US3706317A

US3706317A - Module treating apparatus

Info

Publication number: US3706317A
Application number: US60237A
Authority: US
Inventors: Gerald B Fox; Wray E Dudley; Stuart E Athey
Original assignee: Hobart Manfacturing Co
Current assignee: Hobart Corp
Priority date: 1970-08-03
Filing date: 1970-08-03
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19

Abstract

Food storage modules, tray carts, and other large food handling equipment are sequentially subjected to timed washing and rinsing treatments as they are intermittently conveyed on dollies through a wash chamber and a rinse chamber. Each chamber has a treatment station which includes horizontally and vertically directed power spray apparatus, and the modules are intermittently stopped for relatively short periods of time in which their interiors and exteriors are washed and rinsed with recirculating wash and rinse solutions. Communication between the chambers is controlled by pivotal doors at the inlets and outlets of each chamber which operate in timed sequence with the washing and rinsing operations. The pivotal doors substantially seal the chambers during the power spray operations and minimize intermixing of the wash and rinse solutions. After the simultaneous power sprays in each chamber are completed, the modules are subjected to a hot rinse by separate horizontal and vertical spray apparatus as they are conveyed out of the rinse chamber. Sequencing of the conveyor is controlled from positioning of a dolly at a discharge station.

Description

United States Patent Fox et a1.

[ 54] MODULE TREATING APPARATUS [72] Inventors: Gerald B. Fox; Wray E. Dudley;

Stuart E. Athey, all of Troy, Ohio [73]v Assignee: The Hobart Manufacturing Com pany, Troy, Ohio [22] Filed: Aug. 3, 1970 [21] Appl. No.: 60,237

[52] US. Cl. .....134/57 DL, 134/46, 134/72, 134/129 [5 1] Int. Cl. ..B08b 3/02 [58] Field of Search 134/45, 46, 48, 50, 57 R, 57 DL, 134/72, 95, 123,129,131, 58 R, 58 DL [56] References Cited V V V UNITED STATES PATENTS 2,258,562 10/1941 Arey et a1. ..l34/58 R 2,393,215 1/1946 Arey et al. ...134/58 RX 3,096,775 7/1963 Clarke et a1. ..134/l23 2,947,311 8/1960 Fox et al ...l34/72 X 7 3,277,906 10/1966 Goldman ...l34/57 R 2,864,387 12/1958 Federighi et al ..134/48 X 3,289,238 12/1966 Sorenson et a1. ..l34/123 X FOREIGN PATENTS OR APPLICATIONS Primary ExamineF-Robert L. Bleutge Attorney-Marechal, Biebel, French & Bugg [57] ABSTRACT Food storage modules, tray carts, and other large food handling equipment are sequentially subjected to timed washing and rinsing treatments as they are intermittently conveyed on dollies through a wash chamber and a'rinse chamber. Each chamber has a treatment station which includes horizontally and vertically directed power spray apparatus, and the modules are intermittently stopped for relatively short periods of time in which their interiors and exteriors are washed and rinsed with recirculating wash and rinse solutions. Communication between the chambers is controlled by pivotal doors at the inletsand outlets of each chamber which operate in timed sequence with the washing and rinsing operations. The pivotal doors substantially seal the chambers during the power spray operations and minimize intermixing of the wash and rinse solutions. After the simultaneous power sprays in each chamber are completed, the modules are subjected to a hot rinse by separate horizontal and vertical spray apparatus as they are conveyed out of the rinse chamber. Sequencing of the conveyor is controlled from positioning of a dolly at a discharge station.

3/1953 Great Britain ..'.134/100 2/1934 Netherlands ..l34/ 129 11 Claims, 8 Drawing Figures soul 20 35 1h 20 souz i x l PATENTEDUEC 19 m2 SHEEI 3 0F 4 FIG 7A WMZ M SB

1 MODULE TREATING APPARATUS BACKGROUND OF THE INVENTION With the increase in travel and the need for preparing foods for large groups of travelers, a corresponding need has arisen for a means of quickly and efficiently cleaning food storage cabinets or the like which are used for providing means in large quantities. For example, facilities are required in high-passenger aircraft for feeding 200 or more people on a routine flight. Dinners are pre-prepared and stored in the aircraft in large cabinets or modules, and are heated prior to being served to passengers enroute. Other modules might be used as heating units, frozen food units, cooling units, or ambient temperature units.

