Antiflood device for washing machines

Abstract: Antiflood device comprising a couple of pneumatic valves (16, 17), a couple of hydraulic valves (12, 13) and a feed pipe (F, 23, 26) ending in a rapid attachment (27), for washing machines in general, the pneumatic valves (16, 17) being activated by an electropump (22) placed on the bottom, inside of the machine, characterized by the fact that a couple of pneumatic valves (16, 17) are fixed to a couple of hydraulic valves (12, 13) activated in corresponding cylinders that may be inter­ communitcating, for the water feed (A, 26, 26a) to the tank of the machine.

Description: Washing machines are provided with at least one electrovalve hydraulically connected to the water supply tap and electrically connected to the timer of the machine which controls the opening and the closing of the valve according to the stages of the washing cycles. Any blockage of the electrovalve in the open position can cause dangerous flooding. In order to avoid flooding as a result of any such breakdown, the electrovalve(s) or the valve(s) controlling the water flow must be able to close automatically in the presence of the overflow of water. From EP-A-0 235 766 a safety valve is known, comprising two membrane valves controlled by electromagnets, placed side by side and connected in series. The functioning of this device depends on the hydraulic pressures present in the two valves and is such that in case of overflow, the valve placed in the most downstream position in the flow opens and sends the water to the discharge. Should there be any breakdown in the opening order of the valves, a breakdown warning is provided. From EP-A- 0 234 643 a device is known with a double valve. One of the valves is controlled to close electrically should the normal level of the water in the tank be exceeded while the other valve can be controlled to be closed by the pressure that is established in a flexible water-tight sheath connected to the valves and to the tank of the machine. GM No. 88 00 478.3 provides for a pneumatic pump that directs air (for cooling) onto the manifold of the motor of the machine. Tubular ducts which pneumatically control an interception valve and which also direct air to the motor of the pneumatic pump are also provided. From FR-A-2 622 316 an antiflood device is also known, comprising two pneumatic valves, normally closed, and openable by compressed air, said valves intercepting the flow of water to the machine in the normally closed position. Should there be any breakdown in one of the two valves, no breakdown warning is provided. The subject of the present invention is an antiflood device for washing machines comprising a couple of pneumatically activated valves which control the flow of water to the washing machine. While both the valves are activated to open at the same time due to the action of a pump, when closing they act independently one from the other due to the reaction of elastic means, which means that any blockage of one of the two valves in the open or partially open position, does not interfere with the closure of the other valve. The device is characterised by the fact that the valve which closes is automatically and mechanically blocked in the closure position until the breakdown which has blocked the other valve open or partially open has been repaired. Detailed characteristics of the device will now be described with reference to the attached drawings, in which: Figure 1 illustrates a section of the device according to a vertical plane passing through the axis of the feed pipe; Figure 2 is a view of the two parts, separated, that constitute the rapid attachment coupled in Figure 1; Figure 3 is a top view of said attachment; Figures 4, 5 and 6 illustrate the functional layout of the automatic means that lock one of the valves in the closed position if the other jams in the open position; Figure 7 is a side view of the stopping means that act on the extremities of the valve stems; Figure 8 is a variation of Figure 7; Figure 9 is a plane view of the mechanism which controls the synchronized opening of the two valves; Figure 10 is a side view of part of the same mechanism; Figure 11 is a structural variant of the device in Figure 1; Figure 12 is a particular of Figure 11; Figures 13 to 16 illustrate a variant of the safety means in Figures 4 to 10. With reference to Figures 1, 2 and 3 the device, indicated as a whole by 10, comprises a casing 11, which can be linked to the water source -A- by means of the screw nut -B-. Said