US 3055555 A
Description (OCR text may contain errors)
Sept. 25, 1962 G. R. REITER 3,055,555
LIQUID DETERGENT DISPENSER Filed Nov. 12, 1959 GEORGE R. REITER H IS ATTORNEY INVENTOR United States Patent M 3,055,555 LIQUID DETERGENT DISPENSER George R. Reiter, Trumbull, Conn., assignor to General Electric Company, a corporation of New York Filed Nov. 12, 1959, Ser. No. 852,273 4 Claims. (Cl. 222-207) thousands of operations before failure should occur.
The principal object of the present invention is to provide a novel liquid dispenser that relies upon the relatively higher resistance to flow in the intake line than in the discharge line so that the design may accomplish its function Without the use of valves.
A further object of the present invention is to provide a liquid detergent dispenser for an automatic dishwasher including a valveless pump that utilizes a flexible diaphragm tor the piston, and has a discharge line that is larger than the intake line so that when the pump is actuated the discharge line will carry off most of the liquid that is put under pressure.
The preferred embodiment of the present invention incorporates a pump having a chamber that is fed by a relatively small intake tube and empties into a relatively large discharge tube. The intake tube has a large resistance to flow of the liquid while the discharge tube has little resistance to the flow. The pump includes a piston in the form of a flexible diaphragm that is capable of compressing the liquid by means of an actuator connected to the diaphragm so that most of the liquid will flow through the discharge line. A liquid storage tank is positioned at the mouth of the intake tube and liquid flows by gravity through the intake tube when the diaphragm is drawn back to enlarge the pump chamber. It is necessary that the outlet end of the discharge tube be positioned higher than the storage tank so that the liquid will not be siphoned from the tank.
My invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.
FIG. 1 is a perspective view of a top segment of the wash tub of an automatic dishwasher showing on the outer surface of the tub a liquid storage tank and a liquid dispenser embodying the present invention.
FIG. 2 is a schematic drawing partly in cross section showing the novel pump of the present invention.
Referring in detail to the drawing and in particular to FIG. 1 there is shown a washing compartment or tub 11 which is generally square shaped in plan view. The tub is formed by a series of side walls 12, a top cover and a bottom wall (both of which are not shown). Conventionally the tub will include two or more dish supporting racks and a rotary impeller in the bottom of the tub for paddling the water through the dish racks. Also there will be a water feed pipe for introducing hot water into the tub during both the rinsing and washing cycles. Also it is necessary to provide a means for introducing the detergent into the tub at the precise moment after the dishes have been preninsed. First there is a liquid storage tank 13 for supplying the detergent to a pump 14 which will in turn inject the proper amount of the Patented Sept. 25, 1962 liquid into the tub at the precise moment at the beginning of the washing cycle.
The drawings do not show the method used for supporting the tank and pump trom the outer surface of the tub wall 12, but it should be understood that the mounting means forms no part of the present invention and that standard methods using bolted or welded brackets or clamps would be used in production to insure a firm support for these elements. Part of the wall of the tank 13 is broken away to show a port 15 that extends through the tub wall 12 so that the tank may be filled with detergent from within the tub. Of course, the fill opening of the tank would be supplied with a suitable cap (not shown) so that the water spraying within the tub during the operation of the dishwasher will not dilute the detergent in the tank. The tank will also contain a pressure equalizing bleeder hole in the filler cap or top surface. Accordingly, either the top cover of a portable dishwasher is pivoted open to fill the tank or the dishwasher tub is pulled out from under the counter to expose the top opening of the tub.
The pump 14 of the present invention is best shown in detail in FIG. 2. The pump has a chamber 16 for receiving the liquid from an intake line 17 which extends down into communication with it and for injecting it into the tub through a largediameter discharge line 18 which extends up from chamber 16 into communication with the tub. The pump housing is formed by a metal cup 19 that is covered over by a cup-shaped rubber diaphragm 20. For purposes of illustration this pump design is formed with a metal cup and a rubber cup fastened to each other. However, it should be readily apparent to those skilled in the art that this pump housing could also be formed by a metal cylinder that is open at one end where the opening is closed by a flat rubber sheet or flexible metal sheet that acts as the piston. This pump 14 could be mounted by fastening clamps or brackets from the tub over the tubes 17 and 18 to hold the pump housing stationary with respect to the tub.