The National Sanitation Foundation and the US. Board of Health have established rigid requirements for the cleaning of food handling equipment. These requirements have presented several practical problems for cleaning the aircraft food cabinets, which are rather large, on the order of 6 feet high and feet square, and are difficult to clean because they have deep internal compartments with large doors, as well as tray carts and other large items.

For example, to meet health requirements, definite quantities of cleaning and rinsing solutions maintained at a temperature of about 140 F. and above must be sprayed against the equipment. These requirements are satisfied in conventional washing apparatus by utilizing a long dwell time, generally obtained by pushing the item to be washed through one or more treatment chambers at a relatively slow speed.

This type of apparatus is impractical for the large aircraft food cabinets because excessively long cleaning chambers would be required to achieve the long dwell times. In airports where the modules are cleaned, space is at a premium, and the long cleaning chambers would waste otherwise valuable space. Moreover, conventional cleaning apparatus utilizes curtains or the like to separate the chambers which permit an undesirably high degree of liquid intermixing to occur between chambers. This weakens the washing solution, and a longer wash cycle or a correspondingly longer apparatus is needed to achieve the quality of cleaning required. 9

SUMMARY OF THE INVENTION The present invention is directed to a novel apparatus for efficiently cleaning large food cabinets or chamber and a rinse chamber and means for intermit- I tently moving the modules to treatment stations within each chamber where they are intermittently stopped in the preferred embodiment for about 8 seconds or more. Each chamber has a drainage tank wherein the wash and rinse solutions are recovered, heated, strained and recirculated. The pivotal doors substantially close and seal the chambers from each other and minimize intermixing of the respective solutions while they are simultaneously delivered into and/or over the modules in the respective chambers,

In the preferred embodiment, the modules are intermittently conveyed through the chambers on wheeled dollies. An endless chain conveyor traverses substantially the full length of the apparatus, and has a plurality of dogs which interlock with a bracket mounted on the dollies and move the dollies to the treatment positions in each chamber. The dogs are spaced on the chain and, each time a successive dog moves a distance equal to the length of one treatment chamber, the dog intermittently stops the modules at the treatment stations by actuating a stop switch adjacent the chain assembly.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation of the apparatus of the present invention and showing the module (in dotted lines) opposite the treatment-stations within the treatment section;

FIG. 2 is a partially broken away top view of the apparatus of FIG. 1 and showing the doors of the modules in open positions;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a cut-away view of a dolly platform and showing the bracket depending downwardly therefrom and in interlocked position with one of the dogs (dotted lines);

FIG. 6 is a perspective view of one of the dogs which interlock with the bracket of FIG. 5 and move the dollies through the treatment section; and

FIG. 7 is a diagrammatic wiring diagram showing one system for performing the sequential operations of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, the module treating apparatus of the present invention includes an enclosed treatment section 10 supported by an understructure 11 and adapted to clean modules 12, such as aircraft food storage cabinets or the like. The modules 12 are supported by wheeled dollies 13 which are conveyed through the treatment section 10 on a pair of

horizontal tracks

14 and 15 mounted on the understructure 11. The

tracks

14 and 15 are adapted to lie in a horizontal plane corresponding to ground level, or the floor level in a building, and the understructure 11 is accordingly constructed to fit within and be supported by a cement pit l6or the like.

The understructure 1 1 includes a pair of rectangular frames 17 which are welded or bolted together end-toend and are supported horizontally at their four corners by vertical legs 18. A pair of stainless

steel side walls

19 and 20 are welded to the frames 17 and extend vertically above the plane of the tracks 14 and 15 a distance of about 8-9 feet, and side wall 20 preferably extends to the floor of the pit 16. A horizontal roof 22 encloses the treatment section and is supported across and fastened to the tops of the

side walls

19 and 20.

A drainage basin or tank 24 is supported by each of the frames 17 and is constructed of formed sheets of stainless steel. Each tank 24 has a floor 25 and is formed on one side by the side wall 20 and on the other sides by three formed sheets having generally horizon tal portions 26 which slope downwardly from three sides of the frame ,17, and vertical portions 27 which extend downwardly and are welded to the floor 25. The tanks 24 are filled with water through pipes 28 connected to the side wall 20 and detergent or other cleaning solution is added to the washing chamber tank by suitable means which are not shown.

