Self-reversing Spray Arm Assembly For A Washing Appliance

Abstract

A spray arm in an automatic dishwashing machine is caused to rotate on its axis from the resultant reactive force of a washing liquid conducted through the body of the spray arm and then outwardly as a jetstream. The jetstream is discharged from a nozzle mounted to swivel between two drive positions on the body of the spray arm. The nozzle is intermittently released so that it will react to the force of the washing liquid discharged therefrom and swivel from one of its drive positions to the other and thereby reverse the direction of rotation of the spray arm.

Description

BACKGROUND OF THE INVENTION

In recent years most manufactures of household automatic dishwashing machines have adopted the general construction of a cabinet defining an inner washing chamber having a reactive spray arm rotatably mounted within the chamber. The spray arm is for the purpose of distributing a recirculating flow of washing liquid on soiled articles supported within the chamber, and is reactively driven in rotation by means of the discharge force of recirculated washing liquid emitted from at least one discharge port or orifice on the spray arm. Generally, in today's automatic dishwashing machine, the spray arm is mounted to rotate on a transverse vertically oriented axis. This is particularly true of the so-called portable dishwasher that is provided with means for temporarily coupling it to the kitchen sink faucet and also with respect to the type of dishwasher designed to be integrated with the kitchen cabinetry so that its top wall forms a part of the cabinet counter surface.

The purpose of mounting of the spray arm for rotation is to achieve an improved pattern of washing liquid distribution in the washing chamber. A further refinement that has been proposed to assure that the pressurized washing liquid will contact all of the various surfaces of the items stored in the supporting racks in the washing chamber is the provision of means to successively reverse the direction of rotation of the spray arm during the washing and rinsing steps of the operational cycle. This reversal of rotation of the spray arm can be employed both on the aforementioned type of spray arm that is rotatable on a transverse vertically oriented axis and also on the type of spray arm that is disposed longitudinally for rotation or oscillation on a horizontal axis. The latter type spray arm construction has been suggested particularly for comparatively small counter top dishwasher cabinets. It was from the realization of the comparative efficiency of a reversing spray arm that the need developed for a comparatively low cost and mechanically simplified means for effecting the spray arm's sequential reversal.

It is therefore an objective of the present invention to provide a simplified and reliable means of sequentially reversing a rotating spray arm in an automatic dishwasher.

It is a further objective of the present invention to provide a spray arm sequential reversal means that is adaptable in one form to the type of spray arm that rotates on a transverse vertically oriented axis, and in another form to the type of spray arm that is adapted for rotation or oscillation on its horizontal longitudinal axis.

It is a further objective of the present invention to provide a simplified means for effecting sequential reversal of a rotatable spray arm in an automatic dishwasher that may be automatically controlled by the dishwasher's control means whereby each successive reversal action will occur after a predetermined time lapse.

A later version of the present invention is incorporated in the structure of the invention set forth in an earlier filed copending application, Ser. No. 799,574 of Lauren W. Guth entitled "Washer With Self-Reversing Spray Arm Assembly."

SUMMARY OF THE INVENTION

In one form of my invention I provide, for an automatic article-washing machine having a washing chamber and means for supplying pressurized washing fluid to the chamber, a spray arm assembly including a hollow spray arm adapted to rotate on a transverse axis and to receive pressurized washing fluid through the hollow body thereof. A rotatable jet nozzle is disposed on the spray arm near one end thereof for discharging pressurized washing fluid therefrom and into the washing chamber. The outlet end of the jet nozzle is oriented such that the reactive force of the fluid discharge therefrom will impart rotation to the spray arm. A mechanism is provided in combination with the jet nozzle to lock the jet nozzle in either of two drive positions on the spray arm whereby the spray arm will be caused to rotate in one direction or the other in response to the reactive force of the nozzle's fluid discharge. The locking means is intermittently released so that the jet nozzle will react to the force of its fluid discharge and rotate on the spray arm from its then drive position to its other drive position. The two drive positions are opposite each other so that the rotating spray arm will be slowed, halted, and then caused to move in counter rotation each time the nozzle swivels from one drive position to the other.