casing contains the cylinders 12, 13 which intercommunicate by means of a tubular branch 24. Three groups of pistons are slidably mounted at a prefixed distance in the cylinders 12, 13 and are provided with "OR" sealing strips and are fixed to corresponding stems 14a, 15a. Said stems are also fixed to disc valves 16, 17 slidably mounted in cylindrical chambers 16a, 17a coaxial to and intercommunicating with the cylinders 12, 13. Rated springs 18, 19 keep the disc valves in the position as shown in Figure 1, corresponding to closed valves. Gauged balancing holes bored in the discs 16, 17 are indicated 16b, 17b. The collecting duct -D- intercommunicates the chambers 16a, 17a and is pneumatically connected to the tube section 23 arriving from the electric vibration pump 22, placed inside and on the bottom of the machine and electrically connected to the programmer or timer of said machine. The cylinder 13 is provided with a tubular appendix 25 connected to the tube section 26 which, by means of the rapid attachment connection indicated as a whole by 27, feeds the water into the tank of the machine (not illustrated). -F- indicates a tube-sheath which contains and protects the tube sections 23 and 26. Considering that the piston groups 14, 15 spaced along the corresponding stems 14a, 15a, when the two valves are closed, Figure 1 in the corresponding cylinders define symmetric chambers -E-, -E1- respectively, the device works in the following way: When the device is inactive, the valves are closed, Figure 1; the water being fed from -A- flows into -C- and into chamber -E-, but no further. When the machine is running the programmer or timer feeds electricity to the vibration pump 22, said pump being of limited size, of the type used for acquariums. The pump 22 feeds compressed air into chambers 16a, 17a through the tube section 23 and the collector -D-, downstream of the disc valves 16, 17. When the air pressure prevails over the reaction of the springs 18, 19 it forces the valves 16, 17 to slide together with the pistons 14, 15. The longitudinal and contemporary movement of the pistons 14, 15 in the direction indicated by the arrow X, lets in the water which, from -C- passes on to the chamber -E-, through the tube 24, to -E1- and, through appendix 25, tube 26 and connection pipe 27, enters the tank of the machine. With the two valves open, and the continued action of the pump 22, the excess compressed air flows out through the gauged holes 16b, 17b transversally bored in the discs. When the pump 22 stops, the valves 16, 17 under thrust by the springs 18, 19, return to the closed position. Figure 1 schematically illustrates the mechanism 29 which, if one of the valves jams in the open position, blocks the other in the closed position. This mechanism is described below with reference to Figures 4 to 10 in which the parts corresponding to the parts in Figure 1 are marked by the same reference numerals. According to a preferred version of the invention the mechanism comprises: a couple of independent stops such as "C"-shaped juxtaposed, coplanar clamps 32, 33 with reciprocally interfering arms, shown in detail in Figure 8. Said clamps, slidably mounted on a vertical plane, transverse with respect to the longitudinal axis of the stems 14a, 15a of the valves, Figure 4, as a result of the thrust of the elastic means 36, are able to engage the grooves 30, 31 made in the stems 14a, 15a and present a bevelled inside edge 32b, 33b. The ends of the stems 14a, 15a are tapered and connected to the part with a larger diameter by means of short, inclined planes 14b, 15b parallel to the slope of the bevelled sections 32b, 33b. With the valves in the rest position, i.e. closed, Figures 1 and 4, the grooves 30, 31 are free from the clamps, whose bevelled edges 32b, 33b, pushed by the spring 36, lean in the opposite position on the jacket of the stems 14a, 15a. The pump 22, controlled by the timer of the machine, brings the valves into the position as shown in Figure 5. When the pump 22 stops, so does the supply of compressed air downstream of the discs 16, 17. The reaction of the springs 18, 19 pushes the valves back into position as shown in Figure 4. If, on closing, both the valves are working regularly, the branches 32a, 33a of the stops 32, 33 return from the position shown in Figure 5 - valves open - to the position shown in Figure 4 - valves closed - pushed by the inclined planes 14b, 15b which act on the bevels 32b, 33b against the reaction of the rated springs 36. If, for some reason, one