An entrance frame 29 and an exit frame 30 are attached at their inner ends to the adjacent frame 17 and are supported at their outer ends by vertical legs 31. A pair of longitudinal channel beams 32 (FIG. 4) are welded to the frames and support spaced cross members 33 which have an open space between them for an endless chain conveyor, discussed hereinafter. The cross members 33 are substantially horizontal and support the

tracks

14 and 15, and track 14 is elevated with respect to the track by spaced elevator bars 34 (FIG. 3) which tilt the modules toward the tanks 24 for drainage purposes. A relatively wide track is also supported by the planks 33 to accommodate dollies with shorter wheel bases, if necessary.

For purposes of the present disclosure, the treatment section 10 is divided into .a wash chamber 25 and a rinse chamber 36, but the washing and rinsing operations could also be carried out in a single chamber, with the washing and rinsing treatments being alternately cycled. The

separate chambers

35 and 36 are formed by three pairs of pivotal doors which are simultaneously'closed and opened respectively, by a pneumatic cylinder 37, through connecting links 38. The inlet doors 40A (FIG. 2) are pivotally mounted on the inlet ends of the

side walls

19 and 20,-and the outlet doors 403 on the outlet ends thereof. The central doors 40C are also pivotally mounted on the

side walls

19 and 20, but are located at the center of the treatment section.

The doors extend substantially the full height of their adjacent chambers and, as shown in FIG. 2, pivot between closed positions (solid lines) and open positions (dotted lines). They preferably rotate through 90 angles to allow room for varying sizes of modules and, if the modules have internal compartments, to accommodate cabinet doors (FIGS. 2-4) which may be open during treatment. The doors also include a strip of flexible material 41 attached to their inner vertical ends which overlap when the doors are closed to substantially seal the wash chamber from the rinse chamber to prevent intermixing of the wash and rinse solutions.

The dollies 13 include a flat platform 42 for supporting the modules and a pair of upstanding railings 43 at the longitudinal ends thereof for preventing the modules from sliding off the platform when movement of the dollies are intermittently started and stopped. A downwardly extending bracket 46 (FIG. 5) is secured to each end of each dolly l3, and includes a horizontal lip 47 connected to the platform 42 through a vertical member 48 and side flanges 49. The brackets 46 are secured to the dollies in offset relation to their longitudinal centerlines (see FIG. 3) because the planks 33 are arranged to accommodate a conveyor which will engage shorter wheel base dollies received on the wide track adjacent track 15. v

The conveyor comprises an endless chain 50 which is trained around a sprocket wheel 51 rotatably mounted on the entrance frame 29 near the inlet to the wash chamber 35, and extends longitudinally between the planks 33 substantially the full length of the apparatus to another sprocket wheel 52 rotatably mounted on the exit frame 30 above the legs 31. The chain 50 is driven by a drive motor CM mounted beneath the planks 33, and the motor CM drives a belt 54 which in turn drives the sprocket wheel 52.

A plurality of dogs 55 (FIG. 6) are secured to the chain 50 in predetermined spaced relation, corresponding to the distance between treatment stations, and in the preferred embodiment six such dogs are attached to the chain. Each dog 55 has a rectangular configuration and includes a base 56 with vertical sides 57 and a top 58. A cross-plate 60 is welded across the top half of the front end, and a hooked catcher arm 61 is pivotally biased upwardly against the bottom of the cross-plate 60 by a spring 62 mounted between the catcher arm 61 and the top 58 of the dog. The catcher arm 61 is provided with a rounded boss 63 for facilitating pivotal action, and a pin (not shown) extends through the rounded boss and between the sides 57 of the dog to hold the arm 61 firmly in place. A magnet 64 is mounted on the side of the dog facing the side wall 19.

As the chain 50 travels around the sprocket wheel 51, the hooked end 65 of arm 61 engages the rear end of the lip 47 and pivots downwardly momentarily, and then upwardly to catch the lip between the book 65 and cross-plate 60 (see dotted lines, FIG. 5). This forms an interlock which positively controls the dollies as they are conveyed through the apparatus. The lip 47 is released from the dog 55 when the dog turns downwardly around the sprocket wheel 52 at the other.

end of the assembly.