In another form of the invention a spray arm assembly is provided for an automatic article-washing machine and includes a hollow elongated spray arm adapted for oscillation on its longitudinal axis. A jet nozzle is mounted for rotation on the spray arm body and receives pressurized washing fluid from the spray arm and ejects it outwardly whereby the spray arm is caused to turn on its longitudinal axis by the reactive force of the emitted fluid discharge. A blocking mechanism is provided in combination with the rotatable jet nozzle to hold the jet nozzle in either of two oppositely facing operative positions whereby in one operative position the nozzle is oriented to discharge its jet substantially at a right angle to the axis of the spray arm and thereby cause the spray arm to turn in one direction in response to the reactive force of the jet discharge. The locking mechanism is automatically released when the spray arm has rotated a predetermined distance on its axis whereby the jet nozzle then rotates on its own axis relative to the spray arm to the other drive position. The aforementioned locking mechanism stops the rotating jet nozzle, after it has completed substantially a half revolution, at a drive position whereby its jet flow is directed outwardly in a direction opposite to that of the first mentioned drive position. The reactive force of the jet flow then causes the spray arm to reverse its direction of rotation. The locking mechanism is intermittently automatically released and repositioned, permitting the rotatable jet nozzle to swivel between its two operating positions and thereby impart a continually reversing or oscillatory rotative motion to the spray arm.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view of an automatic dishwashing machine having an oscillating spray arm assembly in accordance with one form of my invention;

FIG. 2 is a plan view of the lower end of the washing chamber in horizontal section in the washing machine shown in FIG. 1;

FIG. 3 is a substantially enlarged view of a portion of the spray arm assembly first shown in FIG. 1, having portions thereof shown in vertical section;

FIG. 4 is a fragmentary elevational view of a portion of the spray arm assembly shown in FIG. 1;

FIG. 5 is a front elevational view of an automatic dishwashing machine having a large section of the cabinet

FIG. 5 is a front elevational view of an automatic dishwashing machine having a large section of the cabinet front side cut away to illustrate an alternate form of the spray arm assembly of my invention;

FIG. 6 is a fragmentary plan view of one end of the spray arm shown in FIG. 5, here shown substantially enlarged; and

FIG. 7 is an enlarged elevational view of certain related components of the spray arm assembly first shown in FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1 there is illustrated an automatic dishwashing machine 11 including a cabinet 11 defining therein a washing chamber 12. Access to the washing chamber 12 is obtained by opening a door 13 pivoted at its lower end and located on the front side of the cabinet 11. Upper and lower dish-supporting racks 14 are supported for slidable movement within the washing chamber 12 so that either may be separately slid outwardly to extend through the cabinet's front access opening to facilitate loading and unloading of tableware therein. The lower end of the washing chamber 14 is defined by a bottom wall or floor portion 15 that separates it from a lower motor-pump compartment 16. Housed within the compartment 16 is a motor-pump assembly 17 including an electric motor 18 that powers a pump means 19 for recirculating washing liquid to and from the washing chamber 12 and for draining washing liquid from the machine to the household sewage system.

The operational washing cycle of such a machine generally includes a number of rinsing and washing steps and a final drying step. In a dishwashing machine such as that shown in FIG. 1, heated water from the household supply line is directed into the washing chamber 12 by a valve means (not shown). The water accumulates to a predetermined level on the floor portion 15 and then a timer control means (not shown) of the machine activates the electric motor to drive the pump 19 in a recirculation operation. In the recirculation operation, the accumulated washing liquid is drained outwardly from the washing chamber 12 by means of a conduit 21 leading to the pump 19 and is then forced upwardly by the pump 19 through a conduit 22 leading to a hollow elongated longitudinally disposed spray arm 25 located within the lower portion of the washing chamber 12.

Generally, clean water is introduced into the machine for the wash step and each rinse step, and detergent is added, by automatic means (not shown), for the wash step. The term "washing liquid" is therefore used herein in a generic sense to refer broadly to any form of cleansing liquid utilized for recirculation in the machine. The washing liquid is distributed from the spray arm 25 by means of orifices 25a spaced therealong (FIG. 2) which separate the flow into a spray pattern over the tableware contained in the racks 14. The recirculation of the washing liquid from the washing chamber 12, through the pump and then through the spray arm, is continued for a predetermined length of time after which the electrical circuit to the motor 18 is automatically interrupted to halt the pumping action. Thereafter, the motor 18 is automatically reenergized in a reverse direction whereby the pump 19 pumps the effluent from the washing chamber 12 and through a drain line 20 to the household sewage system.

