US2597359A - Dishwashing apparatus - Google Patents

Description

May 20, 1952 J. J. MCDONALD ET AL DISHWASHING APPARATUS Filed F'eb. 19,. 1947 2 SHEETS-SHEET l May 20, 1952 J. J. MCDONALD ET Al.

DISHWASHING APPARATUS 2 SHEETS-SHEET 2 Filled Feb. 19, 1947 Patented May 20, T952 DISHWASHING APPARATUS John J. McDonald, Newton, and Stephen D. Klyce, Lexington, Mass., assignors to The McDonald Company, Boston, Mass., a corporation of Massachusetts Application February 19, 1947, Serial No. 729,468

7 Claims.

This invention relates to improvements in dishwashing apparatus and more particularly to such apparatus in which oppositely directed wash sprays impinge from opposite sides upon dishes held in a rack or the like which may be removably supported between the spray pipes or nozzles. Such apparatus customarily has additional rinse sprays for directing rinse water over the dishes subsequent to a predetermined period of operation of the wash sprays.

Heretoiore, dish-washing apparatus of the general type to which the invention relates have had oppositely disposed spray pipes or nozzles for directing wash sprays simultaneously from above and from below against dishes held in a rack between the upper and lower spray pipes. In the prior apparatus, the opposed sprays, supplied from a common pressure supply conduit, cannot eiectually utilize the total available pressure because that total pressure must be divided between the upper and the lower sprays. Also, with the upper and lower wash sprays opposing each other, there is a tendency for the sprays to neutralize each other at the region where the dishes are located and such pressure or force as the individual sprays initially may have had for dislodging food particles from the dishes may be diminished considerably before the wash water comes into washing and food-dislodging contact with the dishes.

It is among the objects of our present invention to provide a dish-washing apparatus wherein upper and lower wash sprays have alternating operation so that the total available pressure of the wash water is utilized alternately for the upper and the lower sprays, and so that the full pressure of the individual sprays is effective for cleaning dishes without diminution by opposing sprays. We have found that a definitely greater efficiency of cleansing action is attained by directing forceful washing sprays alternately in one direction and then in the opposite direction, as compared with prior dish-washing procedures. If food particles are only partially dislodged by the operation of 'the sprays in one direction, a subsequent agitation thereof by the oppositely directed sprays completes the dislodgment, whereas in prior apparatus such particles frequently are lodged at neutralized spray regions and fail of being dislodged.

Another object is to provide a'dish-washing apparatus wherein there are upper and lower oppositely directed wash water spray pipes of which only the upper sprays, for example, operate for a predetermined period of time in response to manual' actuation of a starting mechanism, and then the upper sprays automatically stop and only the lower sprays operate for a predetermined period of time, followed again automatically by operation only of the upper sprays, and so on for a predetermined number of alternations of the sprays and ultimate stopping of both the upper and the lower wash sprays.

A further object is to provide a dish-Washing apparatus having upper and lower oppositely directed wash water sprays alternating automatically through a predetermined wash cycle and then adapted automaticallyl to stop, and having upper and lower oppositely directed rinse water sprays which may be manually or automatically operable from above and below the dishes following stopping of the wash sprays.

A still further object is to provide a dish-washing apparatus having spray means for directing hot water on dishes held in a spray chamber and including means for inducing outflow from the chamber of moisture-laden air and inflow of relatively dry and cool air which is rapidly circulated in drying relation to the dishes subsequent to a wash cycle of the apparatus and prior to opening of the spray chamber for removal of the dishes.

Another object is to provide a dish-washing apparatus wherein upper and lower ywash sprays operate alternately and wherein rinse sprays operate automatically at the end of the wash cycle and are separately operable independently of a wash cycle.

Yet another object is to provide a dish-washing apparatus wherein the wash water is more effectively rid of food particles prior to its re-circulation through the wash water spray pipes, as cornpared with prior comparable dish-washing apparatus.