The solutions in the tanks 24 are heated to a temperature of about 150 F. minimum by a pair of steam injector nozzles 66 (FIG. 2) disposed therein, and this temperature is maintained by valves 67 which are controlled by gauges 68 responsive through sensors 69 to the temperature of the solution in the tanks. The inlet pipes 28 initially fill the tanks 24, and the tanks are continuously drained through a pair of openings 70 (FIG. 1) in the side wall 20 which receive a pair of drainers 72, as water from the fresh final rinse is added. The openings 70 maintain the liquid level in the tanks and the drainers 72 include basket screens which catch foreign matter such as paper wrappers and the like which may clog the

drain pipes

73 and 74.

Four electric motor driven centrifugal pumps are attached to the side wall 20 below track level, two pumps 75 for the wash chamber 35 and two pumps 76 for the rinse chamber 36, and draw liquid into their impeller chambers through inlets 77 (FIG.-3) communicating with the tanks 24. Each pump 75 and 76 delivers solution upwardly through vertical pipes 78 to a series of three rotary spray devices 80 mounted within the respective chambers on the side wall 20. The pipes 78 have horizontal portions 81 which extend across the roof 22 and deliver solution to a further rotary spray head 82 directed downward as shown in FIGS. 2 and 3.

The

rotary spray devices

80 and 82 are preferably constructed along the lines disclosed in US. Pat. No. 3,207,944, which was assigned to the assignee of the present invention, and include a hub cylinder which distributes the fluid along a plurality of radial arms to curved scoops at the ends of the arms. The scoops are curved and direct the flow transversely to the plane of the radial arms. In the present arrangement, the rotary spray devices 80 are arranged on the side wall so the scoops will direct the rotary flow substantially horizontally into the compartments within the modules 12.

Each tank 24 is also provided with a strainer (FIGS. 2 and 3) which includes a series of three screens 85 (FIGS. 2 and 3) having progressively smaller mesh sizes. A baffle 86 is located behind the smallest opening screen to prevent cavitation and assures that the pumps 75 draw the liquid in the tanks down through the screens 85.

The modules 12 are conveyed sequentially to the wash station, where they are stopped and the rotary spray devices 80 deliver the wash solution into theirintemal compartments for eight seconds to loosen any food or other particles therein. Their outer surfaces are simultaneously cleaned by the stationary spray nozzles 83. The

doors

38, 39 and 40, which are closed during each treatment operation, then open and the modules 13 are conveyed to the rinse station and the doors close again. The devices 80 and the nozzles 83 rinse the modules in the same manner, for a predetermined time, and the rinse water acts as a vehicle for carrying the food particles and cleaning fluid to the tanks 24 below. Drainage is completed, the doors 4tlA-C open again and the modules are conveyed out of the cleaning apparatus.

The modules 12 also receive a final fresh water hotrinse as they leave the rinse chamber. A pair of

steam boosters

87 and 88 attached to side wall 20 receive hot water from a hot water source (not shown), and increase the temperature of this water to approximately l80195 F. Booster 87 delivers the extra-hot rinse water through a delivery pipe 89 to a vertical manifold 90 mounted inside wall 20 near the outlet of chamber 36. Booster 88 delivers hot rinse water through another delivery pipe 91 to an L-shaped manifold 93 mounted across the top 22 and down the wall 19. A plurality of spray nozzles S4 on the

manifolds

90 and 93 deliver the hot rinse water against the modules as they move through the outlet doors 39 onto the exit portion of the tracks. The hot rinse water replenishes the rinse solution in tank 24 and its higher temperature lessens the heating load on the steam injectors 66 therein. The l80l95 F. temperature also meets the [1.8. Public Health and National Sanitation Foundation requirements for the sanitizing of food containers.

A hood 95 is preferably provided above the exit portion of the tracks, and a source of negative pressure draws off steam vapors, thereby increasing the rate of drying of the modules 12.

