BACKGROUND ART A dish washer is an appliance for washing dishes automatically by jetting water toward dishes by a pump. FIGS. 1 and 2 show an example of such a dish washer. FIG. 1 is a perspective view of a conventional dish washer, and FIG. 2 shows the dish washer of FIG. 1 schematically for the convenience of illustration.

The dish washer has an outer casing 3 forming an appearance thereof, a washing tub 4 installed in the outer casing 3, and a driving device 11 installed under the washing tub 4. A pair of baskets 12 and 13 are installed in the washing tub 4. The baskets 12 and 13 accommodate the dishes to be washed.

The driving device 11 comprises a sump case 10 for storing water, a supply pump 15 and a discharge pump 17 connected with the sump case 10, a pair of nozzles 38 and 39 respectively installed under the baskets 12 and 13, a pair of supply pipes 24 and 25 for supplying the respective nozzles 38 and 39 with the water pumped by the supply pump 15, a discharge pipe 18 for

discharging the water by the discharge pump 17 to the outside, and a water supply valve 21 for supplying water into the sump case 10.

The supply pump 15 is, as shown in FIG. 3, composed of a pump housing 31, a fan 32 installed in the pump housing 31, and a motor (not shown) for driving the fan 32. The pump housing 31 and the sump case 10 are connected with each other by a suction pipe (not shown). When the supply pump 15 works, the water in the sump case 10 is drawn into the pump housing 31 through the suction pipe, and the drawn water is supplied into the supply pipes 24 and 25. The discharge pump 17 is similar in construction to the supply pump 15.

A user puts the dishes to be washed on the baskets 12 and 13, and then pushes a start button (not shown). Then, the supply valve 21 is controlled to be open by a microprocessor (not shown) so that water is supplied into the sump case 10. When a predetermined amount of water is supplied into the sump case 10, the microprocessor closes the supply valve 21 to stop supplying the water. The microprocessor begins to operate the supply pump 15, whereby the water in the sump case 10 is supplied into the nozzles 38 and 39 through the supply pipe 24 and 25. The nozzles 38 and 39 jet the water toward the dishes accommodated in the baskets 12 and 13, by which the dishes are washed.

The water in the washing tub 4 used for washing the dishes is received again in the sump case 10. While the supply pump 15 continues to operate, the water in the sump case 10 is circulated according to such a process, thereby performing a washing operation. After the dishes are washed completely, the supply pump 15 stops operating and the discharge pump 17 begins to operate, whereby the water in the sump case 10 is discharged outside through the discharge pipe 18.

However, such a conventional dish washer has two pumps 15 and 17, i. e., the supply pump 15 and the discharge pump 17, in order to jet the water in the sump case 10 into the washing tub 4 and discharge the water in the sump case 10 to the outside after the dishes are completely washed.

Therefore, the dish washer is complicated in construction and voluminous, and the manufacturing cost thereof increases.

Further, if a small-sized pump having a small pumping capacity is employed in order to reduce the volume of the dish washer, it is hard to get a sufficient jetting force required in washing dishes and it takes a longer time to drain the water after the washing operation ends.

DISCLOSURE OF INVENTION The present invention has been proposed to overcome the above- described problems in the prior art, and accordingly, the object of the present invention is to provide a dish washer capable of performing both of the functions for jetting and discharging water in the sump case using a single motor, thereby simplifying the construction and decreasing the manufacturing cost.

To achieve the above object, the present invention provides a dish washer having a washing tub for accommodating dishes to be washed and a nozzle for jetting water into the washing tub, comprising: a sump case for storing water to be jetted into the washing tub and for receiving water jetted into the washing tub; a supply pipe for supplying the water in the sump case into the nozzle; a discharge pipe for discharging the water in the sump case; and a device for pumping the water in the sump case into the supply pipe or the discharge pipe selectively.