It is, moreover, our purpose and object generally to improve the structure and eiiiciency of dish-washing apparatus and more especially such apparatus having upper and lower oppositely di- IeCted Wash Water Sprays.

Fig. 5 is a diagrammatic view of the piping and electrical connections; and

Fig. 6 is a fragmentary cross-sectional detail showing the passage for air inflow past the lower portion of the closure when the latter is closed.

Referring to the drawings, upper and lower horizontally disposed wash water spray pipes are indicated at I0 and I2 respectively. The upper spray pipes I0 are supported by and connected to the horizontal manifold pipe I4 while the lower spray pipes I2 are similarly supported by and connected to the horizontal manifold pipe i6. Both of the horizontal manifold pipes I4, I6 are connected to the vertical supply pipe I6 whose lower end is connected to the pump 28 which may be belt driven as at 22 from the electric motor 24.

The spray pipes I0, I2 and their supply pipes I4, I6 and I8 are all enclosed within a generally rectangular housing indicated generally at 26 which defines a chamber 2l within which dishes to be washed may be suitably arranged and supported. One wall of the chamber 2l conveniently may be provided with a transparent panel 28 opposite the region where the washing takes place, which is between the upper and lower spray pipes I0, l2, so that action interiorly of the housing may be observed. Also, an access Opening 30 in the side wall of housing 26 may be closed by any suitable openable closure which, as Shown, is a vertically slidable panel 32. If desired, a similar slidable vpanel 34 may lbe provided in the opposite side wall of the housing. The dishes preferably are arranged in a suitable rack (not shown) which may be inserted in chamber 2'I through the access opening 30.

As best seen in Fig. l, the housing 26 has the inclined bottom wall 35 extending a substantial distance laterally and slightly downwardly from one side wall to the other. Short of the vertical plane of the right hand side wall of the main housing 26, this bottom wall 35 joins the vertical wall 36 which constitutes a side wall of a return chamber 38 which projects substantially beyond the vertical plane of the right hand side wall ofthe main housing 26 and which is open into the interior of the main housing at 40.

Return chamber 38 is suitably mounted on a base 42 and constitutes al support for the main housing 26 above. bottom wall 35 and base 42 for supporting the left hand side portion of the main housing in vertically spaced relation to base 42, as seen in Fig. 1. Legs 44' support the base 42.

The pump 20 conveniently is located in the space between Ibottom wall 35 and base 42, to one side of Vertical wall 36. It is shown primarily supported at 46 on base 42, with its inlet 48 connected to the return chamber 38 and its outlet 50 connected to the lower end of the vertical supply pipe I8. The electric motor 24, for driving the pump, also may be supported on base 42, in

Legs 44 extend between the the space between the base 42 and bottom wall 35 of main housing 26.

According to the invention, a wash water flow control valve indicated generally at 52, is located at the juncture of the lower horizontal wash manifold pipe I6 with the vertical supply pipe I8. As represented in the showing of Figs. 3 and 4, valve 52 is rotatable to connect vertical supply pipe I8 to the upper wash manifold pipe I4, in which position it cuts oi flow from vertical pipe I8 to the lower wash manifold pipe I6, and to connect the supply end of vertical supply pipe I8 to the lower wash manifold pipe I6, in which p0- sition it cuts off flow in vertical pipe I8, beyond the valve, to the upper wash manifold pipe I4.

Alternating rotation of valve 52, first in one direction and then in the opposite direction, is accomplished by the reciprocations of a piston 54 in a cylinder 56 which is reciprocated by fluid under pressure delivered into cylinder 56 first on one side of the piston and then on the other side. As herein shown, the cylinder 56 is connected to the building hot water supply system, the pipe 58 Ibeing arleader from such a system and extending vertically within main housing 26 with itsA open lower end preferably disposed below the access opening 30, for supplying hot wash water to thelower portions of the housing, especially to the return chamber 38, it being understood that soap or the like is added to the wash water as may be desired. A manual valve 60 in pipe 58 will be closed excepting when the housing is being supplied with wash water.