The schematic diagram of the control system for the machine is shown in FIG. 7. A three phase AC. power supply 97 provides power to the various pump motors and the conveyor motor CM. Details of these circuits are described hereafter. A transfonner 98 provides at its secondary a lower voltage A.C. for the control circuits, across the lines L1 and L2. A fullwave rectifier circuit provides an output on the lines 100 to one of the windings of the conveyor motor CM, for purposes of dynamic braking. Details of this circuit are explained in connection with the operating sequence hereafter. A manually operated normally open start switch is provided, together with a manually operated normally closed stop switch 107. These are push button operated switches which may be conveniently located at the entrance ending of the machine, as shown in FIG. 1. Additional start and stop switches (not shown) may be provided at other convenient locations, and appropriately incorporated in the circuit. These are not shown in order to simplify the diagram.

A selector switch SS, which is manually operated, provides for either full automatic or semi-automatic operating modes of the machine. For purposes of initial description of the control, the automatic mode is assumed, and the switch SS is shown in this Position. The switches which sense the position of the doors in the machine are designated respectively as the door open switch D0 and the door closed switch DC. For purposes of description, it will be assumed that the doors are initially in the open position, in which case the switch D0 is closed to complete the appropriate control circuits, and the switch D0 is open. Assuming that one of the conveyor dogs is located at the conveyor switch CS, it will be closed by reason of the presence of a magnet at the switch. If the operator then closes the start switch 105, power will be applied to the coil of relay R1, closing its contacts [HA and completing a holding circuit around the start switch 105, which is spring loaded to open when manual pressure is released. The relay R1 will thus remain energized. In addition, a circuit will be completed through the conveyor switch CS to the coil of relay R4, and its contacts RSA will close, and its normally open contact R48 will open. A circuit is thus completed through contacts R4A to energize the air control solenoid SDC which applies air pressure to the door operating cylinder in a direction to close the doors. At the same time, opening of the contacts R4B will break the circuit supplying the power to the control solenoid SDO which other wise applies air pressure to the pneumatic cylinder tending to open the doors. As a result of the energizing of relay R4, the doors in the machine move to the closed position.

Closing of the contact R4A also completes a holding circuit across the conveyor switch CS. In addition, the normally open contacts R4C close to complete the circuit energizing the coil of relay R5, however this circuit is opened by reason of the fact that the switch D0 is open, and the relay R5 does not function at this time. Closing of contacts R4A also completes a circuit through the coil of relay BC, which in turn closes its contact BCl and 8C2, applying direct power through line 100 to the conveyor motor CM, causing dynamic braking of that motor. Thus the conveyor system is braked to a static position, and the modules will not move during the following operations.

In addition, the normally closed contacts BC3 open in the circuit from the switch D0 to the coil of relay R5, thereby breaking that circuit in addition to the fact that the switch D0 is open. Since the door closing con- At the time that contact R4A closes, a further circuit is completed to a delay relay BT, having a delay of about two seconds, and it opens its contacts BTl in the circuit of the brake relay BC, thus the contacts RC1 and BC2 open after the conveyor has been braked to a stop, but no power is supplied to the conveyor motor CM, and the conveyor remains stationary.

When the doors close the switch DC, and this completes the circuit to the delay timer WT, power immediately is applied to the coil of WT, and this completes a circuit through the normally closed contacts WTl to the coils of the control relays or contactors WC and RC which control the power supply to the wash and rinse pumps 75 and 76. When WC is ener gized, the three contacts in the power supply lines to motors WMl and WM2 are closed, and these motors then drive the two pumps 75. Similarly, energizing RC closes its contacts in the power supply to the motors RMl and RM2, which immediately drive the pump 76. Liquid then is recirculated through these pumps and the corresponding rotary spray heads, over the modules or other items in the

chambers

35 and 36.

When the timing relay WT runs out its time, it opens its contact WTl and closes its contacts WTZ. This removes power from the motor control contactors WC and RC, and applies power to the relay of a conveyor delay timer CT, which has a delay time of about eight seconds. Since the pumps have stopped, and no further action has yet been initiated, a draining period is provided where the items remain in the

chambers

35 and 36, with the doors closed, while liquid drains from the item back into the tank.

After this delay, the timing relay CT closes its contacts CTl, which completes a holding circuit to its own coil, and also a holding circuit through WT2 to the coil of the .wash timing relay WT. The normally closed contacts CT2 are open, and this removes power from the pneumatic control solenoid SDC for the door closing operator, and also removes power from the brake timer relay BT. The coil of the brake contactor BC likewise has power removed from it, its contacts BCl and BC2 open to remove power from the braking circuit to the motor CM, and the contact BC3 returns to its closed position.

