GB2037880A - Apparatus for Supplying a Fluid Additive to a Dish Washer - Google Patents

Abstract

Pressurized water is fed to the driving cylinder 1 alternately through inlets 16, 17 in the end walls 5 and 6, causing reciprocation of both pistons 2, 4. Detergent or other additive is thereby sequentially drawn into cylinder 3 through valved inlet 18, forced through the valved bore 20 in piston 4, and expelled from cylinder 3 through valved outlet 19 in end-wall 7. It can then optionally be mixed with water from cylinder 1. Low-friction seals are provided by O-rings 2', 4', 15. For ease of maintenance and adjustment the cylinders 1, 3 are detachably and sealingly seated in annular grooves (10-13) in the end walls 5, 6, 7. The driven cylinder 3 is of smaller diameter than cylinder 1, thus giving a high pressure to the detergent. The output volume is adjustable via screw 43. <IMAGE>

Description

SPECIFICATION Apparatus for Supplying a Fluid Additive to a Dish Washer This invention relates to an apparatus for supplying e.g. a dish-washing detergent, wetting agent or other detergent to a dish washer, spray nozzle or the like.

It is known to use for this purpose an apparatus including two cylinder spaces, one attached annularly about the other, and a piston in each cylinder space, where the piston rods project from the cylinder spaces in the same direction and are coupled together outside said spaces so that the pistons move in common. By supplying pressure water to one cylinder space and alternatingly to one and the other piston end, this piston and therewith also the other piston are driven and suck dishwashing detergent, wetting agent etc.

from a container and pump it over to a dish washer. The apparatus can operate fully satisfactorily, but its manufacture and assembling is very tedious and complicated and, moreover, correct adjustment of the pistons and piston rods relative to the cylinders involves some difficulty.

The present invention has the object to provide an apparatus for supplying a dishwashing detergent, wetting agent or other detergent etc.

to a dish washer, spray nozzle etc., which apparatus has a simple structural design and therefore is easy to manufacture and assemble, and which renders it possible to more easily and accurately adjust the movable parts relative to their guides.

This object may be achieved according to the present invention by an apparatus design having the features defined in the attached claims.

The invention is illustrated by way of an embodiment in the accompanying drawing, in which the Figure is a longitudinal section of an apparatus according to the invention.

The apparatus according to the invention comprises a cylinder 1 with a driving piston 2 provided with a sealing ring 2' in the form of an O-ring, and an additional cylinder 3 with a working piston 4 provided with a sealing ring 4' in the form of an O-ring. The two cylinders 1, 3 are mounted one after the other and extend longitudinally along a common axis. An intermediate piece 5 forms the end wall at one end of both cylinders 1, 3 while separate end walls 6, 7 are attached at the other end of the cylinders. The intermediate piece 5 as well as the end walls 6, 7 preferably are made of bronze cast in sand. The cylinder wall of the cylinders 1, 2 is formed each of a pipe 8, 9, for example of steel, and the ends of the pipes are secured in annular grooves 10, 1 1 in the intermediate portion 5 and in annular grooves 12, 13 in the end wall 6 and 7, respectively.The pipes 8, 9 are sealed against the intermediate piece and end walls by means of sealing rings in the form of O-rings attached on the bottom of the grooves 10-13 as shown in the Figure. Bolts (not shown) and for example four in number are mounted between the intermediate piece 5 and one and, respectively, the other end wall 6, 7 in order to hold together the cylinders 1, 3. Of the cylinder spaces 1' and 3', respectively, formed in the cylinder 1 and the cylinder 3, respectively, the cross-sectional area of the cylinder space 1' is greater than the cross sectional area of the cylinder space 3' for a reason which will be explained below.

The driving piston 2 in the cylinder space 1' and the working piston 4 in the cylinder space 3' are attached each at one end of a piston rod 14 common to both pistons and preferably made of stainless steel. Said piston rod 14 extends slidably through the intermediate piece 5 and is sealed against the same by a pair of sealing rings 15 in the form of O-rings.

The intermediate piece 5 and end wall 6 each have a through bore 1 6, 1 7 opening into the cylinder space 1' on each side of the driving piston 2.

The intermediate piece 5 further has an inlet channel 18, and the end wall 7 has an outlet channel 19, which channels open into the cylinder space 3' on each side of the working piston 4.

Said piston 4 has a through channel 20 forming a connection between the portions of the cylinder space 3' located on each side of the working piston 4. In each of said channels 18, 19, 20 a check valve 21, 22 and 23, respectively, are inserted. Each of these valves includes a stainless steel ball 24, 25 and 26, respectively, which by action of a stainless spring 27, 28 and 29, respectively, close the channel in question.

The supply channel 18 is intended to be connected by a conduit 30 with stop valve 31 to a container 32 containing liquid dishwashing detergent, wetting agent etc., as indicated schematically by dash-dotted lines, as this supply means may have varying design. The outlet channel 19 is intended to be connected by a conduit to a dish waster (not shown). As set screw 43 is mounted adjustably in the end wall 6 as a stop member for the driving piston 2.

