US2710618A - Dishwasher - Google Patents

Description

June 14, 1955 Filed Oct. 18, 1952 H. M. RUMBAUGH DISHWASHER 4 Sheets-Sheet l INVENTOR. HUGH M. RUMBAUGl-l June 14, 1955 H. M. RUMBAUGH 2,710,618

DISHWASHER Filed Oct. 18, 1952 4 Sheets-Sheet 2 I mmvron. HUGH M. RUMBAUGH FIG. 2

June 14, 1955 H. M. RUMBAUGH DISHWASHER 4 Sheets-Sheet 3 Filed Oct. 18, 1952 INVENTOR. HUGH M. RUMBAUGH June 14, 1955 Filed Oct. 18, 1952 H. M. RUMBAUGH DISHWASHER FIG. 4

4 Sheets-Sheet 4 FIG. 5

INVENTOR. HUGH M. RUMBAUGH DISHWASHER Hugh M. Rumbaugh, Bath, Uhio Application October 13, 1952, Serial No. 315,455

2 Claims. (Cl. 134-183) This invention relates to improvements in dishwashers and more particularly, to simple and efficient dishwashers of the domestic type. The present application is a continuation of my copending application, Serial Number 137,509 for Smooth Impeller Dishwasher, filed January 9,

1950, now Patent No. 2,624,356 issued January 6, 1953.

Heretofore, domestic dishwashers have been relatively complex in construction and difficult to install and, as a consequence, have been among the more expensive and less widely used household appliances. One reason for relatively poor reception of dishwashers was the failure of early commercial models to wash the dishes clean; while substantial improvement in this respect has been made, part of such improvement is due to improvements in available detergents, the balance being due to development of relatively complex impeller constructions. To an extent, however, the commercially employed prior art impeller constructions have been self-defeating, since they are used in conjunction with fine mesh screens to prevent recirculation of solid matter and to prevent accidentally dislodged ware from being bent or broken in the impellers.

Another reason for the relatively restricted use of dishwashers has been that they have been difficult to load and unload, requiring special cabinets which increased the cost of manufacture and installation and frequently decreased the amount of usable counterspace available in a kitchen if installed adjacent counter-height cabinets. Such counter-height dishwashers that have a fixed counter top are customarily provided with front-opening doors which are difficult to seal and sliding racks which require a relatively complex sliding suspension. A final disadvantage of prior art domestic dishwashers is that, despite the claims of the manufacturers, none are too efficient and depend in most instances upon a splash type of rinsing by detergent solutions for their cleaning action.

It is an object and advantage of this invention to provide a simple, eflicient and relatively inexpensive domestic dishwashing unit which requires no special cabinet but which may be housed in conventional counter-height stock kitchen cabinets, either by removing the shelves or drawers in previously installed cabinets (preferably those having vertically hinged door fronts) or, if the kitchen is being remodeled or being built at the time of installation, by employing conventional prefabricated, doored units from which the shelves have been omitted. It is to be understood that a dishwashing unit made according to this invention is particularly adapted to be installed under the drainboard portion of most sink units.

It is a further object of this invention to provide a dish- Washing chest construction which is effectively sealed and which is provided with a simple suspension permitting the chest to be projected for easy loading and unloading, but supporting the unit within a counter-height housing during the dishwashing operation and other times.

Other and further objects an advantages of this invention will be apparent from the following specification, claims, and drawings, in which atent Fig. 1 is a side elevation, partly broken away, for a dishwashing unit made according to this invention.

Fig. 2 is a vertical section taken along line 2-2 of Fig. 1.

Fig. 3 is a vertical section taken along line 3-3 of Fig. 2.

Fig. 3a is a greatly enlarged sectional detail of the impeller and vane shown in Fig. 3.

Fig. 4 is a detail section taken along line 44 of Fig. 3.

Fig. 5 is a reduced side elevation similar to Fig. 1, but showing the chest in the loading and unloading position.

As shown in Fig. 1 of the drawings, the dishwashing unit is adapted to be mounted within a conventional counter-height cabinet 1, shown in construction lines, having a front-opening door or doors 2 but from which the usual shelves or sliding drawers have been removed. Thus, my unit may be installed in existing kitchens without necessitating extensive remodeling and rebuilding of the counter. For new construction or where the entire kitchen counter is being remodeled or replaced, inexpensive stock cabinets without shelves may be employed. By providing a unit which may be housed in an existing cabinet structure without requiring extensive remodeling, this invention overcomes one of the major objections to prior domestic dishwashers, for in many instances the installation and remodeling costs equaled or exceeded the cost of the dishwasher, per se.

As shown in the drawings, the dishwasher unit 10 comprises a suitableframe 11 adapted to be placed within the cabinet 1 and leveled on the floor 3. The frame 11 is provided with a transverse main supporting shaft 12 upon which the chest 20 is pivotally mounted by means of the bearings 13 carried at the bottom of the chest 20 and journaled on the shaft 12. In its normal vertical position, as shown in Fig. 1, for example, the bottom of the chest also rests on a transverse supporting bar 14 located to the rear of the shaft 12 and is held on said bar 14 by means of the counter-balancing tension spring 15 connecting a clevis 16 carried by the bottom of the chest and a clevis 17 carried by the frame 11.