At the end of the time period of the CT timing relay, its contact CT3 also closes, completing the circuit to energize the door opening pneumatic solenoid SDO, and also completing a circuit to the solenoid RV of the final rinse control valve. This solenoid valve then opens to supply fresh rinse water to the pipe 91 and the final rinse spray heads 93, before the conveyor begins to move. At this time the doors are moving to the open position, and when they reach this position, the switch DO closes, completing a circuit to the conveyor contactor CC, which in turn is energized to supply power to the conveyor motor CM. This causes the conveyor to advance and the dollies carrying the items are moved towardthe discharge end of the machine, from left to right as viewed in FIG. 1. At the same time, the rinse timing relay RT .is energized, and commences its ten second delay period.

As the conveyor operates, movement of the dog away fromthe conveyor switch CS causes it to open. Also, when the contactor coil CC is energized, a circuit is completed to-relay R5, actuating it and openingits normally closed contact RSA. The relay R5 operates with a slight delay, of about 0.75 seconds. When contacts R5A open, this deenergizes relay R4, and contacts R4C open to deenergize relay. R5. Contacts R48 close, and this completes a holding circuit through the switch DO and the closed contacts BC3 to the coil of contactor CC, and also through the coil of the RT relay. Opening of contacts R4A removes power from the washing timer relay WT and from the conveyor timer relay CT. After its time delay expires, the rinse timer relay RT actuates, and the normally closed contact RTl opens, removing power from the rinse valve solenoid RV. This causes the final fresh water rinse to stop, however by this time the conveyor has moved the module, or other units being washed, from the chamber 36 entirely past the final rinse spray heads.

With the relay RT now actuated, its contact RT2 closes, energizing the coil of relay R3, which in turn closes its contacts RSA, completing a holding circuit to its own coil. In addition, relay contacts R38 and R3C, associated with the selector switch SS, close and open respectively, upon energizing of relay R3. The conveyor continues to operate until the next dog aligns with the conveyor switch CS, at which time this switch closes. Power is then applied to relay R4, which immediately energizes. .Its contacts R4B open, breaking the power supply to the conveyor contactor CC, which in turn is deenergized and stops the conveyor motor. Contacts-CCI and CC2 then close. This applies power to the rectifier circuit of the dynamic braking control, and also applies power to the relay BC. The rinse timer relay RT is deenergized, and RTl closes.

Because R4 is energized, contacts R4B open and the door opening solenoid SDO is deenergized; also R4A closes and the door closing solenoid SDC is energized, the doors then moving to their closed position. The cycle will then repeat unless stopped at any time by opening the stop switch 107.

If the selector switch SS is in the semi-automatic mode position, the general sequence of operation for one cycle is the same. However, at the end of the cycle when R4 is energized, a circuit is completed through contacts R4A, R38, and the now closed contacts of switch SS, to the coil of relay Rsp. Its contacts Rspl open, and the coil of relay R1 is deenergized, opening contacts RlA in the start holding circuit. The doors are left open, and start switch must again be closed manually to begin the next cycle.

It should be noted that one of the contacts of the selector switch SS controls the indicator lamp 110. When the switch is in the automatic position, the lamp 10 is energized to give a visible indication that the machine is in the fully automatic mode.

Referring .to FIG. 7A, the lower portion of this diagram shows the thermostatic control for the steam booster heaters in the system. The master heater switch 120 is shown in the off position. Since this switch is turned on, control of the solenoid operated steam valve 122 is provided by the thermostatic control 124 which in turn responds to a suitable temperature sensor 125 in the second tank below the chamber 36. Similarly, the solenoid operated steam control valve 127 is under the control of the thermostat 128 which responds to the sensors 130 appropriately positioned to sense the temperature of the final rinse water. The second contacts of the heater control switch 120 merely control an indicator lamp 132 which is energized when the heater controls for power is applied by closing the switch 120.