Here, the pumping device comprises: a pump housing having a suction port, a supply port, and a discharge port connected to the sump case, the supply pipe, and the discharge pipe, respectively; a fan installed in the pump housing; a driving motor for rotating the fan; and a means for closing the supply port or the discharge port selectively. The driving motor is capable of rotating the fan bilaterally, and the closing means is operated by a water flow formed in the pump housing according to a rotational direction of the fan.

According to a preferred embodiment, the closing means is comprised of a closing member having a plate-shaped closing part capable of being slid along a guide groove formed near the supply port and the discharge port, and an operation part protruding inward the pump housing from the closing part.

The operation part is operated by the water flow in the pump housing so that the closing part is moved along the guide groove.

According to another preferred embodiment of the present invention, the closing means is composed of a closing member installed between the supply port and the discharge port so as to be capable of being pivoted, the closing member for closing the supply port or the discharge port selectively according to a pivoting position thereof. The closing member is pivoted by the water flow formed in the pump housing. Preferably, the closing member comprises: a rod part of which one end is hinged at a position between the supply port and the discharge port; and a spherical valve part installed at the other end of the rod part, the valve part for closing the supply port or the discharge port selectively.

The closing member can be composed of a pair of plate parts connected with each other at a right angle, of which a connection part is hinged at a position between the supply port and the discharge port.

According to the present invention, both of the jetting operation of water

for washing the dishes and draining operation of water after washing the dishes ends can be performed by a single pump. Therefore, the number of components and the size of the dish washer can be reduced.

BRIEF DESCRIPTION OF DRAWINGS The present invention will be better understood and its various objects and advantages will be more fully appreciated from the following description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view of a conventional dish washer; FIG. 2 is a schematic side sectional view of FIG. 1; FIG. 3 is an enlarged sectional view of a supply pump shown in FIG. 1; FIG. 4 is a perspective view of a dish washer according to the present invention; FIG. 5 is an enlarged sectional view of the first embodiment of a pump shown in FIG. 4; FIGS. 6 and 7 are transverse sectional views of FIG. 5; FIG. 8 is an enlarged sectional view of the second embodiment of a pump shown in FIG. 4; FIGS. 9 and 10 are transverse sectional views of FIG. 5; FIG. 11 is an enlarged sectional view of the third embodiment of a pump shown in FIG. 4; and FIGS. 12 and 13 are transverse sectional views of FIG. 5.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with

reference to the accompanying drawings.

The dish washer has, as shown in FIG. 4, an outer casing 43 forming an appearance thereof, a washing tub 44 installed in the outer casing 43, and a driving device 51 installed under the washing tub 44. A pair of baskets 52 and 53 are installed in the washing tub 54. The baskets 52 and 53 accommodate the dishes to be washed.

The driving device 51 comprises a sump case 50 for storing water, a pump 55 connected with the sump case 50, a pair of nozzles 78 and 79 installed under the baskets 52 and 53, respectively, a lower supply pipe 64 and an upper supply pipe 25 for connecting the respective pumps 55 with the nozzles 78 and 79, and a discharge pipe 58 for discharging the water by the pump 55 to an outside. The pump 55 is, as shown in FIGS. 5 through 7, composed of a pump housing 95, a fan 81 installed in the pump housing 95, and a driving motor 82 for driving the fan 81. The driving motor 82 is capable of rotating bilaterally, and therefore, the fan 81 can be rotated bilaterally by the driving motor 82.

The pump housing 95 has a suction port 60a, a supply port 66a, and a discharge port 58a, with which a suction pipe 60, a main supply pipe 66, and a discharge pipe 58 are connected, respectively. The suction pipe 60 connects the sump case 50 with the pump housing 95. While the pump 55 is operating, the water in the sump case 50 is drawn into the pump housing 95 through the suction pipe 60. The main supply pipe 66 is connected with both of the upper and lower supply pipes 64 and 65. While the pump 55 is operating, the water in the pump housing 95 is supplied into both of the upper and lower supply pipes 64 and 65 through the main supply pipe 66.

