US 3102666 A
Description (OCR text may contain errors)
Sept. 3, 1963 M. FRESARD 3,102,566
PROCESS FOR THE PROJECTION OF WATER FOR WASHING DISHES AND A WASHING MACHINE FOR CARRYING OUT SAID PROCESS Filed Aug. 19, 1960 2 Sheets-Sheet l Sept. 3, 1963 M. FRESARD 3,102,666
PROCESS FOR THE PROJECTION OF WATER FOR WASHING DISHES AND A WASHING MACHINE FOR CARRYING OUT SAID PROCESS Filed Aug. 19, 1960 2 Sheets-Sheet 2 United States Patent "ice 3,102,666 PROCESS FOR THE PROJECTION OF WATER FOR WASHING DISHES AND A WASHING MACHINE FOR CARRYING OUT SAID PROCESS Marcel Fresard, Geneva, Switzerland, assignor to Mefina ISA? Fribourg, Switzerland, a corporation of Switzer- Filed Aug. 19, 1960, Ser. No. 50,726 Claims priority, application Switzerland Aug. 26, 1.959 3 Claims. (Cl. 222-373) Numerous types of dish washing machines are known wherein the washing water is pulsated by means of compressed air. However, in these known machines, the compressed air etfects either simply a stirring in the vat containing the washing water, or drives in a continuous jet the washing water in the direction of the dishes to be cleaned.
Experience has shown that the washing efiect obtained in known washing machines was either insufiicient, or much too slow, by reason of lack of vigour of the jets of water pulsated against the dishes.
The invention tends precisely to remedy this inconvenience. It has for its object a process for the projection of water for Washing dishes, characterised in that alternatively a number of injection tubes are charged successively with a predetermined volume of water and that then this volume of water is expelled from each tube by injecting compressed air into this,
The invention also has for its object a dish washing machine allowing of carrying out the process indicated above and comprising at least one vat and a number of ejection devices permitting of creating in the vat a number of jets of water subjected to a pressure of air. This Washing machine is characterized by the fact that each ejection device comprises a tube of which one end is open, the other end communicating, on the one hand, with a supply of water and, ion the other hand, with an inlet for compressed air, a non-return valve controlling the supply of water into the tube, whilst a valve, the opening of which is actuated alternatively, controls the inlet of compressed air into the tube, the whole being arranged in such a manner that during the opening controlled by the valve, the compressed air ejects the volume of water contained in the tube, the non-return valve preventing the backflow of pulsated water into the water supply passage, said non-return valve permitting of a fresh filling of the tube when the air valve is closed.
One form of construction of the washing machine according to the invention is shown diagrammatically and by way of example in the accompanying drawings, where- 1n:
FIG. 1 is a general view in axial section of this washing machine.
FIG. 2 is a view to a larger scale of an injection device, in the normal position.
FIG. 3 is a view similar to the preceding one showing the ejection device in the active position.
This dish washin g machine comprises a vat 1 in which is disposed, preferably in a movable manner, a crate or basket adapted to receive the dishes 3. This vat 1 is closed near the bottom by a base 4 of slightly conical shape in the example shown, so as to permit of collecting the washing water through a grid 5 in a collecting reservoir 6. This washing machine is provided with a number of water ejecting devices 7, each comprising a tube 8 disposed vertically through the base 4. The upper extremity 9 of each tube 8 is open.
As regards the other extremity 10 of the tube 8, it communicates, on the one hand, with the water supply 11 and, on the other hand, with the inlet 12 for compressed air.
As will be seen in FIGS. 2 and 3, the lower end 10 of each tube 8 is secured to a body 13 having an axial passage 14 extending towards the bottom of the tube 8. At
3,102,666 Patented Sept. 3, 1963 the side of the passage 14 is located an opening 15 through which the supply \of water is adapted to take place. Intact, the pipe 11 for the supply of water is connected to the body 13 in a seating 16 provided on the side of this. In the seating 16 is mounted a non-return or normally open valve 17 constituted, in this particular case, by a steel blade clamped at one of its edges between a shoulder 18 of the body 13 and a washer 19 clamped in the seating 16. Said non-return valve 17 is therefore of the automatic control type and closes when a pressure of a predetermined value applied in the passage 14, which prevents any back-flow into the pipe 11. The lower part of the passage 14 is terminated by an orifice 20 opening into a space 21. It is precisely this space 21 to which is connected the pipe 12 for the supply of compressed air. The edge 22 of the orifice 20 forms the seat of a normally closed valve 23 controlling the inlet of compressed air into the tube 8. This valve 23 comprises a fluidtight joint 24 carried by an armature 25 secured to a tubular shaft 26 capable of sliding axially in a core 27 of soft iron, against the action of a spring 29*. Said core of soft iron 27, forms part of an electromagnet of which the coil is shown at 28 in FIGS. 2 and 3. The iron core 27 as also the coil 28, close the space 21 towards the bottom, in a fiuidtight manner. In fact, the iron core 27 is screwed in the downward extension forming part of the body 13.