The intermittent movement of the dollies places them in a stationary position during the power wash and power rinse treatments, where the articles which they carry receive the power sprays. This arrangement allows a short cleaning sequence, and also enables the treatment chamber to be shorter than might be needed with continuous movement of the conveyor past the spray nozzles. The dogs control the intermittent movement of the dollies and stop them at their desired location opposite the spray devices, and their interlock with the dollies improves the dependability of the apparatus and prevents the interior of the heavy items from carrying the dollies out of proper position.

The apparatus of the present invention cleans large food cabinets efficiently in a matter of seconds. To do this it forcefully propels hot cleansing solutions horizontally and vertically downward against the cabinets or other items and into their interiors and around the exteriors, thereby effectively loosening food or other particles, which are quickly drained to the tanks below. 4

The arrangement achieves a short dwell time and conserves valuable space by providing a sequential operation of moving the module into a chamber, posi-. tively stopping the module opposite horizontally and vertically downward acting rotary spray treatment apparatus, closing the chamber subjecting the module to a high temperature power washing for a predetermined short period of time, opening the chamber, moving the module to a rinse chamber where it is subjected to a high temperature power rinsing operation, and then rinsing the module with further hot rinse water as it moves out of the rinse chamber.

The pivotal doors control communication between adjacent treatment chambers and when closed, effectively sea] the chambers and substantially minimize intermixing of the wash and rinse solutions. The wash and rinse solutions are also continuously recirculated and replenished, and the extra hot rinse water replenishes the recirculating rinse solution.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this rinse chamber with horizontally and vertically directed power rinsing means disposed therein, said chambers having aligned inlets and outlets,

conveyor means including supports for the items for conveying the items through said chambers,

control means for intermittently stopping said conveyor means when said supports are opposite said power washing means and opposite said power rinsing means, respectively,

doors responsive to said control means for closing said inlets and outlets,

said control means including circuit means responsive to closing of said doors for actuating said power wash and power rinsing means for a predetermined period of time and then opening said doors and thereafter starting said conveyor means,

said conveyor means including a motor-driven endless conveyor having regularly spaced dogs thereon releasably connected to said supports for the items, and said control means including a switch controlling movement of said endless conveyor and actuated by said dogs, said dogs being spaced along said conveyor to actuate said conveyor control switch when said supports are opposite said power washing and said power rinsing means.

2. Apparatus as defined in claim 1 wherein said supports are mobile dollies having depending coupler brackets arranged for locked coupling to said dogs for positively controlling the movement of said dollies through said chambers.

precise form of apparatus, and that changes may be 3. Apparatus as defined in claim 2, said conveyor means including tracks extending through said chambers and arranged to guide said mobile dollies for positioning the items to be cleansed with respect to said power washing and power rinsing means.

4. Apparatus as defined in claim 3 wherein said tracks are at slightly different levels sufficient to tilt the items in a frontward and downward direction to drain cleansing liquid from any compartments in the items.

5. Apparatus as defined in claim 1 including spray means at the outlet of said rinse chamber providing a final rinse to items being conveyed out of said rinse chamber, and said control means including a circuit responsive to opening of said closure means and connected to actuate said final rinse spray means for a predetermined period of time as said conveyor operates.

6. Apparatus for cleansing food service equipment items including cabinets having internal compartments therein, wherein the items to be cleansed are large and heavy and are supported on mobile dollies for transporting the items to and from a vehicle or the like and to service areas for cleaning and stocking with a new supply of food, comprising an elongated housing having power operated closure means defining at least one cleansing chamber with aliwed inlet and outlet controlled by said closure means,

an open top tank beneath said chamber,

tracks extending through said housing over said tank for guiding and supporting the dollies,

horizontally and downwardly directed wash arms in said chamber for directing cleansing liquid over ll the exterior and into the interior of items on the dollies,

motor driven pumps connected to deliver liquid from said tank to said wash arms,

a final rinse spray head adjacent said outlet and having an automatic valve controlling the spraying of cleansing liquid from said final spray head,

a motor driven endless conveyor extending through said housing and beyond said inlet and outlet,

dogs on said conveyor for coupling to the dollies,

control means including electrical circuits connected to sequence the operation of said conveyor, said closure means, said pumps, and said automatic valve,

said control means including a sensor adjacent said tracks outside of said outlet and responsive to the location of a conveyor dog adjacent to said sensor for stopping said conveyor and thereby locating at least one dolly within said chamber and in correct alignment with said wash arms,

a control circuit for said closure means operative to open said closure means and to inhibit operation of said conveyor except when said closure means are open,

a control circuit for said pumps arranged to operate said pumps only when said conveyor is stopped and said closure means are in the closed position, and

a control circuit for said automatic valve arranged to open said valve only when said closure means are open and said conveyor is operating to transport a dolly through said outlet toward the location of said sensors.