The supply port 66a of the main supply pipe 66 and the discharge port 58a of the discharge pipe 58 are adjacent to each other in the pump housing

95. A closing member 71 is installed on the supply port 66a and the discharge port 58a. The closing member 71 has a plate-shaped closing part 73, and an operation part 75 formed at the central area of the closing part 73.

A guide groove 77 is formed in an area adjacent to the supply port 66a and the discharge port 58a, and the closing part 73 is assembled with the guide groove 77. The closing part 73 can be slid along the guide groove 77, and closes the supply port 66a or the discharge port 58a selectively, according to the position thereof in the guide groove 77 as shown in FIGS. 6 and 7.

The operation part 75 protrudes from the closing part 73 toward the inner side of the pump housing 95. The operation part 75 functions to move the closing part 73 according to the rotational direction of the driving motor 82.

That is, if the fan 81 is rotated clockwise by the driving motor 82 as shown in FIG. 6 with arrows, the water flow formed in a clockwise direction gives a downward force to the operation part 75, whereby the closing part 73 is moved downward along the guide groove 77. Therefore, the main supply pipe 66 is opened and the discharge pipe 58 is closed.

Meanwhile, if the fan 81 is rotated counterclockwise by the driving motor 82 as shown in FIG. 7 with arrows, the water flow formed in a counterclockwise direction gives an upward force to the operation part 75, whereby the closing part 73 is moved upward along the guide groove 77.

Therefore, the main supply pipe 66 is closed and the discharge pipe 58 is opened.

A guide member 87 is installed between the closing member 71 and the fan 81. The guide member 87 guides the water flow formed in the pump housing 95 so that the water can flow toward the operation part 75 while the fan 81 is rotating.

Hereinbelow, the operation of the dish washer having the above- described construction according to the present invention will be described.

A user puts the dishes to be washed on the baskets 52 and 53, and then pushes a start button (not shown). Then, a supply valve (not shown) is controlled to be opened by a microprocessor (not shown) so that water is supplied into the sump case 50. When a predetermined amount of water is supplied into the sump case 50, the microprocessor closes the supply valve to stop supplying the water.

The microprocessor begins to operate the driving motor 82 so as to rotate the fan 81 in the clockwise direction, whereby the main supply pipe 66 is opened and the discharge pipe 58 is closed as shown in FIG. 6. Therefore, the water in the sump case 50 is drawn into the pump housing 95 through the suction pipe 60, and then the drawn water is supplied into the upper and lower supply pipes 65 and 64 through the main supply pipe 66. The water is then jetted by the nozzles 78 and 79 toward the dishes accommodated in the baskets 52 and 53, whereby the dishes are washed.

The water in the washing tub 44 used for washing the dishes flows into the sump case 50. While the pump 55 continues to operate, the water in the sump case 50 is circulated according to such a process, thereby performing a washing operation.

After the dishes are washed completely, the microprocessor drives the driving motor 82 so as to rotate the fan 81 in the counterclockwise direction, whereby the main supply pipe 66 is closed and the discharge pipe 58 is opened as shown in FIG. 7. Therefore, the water in the sump case 50 is drawn into the pump housing 95 through the suction pipe 60, and then the drawn water is discharged to the outside through the discharge pipe 58.

According to the present invention, by the driving motor 82 capable of

rotating bilaterally and a closing member 71 driven by the direction of water flow formed in the pump housing 95, both of the operations for supplying and discharging the water can be performed by a single driving motor 82.

Therefore, the number of components and the size of the dish washer can be reduced.

Meanwhile, FIGS. 8 through 10 show another embodiment of the pump employed in the dish washer according to the present invention shown in FIG.

4. In the present embodiment, parts substantially identical to those of the pump 55 shown in FIGS. 5 through 7 are referred to with the same reference numerals.

