Dishwasher

Abstract: The water sprayer (20; 20A) of a dishwasher is provided with means (22; 60) whereby its radial extent can be varied during rotation to ensure that water is sprayed into the corners of the washing chamber (3) of the dishwasher. In one embodiment, the means (20) comprised a pivoting arm (22). In another embodiment, the sprayer is telescopic.

Description: The present invention relates to a dishwasher comprising a washing chamber having a wall, and a rotating sprayer in the chamber for spraying water onto items to be washed, the wall not being both annular and coaxial with the axis of rotation of the sprayer. Dishwashers accommodate tableware such as dishes, knives, forks and spoons therein, takes up a certain amount of water from an external water source and spray the water at high pressure, using a pump and a spray nozzle, in order to wash the tableware. For best results, water should be uniformly sprayed toward the tableware. Accordingly, a rotary spray nozzle is used in dishwashers. As the spray nozzle rotates, water is sprayed in the direction of rotation, with a result that the tableware is washed uniformly. Figure 1 shows a conventional dishwasher. A door 2 which is rotatably openable and closable is provided in one side of the body 1 of the dishwasher. A washing space 3 is formed in the body 1. Two baskets 4, 5 accommodating tableware (not shown) are slid into upper and lower positions respectively. A water sprayer 6 is located under the lower basket 5. A spindle 7 is connected with the centre of the water sprayer 6. The spindle 7 is rotatably supported by a connection tube 8 protruding from the bottom of the washing space 3. Thus, the water sprayer 6 can be rotated together with the spindle 7. A sump case 10 for collecting the water dripping from the bottom of the washing space 3 through a filter 9 and a pump 11 for pumping water from the sump case 10 are disposed on the bottom of the washing space 3. A pump discharge tube 12 is connected to the water sprayer 6 via the connection tube 8 and the spindle 7. A plurality of nozzles 13 for spraying water toward the basket 5 are formed in the water sprayer 6. The plurality of nozzles 13 are designed in such a pattern that the spraying of the water causes the water sprayer 6 to rotate in one direction (see Figure 2). Although not shown in the drawing, a water sprayer for spraying water in the same principle with a similar structure as in the lower basket 5 is installed under the upper basket 4. A heater 14 is provided for drying the washed tableware. Referring to Figure 2 showing a dishwasher including a rotary water sprayer, tableware disposed in a circular zone where the water sprayer 6 moves is washed well within the rectangular washing space 3 defined by inner walls 15 of the dishwasher body. However, the corners 17 form dead zones which are not influenced by the spray 6 from the nozzles 13. As a result, tableware placed in the baskets in the dead zones are not washed well. US-A-5464482 discloses a dishwasher in which the sprayer is configured such that its radial extent adapts during its rotation so that a radially outer part of the sprayer follows the wall. The disclosed sprayer has an end portion that is driven by gears from the main drive shaft such that the end portion projects into the corners of the dishwasher's chamber as the sprayer rotates. A dishwasher according to the present invention is characterised in that the end of said radially outer part is in contact with the wall and the radial extent of the sprayer is set, during rotation thereof, by means of the contact between the wall and the end of said radially outer part. Consequently, if the chamber is rectangular, for instance square as is commonly the case, the sprayer extends into the corners as it rotates thereby eliminating the aforementioned dead zones. Other possibilities are also created by the present invention. For instance, if the chamber wall is annular, the axis of rotation of the sprayer need not be coaxial with the chamber. Preferably, the axis of rotation of the sprayer extends vertically through the chamber. However, the sprayer could be arranged to rotate about a horizontal axis, in which case the aforementioned wall may be the ceiling of the chamber. In one preferred embodiment, the sprayer comprises a main portion extending radially from the axis of rotation of the sprayer and a pivoted portion pivotably mounted to the radially outer part of the main portion, the pivoted portion contacting the wall and pivoting about an axis parallel to the axis of rotation of the sprayer so as to vary the radial extent of the sprayer during rotation. In another preferred embodiment, the sprayer comprises a telescopic arm. Preferably, a wheel or roller is mounted at the radially outer part of the sprayer for engaging the wall during rotation of the sprayer. This is to reduce friction between the wall and the sprayer. Accordingly other friction reducing measures could be employed. Preferably, the sprayer comprises first and second arms extending in opposite directions. This helps balance the forces on the sprayer's spindle. More preferably, the radial extent of both arms varies during rotation of the sprayer. Embodiments of the present invention will now be described, by way of example, with