A principal point of novelty in this invention is the relative sizes of the intake and discharge lines 17 and 18, that is, the relative size of the mini-mum cross-sectional area of the discharge line and of the intake line. The intake line 17 is formed by a small tube with an ID. of about V that connects at one end to the tank 13 and at its other end to the metal cup 19 of the pump housing at 21. The pump 14 is mounted lower than the tank 13 as is best seen in FIG. 1 so that the liquid detergent will flow by gravity into the pump chamber 16. The rubber diaphragm 20 is normally urged to its retracted position shown in FIG. 2 to obtain the maxi mum size chamber within the pump so that the pump will always be supplied with a sufiicien-t amount of detergent for injecting into the tub. The diaphragm is operated upon by an actuator or link member 22 that is pivotally connected at its top end to embossments 23 formed on the diaphragm 20, while its opposite end is pivotally connected to a flange of an angle bracket 24 that is fastened to the outer surface of the tub wall 12. There is a tension spring 26 that is fixed .at one end to the tub wall and connected at its other end to the actuator 22 to hold the actuator in the retracted position. A solenoid 27 is likewise mounted on the bracket 24 and it has an armature 25 that is connected to the mid-portion of the actuator 22. Hence, when a control switch 28 of the solenoid circuit is closed the armature of the solenoid will shift to the left forcing the rubber diaphragm to be compressed within the metal cup 19 and putting the liquid detergent under pressure. Because of the relatively small diameter of the intake tube 17 and the relatively large diameter of the discharge tube 18 with an ID. of about most of the liquid will be forced through the discharge line and out into the tub. Notice in FIG. 1 that the uppermost end of the discharge tube 18 extends through the tub wall 12 at a point higher than the tank 13 to prevent the tubes from siphoning the liquid from the tank. Also, the end of the discharge tube is provided with a deflector cap 29 having enlarged openings 30 on the side facing the tub wall '12 that are protected from the spray of the dishwasher so that the streams of water playing within the tub during the washing cycle will not flow back into the discharge line and into the pump, resulting in a dilute solution.
Having described above my novel invention of a valveless pump system for dispensing liquids, it will be readily appreciated 'by those skilled in this art that the Liquid need not be a detergent; the tub need not be for a dishwasher, but it could be used with an automatic clothes washer. A solenoid need not be used as the actuator. It could just as well be a heat motor or a spring biased latch mechanism that is controlled by a cam on the automatic cycle timer. In the illustrated embodiment of this invention air can be trapped in the pump above the discharge tube 18. A modification would be to locate the discharge tube at the top of the pump housing or alternatively to turn the pump over on its side so that the discharge tube is at the highest point of the pump housmg.
Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore, that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modification-s which are within the true spirit and scope of this invention as claimed.
What I claim as new and desire to secure by Letters Patent of the United States is:
1. A liquid dispenser comprising a pump housing with a chamber that includes a fluid-tight reciprocating piston which moves in one direction to enlarge the chamber and moves in an opposite direction for decreasing the chamber space, a small intake line extending down into communication with the pump chamber for feeding liquid by gravity into said chamber, and a discharge line having a minimum cross-sectional area at least several times larger than the intake line leading up from the chamber so as to have a lower resistance to flow than the intake line, whereby when the liquid enters the chamber through the intake line and the piston is actuated to compress the liquid, the higher resistance to flow of the small intake tube will cause most of the liquid in the chamber to be forced out of the larger discharge tube, thereby functioning as a valveless pump.
2. A washing apparatus comprising a washing tub and a liquid detergent storage tank mounted on an outer side wall of the tub, a detergent dispenser likewise mounted on the outer side of the tub but positioned lower than the storage tank, the dispenser comprising a pump chamber and a fluid-tight resilient diaphragm that is coupled with an actuator, a small diameter inlet tube joined at one end to the bottom of the storage tank and at its other end to the pump chamber so that the detergent will feed by gravity into the chamber, and a discharge tube with a larger cross-sectional area than that of the inlet tube leading from the chamber and into the tub at a point higher than the storage tank, the large discharge tube having less resistance to flow than the small inlet tube so that when the actuator causes the diaphragm to move inwardly of the pump chamber to compress the liquid detergent, most of the liquid in the chamber will flow through the discharge tube and into the tub so that the dispenser represents a valveless pump.
3. A liquid detergent dispensing system for supplying a measured quantity of detergent to a washing apparatus, the system comprising a detergent storage tank, a valveless pump for the detergent positioned lower than the tank, and a small intake line feeding the liquid to the pump by gravity, and a discharge line that is at least several times larger in cross-sectional area than the intake line with a relatively low resistance to flow as compared with the resistance to flow of the small intake line, the discharge line leading from the pump and discharging into the Washing apparatus at a point higher than the storage tank, so that in one condition of the pump the liquid will feed from the tank to the pump, and in another condition of the pump the liquid will be under pressure and most of the liquid will pass through the discharge line with only a small amount flowing back into the intake line.
4. A valveless pump for a liquid detergent dispensing system, the pump comprising a housing forming a chamber and having an intake line and a discharge line both extending down into communication therewith so that liquid is fed by gravity from said intake line to said chamber, the intake line having a small bore with relatively ligh resistance to flow While the discharge line has a bore with a minimum cross-sectional area substantially larger than said intake line so that it has substantially less resistance to flow, a fluid-tight rubber-like dia- References Cited in the file of this patent UNITED STATES PATENTS Kinney Oct. 21, 1913 Laing Dec. 23, 1958 Seiler Mar. 22, 1960