As shown in FIGS. 1 and 2, the bottom wall or floor portion 15 of the chamber 12 is formed to have a downward depression generally toward its center so that the accumulated liquid in the washing chamber 12 will gravitate toward a drain opening 15a leading to the drainage conduit 21. As shown most clearly in FIG. 3, one end of the bottom wall 15 is formed with spaced-apart projections 15b directly beneath one end of the spray arm 25. The upward projections have a concave trough 15c formed therebetween and beneath the spray arm end. The spray arm 25 is supported at each end by suitable pillow blocks 26 to enable it to rotate about its longitudinal axis as will be hereinafter further described.

In the form of the improved spray arm assembly of my invention illustrated in FIGS. 3 and 4, the longitudinally elongated spray arm 25 has a jet nozzle 30 mounted thereon for rotation on an axis perpendicular to the axis of rotation of the spray arm 25. The jet nozzle 30 has a tubular body whereby washing liquid can be received therethrough from the hollow body of the spray arm 25 and ejected outwardly into the washing chamber 12 of the dishwashing machine 10. The body of the nozzle 30 has a compound curved configuration, in which the inner nozzle portion 31 extends perpendicularly outwardly relative to the axis of the spray arm 25. An intermediate nozzle body portion 33 extends from the outer end of the portion 31 and is disposed perpendicular to the axis of rotation of the jet nozzle, which is the longitudinal axis of portion 31. An outer end portion 34 of the nozzle 30 is a comparatively short portion disposed with its axis perpendicular to the axis of the intermediate body portion 33.

The jet discharge emitted from the open end of the body portion 34 will exert a reactive force or counterimpedus against the nozzle 30 and urge it to rotate about the axis of the major body portion 31. The body of the nozzle 30 is preferably of a smooth tubular construction having a constant diameter therethrough. The inner end of the nozzle 30 is provided with a radially outwardly extending annular flange portion 32 which serves to retain it in its mounted position while permitting it to rotate in the intended manner. An integral lateral projection or finger 35 extends outwardly from the major body portion 31 of the nozzle 30 for a purpose hereafter described.

The nozzle 30 is supported on the spray arm 35 by means of a supporting member 36 having a curved saddle portion 37 shaped to conform to the outer configuration of the spray arm 25. A hollow cylindrical portion or collar 38 extends centrally outwardly from the salle portion 37 and serves as a supportive socket for the nozzle 30. The supporting member 36 may be fastened to the spray arm body by means of rivets 39, and is disposed thereon in a position whereby the opening through the collar 38 is in alignment with the opening of similar size through the body of the spray arm 25 for both to accommodate portion 31 of the nozzle 30. It should be noted that the tubular body portion of the nozzle 30 may be formed from rigid plastic, with the lower end flange 32 being formed separately and fixed in the position shown by use of a suitable bonding agent or by screw threading to the nozzle. This would be done after the tubular portion of the nozzle 30 has been placed in its position within the collar 38 of the supporting member 36.

A nozzle control rod or lever 40 constitutes a part of a locking mechanism, in combination with the finger 35, that acts to prevent the nozzle 30 from rotating continuously on its axis when washing liquid is being received therethrough from the spray arm 25 and discharged to the washing chamber 12. Lever 40 extends laterally over the spray arm 25 and is pivotally attached to the side of the collar 38 by a screw 46 that extends through an opening in an intermediate lever portion 43 and thence into a threaded socket in the sidewall of the collar 38. The lever 40 is curved at its intermediate lever portion 43 and has a pair of upwardly projecting lugs spaced apart relative to each other whereby a lug 44 is disposed on one side of the jet nozzle 30, and a similar lug 45 is disposed on the opposite side of the nozzle 30.