reference to Figures 3 to 20 of the accompanying drawings, in which:- Figure 1 is a partly cut away perspective view of a conventional dishwasher; Figure 2 is a plan view showing the spraying zone of a conventional water sprayer apparatus of a dishwasher; Figure 3 is a partly cut away perspective view of a first dishwasher emboying the present invention; Figure 4 is a plan view showing the operation of the water sprayer apparatus of the dishwasher shown in Figure 3; Figure 5a is a partly cut away plan view of the water sprayer apparatus shown in Figure 4; Figure 5b is a partly cut away plan view of the water sprayer apparatus shown in Figure 4 in which an auxiliary nozzle member is bent; Figure 6 is a cross-sectional view showing how water is supplied from the main nozzle member to the auxiliary nozzle member and sprayed in the state shown in Figure 5a. Figure 7 is an exploded perspective view showing a roller support structure of the auxiliary nozzle member; Figure 8 is an exploded view of the roller support of Figure 7; Figure 9 illustrates the use of a spherical roller instead of a cylindrical roller shown in Figure 7; Figure 10 is an exploded perspective view showing another example of a roller support structure of an auxiliary nozzle member; Figure 11 is a sectional view of the roller support structure of Figure 10. Figures 12a, 12b and 12c are side views showing the roller of Figure 11 with the sprayer vibrating; Figure 13 is a plan view of a modified example of the auxiliary nozzle member according to the first embodiment; Figure 14 is an exploded sectional view of the auxiliary nozzle member shown in Figure 13; Figure 15 is a partly cut away perspective view of a second embodiment of a dishwasher according to the present invention; Figure 16 is a plan view showing the operation of the water sprayer apparatus of the dishwasher shown in Figure 15; Figure 17 is a sectional view showing the telescopic nozzle member of Figure 16 in its extended state; Figure 18 is a sectional view of telescopic water sprayer; Figures 19a, 19b, 19c and 19d are sectional views showing various sectional shapes suitable for the telescopic water sprayer; and Figure 20 is a plan view of a preferred form of wall of a dishwasher body. Referring to Figure 3, a dishwasher comprises a body 1 and a door 2 opening to a washing space 3. Baskets 3, 4 are provided in the washing space 3 for tableware. A water sprayer 20 is mounted to a vertical spindle 7 centrally located at the bottom of the washing space. Water is supplied to the sprayer 20 via a connection tube 8 and a filter 9. A heater 14 is also provided at the bottom of the washing space 3. The improved water sprayer 20 includes a main nozzle member 21, and an auxiliary nozzle member 22 which is pivotably connected to one end of the main nozzle member 21. An auxiliary nozzle member 22 can be connected to the other end of the main nozzle member 21. The main nozzle member 21 and the auxiliary nozzle member 22 have a plurality of nozzles 23, 24. The nozzles 23 formed in the main nozzle member 21 are designed such that the main nozzle member 21 rotates in one direction when water sprays out of them. When the main nozzle member 21 rotates, the auxiliary nozzle member 22 rotates with it. Referring to Figure 4, the main nozzle member 21 rotates in a circular zone 16 and sprays water as in the conventional dishwasher. The auxiliary nozzle member 22 has a circular zone 18 having a larger radius than that of the main nozzle member 21. When the auxiliary nozzle member 22 moves near wall portions other than corner portions 17 of walls 15, the end portion of the auxiliary nozzle member 21 is pressed by the walls 15 and pivoted back. As a result, the auxiliary nozzle member 21 moves around a non-circular zone, the radius of which varies substantially, and sprays water. Thus, the water can be sprayed into the corners 17 that are not reached by the water from the main nozzle member 21. A roller 19 attached in the end of the auxiliary nozzle member 22 rolls along the walls 15 to thereby reduce a friction between the walls 15 and the auxiliary nozzle member 22. Referring to Figures 5a and 5b, a hinge accommodator 25, a guiding groove 26 and a stopper 27 are concentrically formed in the end of the main nozzle member 21. In correspondence thereto, a hinge portion 28, which is rotatably accommodated in the hinge accommodator 25, and a guiding rib 29, which moves along the guiding groove 26, are provided in the auxiliary nozzle member 22. A spring 30, inserted into the guiding groove 26, elastically presses the guiding rib 29 to make the auxiliary nozzle member 22 pivot in the clockwise direction. The stopper 27 stops the clockwise pivoting of the auxiliary nozzle member 22 in the state shown in Figure 5a so that the auxiliary nozzle member 22. On the contrary, when the auxiliary nozzle member 22 is pressed by the walls 15, the spring 30 is compressed, which can make the auxiliary nozzle member pivot to a certain extent in the anticlockwise direction, as shown in Figure 5b. The auxiliary nozzle member 22 has an opening 31 formed in the hinge portion 28 as well. The opening 31 is opened and closed according to the rotational position of the auxiliary nozzle member 22. If the opening 31 is open as shown in Figure 5a, water