A pipe 62 leads from pipe 58 on the supply side of manual valve 60 and has a four-way valve 64 therein for passing water under pressure through conduit 66 to cylinder 56 on the upper side of piston 54 while the cylinder at the lower side of the piston is connected through conduit 68, valve 64 and conduit 10 to vertical pipe '58 on the apparatus side of manual valve 60, or for passing water under pressure through pipe 68 to cylinder 56 on the lower side of piston 54 while the cylinder at the upper side of the piston is connected through pipe 66, valve 64 and pipe 'I0 to vertical pipe 58, as before. Hence, when pressure liquid is acting at one side of piston 54 to drive it in one direction in cylinder 56, the cylinder at the other side of the piston is connected for exhaust of liquid into the housing of the apparatus.

Piston 44 has a piston rod 'I2 depending through the lower end of cylinder 56, with link connection at 14 toan arm 16 which is rigid with the rotatable element of wash water supply control valve 52. When the piston is driven in one direction, valve 52 is operated to connect only the upper wash spray pipes I0 for discharge, and when the piston is driven in the opposite direction, valve 52 is operated to connect only the lower wash spray pipes I2 for discharge.

It is a feature of the invention that the upper and the lower wash water sprays operate alternately. For example, the upper and lower wash sprays may operate alternately with the upper sprays on for six seconds, and then olf for six seconds and with the lower sprays off for six seconds while the upper sprays are on, and on for six seconds while the upper sprays are olf. A washing cycle may extend through sixty seconds, for example, with the upper sprays on live times for six second operations during the cycle and with the lower sprays similarly on flve times for six second operations during the cycle, although the time period of operation and the number of operations per cycle may be varied as desired.

As hereinbefore described, the reciprocations of piston 54 operate the wash water supply control valve 52 to attain alternating operation of the upper and lower wash sprays I0, I2, and operation of the four-way valve 64 effects the reciprocation of the piston. The automatic control and timing of these mechanisms, according to the present disclosure, enables the automatic performance of a predetermined wash cycle in response to mere depression of a button. However,

a predetermined cycle of alterations of the'upper and lower wash sprays may be initiated and maintained in any desired manner and by any means, and it should be understood that the electric control as illustrated is merely exemplary.

As herein shown, a cam shaft 18 may be mounted at any convenient location, such as on the top wall 28 of the main housing. The cam shaft is driven through gears 88 by a small electric motor 82 which may be a 2 R. P. M. motor, for example, so that the cam shaft, through gears 88, makes one complete revolution in seventysix seconds, for example. However, for a purpose which later will appear, the disclosed em bodiment of the invention includes a clutch |9 for the cam shaft, and the clutch is disengaged excepting when the motor 82 is energized. Hence, when the motor 82 is de-energized, the cam shaft 18 is disconnected from its motor drive and is free to be rotated independently of the motor and the gears 88. Clutch 79 may be operated by a solenoid 8| whose coil is connected (Fig. 5) to the circuit of motor 82 so as to be energized whenever the motor is energized. Solenoid 8| has its armature 83 spring actuated in one direction and connected to the pivoted clutch-actuating lever 85. When the solenoid 8| is energized, its armature is actuated in opposition to its spring to engage the clutch, and the clutch continues engaged so long as motor 82 is in operation. Hence, the cam shaft 'I8 is rotated whenever motor 82 operates but is disconnected from the motor as soon as the motor stops. This latter is important in that it is desirable to re-set the cam shaft to a predetermined starting position following each complete or partial rotation thereof. For this purpose, a spring 81 has one end anchored and its other end connected to the cam shaft 'I8 or to some element rigid with the cam shaft, so that, as the cam shaft is rotated in one direction by the motor 82, energy is stored in the spring which restores the cam shaft to its starting position, determined by stop pin 89, as soon as the clutch 79 is disengaged when motor 82 stop-s.