7. Apparatus as defined in claim 6 including a timer control for said pump circuit arranged to stop said pumps a predetermined time prior to opening of said closure means whereby a period of time is provided for drainage of liquid from the items into the tank before said conveyor is again operated.

8. Apparatus as defined in claim 7, wherein one of said tracks is slightly elevated with respect to the other to tilt the dollies and items supported thereon for promoting drainage of liquid from the internal compartments of the items being cleansed.

9. Apparatus as defined in claim 6, including a control circuit for braking said motor driven conveyor in response to positioning of a dog adjacent to said sensor whereby inertia of the dollies and the heavy items thereon is overcome and the items are correctly aligned with said wash arms.

10. Apparatus as defined in claim 6, including sensing switch means mounted for operation by said closure means in the open and closed positions thereof to signal the location of said closure means during the sequence of operation.

11. Apparatus as defined in claim 6, wherein said control means includes a selector switch connected to said control circuits providing for continuous sequencing of the control means in one position, and providing for operation of the control means through one sequence at a time in another position.

a is =0: a: I

MI I m1:

Claims

1. Apparatus for cleaning large fooD service items and the like, some of which have front opening compartments, comprising a wash chamber with horizontally and vertically directed power washing means disposed therein, a rinse chamber with horizontally and vertically directed power rinsing means disposed therein, said chambers having aligned inlets and outlets, conveyor means including supports for the items for conveying the items through said chambers, control means for intermittently stopping said conveyor means when said supports are opposite said power washing means and opposite said power rinsing means, respectively, doors responsive to said control means for closing said inlets and outlets, said control means including circuit means responsive to closing of said doors for actuating said power wash and power rinsing means for a predetermined period of time and then opening said doors and thereafter starting said conveyor means, said conveyor means including a motor-driven endless conveyor having regularly spaced dogs thereon releasably connected to said supports for the items, and said control means including a switch controlling movement of said endless conveyor and actuated by said dogs, said dogs being spaced along said conveyor to actuate said conveyor control switch when said supports are opposite said power washing and said power rinsing means.

3. Apparatus as defined in claim 2, said conveyor means including tracks extending through said chambers and arranged to guide said mobile dollies for positioning the items to be cleansed with respect to said power washing and power rinsing means.

6. Apparatus for cleansing food service equipment items including cabinets having internal compartments therein, wherein the items to be cleansed are large and heavy and are supported on mobile dollies for transporting the items to and from a vehicle or the like and to service areas for cleaning and stocking with a new supply of food, comprising an elongated housing having power operated closure means defining at least one cleansing chamber with aligned inlet and outlet controlled by said closure means, an open top tank beneath said chamber, tracks extending through said housing over said tank for guiding and supporting the dollies, horizontally and downwardly directed wash arms in said chamber for directing cleansing liquid over the exterior and into the interior of items on the dollies, motor driven pumps connected to deliver liquid from said tank to said wash arms, a final rinse spray head adjacent said outlet and having an automatic valve controlling the spraying of cleansing liquid from said final spray head, a motor driven endless conveyor extending through said housing and beyond said inlet and outlet, dogs on said conveyor for coupling to the dollies, control means including electrical circuits connected to sequence the operation of said conveyor, said closure means, said pumps, and said automatic valve, said control means including a sensor adjacent said tracks outside of said outlet and responsive to the location of a conveyor dog adjacent to said sensor for stopping said conveyor and thereby locating at leasT one dolly within said chamber and in correct alignment with said wash arms, a control circuit for said closure means operative to open said closure means and to inhibit operation of said conveyor except when said closure means are open, a control circuit for said pumps arranged to operate said pumps only when said conveyor is stopped and said closure means are in the closed position, and a control circuit for said automatic valve arranged to open said valve only when said closure means are open and said conveyor is operating to transport a dolly through said outlet toward the location of said sensors.