US2567509A

US2567509A - Impeller for dishwashing machines

Info

Publication number: US2567509A
Application number: US90978A
Authority: US
Inventors: Harold G Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-05-02
Filing date: 1949-05-02
Publication date: 1951-09-11
Anticipated expiration: 1968-09-11

Description

, INVEN TOR. fi/memo 6 DAV/l5 BY A 77'0P/YE) Sept. 11, 1951 H. G. DAVIS IMPEILLER FOR DISHWASHING MACHINES Filed May 2, 1949 Patented Sept. 11, 1951 UNITED STATES PATENT OFFICE IMPELLER FOR DISHWASHING MACHINES Harold G. Davis, Denver, 0010.

Application May 2, 1949, Serial No. 90,978

2 Claims. 1

This invention relates to an impeller for dishwashing machines of the type in which an impeller is placed in the bottom of a dish-containing tank for the purpose of throwing the water upwardly through the dishes. It is more particularly designed as an improvement over the impeller shown in applicants Patent No. 1,934,970 and i designed for use in a machine of the type illustrated in applicants Patent No. 2,047,177.

The principal object of the invention is to provide a construction in which the stream of water will be thrown upwardly at an angle to the vertical and this stream will be continuously rotated about the vertical axis so as to strike the dishes at an infinite number of different angles so as to efficiently cleanse the same.

Other objects are: to provide highly efilcient means for guiding the water thrown by the impeller which will operate efliciently at a low level of water in the tank; to provide an efiicient oiling device for the impeller which will prevent the oil from being forced from the bearings under the influence of heat; to provide highly eflicient bearing sealing means which will prevent the entry of water into the bearings; and to provide an effective brake construction by means of which the speed of gyration can be pre-set at any desired speed.

Other objects and advantages reside in the detailv construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a plan view of the improved. impeller.

-Fig. 2 is a vertical section therethrough taken on the line 2-2, Fig. 1. In this view the impeller blades have not been cut by the section for the purpose of clarity of illustration.

Fig. 3 is a detail cross-section taken on the line 3 -3, Fig. 2.

Fig. 4 is a similar cross-section taken on the line 44, Fig. 2.

In the drawing, the related parts of the dishwasher have been omitted since this application pertains only to the impeller portion thereof. However, the position of the bottom of a dishwashing tank is indicated at In and the position of the top of a fan housing is indicated at ll.

The entire structure is supported in a cylindrical outer housing l2 having a top peripheral flange IS. The flange rests upon a suitable sealing gasket 14 which seals it to the bottom ID of the tank. A similar sealing gasket I5 is placed between the two members In and II and the entire structure is clamped to the members l9 and H by means of a clamp nut Hi. The bottom ll] of the outer housing is closed by a threaded bottom cap H.

An inner housing [8 is rotatably mounted within the outer housing l2 and extends above the top thereof. The upper extremity of the inner housing terminates in a bearing cup I9, the axis of which is at an acute angle to the axis of the inner housing l8. This angle may be any suitable degree, it having been found that an angle of 17 is the most satisfactory. The cup i9 is enclosed by means of a top cap 20 threaded thereon.

A hollow, cup-like bearing member 2| is threaded on the lower extremity of the inner housing 58 and is rotatably mounted within the outer housing 42 so as to rotatably support the latter and maintain it accurately on its axis. The interior of the hollow bearing member 2| is sealed from the interior of the tank b means of an inverted sealing cup 22 which is constantly urged against the top of the outer housing 12 by means of a compression spring 23 which rests on the bottom of the bearing member 2|.

It can be seen that the above construction allows the inner housin to rotate freely about its axis, the rotation being snubbed by the friction between the cup 22 and the top of the housing 12. This snubbing action can be pre-set by choosing the spring 23 of the proper strength.

A trunnion bearing 24 is rotatabl mounted in the cup I9 and carries a hollow, axially-extending spindle 25 which extends through and above the cap 20. The bearing 24 is sealed from the interior of the tank by means of an inverted sealing cup 26 and sealing spring 21, similarly to the previously described sealing means. The cup 26 is constantly urged against the cap 20 by means of the action of the spring 27.

A hollow impeller hub 28 is wedged on the spindle 25, the latter being tapered to receive it. The skirt of the hub 28 extends downwardly about the cup [9. Two oppositely-projecting, tangentially-mounted, curved impeller blades 29 project oppositely outward from the skirt of the hub 23. These blades are so curved as to impart a scooping action on the water to throw it upwardly about the axis of the spindle 25 in a more or less'confined spiral stream.