In the operation of the spray arm mechanism shown in FIGS. 1--4, the lever 40 serves as a trigger or tripping lever for repeatedly locking and releasing the rotatable nozzle 30. Reference to the disposition of the components of the spray arm assembly in FIG. 3 shows that the finger 35, laterally jutting from the sidewall of the nozzle 30, is abutting against lug 45 of the lever end portion 42. With the nozzle end portion 34 oriented to the right as shown in FIG. 3, washing liquid discharged therefrom will tend to drive the spray arm about its longitudinal axis in a counterclockwise direction since the nozzle 30 is prevented from turning on the spray arm because of the engagement of the finger 35 with the lug 45. As the counterclockwise rotation of the spray arm 25 proceeds, the outer end of the lever arm portion 41 will be moved downwardly so that it will strike an upwardly projecting boss 48. The boss 48 is formed in the washing machine's bottom wall 15 on one of the floor projections 15b. When the lever arm end portion 41 strikes the boss 48, the lever 40 will stop moving while the counterclockwise rotation of the spray arm 25 continues, thus causing a relative pivoting movement of the lever 40 relative to the spray arm about the screw 46. In a relative sense, the lever 40 will pivot on the screw 46. The lever end portion 42 will move relative to the nozzle 30 and thereby move the lug 45 out of engagement with the nozzle finger 35. The nozzle 30 is then free to rotate on its axis in response to the force of the jet discharge emitted therefrom. When the nozzle 30 thus turns on its axis relative to the spray arm 25, the finger 35 will be reengaged by the lug 44. This will halt the nozzle 30 at its other drive position wherein the nozzle end 34 will be disposed in a direction opposite to that shown in FIG. 3. With the nozzle 30 prevented from turning on its own axis relative to the spray arm 25, the impedus of the jet discharge from the nozzle 30 is translated through to the rotatable spray arm 25. The spray arm 25 is thus caused to rotate in a clockwise direction until the lever end 42 swings downwardly and contacts the boss 49. The lug 44 is thereby disengaged from the nozzle finger 35 thus releasing the nozzle 30 for rotation and a complete repetition of the spray arm reversal action. This reversal action will continue repeatedly, so long as washing liquid is being pumped outwardly through the spray arm and thence from the nozzle 30.

An alternate embodiment of my invention involves the utilization of a rotatable jet nozzle disposed on the end of a spray arm to reverse the rotation of the spray arm about a transverse spray arm axis. In FIG. 5 there is illustrated an automatic dishwashing machine 55 having a cabinet 56 defining an inner washing chamber 57. Access to the washing chamber 57 is obtained by opening a substantially large front door 58 which is hinged along its lower edge. With the front access door 58 in the open position, a pair of upper and lower dish-supporting racks 59, movably mounted within the washing chamber 57, can be manually pulled outwardly to extend through the access opening to permit loading and unloading tableware therein. The washing chamber 57 has a lower bottom wall or floor portion 60 that separates it from a motor-pump compartment 61. Housed within the compartment 61 is a motor-pump assembly 62 including an electric motor 63 that drives a recirculation and discharge pump 64. The washing chamber floor portion 60 is provided with an upwardly humped portion 60a, and a pedestallike conduit 65 extends upwardly therethrough from the pump 68 to provide recirculated washing liquid to a hollow spray arm 70. The spray arm 70 is rotatably supported on the upper end of the conduit 65 and has a plurality of spaced-apart orifices 71 in the upper surface thereof (FIG. 6) for providing a uniform spray pattern over tableware contained in the racks 59 thereabove.

Just as described with reference to the dishwashing machine illustrated in FIG. 1, water is directed into he washing chamber 57 by a valve means (not shown). After a timed interval, the accumulated liquid is drained outwardly from the washing chamber 57 through a collecting sump 66 that carries it downwardly to a conduit 67 and thence into the pump 64. The motor 63 is automatically energized to drive the pump 64 and thereby pump the washing liquid upwardly through the conduit 65, thence into the spray arm 70, and then to the washing chamber 57 as a cascading spray. At the end of each rinse or wash step in the operational cycle of the dishwashing machine, a diverter valve (not shown) in the housing of the pump 64 is automatically repositioned whereby the washing liquid is pumped outwardly through a discharge conduit 68 to the household sewage system. The improved spray arm assembly utilized in the dishwasher machine in FIG. 5 is shown in greater detail in FIGS. 6 and 7.

FIG. 7 illustrates that an opening 72 is provided in the upper side of the spray arm 70, adjacent one end of the spray arm, for mounting a rotatable nozzle 73. The nozzle 73 is illustrated in FIG. 7 as having a comparatively narrow intermediate neck portion 74 and a lower end annular flange portion 75. The portion of the jet nozzle 73 that is above the intermediate neck portion 74 is substantially the same as the configuration of the jet nozzle described heretofore with reference to the first embodiment shown in FIGS. 1 through 4, so it is referred to generally after as upper nozzle portion 76. The jet nozzle 73 is provided with an integral laterally extending finger 78 that operates cooperatively with a pivotal plate 80 for locking and releasing nozzle 73 in the operation of the spray assembly.