The cam shaft 18 has a cam 84 fixed thereon with a high part which may have approximately 272 degrees of extent around the periphery of the cam, for maintaining a switch arm 86 closed during slightly more than three quartersy of a revolution of the cam, representing a time period of sixty seconds, for example. The switch arm 86, when closed, completes an electric circuit Athrough the pump motor 24 and maintains the pump 28 in operation until the switch arm 86 drops to the low part of cam 84 at the end of sixty seconds, which is the predetermined duration of the wash cycle in the illustrated embodiment.

Another cam 88, fixed on cam shaft 18, controls a switch arm 98 which is held closed throughout almost a complete revolution of the cam, there being only a short low part on the cam to which the switch arm 98 drops at the end of each complete revolution. Switch arm 98, when closed, completes a holding circuit through the cam shaft motor 82 so that this motor, having been started by depression of push button switch 92, continues in operation throughout the predetermined seventy-six second complete cycle of the apparatus as herein disclosed. As soon as motor 82 is started, cam 88 closes switch arm 98 to complete the holdingcircuit through motor 82. Also, the cam 84 immediately closes switch arm 88 to start the pump motor 24 to keep the 6 pump motor operating for sixty seconds or for slightly more than three quarters of a revolution of cam shaft 18.

A third cam 94, iixed on cam shaft 18, operates a switch arm 96 which controls the solenoid 98 which shifts the four-way valve 64 for attaining alternating operation of theupper and lower wash sprays. As shown diagrammatically in Fig. 5, valve 64 may have an operating arm v|88 connected to the armature |02 of the solenoid 98. with a spring |84A urging the armature to its outermost position as seen -in Fig. 5 wherein the valve 64 is set in its position connecting the supply pipe 58 throughpipe 62 to the pipe 66, and connecting pipe 68 yto pipe 18. When solenoid 98 is energized, it draws armature |82 to the right in Fig. 5, thereby to effect a. clockwise rotation of valve 64 to connect the branch supply pipe 62 to pipe 68 leading to the under side of cylinder 56 and to connect pipe 66 from the top side of the cylinder to connecting pipe 18, for exhaust. When solenoid 98 is de-energized its armature |82 returns to its position of Fig, 5, to effect a counter-clockwise rotation of valve 64 back to its position yof Fig. 5.

Cam 94, as shown, has five high portions equally distributed around Yapproximately 272 degrees of the cam, and the switch arm 96 alternately engages the high and the low portions of the cam.

In the embodiment herein represented, the cam 84 energizes solenoid 98 for iive six-second periods at six second intervals during the iirst sixty seconds of cam rotation, so that the upper and lower wash sprays will be alternately on and off live times during the wash cycle and each on period will be of six seconds duration and each oi period excepting the final off of the cycle ywill be of six second-s duration.

After the pump 28 has stopped, at the end of the sixty second wash cycle, the washed dishes are rinsed with clean hot water before being removed from the apparatus. For this purpose we provide a suitable number of upper rinse spray nozzles |86 and a similar number of lower rinse spray nozzles |88 within the chamber 21. As herein shown, all of the rinse spray nozzles are connected together for simultaneous operation, they being supplied with clean hot water under pressure through branch pipe ||8 which is connected to the hot water supply pipe 58 on the pressure side of manual valve 68. However, fiow to the rinse spray nozzles normally is prevented by the solenoid valve ||2 in the branch pipe ||8 whose solenoid I4 is energized to open valve I 2 only during the final eight seconds or so of each complete cycle of the apparatus. To this end, thecam shaft 18 has a fourth cam ||6 fixed thereon for controlling a switch arm ||8 which opens and closes a circuit through the solenoid I4. Cam I I6 has a single high portion designed to hold switch arm I8 closed only during the final eight second period of a complete revolution of cam shaft 18. Hence, during the sixty second wash cycle, solenoid ||4 will be de-energized and valve I2 will be closed. In the embodiment represented, the rinse valve ||2 continues closed for eight seconds after the wash cycle is complete and is open only during the last eight seconds of a complete seventy-six second cycle of the apparatus. This eight second delay between the stopping of the wash sprays and starting of the rinse sprays allows time for the usual dripping from the wash sprays to stop, thus avoiding dripping of washfwateron the dishes after they have been rinsed, which wouldfobjectionably spot the dishes. At the end of the rinse cycle the switch arm ||8 drops tothe low part of cam ||6 to deenergize solenoid ||4, and switch arm 90 drops to the low portion of cam 88 to stop the cam shaft motor 82, and the apparatus stops in readiness for commencement of a new cycle after the washed dishes have been removed and another rack of dishes to be washed has been inserted in chamber 21. The new cycle may .be initiated as before by merely depressing button switch 92.