As will be seen in FIGS. 2 and 3, a passage 29 places the internal portion of the space 21 into communication with the bore 30 in which the tubular spindle 26 can slide. On the other hand, openings 31 are drilled in the armature 25. Said passage 29 and the openings 31 permit the pressure of air obtaining in the space 21 to act on all the faces of the movable armature 25 in such a. manner as to practically equilibrate this relatively to this pressure of compressed air.
In the normal position and as shown in FIG. 2, the spring 39 maintains the valve 23 closed, the joint 24 hearing against the seat 22.
When an electric current energizes the coil 28 0f the electromagnet, the armature 25 is attracted and pressed against the upper part of the core 27, whereby the valve 23 is moved vfrom its seat 22 and permits the compressed air supplied by the pipe 12 to be introduced through the orifice 20 into the passage 14 and thus into the tube 8 so as to provoke the ejection of the volume of water contained in said tube 8. During an ejection phase of the charge of water contained in the tube 8 and the passage 14 and by reason of the augmentation of the pressure obtaining in said passage 14, the automatic non-return val e 17 is maintained in a closed position, which prevents any back-flow of air or water into the pipe 11 for the supply of water. 'When the supply of current to the coil 28 ceases, the valve 23 is pressed against its seat 22 by the spring 39, whereby the inlet for compressed air into the tube 8 is closed.
Any known means may be utilised for supplying, in an alternative manner by current impulses, the coil 28 of each of the electromagnets of the ejection devices 7. It is possible, for example, to use for this purpose a rotary current distributor. The frequency of the ejection phases of water from each of the tubes 8 is determined by the time of filling of these same tubes 8 with water during the rest phase shown in FIG. 2. It will be obvious that it is possible to augment the frequency of the water ejection phases by provoking a forced supply of water from the pipe 11, by placing this under pressure at least during the rest or filling phase of the tube 8- shown in FIG. 2. This momentary placing under pressure of the pipe 11 may be eifected by taking pressure, either directly on the side of the tube 8, or from the supply circuit of compressed air of the machine.
As shown in FIG. 1, a complete battery of injection devices 7 is located under the bottom 4 of the vat 1. This battery of ejection devices 7 is supplied with water from the collecting reservoir 6 located underneath the vat 1. In fact, each ejector device 7 is connected by its own pipe 11 to the lower portion of the reservoir 6. This reservoir is connected to the water teed circuit by a supply passage 32, controlled by a blade or valve 33. A discharge passage 34 is provided at the collecting reservoir 6, which passage is cont-rolled by a blade or valve 35. Said reservoir 6 also contains an electric heating body 36 adapted to be switched on by a switch 37.
An aggregate 38, which may comprise a transformer and an air compressor driven by an electric motor, is located under the vat 1; a clockwork may be disposed in the aggregate 38 or at any other point of the machine and adapted to control each washing and emptying phase of the machine by acting, for example by electro-magnetic means, on the gates or valves 33 and 35. This clockwork may also act :on the contactor 37 for switching on the heating phase and for disengaging the heating body 36 before the emptying phase of the water soiled by the washing. Preferably also, there is disposed in the aggregate 28 the distributor supplying current impulses to each of the electromagnets 27, 28.
The process of projection of water set in operation in the washing machine described above, and which consists in alternatively charging the ejection tubes 8 with a predetermined volume of Water and then expelling said volume of water from the tubes 8 by injecting compressed air into these, permits of obtaining an ejection of water much higher than was the case in processes set in operation by known washing machines. In .fact, each of the ejection tubes 8 functions in a manner similar to a gun in which the explosion of a charge of powder is replaced by the action of compressed air, the projectile being constituted by the volume of water contained in the tube '8.
Numerous modifications in construction of the machine illustrated in the drawing may be imagined. Thus, all the ejection tubes 8 need not necessarily be disposed vertically; some thereof may be disposed slopingly or in any suitable positions on the periphery of the vat 1, provided that the filling of these tubes with water may be effected normally during the resting phase of each ejection device 7.
1. A dishwashing machine, comprising, a vat, a plurality of ejection tubes mounted in said vat, each of said tubes having an upper end opening into said vat and a bottom end comn'lunicating with a pair of valved openings in the tube, one of said valved openings in each tube connected to a supply ofliquid and provided with a nonrnflly open valve for admitting of a predetermined volume of liquid into the tube, the other of said valved openings in each tube connected to a source of compressed air and provided with a normally closed valve, means for successively actuating said normally closed valves, such that following the admittance of predetermined volumes of liquid into the tubes through the normally open valves, said activating means is alternatively excited to successively open said normally closed valves to admit measured amounts of compressed air into the tubes whereby the normally open valves are closed by the compressed air and the liquid is expelled from the open ends of the tubes.
2. A washing machine accordingto claim 1, characterized in that each of said normally closed valves controlling the intake of air to said tubes is actuated by an electro-magnet subject to impulses of current causing alternative opening and closing of the valve.
3. A washing machine according to claim 2, characterized in that each of said valves is mounted on an armature capable of being moved into the field of said electromagnet, a chamber containing compressed air surrounding said armature, passages through said armature to permit the compressed air to act in equal fashion upon all faces of the armature so as not to interfere with the actuation of said valve when said elect-ro-magnet is energized.
References Cited in the file of this patent UNITED STATES PATENTS