passes through the passage 21 to the impeller nozzles 35 and slots 33. The liquid after discharge from the impeller 10 passes through the filter screen 27 into the sump 25 before it is recycled by the pump 30.

Referring to FIGURES 4 and 5 a further embodiment of an impeller is illustrated comprising two similar pressed metal sheets assembled to form a cylindrical whole. The impeller is provided with nozzles or lobes 37 terminating in discharge slots 36 and, in operation, is mounted on the supply tube 12 as in the FIGURE 3 construction. 38 indicates a front plate for attachment to the driving spindle 16, and a back plate 39 having bearing 40 mounted therein is also incorporated.

What is claimed is:

1. A liquid impelling apparatus for a dish washing machine, said apparatus comprising a rotary spray impeller head, a fixed hollow support member having perforated walls on which the spray impeller head is mounted for rotation, internal liquid passages in said spray impeller head, each of said passages having a series of discharge orifices extending lengthwise thereof and the individual orifices facing at an angle other than radial and in the direction of rotation of the spray impeller head, means including a pump for supplying liquid to said support member for delivery through said passages and said orifices, and means for continuously rotating said spray impeller head oppositely to the direction of reaction of the jets issuing from said orifices and said interior passages causing the mass of liquid therein to revolve bodily with said impeller head whereby the velocity of the jet liquid is the vector sum of the emergence velocity due to the impressed centrifugal head of liquid plus the rotational velocity of the jet orifices.

2. A liquid impelling apparatus for a dish washing machine said apparatus comprising a rotary tubular spray impeller head, a liquid supply tube on which said spray impeller head is mounted for rotation, means for delivering liquid from said supply tube into said tubular spray impeller head, said spray impeller head comprising a Wall defining an interior chamber and being formed with a series of discharge orifices facing at an angle other than radial and in the direction of rotation of said spray impeller head, means including a pump for supplying liquid to said supply tube for delivery through said orifices, means including a driving spindle extending through said supply tube and being connected to said spray impeller head for continuously rotating said spray impeller head oppositely to the direction of reaction of the jets issuing from said orifices, and a series of axially extending ribs within the chamber adjacent said wall to constrain the liquid therein to revolve bodily with said impeller head and thereby to be centrifugally forced outwardly against said wall in a compact ring-like mass for being discharged by fluid pressure outwardly through said jet orifices at said angle, the velocity of the jet liquid leaving said spray impeller head being the vector sum of the emergence velocity due to the impressed centrifugal head of liquid in the chamber plus the rotational velocity of the jet orifices.

3. A liquid impelling apparatus for a dish washing machine as claimed in claim 2, in which the means for rotating the spray impeller head includes a shaft extending through the support member.

4. A liquid impelling apparatus for a dish washing machine as claimed in claim 2, in which the support member comprises a liquid supply tube and in which the means for rotating the spray impeller head comprises a driving spindle extending through the supply tube and to which spindle the outer end of the spray impeller head is secured.

References Cited in the file of this patent UNITED STATES PATENTS 1,759,629 Riley May 29, 1930 1,997,897 Conley Apr. 16, 1935 2,209,113 Dietsche July 23, 1940 2,357,050 McCrum Aug. 29, 1944 2,734,520 Abresch Feb. 14, 1956 2,939,636 Mullin June 7, 1960 FOREIGN PATENTS 209,405 Great Britain Mar. 17, 1925