It is usual to maintain the wash Water in dishwashing machines at a temperature around 140 F., and to have the temperature of the rinse water in the neighborhood of 190 F. Notwithstanding that these temperatures are somewhat below the boiling temperature of the water, there nevertheless is a considerable amount of vaporization of the hot water and, in the absence of preventive measures, the hot vapor ccnned within the machine has constantly increasing pressure which, when released by opening the wash chamber closure 32, would rush out much in the manner of a gust of steam. According to the invention the moisture-laden air is exhausted from chamber 2`| before the closure 32 is opened. A fan is provided in a flue conduit |22 which latter opens into the chamber 21. As herein shown, the fan |20 is connected for operation whenever a main switch |24 is closed, excepting during the wash cycle.

It is important to note, however, that provision is made for inflow of relatively dry and cool air to take the place of the hot moisture-laden air being exhausted through flue conduit |22. As best seen in Fig. 6, there is an opening |26 past the lower margin of closure 32, and exterior air streams into chamber 21 whenever fan |20 is operating, and the incoming relatively dry and cool air flows between and around the dishes in the chamber. 21 of objectionable moisture-laden hot air prior to opening of closure 32, but induces inflow of air which dries or partially dries the dishes prior to opening of the closure 32.

In Fig. 5, there is represented one effective embodiment of electrical control means whereby operation of the fan is controlled and whereby the described wash cycle of alternate operations of the upper and lower wash sprays may be followed by operation of the rinse sprays. As shown, the cam-controlled operation of the switch arm 86, for controlling the pump motor 24, acts through a relay |28 which initially is energized by a momentary manual depression of button switch 92. Relay |28 has the three movable contacts |29, |30, |3|', of which the contact |30 closes a circuit through the pump motor 24, and contact |3| closes a circuit through the cam-shaft motor 82 and clutch relay 8| in response to energization of relay |28. Relay contact |29 also closes in response to energization of relay |28 and completes a holding circuit through relay |28 after switch arm 86 has been closed by cam 84. The initial closing of a circuit through cam-shaft motor 82 and clutch relay 8| starts rotation of cam shaft T8 whose cam 84 immediately closes switch arm 86 to complete the holding circuit through relay |28 and this circuit continues closed throughout the wash cycle and then opens to de-energize relay |28 when switch arm 86 drops to the low part of cam 84, with consequent opening of the circuit through pump motor 24.

The initial rotation of cam shaft 18 also effects closing of switch arm 90 by the holding cam 88, thereby to complete a holding crcuit through Hence fan |20 not only rids chamber cam-shaft motor 82 and clutch relay 8| independently of relay |28, and this latter holding circuit is maintained closed through a complete wash and rinse cycle of the machine or throughout substantially a complete rotation of holding cam 88.

Contact |3| of relay |23 upon de-energization of the relay, closes a circuit through the motor of fan |20 so that the fan will be operating at all times, when main switch |24 is closed, excepting during the wash cycle.