The hub 28 is held in place on the spindle 25 by means of an oil cup 30 threaded onto the upper extremity of the latter. The interior of the cup is open to the hollow interior of the spindle 25. The cup is closed by means of a threaded cup cap 3| provided with a suitable sealing gasket 32 which forms an air tight seal on the cup 30.

It has been found in prior impeller mountings that when the latter become heated through the action of the hot water and the friction of rotation, the oil therein will be expanded and forced through the bearings into the tank. In the improved construction, any expansion in the oil is absorbed in compressing the entrapped air in the top of the oil cup 30 so that the oil will not be forced from the bearings.

The impeller is driven through the medium of a drive shaft 33, the lower extremity of which projects below the bottom cap I1. The lower extremity is suitably threaded, as shownat 34, to provide a connection for any suitable driving element. A sealing skirt 35 is formed on and surrounds the shaft 33 immediately above the cap IT. This skirt contains a sealing cup 36 against which :a spring 31 acts to seal the housing above the shaft 33. The spring 3'! acts to constantly urgethe cup 36 against the cap I? to prevent water or other liquid from entering the outer housing l2.

A section of flexible shafting 38 is fixedly secured in the shaft 33 in any desired manner, such as by soldering it in a receiving socket therein.

The upper extremity of the shaft 33 contains a conical concavity in which the flexible shaft 38 may move. The upper extremity of this shaft 38 terminates in a terminal member 39 which rests in the hollow spindle 35. The terminal member is notched and a key member 40 in the spindle extends across this notch to provide a driving connection for the impeller which will allow freedom for axial movement of. the terminal member 39. I

The bearing member 2| and the inner housing 18 are supported on a combination thrust and bearing member 41 which is rotatable within the outer'housing I2. The thrust member 4! has the proper thickness to support the inner housing 18 at the desired heighth when the cap ll has been screwed in place to its final position. It is this bearing member 4| which supports the entire rotating assembly at the proper heighth in the tank.

The inner housing [8 is rotated through the whirling action of the bent flexible shaft 38, and this action is retarded by the friction between the elements 22 and 13 to the desired gyration speed.

The speed of gyration is still further controlled by means of a flat vane plate '44 which is attached to the inner housing l8 by means of suitable screws 45. The vane plate 44 acts as a drag through the .water in the tank to retard the gym-- tion speed of the inclined impeller. The curved cross-section of the blades 29 tends to throw the water upward in an inclined stream concentric with the inclined axis of the impeller. It has been found desirable to divert a portion of this stream rearwardly from the direction of rotation to increase the cleansing action. This is accomplished by means of an arcuate inclined scoop 42 which is supported over the lowermost side of the path of the blades 29 upon a scoop arm 43 which is formed on and extends from the vane plate 44. The scoop acts to divert a strong stream of water rearwardly from the direction of rotation and against the dishes to be washed.

It will be noted that the arm 43 is arched as shown at 46 to allow it to pass the projecting impeller mechanism and that the scoop is over the lowest position of the blades so that it will receive water even though the water level in the tank be below the middle of the impeller.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the inven-- tion.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. In a dishwashing machine of the type having a tank, means for agitating water in said tank comprising: a rotatable shaft housing extending vertically through the bottom of said tank; a bearing cup formed on the top of said housing and inclined to one side at an acute angle to the axis of said housing; an impeller mounted to rotate about said cup co-axially therewith; means for rotating said impeller; and an arcuate, inclined scoop mounted on said shaft housing and positioned over said impeller at one side of the axis thereof, the incline of said scoop being positioned to direct water rearwardly from the direction of rotation of said impeller.

2. In a dishwashing machine of the type having a tank, means for agitating water in said tank comprising: a rotatable shaft housing extending vertically through the bottom of said tank; a bearing cup formed on the top of said housing and inclined to one side at an acute angle to the axis of said housing; an impeller mounted to. rotate about said cup co-axially therewith; means for rotating said impeller; and an arouate, inclined scoop mounted on said shaft housing and positioned over said impeller at one side of the axis thereof, the incline of said scoop being positioned to direct water rearwardly from the direction of rotation of said impeller, said scoop being positioned over the lowermost side of said impeller; and a supporting arm secured to said shaft housing and extending radially outward beneath the high side of said impeller, thence upward and over said impeller to a connection with said scoopfor supporting the latter.

HAROLD G. DAVIS.

REFERENCES CITED I The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 911,412 Lang Feb. 2, 1909 1,934,970 Davis Nov. 14, 1933 2,398,733 Wenzel Apr. 16, 1946