In the present embodiment, the construction of the pump housing 95, the fan 81, the driving motor 82, the main supply pipe 66, and the discharge pipe 58 is substantially same as in the above-described embodiment.

In the present embodiment, a holder 111 having an assembly recess 113 is installed between the supply port 66a of the main supply pipe 66 and the discharge port 58a of the discharge pipe 58 and a closing member 101 is assembled with the holder 111.

The closing member 101 has a rod part 105, a pin part 106 installed at one end of the rod part 105, and a spherical valve part 103 installed at the other end of the rod part 105. The pin part 106 is inserted into the assembly recess 113, whereby the rod part 105 is assembled with the holder 111 so as to be capable of being pivoted about the pin part 106. The valve part 103 closes the main supply pipe 66 or the discharge pipe 58 selectively according to the pivoting position of the rod part 105.

That is, if the fan 81 is rotated clockwise by the driving motor 82 as shown in FIG. 9, the rod part 105 pivots downward by the water flow formed in a clockwise direction. Therefore, the main supply pipe 66 is opened and the

discharge pipe 58 is closed.

If the fan 81 is rotated counterclockwise by the driving motor 82 as shown in FIG. 10, the rod part 105 pivots upward by the water flow formed in a counterclockwise direction. Therefore, the main supply pipe 66 is closed and the discharge pipe 58 is opened.

Meanwhile, packing members 115 and 117 are installed on the supply port 66a of the main supply pipe 66 and the discharge port 58a of the discharge pipe 58, respectively. By the packing members 115 and 117, the valve part 103 can close the main supply pipe 66 and the discharge pipe 58 more tightly.

FIGS. 11 through 13 still show another embodiments of the pump employed in the dish washer according to the present invention shown in FIG.

4. In the present embodiment, parts substantially identical to those of the pump 55 shown in FIGS. 5 through 7 are referred to with the same reference numerals.

In the present embodiment, the construction of the pump housing 95, the fan 81, the driving motor 82, the main supply pipe 66, and the discharge pipe 58 is substantially same as in the above-described embodiment.

In the present embodiment, the closing member has a pair of plate parts 123 and 125 connected with each other at a right angle. A pin 129 is installed at the connection part of the closing member 121, and the pin 129 is inserted into the a pin recess 128 formed between the supply port 66a of the main supply pipe 66 or the discharge port 58a of the discharge pipe 58.

Therefore, the closing member 121 can pivot about the pin 129, and the main supply pipe 66 and the discharge pipe 58 are selectively closed by the closing member 121 according to the pivoting position thereof.

That is, if the fan 81 is rotated clockwise by the driving motor 82 as

shown in FIG. 12, the closing member 121 pivots downward by the water flow formed in a clockwise direction. Therefore, the main supply pipe 66 is opened and the discharge pipe 58 is closed. If the fan 81 is rotated counterclockwise by the driving motor 82 as shown in FIG. 13, the closing member 121 pivots upward by the water flow formed in a counterclockwise direction. Therefore, the main supply pipe 66 is closed and the discharge pipe 58 is opened.

According to the present invention, while one of the plate parts 123 or 125 closes the main supply pipe 66 or the discharge pipe 58, the other plate part 125 or 123 functions like the operation part 75 of the embodiment shown in FIGS. 5 through 7, that is, functions to operate the closing member 121 according to the water flow formed in the pump housing 95.

A guide member 87a is installed between the closing member 121 and the fan 81. As described above, the guide member 87a guides the water flow formed in the pump housing 95 so that the water can flow toward the closing member 121 while the fan 81 is rotating.

As described above, according to the present invention, since the supply pipe or the discharge pipe is selectively opened according to the direction of water flow formed in the pump housing, both of the jetting operation of water for washing the dishes and the draining operation of water after washing the dishes can be performed by a single pump. Therefore, the number of components and the size of the dish washer can be reduced.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, wherein the spirit and scope of the present invention is limited only by the terms of the appended claims.