of the two valves, for example the one indicated by 17, jams in the open position, Figure 6, while the other regularly returns to the closed position, the branch 32a of the stop 32, pushed by the spring 36, is released into the groove 30 of the stem 14a and blocks valve 16 in the closed position. In these conditions the water delivery cannot go further than the chamber -E- of the device, Figure 1, or the chamber -E1- if the jammed valve is 18. According to a structural variant of the stopping means, which cooperate with the extremities of the valve stems, said means can be structured in the form of a couple of levers 37, 38, crossing each other as X, revolving with respect to the pins 37a, 38a, Figure 8. It is indispensable that, on opening, the movement of the valves is synchronous and uniform so that the mechanism only intervenes when one of the valves jams on closing. In fact, any differing air pressure values in the chambers 16a, 17a, would alter the synchronism of the movement on opening the two valves with the danger that the slower valve could block in the closed position. In order to ensure the synchronous opening of the two valves, particularly at the beginning of the opening movement and until the grooves of both the stems have not overtaken the transverse plane of interference with the stops 32, 33, synchronizing means are provided, as illustrated in Figures 9, 10. A lever 25, with double cross transverse branches 25a, 25b, presents the extremities of the branch 25 mounted linked in fixed parallel support slots 41. A traction spring 39 is anchored to the double cross lever at a fixed point 42. When the valves are closed the spring 39 holds the lever 25 in the position as shown by the continuous lines in Figure 10, therefore while the transverse branch 25a engages the corresponding transverse concave grooves 15d, symmetrically borne by the stems 14a, 15a of both the valves, the other transverse branch 25b of the double cross lever engages the peak of an obtuse angle which is to be found in a fixed bracket 44, made up of a sector 43 sloped with respect to a second sector 43b, parallel to the axis of the valve stems. When the valves begin to open the compressed air sent to the chambers 16a, 17a by the pump 22, downstream of the discs 16, 17, could reach the two chambers with different pressure values which would tend to differentiate the speed of advancement and opening of the valves. This, or any other cause that could differentiate the speed of advancement of the valves on opening, could cause the slower valve to block in the closed position. The stems 14a, 15a being initially coupled, in such a way that they can be automatically separated by the transverse branch 25a, are initially forced to advance in synchronism. The angular movement imposed on the lever 25 by the sliding of the stems in the direction indicated by the arrow -X- in Figure 10, causes the transverse branch 25a to travel along the sloped sector 43 of the bracket 44, forces the pins 25c to move along the holes 40 while the branch 25a disconnects from both the stems. The reaction of the spring 39 brings the lever 25 back to the original position against a fixed point stop 42. When the valves return to the closed position the bevelled part 45 of both the stems comes into contact with the branch 25a of the lever 25 and, overcoming the reaction of the spring 39, takes the mechanism back to the position indicated by continous lines in Figure 10. The components of the mechanism are sized so as to guarantee that when the stems 14a, 15a disconnect from the common engagement 25a, the concave grooves 30, 31 of said stems have passed beyond the transverse plane of interference with the stops 32, 33. In the variant in Figure 11, the tube section 113 which communicates with the connection -A-,-B- to the water supply, is contained in the casing 112. Its extremity 114, funnel-shaped, is connected to the tube section 26 which feeds water to the tank of the machine. The pneumatic pump 22, of the vibration, centrifugal or any other suitable type, feeds compressed air to the cylinders 116, 117 through the tube section 26a, the rapid release valve 115 and the tube section 26. The pistons 118, 119 respectively slide in said cylinders against the reaction of the spring 120. At the extremities of the shafts of said pistons the extremities of levers 121, 122 are articulated which engage the stems 140, 141 respectively of valves 123, 124 and present the opposite extremity articulated at fixed points 125, 126 of the