The cam 04 which, as previously explained, effects five six-second energizations of relay- 98 at six-second intervals, to provide the alternating operation of the upper and lower wash sprays, is eiective only so long as the relay |28 continues energized. The rinse cam I6, on the other hand, can close a circuit through the solenoid ||4 of the rinse valve ||2 independently of the relay |28, and does so close a circuit during the nal eight seconds of each complete wash and rinse cycle of the machine, at which time the relay |28 is deenergized.

It frequently is desirable to operate the rinse sprays independently of any wash cycle. For example, glassware may be washed by other means than the present apparatus, and it may be desired to only rinse the glassware in the present apparatus. According to the invention such an independent rinsing may be effected by merely closing a rinse button switch |32, assuming that main `switch |24 is closed. A fifth cam |34 on cam shaft 'I8 actuates switch arm |36 which controls a holding circuit through a rinse control relay |38 and energization of cam shaft motor 82.

Closing of switch |32 energizes relay |38 which causes closing of the movable contacts |40, |42 and |44 of the relay. Closing of relay contact |40 completes a circuit through cam shaft motor 82 and clutch relay 8| which promptly rotates cam shaft 18. Closing of relay contact |42 conditions a holding circuit for relay |38 so that the holding circuit is completed through the relay as soon as cam |34 rotates to close its switch arm |36, and the relay continues energized until the switch arm |36 drops to the low portion of cam |34. Closing of relay contact |44 energizes the rinse valve control relay ||4 to start the rinse sprays |06, |08 which continue on so long as the control relay |38 is energized. The single high portion of cam |34 may be adapted to hold cam switch arm |36 closed for an eight second rinsing period, at the end of which switch arm |36 will drop to the low portion of cam |34 to de-energize relay |38, and opening of relay contacts |40, |44 de-energizes motor 82 and rinse solenoid ||4. The cam |34 may be similar to cam ||6 but has its high portion at the start of a rotation while the high portion of cam I6 is at the end of a rotation. Excepting when control relay |38 is energized, the closing of switch arm |36 by cam |34 has no effect, as during the operation of the apparatus for a washing followed by a rinsing.

After a separate rinsing operation, the spring 81 acts to re-set the cam shaft 'I8 as soon as clutch 'I9 disengages following de-energizing of motor 82 and solenoid 8|. Also, a push-button stop switch |45 is provided by which the operation of the apparatus may be stopped at any stage of a wash or rinse cycle, in which case the said spring 81 resets the cam shaft.

The cam shaft 18, its motor 82, all of the cam switch arms and the relays 8|, |26, |38 may be mounted as a unit in a suitable casing |46 as indicated in Fig. 1, with the push buttons 92, |34

9 and |45, and main switch |24, accessible at the front of they apparatus.

It will be apparent from the foregoing that the invention provides an extremely efficient dishwashing apparatus which, as shown, goes through a complete cycle in response to mere depression of button 92, including a sixty second wash cycle and an eight second rinse cycle. During the wash cycle, the dishes arevsubjected to the forceful action of the wash sprays alternately, from above and from below the dishes in chamber 21, with the upper sprays operatingv at full pressure for six second periods at six second intervals, and with the lower sprays similarly operating during the intervals when the upper sprays are 01T. This full pressure alternating operation of the wash sprays attains a definitely greater washing eiiiciency as compared with the prior practice of splitting the available pressure between simultaneously operating upper and lower wash sprays.l Also the invention avoids any neutralizing of the agitating eieot ofthe sprays, with each series of sprays acting entirely separately and uninuenced by the opposed series of sprays. What food particles may notbe entirely dislodged by the sprays operating with full force in one direction will be removed by the following sprays operating with full force in the opposite direction.

After the wash sprays have accomplished their work during sixty seconds of a complete cycle of the apparatus, the rinse sprays, above and below the dishes, operate simultaneously for eight seconds to thoroughly rinse the dishes prior to their removal at the end of the complete cycle.

VWhenever desired, rinsing may be effected independently of a wash cycle by merely closing the rinse button switch |32 to initiate a rinse cycle of eight seconds duration, for example.