The plate 80 has a substantially large opening 81 therein, and oppositely disposed portions of the plate 80 extend inwardly into the area of the opening 81 to form shoulders 82 ad 83. The plate 80 is pivotally fastened by means of a rivetlike fastener 84 disposed at one end of the plate 80, as shown in FIG. 6. FIG. 6 also shows that the plate 80 is provided with an outward extending finger portion 85. A vertically oriented stationary post 86 extends upwardly from the floor portion 60 (FIG. 5) and has a blocklike head portion 87 located at the upper end thereof, with an arm 88 extended from the head portion 87, for contacting the plate finger 85.

Assuming that when operation of the dishwashing machine shown in FIG. 5 is initiated, the nozzle 73 is disposed in the drive position presently shown in FIG. 6, washing liquid discharged from the nozzle 73 exerts a counterforce thereagainst, and since the jet nozzle is unable to turn because the finger 78 is in contact with the shoulder 82, the force is translated through to the spray arm 70 and it is caused to rotate counterclockwise, as viewed from a position looking downward thereon.

It will be noted with reference to FIG. 6 that counterclockwise rotation of the spray arm 70 will cause the plate 80 to be pivoted on its pivot point or fastener because the plate finger 85 will be displaced by striking the stationary arm 88 extending outwardly from he post head 87. Such pivotal action applied to the plate 80 will cause the shoulder 82 to move out of the path of the jet nozzle finger 78, thus releasing the jet nozzle for rotation on its vertical axis. The jet nozzle will then react to the force of the jetstream emitted therefrom and rotate clockwise as viewed in FIG. 6, until the finger 78 engages against the shoulder 83. This engagement will lock the nozzle 73 at is other operative position. It will be noted that the plate 80 will move or pivot, when the finger 85 strikes the arm 88, in a short arc limited by finger 83 striking the side of nozzle 73, such that the finger 85 remains in engagement with the arm 88, thus halting the spray arm rotation. The finger 78, being in the same horizontal plane as the plate 80, tracks against the plate edge defining the periphery of the opening 81. Thus, as the nozzle 73 rotates, the nozzle finger 78 tends to urge the plate back to the position shown in FIG. 6. The nozzle 73, however, is now positioned to direct its stream in a direction opposite to that of the drive position shown in FIG. 6, and will therefore cause the spray arm 70 to rotate in a clockwise direction. As the spray arm 70 is urged to rotate in a clockwise direction the plate finger 85 again strikes the fixed arm 88 and thereby pivots the plate 80 and causes the shoulder 83 to move away from engagement with the nozzle finger 78. The nozzle 73 is then free to react to its jet discharge and rotate back to the first described drive position where the finger 78 again engages the shoulder 82. The rotation of the spray arm 70 will be continuously reversed as heretofore described so long as washing liquid is being pumped through the spray arm 70 and outwardly through the nozzle 73.

Referring now to FIG. 7 it will be seen that the mechanism shown in FIGS. 5 and 6 can be modified so that the reversal of the rotation of the spray arm 70 can be automatically timer controlled. In other words, instead of being reversed at each full revolution, as would be true with the use of the stationary post 86, the mechanism may be modified whereby the spray arm 70 can complete a predetermined number of turns on its axis before the reversal action is initiated.

FIG. 7 shows that a tubular post 89 may be mounted on the washing chamber floor portion 60 and be provided with a vertically reciprocable rod 90 carried within the post 89. The rod 90 has a lower end that projects through an opening in the floor or bottom wall 60 and has a laterally extending lower end portion 91 for connecting it to a drive mechanism mounted beneath the chamber bottom wall 60. The upper end of the rod 90 is provided with a head portion thereon that is similar to the head portion 87 shown in FIG. 6. A rigid arm 93 extends laterally from the head 92 for engaging the finger 85 projecting outwardly from the pivotal plate 80. An annular flexible seal 95 is disposed within the upper end of the post 89 for sealing around the rod 90 to prevent washing liquid from leaking down through the post 89.

The drive mechanism for the rod 90, mounted beneath the chamber bottom wall 60, includes an arcuate-shaped lever 96 pivotally mounted at point 97. The lever 96 has an opening 98 provided at one end thereof for engaging the lower end portion 91 of the rod 90. The lever 96 is connected at its pivot point 97 through a rigid bracket 100 extending downwardly from the undersurface of the chamber bottom wall 60, and a wire spring 101 is provided to urge the lever 96 normally in a clockwise direction on its pivot point 97, as viewed in FIG. 7, whereby the rod 90 will normally be urged upwardly in the tubular post 89. A downward extending end 99 of the lever 96 is interconnected by a rod 102 to a horizontally movable armature 103 of a stationary solenoid 104.