tubular body 113. In the position illustrated in Figure 11, the valves 123, 124 are closed. The water flowing into chamber -C- goes no further. When the pump 22 starts up, the compressed air overcomes the reaction of the spring 20, pushes the pistons 118, 119 to run in the direction indicated by the arrows causing the levers 121, 122 to open the valves 123, 124. The water being fed from -C- through the duct -D- passes into the chamber -E- and, through duct -F- and tube section 26, reaches the tank of the machine. The open position of the valves 123, 124 is shown in Figure 12. The rapid escape valve 115, provided with an overflow opening, as is known, works in the following way: when the pump 22 is running, the light elastic membrane 128, under pressure, closes the discharge 129, the compressed air reaches the tube section 26 thanks to the perimetral deformation of said membrane (see particular -H-). When the pump stops the reflux of compressed air raises the membrane 128, as shown by -G-, and allows the air to leave through the discharge 129. The safety mechanism, already described in Figures 4 to 10 is indicated by 29. According to a structural variant of said safety mechanism, with reference to Figures 13 to 16, a guide 131 is slidably mounted, against the reaction of a return spring 139. The guide 131 supports the movable clamping hinged elements 132, 133, reciprocally drawn together in contrast with the spring 138, reacting to compression. The elements 132, 133 are provided with concave grooves engaged by the stems 140, 141 of the pistons 118, 119. The fixed stops are indicated 134, 135 and 136, 137. The pump 22 activates the pistons 118, 119 illustrated in the rest position in Figure 13. Said pistons advance in parallel in the direction indicated by the arrow -I- as they are linked to the clamping elements hinged on the guide 131. When the profiles of the opposite sides of the elements 132, 133 come into contact with the fixed stops 134, 135, they are forced to converge, as illustrated in Figure 14, thereby freeing the stems 140, 141 of the pistons which, having overcome the first critical phase, as previously described, complete the rest of the run independently the one from the other until they reach the position illustrated in Figure 15. If when the valves close, one of the pistons or the valve associated to one of the pistons jams in the open position, the valve and piston that are working return to the initial position while the others remain in the blocked position, as shown in Figure 16. The spring 139 brings the guide back to the start position. The safety mechanism according to the variant described is structurally simpler than that shown in Figures 4 to 10, but in comparison, has the disadvantage of not blocking the water delivery to the tank of the machine in case of breakdown of one of the valves. In Figures 1, 2 and 3, one extremity of the corrugated tube -F- which contains and protects the tube sections 23 and 26, is connected to the bottom of the device 10 while the opposite extremity is connected to the duct 50 of the rapid attachment 27. The collar 52 is fixed in said duct, for example, by means of screws 50, Figures 2, 3, said collar being provided with coupling sockets 53, 54, respectively to connect the tube sections 26 for the water and 23 for the air. The cylindrical and concave part 55, fixed to the machine 60 is coupled in the coupled to the collar 52; said part 55 is provided with anular, pneumatic and hydraulic "OR" sealing strips. The water being fed through the radial windows 56 reaches the socket 57 connected to the tube branch 26a which inputs into the tank of the machine; the socket 58 is for the discharge of any small quantities of drawn water collected in a special container placed inside, on the bottom of the machine. The closed bottom of the part 55 supports the short cylindrical diametrally bored pin 55a which, when the two parts of the attachment are coupled, Figures 1, 2, projects through the transverse opening 52a made in the duct 50. When the attachment is coupled as in Figure 1, a split pin 59 is inserted and spread open in the diametral hole in the pin 55a thus longitudinally blocking the two coupled parts. The duct 50 remains free to move around the axis of the pin 55a which allows for the best positioning of the tube group 23, 26, -F-, both for mounting and for any changes in position of the machine. The device is not limited to the example described and illustrated but can comprise any other similar or equivalent solution.