Any suitable strainer |48 may be provided in the return chamber 38 within which may be suspended a suitable bag |50 of fabric or the like, for collecting food particles and other foreign matter from the water returning to the return chamber 38. A removable drain board |52 directs the returning water into the bag |50 which latter is of a sort to be thrown away when it has collected such a quantity of foreign matter that water cannot pass freely through the bag and strainer for re-circulation by pump 20. This ensures against food particles and thelike being in the re-circulated wash water.

While we have disclosed an embodiment of the invention wherein the control is entirely electric, it should be understood that othermearis may be employed to initiate a wash cycle of alternately operating wash sprays operating. alternately from above and below the dishes to be washed. Also, any suitable means, manual or automatic, may be employed for initiating a predetermined pe-l riodof operation of rinse sprays after a .wash cycle has been completed, or independently of a wash cycle.

We claim as our invention:

1. In a dish-washing apparatus, upper and lower wash water spray conduits substantially oppositely disposed in spaced horizontal planes, the upper spray conduits having spray outlets opening toward the lower spray conduits. and the lower spray conduits having spray outlets opening toward the upper spray conduits, whereby both the upper and lower sprays are directed acrossl substantially the same region but in generally opposite directions, a pump having conduit Iconnection to the said vspray conduits for a 10 delivering wash water to said spray conduits, flow control means in said connection movable to one position in which the pump output is directed only to the upper spray conduits and movable to another position in which the pump output is directed only to the lower spray conduits, means for driving said pump, and mechanism responsive to operation of said pump driving means for quickly shifting said flow control means intermittently between its two said positions, thereby to maintain substantially continuous sprays of wash water at full pump pressure across said region but with the said sprays directed across said region alternately in generally opposite directions. i

2. In a dish-washing apparatus, upper and lower wash water spray conduits substantially oppositely disposed in spaced horizontal planes,

the upper spray conduits having spray outlets opening toward the lower spray-conduits and the lower spray conduits having spray outlets opening toward the upper spray conduits whereby both the upper and lower sprays are directed across substantially the same region but in gen-- upper spray conduits and movable to anotherA position in which the pump output is directed only to the lower spray conduits, means for driving said pump, mechanism responsive to starting of said pump driving means for maintaining the pump in operation for a predetermined wash period and for automatically` stopping it at the end of the wash period, said mechanism including means connected to said flow control means and operative to quickly shift said means from one of its said positions to the other alternately at predetermined intervals during the saidwashl period of operation of the pump thereby to provide substantially continuous wash water sprays downwardly and upwardly in said region alternately from said upper and lower spray conduits. throughout said predetermined wash period of operation of the pump.

spray means in opposed relationship, and upper and lower rinse water spray means, said wash water spray means and said rinse water sprayA means being located and adapted to direct their sprays in substantially the same region, means for supplying wash water under pressure to said washY water spray means, means for supplying rinse water under pressure to said rinse water spray means, flow-control means for the wash water supply operative in one position to direct the wash water at full pressure only to the upper,

wash water spray means, and operative in another position to direct the wash water at full pressure only to the lower wash water spray means, means for quickly shifting the said positions of the now-control means a predetermined number of times at predetermined time intervals during a predetermined wash period of Operation of the apparatus thereby to provide substantially continuous spraying, throughout the wash period but with theupper V4and lower spray means operating alternately, and means for opening the rinse water supply means automatically after a predetermined interval following the wash period thereby to start the rinse water sprays only after the said interval within which dripping 11 from the upper wash water spray means will, have stopped.