The chest 20 is provided with a lid 21, hinged to the rear wall of the chest and provided with a suitable elbow linkage 22 for holding the lid open when the lid is manually raised by means of the knob 23. The joint between the upper edges of the chest walls and the lid is simply and effectively sealed by a hydrostatic seal comprised simply of rods or tubes 24 of resilient material, such as soap and grease resistant synthetic rubber, secured to the upper inner margin of the walls of the chest so that the inner margin of the lid 21 will rest upon the upper surfaces of the cylindrical rods '24. It is to be noted that the rods 24 are made of resilient material only to insure that a continuous line of tangency between the lid and the rods will be maintained rather than to depend upon a distortion of the rods to effect a water-tight seal. As will be evident from the portion of the rods 24, shown in section in Figs. 1 to 3, the hydrostatic seal is effected by a miniscus of water which will be held between the rod 24 and the undersurface of the lid 21 by the bight between the adjacent surfaces of these two members.

The lid 21 also preferably carries the incoming water distributor comprised of a grid of pipes 25 provided with spray jet orifices 26 to distribute incoming wash or rinse water over ware in the chest 20. The grid of pipes 25 is connected by the flexible conduit 27 to hot and cold water lines through timer controlled valves (not shown).

Mounted in a corner of the chest 20 is the vertical vent pipe 30 having a lower opening 31 in the lower part of the chest but above the maximum liquid level therein. The upper open end of the pipe 34 extends through a suitable opening 33 in the top 21 to vent steam from the chest to the atmosphere. The length of the tube effectively baffles entrained moisture, and, being straight, is easily cleaned.

The lower portion of the chest is provided with a removable grid resting upon the angles 36. The grid 35 is preferably quite open to permit the high velocity Wash water to pass therethrough without substantial diminution of velocity or interference, but is of sufficiently close mesh to retain small pieces of silverware or the like which might fall through or be displaced from the removable rack 37 which supports the dishes and other ware to be washed. The use of mesh to retain silverware, it should be pointed out, is primarily for convenience to avoid having to retrieve the ware from the bottom of the chest 20, since the smoth surface of the roll 49 has no projections to break or bend ware, as in conventional dishwasher impellers of the paddle, disk, or propeller type. In this connection, it should also be pointed out that the specific construction and arrange ment of the racks and the location of the ware thereby is primarily a matter of choice except that, to obtain maximum effect from the scouring action of the high velocity Wash water, the racks are preferably arranged to hold dishes and like flatware in a generally vertical plane extending from the front to rear of the chest and slightly tilted transversely to the cylinder 49, as shown in Fig. 2, for example.

Wash and rinse water and detergent solutions are directed on the ware carried above the grid 35 by means of one or more high speed spray cylinders 40, two being shown in the embodiment of Figs. 1 to 5. The cylinders 40 are preferably hollow and provided with smooth outer surfaces adapted to be partly submerged in the liquid carried in the lower portion of the chest 20, the liquid level in the lower or sump portion of the chest being maintained by the overflow pipe 57 connected to the main drain pipe 58 for discharge to the sewage system. The overflow pipe preferably maintains the height of the water in the sump portion of the chest 20 so that from approximately one-third to one-sixth of the surface of the cylinder is submerged.

The cylinders 40 extend transversely across the width of the chest 2% and are mounted on the shafts 41 journaled in conventional packed and sealed bearings 42 carried by the side walls of the chest 20. At one end the shafts 41 carry the V-belt pulleys 43 driven by the V-belt 44 which, in turn, is driven by the pulley 46 of the motor 45. The motor is mounted on a base block 47 pivoted at one side on the base block pivot 48 supported by the frame 11. As shown in Fig. l, for example, the length of the belt 44 is such that, in passing around the cylinder pulleys 43 and the motor pulley 46, the motor 45 and block 47 are lifted and the tension on the belt 43 is a component of the weight of the hinged motor and block.

It has been found that the velocity of the Water thrown by the cylinders 49 is reatly increased and the included angle of such water may be controlled by directing vanes 56 generally tangent to but not touching the outer surface of the cylinders 40. The edges 51 of the vanes 50 adjacent the cylinders 40 are preferably curved so that, in section, the adjacent surfaces of the cylinder and the vanes constitute the throat of a nozzle, and each cylinder and its associated vane thereby constitute a continuous elongated jet extending transversely of the chest 29. The effective nozzle cross-section provided by the cylinder 40 and vane edge 51 is shown in Fig. 3a. The very noticeable increase in velocity of the liquid thrown by the cylinders 49, when the vanes 56 are employed, over the velocity when such vanes are omitted is attributed to the instantaneous pressure head (developed between the cylinder surface and the vane edge 51 as the liquid is drawn by its viscosity into the bight between the surfaces) becoming converted to a high velocity head due to the nozzle throat efiected by the convergence of the adjacent surfaces of the cylinder 4% and the vane edge 51. Another evident factor contributing to the efiiciency of the cylinder and vane connection is that turbulence developed as the cylinder surface leaves the liquid level, when no vane is present, is absent or greatly minimized when a vane 50 is employed. lfithout the vane 50, the cylinder 40 will lift a volume of liquid which is not thrown as a spray but falls back to the liquid level in the sump, creating useless turbulence. 'vi h a vane 50, instead of such uselessly turbulent water '2 present, a relatively constant, non-turbulent large iiscus 53, as indicated in Fig. 3, is maintained. In addition to the nozzle effect of the vane edges 51, therefore, the vanes 50 also apparently control the weight of water thrown by the cylinder 40 and eliminate the loss of energy which occurs when a substantial volume of liquid is simply lifted above the liquid level and then falls back without being thrown against the ware.