is introduced from the main nozzle member 21 to the auxiliary nozzle member 22 via the opening 31. The introduced water fills the main nozzle member 22 as shown in Figure 6, and then sprays upwards via the nozzles 24. Figure 7 shows the structure of supporting a roller 19A of the auxiliary nozzle member 22. The roller 19A comprises a cylinder and pins 32 protruding on the upper and lower end surfaces of the cylinder. A roller bracket 33 has support pieces 34 having pin holes 35 for supporting the pins 32 of the roller 19A, and an engaging hole 36 and engaging jaws 37 for preventing detachment. A bracket holder 38 is integrally formed in the auxiliary nozzle member 22 or separately attached from the auxiliary nozzle member 22. The bracket holder 38 has an engaging protrusion 39 and a retainer 40 which correspond to the engaging hole 36 and the engaging jaws 37 of the roller bracket 33, respectively. Figure 8 shows a state in which the cylindrical roller 19A frictionally contacts the walls 15. Figure 9 shows the state where a spherical roller 19B is used instead of the cylindrical roller 19A. The cylindrical roller 19A linearly contacts the walls 15. On the contrary, the spherical roller 19B contacts the walls at a point thereby reducing the contact resistance. Figures 10 and 11 shows another example of a roller support structure for the auxiliary nozzle member 22. A roller bracket 42 of the spherical roller 19B is rotatably supported in a roller supporter 52 of the auxiliary nozzle member 22 via a rotational support ring 47. The roller bracket 42 is cylindrical and has support wings 44 on which there is a respective pin hole 45 for supporting each pin 41 of the spherical roller 19B, and an annular engager 46 which is formed in the cylindrical body. The rotational support ring 47 has a boss 48 which is fitted into the roller bracket 42, a hook 49 which is formed in the periphery of the boss 48 and engaged with the annular engager 46, an opening portion 50 which enables the hook 49 to enter, and a thread portion 51 which is formed opposing the boss 48. A thread groove 53 with which the thread portion 51 of the rotational support ring 47 is engaged is formed in the support portion 52 of the auxiliary nozzle member 22. Here, the cylindrical roller 19A can be used instead of the spherical roller 19B. In order to engage the rotational support ring 47 with the thread groove 53 of the support portion 52, a separate screw can be used instead of the thread portion 51. In such a structure, the roller bracket 42 is not detached by the hook 49 of the rotational support ring 47 which is engaged into the annular engager 46, but rotates around the boss 48. Thus, when the auxiliary nozzle member 22 rotates, it is inclined according to its weight, or when the auxiliary nozzle member 22 vibrates perpendicularly with respect to the rotational plane by inner or outer certain factors, it rotates in correspondence to the vibration direction as shown in Figures 12a through 12c. As a result, the pin 41 of the roller 19B and the walls 15 maintain a posture in parallel with each other. Thus, a smooth contact rotation of the roller 19B can be accomplished irrespective of inclination or vibration of the auxiliary nozzle member 22. A phenomenon that the auxiliary nozzle member 22 hesitates to contact the walls 15 due to its friction therebetween can be removed when the auxiliary nozzle member 22 rotates. Figures 13 and 14 show the structure of an auxiliary nozzle member 22A. The auxiliary nozzle member 22A includes a connection tube 53 and the nozzle tube 55. An additional plate 58 is added under the nozzle tube 55 in order to prevent thermal variation. The connection tube 53 has a hinge portion 28 and the guiding rib 29 which are connected with the hinge accommodator and the guiding groove of the above-described main nozzle member. The nozzle tube 55 has a plurality of nozzles 24, a male thread portion 56 which is threadedly connected to a female thread portion 54 of the connection tube 53, and protrusions 57 for fixing the additional plate 58. The additional plate 58 has holes into which the protrusions 57 are fitted, and is installed to enclose the bottom of the nozzle tube 55 by welding the protrusions 57. The nozzle tube 55 of the auxiliary nozzle member 22A is threaded connected with the connection tube 53. Accordingly, when the nozzle 24 is clogged or damaged in use, the nozzle tube 55 can simply separated from or connected with the connection tube 53 during repair or replacement. A material of high durability with respect to heat such as metal is used as the additional plate 58. Accordingly, the nozzle tube 55 is prevented from being thermally varied due to the heater 14 for a drying function of the dishwasher shown in Figure 3. The same roller support structure can be applied in the nozzle tube 55 of the auxiliary nozzle member 22A, as the above-described roller support structure. Also, the additional plate 58 for preventing thermal variation can be added to the auxiliary nozzle member 22. Next, Figures 15 through 20 are views involving a water sprayer apparatus of a dishwasher according to a second embodiment of the present invention. Referring to Figure 15, a dishwasher comprises a body 1 and a door 2 opening to a washing space 3. Baskets 3, 