The aforesaid through bores 1 6, 1 7 to the cylinder space 1' are connected by schematically shown conduits 33, 34 to a multi-way valve (or multi-way vales) 35, which preferably are of magnet valve type and adjustable by means of, for example, a time relay or the like. A conduit 36 for pressure water is connected to the multi-way valve 35, and conduits 37, 38 are connected to the dish washer (not shown). In said lastmentioned conduits 37, 38 manually or mechanically controlled two-way valves 39, 40 are mounted for closing or opening to drain pipes 41,42. The details 33-42 are described only by way of proposal, because they may have different design and, therefore, are shown by dash-dotted lines. Their design is described for explaining the operation of the apparatus according to the invention.The apparatus operates as follows on the basis of the piston setting shown in the Figure. Pressure water is supplied preferably from a water mains through the water conduit 36 to the multi-way valve 35, which is controlled by the time relay, so that the valve 35 closes the connection between the conduits 36 and 34 and opens the connection between the conduits 34, 38 and between the conduits 36, 33. Thereby pressure water is pressed in beneath the driving piston 2 through the conduit 33 and through bore 16 and forces the piston upward. At the same time the water above the piston 2 flows off through the through bore 17 and conduits 34, 38 to the dish washer or possibly to the drain pipe 42.When the driving piston 2 assumes the top position, the time relay readjusts the multi-way valve 35 so that pressure water is introduced above the driving piston 2, and the water beneath the driving piston flows off through the through bore 16 and conduits 33, 37 to the dish washer or possibly to the drain pipe 41.

The working piston 4 coupled together with the driving piston 2 follows along with the latter.

At the upward movement of the working piston, the dishwashing detergent etc. in the portion of the cylinder space 3' above the working piston is pressed through the through channel 20 and the check valve 23 to the cylinder space portion beneath the working piston, because the check valve 22 closes against fiow-off of dishwashing detergent through the inlet channel 18.

At the downward movement of the working piston 4, the dishwashing detergent in the cylinder space portion beneath the working piston is passed out through the check valve 21 and outlet channel 19 to the connected conduit and dish washer. At the same time a suction effect arises in the cylinder space portion above the working piston, so that dishwashing detergent from the container 32 flows into said lastmentioned cylinder space portion via the conduit 30 and the inlet channel 18 and through the check valve 22.

The illustrated embodiment of the apparatus according to the invention particularly has the advantages, that the water and the dishwashing detergent are transported separated from each other through the apparatus. It is thereby possible to stop the water supply to the dishwasher by the valves 39, 40 and allow water driven out from the cylinder space 1' to flow off through the waste pipes 41, 42 and at the same time to supply only dishwashing detergent to the dish washer. This implies the possibility of being able, as often is desired, to add to dishes newly inserted in the dish washer only dishwashing detergent and first thereafter to supply water and after completed dishwashing possibly to add wetting agent etc.

and finally only water for rinsing.

Due to the smaller cross-sectional area of the working piston than of the driving piston, a higher expelling pressure for the dishwashing detergent etc. in the cylinder space 3' is obtained than for the pressure water in the cylinder space 1'.

Owing to the high expelling pressure, the amount of dishwashing detergent can be reduced, and as also the amount of dishwashing agent supplied per stroke can be changed by changing the stroke length of the driving piston by adjusting the set screw, the batching of dishwashing detergent is the most suitable one for saving expensive dishwashing detergent.

Further advantages which may be achievable by apparatus according to the invention are a simple structural design without sealing problems, its easy adjustability for safe and noiseless operation and correct batching, easy disassembly and re-assembly for servicing, and relatively small overall dimensions. Further possible advantages are that the apparatus can be positioned arbitrarily vertical or horizontal, and that it is reliable in operation because of its small number of movable parts and lowest possible inner friction.

The invention must not be regarded restricted only to the embodiment described and shown in the drawing, but can be modified within the scope of the invention. The construction and mutual connection of the cylinder walls and their end walls, for example, can be modified, the design of the check valves can be varied, and the check valve in the outlet in the end wall can be placed closely outside the same. The multi-way valve or valves can be controlled, for example, by a suitable minicomputer.

Claims (4)

Claims

1. Apparatus for supplying a fluid additive at a controllable rate to a dishwasher or spray nozzle, said apparaus comprising: opposed coaxial driving and driven hydraulic cylinders with respective driving and driven pistons, said cylinders having a common end wall with an axial aperture therethrough; an axially movable elongate connecting rod passing sealingly through said aperture, said rod connecting said pistons for common axial movement; inlet/outlet means at or adjacent each axial end of said driving cylinder for supplying a pressure fluid to said cylinder alternately on opposite axial sides of said driving piston to cause reciprocation of both pistons;; an inlet and outlet communicating regions of the driven cylinder on respective different axial sides of the driven piston to the exterior thereof, and a flow passage in said driven piston communicating said regions, said inlet, outlet and flow passage having associated one-way valve means arranged so that reciprocation of said pistons acts to pump the fluid additive in through said inlet and out through said outlet of the driven cylinder.

2. An apparatus for supplying dishwashing detergent, wetting agent, other detergent etc. to a dish washer, spray nozzle or the like, comprising a double-acting driving piston and a double-acting working piston with a smaller diameter than that of the driving piston and each mounted in a respective one of two cylinders, which are in the form of pipes and arranged along one and the same axis and separated by an intermediate portion, which forms one end wall in each cylinder, said driving piston and working piston having in common a piston rod, which sealingly extends through said intermediate portion, and wherein the intermediate portion is in the form of a separate intermediate piece, which is provided with an annular groove with a sealing, in which groove one end of the tubular cylinder provided with the driving piston is secured, and with an additional annular groove with a sealing, in which groove one end of the cylinder provided with the working piston is secured; and the end walls of the other ends of the cylinders also have annular grooves with sealings, in which grooves the other end of the respective cylinder is secured; the cylinders and the intermediate piece being held together detachably by bolts between the intermediate portion and, respective ones of the other end walls.

3. An apparatus as defined in claim 2, wherein the intermediate portion is provided both with a through bore (16) into the cylinder space (1') for the driving piston (2) and a through bore (18) into the cylinder space (3') for the working piston (4), and that in said lastmentioned through bore (18) a check valve (21) is mounted which allows flow only in the direction to said lastmentioned cylinder space (3').

4. Apparatus for supplying a fluid additive constructed and arranged substantially as described herein with reference to the accompanying drawing.