4. In a dish-washing apparatus.v upper and lower wash water spray conduits arranged in generallyl horizontally opposed relationship,v and upper and lower rinse water spray conduits arranged and adapted tov discharge their sprays generally in the same region in which the wash sprays discharge, a pump connected to the washY water spray conduits for supplying wash water thereto at a predetermined pressure, a: rinse water supply conduit connected to the rinse water spray' conduits for supplying rinse water thereto at a predetermined pressure, a. valve controlling the water supply to thev rinse.A water spray conduits, a wash water control valve between the said pump and the upper and lower wash water sprayV conduits and operative. inonev position to direct the full pump outputtothe upper wash water spray conduits and operative. in another position to direct the full pumpoutput to the lower wash water spray conduits, meansforstarting and stopping thevpump, and means responsive to the rinse water supply pressure for automatically quickly shifting said` wash water control valvev alternately and at` intervals, from.v one of its said positions to the other whenever said pump is operating.

5. In a dish-washing apparatus having upperand lower washwater spray conduits in generally horizontal opposed relation and adapted toA direct. sprays of wash Water generally in the same area but in opposite directions, upper and lower rinse water spray conduits arranged and adapted to direct sprays of rinse water in oppositel directions generally in the same area in whichl the wash sprays are directed, the combination therewith. of means for supplyingr wash water to thevupper wash water sprays a, predetermined number of. times at predetermined intervals and for. supplying wash water to the lower. washwater-sprays substantially throughout the said intervals when the upper wash water spray conduits are not. bel ing supplied, and means operative only after the wash sprays have stopped for supplying rinsev water to the upper and lower rinse water sprayv conduits simultaneously thereby to provide oppositely directed simultaneous upper and lower rinse sprays in the same region previously trav.-`

ersed by the alternating upper and lower wash sprays.

6.` In` a dish-washing apparatus, upper and lower wash` water spray pipes in generally horizontal opposed relation and adapted to directv sprays of wash water generally'in the same. area: but in opposite directions, and upper and` lower rinse water spray nozzles arranged and adapted to direct sprays of rinse water in opposite directions generally in the same` `area in which the wash sprays are directed, a pump for delivering wash water toy said wash water spray pipes, a wash water control valve operative inone position to direct the full pump output only to the upper wash water spray pipes and operative in another position to direct the full pump4 output only to the lower wash water spray pipes, means for drivingthe pump for a predetermined wash period and for stopping it at the` end of the period, means operative only during; said wash period for quickly shifting said wash waterv control valve between its said positions a prede,-l

l2 termined number of times at predetermined intervals during said wash period thereby to provide substantially continuous wash sprays throughoutthe wash period with the upper and lower sprays discharging' alternately, and means for supplying rinse water to both the upper and lower rinse water spray nozzles simultaneously and automatically only at the end of a predetermined drip/periodv following said wash period.

7. In a dish-washing apparatus having upper and. lower washwater spray pipes in generally horizontal opposedlrelation and adapted to direct spraysv of Wash water generally in the same area butin opposite directions, and upper and lower rinse'ewater spray nozzles arranged and adapted to direct sprays of rinsewater in opposite directions generally in. the same area in which the wash.spraysv arev directed, a chamber below said spray: pipes and nozzles for holding a 'supply of wash water, a hot water pressure supply conduit for supplying hot rinse water to said upper and lower. spray' nozzles and for replenishing the supply oi wash water in said chamber, manual means inv saidy conduit for controlling the replenishingrofsaidl chamber, electrically operated means for controlling the supply of rinse water to saidspray nozzles, a pump for delivering wash water from said chamber to said wash water spray pipes, electrically operated means for driving the pump, including meansv for stopping it at. the end. of a predetermined period of operation, a valve operative in one position to direct all. of-l the; pumpA output only tol the upper wash water spray pipes and operative in another position to direct all of the pump output to only the lower wash water spray pipes, means including a cylinder and pressure-actuated piston for alternating the positionsv of' said valve a predetermined number, of times automatically at predetermined intervals during said period of operation of thepump, and means operative following stopping ot thepum-pfor opening said rinse water control means fora predetermined period following stopping ofthe pump.

JOHN J. MCDONALD. STEPHEN D. KLYCE.

REFERENCES CITED The following references are of record in the le ot this patent:

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