It should also be apparent from the foregoing that another advantage of the cylinder 40 is that they throw a continuous, uninterrupted high velocity jet of water across the width of the chest. Dead-spots or zones of varying intensity, such as are developed by impellers of the paddle, propeller or disk-type, are eliminated and, due to the high velocity of the spray particles, the ware against which they are directed is scoured rather than rinsed, thereby efliciently removing adhered food par- "cles. Further, because the included angle of the high velocity spray from the cylinders may be determined, the ware in the racks 37 may be located with respect to the cylinder 4i so that the initial impact of liquid thrown by the cylinders 46 is against the ware, rather than against the walls of the chest 29 which, with a consequent loss of kinetic energ deflect the spray against the ware. in short, the cylinders 49 permit the washing energy to be expended largely against the ware, rather than dissipated against the walls of the chest containing the ware.

At various times during the washing operation and at the end thereof, the washing liquid is drained from the sump portion of the chest 20 by means of a drain opened and closed at predetermined intervals by the valve 56. Beyond the valve 56, the overflow pipe 57 and drain 55 connect with a main drain pipe 58 connected to the sewage system through a trap with conventional swingng fittings (not shown). The inlet and draining of Wash and rinse water as well as the operation of the motor 59 are all preferably controlled through a suitable and conventional cyclic timer (not shown), the operation of the timer for a cycle being initiated by the starter button 59 located on the front of the chest 2 To load and unload the washing unit 19, the doors 2 of the housing cabinet 1 are opened and the entire chest is tilted outwardly by pivoting the chest 26 about the shaft 12 against the effect counterbalancing spring 15. As shown in Fig. 5, when the center of gravity of the chest is carried forward of the shaft 12, the chest will continue to tilt until the bottom rests against the stop 19, in which position the lid 21 may be raised and the chest opened for convenient and accessible loading and unloading. In the loading and unloading positions shown in Fig. 5, the motor 45 is raised by the belt 44 by operation of the floating suspension of the motor afforded by the pivoted block 47. Connection of the inlet and drain piping is maintained by means of flexible tubing or swingconnections (not shown).

it should be apparent from the foregoing that the advantages of the tilting chest construction are not confined to the preferred cylinder and vane type of water impeller as shown in the preferred embodiment, but the chest 28 may be provided with any other type of water impeller mechanism. Likewise, a dishwasher having advantages of the foregoing embodiment does not require a plurality of impeller cylinders but may employ a single cylinder, with or without jet directing vanes.

it is to be understood that my invention is not limited to the specific embodiments disclosed but may be variously modified to include any one or more of the several features as claimed in the appended claims.

What is claimed is:

l. A dishwashing unit comprising a chest adapted to enclose ware to be washed, a frame, means supporting said chest pivotally on said frame about a pivotal axis extending transversely of said frame, said frame comprising a base portion extending under said chest and up to the level of said pivotal axis on either side of said chest, means maintaining said chest in a normally vertical position but permitting said chest to tilt forwardly about said axis, and a normally horizontal lid for said chest pivoted about a transverse axis located along one of the sides of the top of said chest, whereby, when said chest is pivoted forwardly said lid may be raised without interference with a surface extending over said lid when said chest is in its normal vertical position and access for loading and unloading said chest is provided, a floating motor support carried by said frame, a motor carried by said motor support, and an impeller within said chest driven by said motor, said chest, frame, motor support and motor constituting a unitary assembly adapted to be supported on a floor or base independently of the sup-- porting structure for said surface.

2. A dishwashing unit comprising a chest adapted to enclose ware to be Washed, a frame, means supporting said chest pivotally on said frame about a pivotal axis extending transversely of said frame, said frame comprising a base portion extending under said chest and up to the level of said pivotal axis on either side of said chest, means maintaining said chest in a normally vertical position but permitting said chest to tilt forwardly about said axis, and a normally horizontal lid for said chest pivoted about a transverse axis located rearwardly on said chest, whereby, when said chest is pivoted forwardly said lid may be raised without interference with a surface extending over said lid when said chest is in its normal vertical position and access for loading and unloading said chest is provided, a floating motor support carried by said frame, a motor carried by said motor support, and

References Cited in the file of this patent UNITED STATES PATENTS 1,055,519 Conser Mar. 11, 1913 1,240,298 Best Sept. 18, 1917 1,651,083 Brotz Nov. 29, 1927 2,443,761 Bailey June 22, 1948

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