It can be readily seen that electrical energization of the solenoid 104 retracts the rod 102 and pivots the lever 96 whereby the rod 90 is drawn downwardly. Such downward movement of the rod 90 places the arm 93 into the path of movement of the finger 85 extended from the plate 80. Interrupting the current through the solenoid 104 releases the armature 103 so that it moves outwardly and allows the spring 101 to urge the lever 96 to the position shown in FIG. 7, thereby raising the rod 90. This moves the arm 93 out of the path of the finger 85.

Thus, the reversal action of the spray arm mechanism described herein with reference to FIG. 6 can be automatically timer controlled whereby the reversal action will take place after a predetermined time lapse. For example, it may be considered desirable to have the spray arm 70 rotate on its transverse axis in one direction for a time interval of 15 seconds and then reverse it so that it will rotate in the other direction for an interval of 15 seconds. The electrical circuit to the solenoid 104 can be adapted to be closed by the timer control means (not shown) of the washing machine whereby the solenoid will be momentarily energized every 15 seconds during each wash and rinsing step of the operational cycle of the dishwashing machine.

As will be evident from the claims appended hereto, it is not intended that the invention be limited only to the embodiments described heretofore or to the particular detailed construction of the examples illustrated in the accompanying drawings.

Claims

I claim:

1. In an automatic article-washing machine having a washing chamber and means for supplying pressurized washing fluid to said chamber, an automatically reversing spray arm assembly comprising:

a. a hollow spray arm mounted for rotation and adapted to receive said pressurized washing fluid therethrough,

b. a nozzle mounted to rotate on said spray arm, on an axis perpendicular to the longitudinal axis of said spray arm, for discharging the pressurized washing fluid into the wash chamber and for rotating said spray arm on said perpendicular axis as a result of the reactive forces of the fluid discharge therefrom,

c. locking means on said spray arm to maintain said nozzle alternatively in at least two different fixed positions relative to said arm, and

d. means for intermittently releasing said locking means whereby said nozzle is permitted to rotate on said perpendicular axis, as a result of the reactive force of the washing fluid discharge, from one fixed position to another relative to said spray arm and thereby cause said spray arm to reverse its direction of rotation.

2. A reversing spray arm assembly in an automatic dishwashing machine comprising:

a. a rotatable spray arm adapted to receive a pressurized liquid,

b. a rotatable jet nozzle on said spray arm, adapted to receive pressurized liquid from said spray arm, and continuously discharge said liquid as it is received, for imparting rotative movement to said spray arm from the resultant reactive force of liquid discharge flow therefrom, and

c. said rotatable jet nozzle being adapted to move relative to said spray arm and thereby change the direction of liquid discharge flow therefrom and reverse the direction of rotation of said spray arm, and

d. releasable locking means for engaging and maintaining said nozzle in a fixed position relative to said spray arm, and means for intermittently releasing said locking means so that said nozzle will rotate on its axis in response to the resultant reactive force of the liquid discharge flow.

3. The invention of claim 2, wherein said spray arm is a longitudinally elongated structure having an internal liquid passageway therethrough with discharge apertures spaced apart therealong for directing respective streams of washing liquid therefrom, said spray arm is adapted to be oscillated on its longitudinal axis, and said releasable locking means permits successive oscillations of said spray arm.

4. The invention of claim 2, wherein said spray arm is a longitudinally elongated structure adapted for rotation on a transverse axis.

5. A reversing spray arm assembly in an automatic dishwashing machine comprising:

a. a rotatable spray arm adapted to receive a pressurized fluid,

b. a fluid discharge means on said spray arm for imparting rotative movement to said spray arm from the resultant reactive force of fluid discharge flow therefrom, and

c. said fluid discharge means being adapted to move relative to said spray arm and thereby change the direction of fluid discharge flow therefrom and reverse the direction of rotation of said spray arm,

d. releasable locking means for releasing and maintaining said fluid discharge means in a fixed position relative to said spray arm, and

e. means for intermittently releasing said locking means, including means adapted to be intermittently electrically energized.