4 are provided in the washing space 3 for tableware. A telescopic water sprayer 20A is mounted to a vertical spindle 7 centrally located at the bottom of the washing space. Water is supplied to the sprayer 20 via a connection tube 8 and a filter 9. A heater 14 is also provided at the bottom of the washing space 3. The telescopic water sprayer apparatus 20A is made by connecting a retractable nozzle member 60 whose length is varied to the main nozzle member 21A. The main nozzle member 21A has a plurality of nozzles 23. The main nozzle member 21A is rotated by water spraying from the nozzles 23. The retractable nozzle member 60 includes a plurality of nozzle tubes 61a, 61b, 61c as shown in Figure 16. The nozzle tubes 61a, 61b, 61c are inserted into a nozzle tube having a larger sectional area than the other nozzle tube including a main nozzle tube as shown in Figures 17 and 18, respectively and accommodate the other nozzle tubes smaller than its own sectional area. Accordingly, during rotation of the main nozzle member 21A, the main nozzle member 21A protrudes axially from the main nozzle member 21A by centrifugal force and the pressure of the water introduced therein. The nozzle tubes 61a, 61b, 61c are not prevented from being detached in the direction of extending the length by outer stoppers 62 which are formed in one end and inner stoppers 63 which are formed in the other end, respectively. The roller 19 for contacting the walls 15 of the dishwasher body on a rolling contact manner is attached to the nozzle tube 61c. Referring back to Figure 16, the main nozzle member 21A sprays water using the circular zone 16 rotating at a given diameter. The retractable nozzle member 60 rotates at the state where it has been pressed by the walls 15 and then retracted as shown by a virtual line according to the rotational position of the main nozzle member 21A. Then, the retractable nozzle member 60 is extended by centrifugal force and the pressure of the introduced water at the corners 17 defined by the walls 15, in which case water is sprayed from the nozzles 24 formed on each exposed nozzle tube 61a, 61b, 61c as shown by the solid line. Thus, water can be sprayed to the corners 17 which are not influenced by the main nozzle member 21A. The main nozzle member 21A and the nozzle tubes 61a, 61b, 61c of the retractable nozzle member 60 have various sectional shapes such as a circle (Figure 19a), a triangle (Figure 19b), an oval (Figure 19c) and a rhombus (Figure 19d). Figure 20 shows a preferred wall of a dishwasher body to which the telescopic water sprayer 20A is applied. Here, the corner 17 defined by the walls 15 is formed as an arc 64 not a straight angle. The arc 64 allows the roller 19 to smoothly contact and move at the corner 17, to thereby reduce impact noise and assist the retractable nozzle member 60 to smoothly retract into the main nozzle member 21A. The present invention enhances washing effectiveness of a dishwasher and increases useable portion of the washing space.

Claims: A dishwasher comprising a washing chamber (3) having a wall (15), and a rotary sprayer (20; 20A) in the chamber for spraying water onto items to be washed, the wall not being both annular and coaxial with the axis of rotation of the arm (20; 20A), the sprayer (20; 20A) being configured such that its radial extent adapts during its rotation so that a radially outer part (19) of the sprayer (20; 20A) follows the wall (15), characterised in that the end of said radially outer part (19) is in contact with the wall and the radial extent of the sprayer (20; 20A) is set, during rotation thereof, by means of the contact between the wall and the end of said radially outer part (19). A dishwasher according to claim 1, wherein the chamber (3) has four walls (15) arranged in a rectangle. A dishwasher according to claim 2, wherein the walls (15) are arranged in a square. A dishwasher according to claim 1, 2 or 3, wherein the axis of rotation of the sprayer (20; 20A) extends vertically through the chamber (3). A dishwasher according to any preceeding claim, wherein the sprayer (20) comprises a main portion (6) extending radially from the axis of rotation of the arm and a pivoted portion (22) pivotably mounted to the distal end of the main portion (6), the pivoted portion (22) contacting the wall (15) and pivoting about an axis parallel to the axis of rotation of the sprayer (20) so as to vary the radial extent of the sprayer (20) during rotation. A dishwasher according to any one of claims 1 to 4, wherein the sprayer comprises a telescopic arm (20A). A dishwasher according to any preceding claim, wherein a wheel or roller (19) is mounted at a radially outer part of the sprayer (20; 20A) for engaging the wall (15) during rotation of the sprayer (20, 20A). A dishwasher according to any preceding claim, wherein the sprayer comprises first and second arms (20; 20A) extending radially in opposite directions. A dishwasher according to claim 8, wherein both arms are arranged such that their radial extents adapt during its rotation such that their distal ends (19) follow the wall (15).

Inventors: JO YUNGMAN, KIM SINYONG, JO, YUNGMAN, KIM, SINYONG
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO., LTD.
Application year: 1997
Main classification: A47L15
IPC codes: A47L15