Claims: Antiflood device for washing machines, comprising two pneumatic valves (16, 17), normally closed, and openable by compressed air, said valves intercepting the flow of water to the machine in their normally closed position, whereby in the case of breakdown of one of the two valves, in the open or partially open position, the other valve closes independently from the first valve, characterized in that the valve which closes completely is automatically and mechanically blocked in the closed position. Antiflood device according to claim 1, characterised in that said valves (16, 17), which are in particular of the disc-type, operates in respective chambers (16a, 17a) against the reaction of elastic means (18, 19), said chambers (16a, 17a) communicating with respective cylinders (12, 13), each having a piston assembly (14,15) connected to the respective valve (16, 17). Antiflood device, according to claim 2, characterised in that each piston assembly (14,15) defines in the inside of the corresponding cylinder (12, 13) a subchamber (E, E1), the two subchambers (E,E1) intercommunicating when the two valves are in the open position, particularly by means of a tubular connection (24). Antiflood device, according to claim 2, characterised in that one of the cylinder (12) is connected to a water supply tap (A, B), while the other cylinder (13) is connected to a tube (25) provided with a water supply pipe (27) for the connection to the machine (60). Antiflood device, according to claim 3, characterised in that the two chambers (16a, 17a) are connected by means of a pneumatic connection (D), the latter being further connected, by means of a tube (23), to an electropump (22) for directing compressed air into the valves chambers (16a,17a). Antiflood device according to claim 1, characterised in that the safety mechanism for blocking one of the valves in the closed position comprises stop means (32, 33), which cooperate with elastic means (36), which automatically engage concave grooves (30) radially supported by the stems (14a, 15a) of the two valves. Antiflood device according to one or more of the previous claims, characterised in that the free ends of the stems of the valves are provided with short inclined sections (14b, 15b), transverse with respect to the axis of said stems, said inclined sections cooperating with corresponding bevelled sections (32b, 33b) of the stop means (32, 33). Device according to claim 6, characterised in that, during the initial opening phase of the valves, the stems (14a, 15a) are transversely engaged by a rod (25a) being part of a mechanism which comprises elastic attracting means (39), in order to achieve longitudinal, synchronous movement of both the stems, until the grooves (30) have passed the transverse plane of interference with the stops means (32, 33). Antiflood device for washing machines, according to claim 8, characterized in that the rod (25a) that engages the grooves in the stems (14a, 15a) is part of a mechanism comprising a double cross lever (25, 25a, 25b) hinged (25c) to openings (40) of fixed brackets (41). Antiflood device according to claim 9, characterized in that the extremities of a branch (25b) of the double cross lever (25) are mobile with respect to inclined planes (43) of said fixed brackets. Antiflood device according to claim 5, characterized in that the pump (22) is a vibration electropump. Antiflood device according to at least one of the previous claims, characterized in that the means for the synchronous advancement of the valve stems (14, 15) comprise a rod (25a) which transversely engages both the stems in corresponding concave seats, from which said rod is disconnected when said stems, in synchronism, have completed a longitudinal run having a prefixed amplitude. Antiflood device according at least one of the previous claims, characterized in that a couple of pneumatic pistons (118, 119) controls the synchronism, on opening, against the reaction of the spring (120), of the corresponding valves (123, 124) by means of levered articulations (121, 122). Antiflood device according to claims 1, characterized in that the safety mechanism that ensures the synchronous movement of the valves (123, 124) on opening, comprises a guide (131) slidingly mounted with respect to a fixed support (130), against the reaction of elastic means (139), and in that elements (132, 133) are articulated with respect to said guide, activated by clamping movements which constrain the valve stems (140, 141) until coming into contact with fixed stops which cause the valve stems to disconnect from said elements (132, 133). Antiflood device, according to one or more of the previous claims, characterized in that the tubes (23, 26) provided for the pneumatic connection of the valves chambers (16a,17a) to the electropump (22) and for the supply of water to the machine (23, 26) are enclosed within a third flexible tube (F), the tubes ends (23,26,F) being connected to respective sockets (53,54) of a first connector (50). Antiflood device according to the previous claim, characterised in that the first connector (50) is provided for being coupled with a second connector (55) fixed to the body of the machine (60), means (55a,59) being provided for longitudinally blocking the two connectors (50,55) once they have been mutually coupled. Antiflood device according to the previous claim, characterised in that said blocking means (55a,59) allows for the angular movement of the first connector (50) with respect to the second connector (55).

Inventors: FORNASARI PAOLO, FORNASARI, PAOLO
Applicants: ELTEK SPA, ELTEK S.P.A.
Application year: 1989
Main classification: D06F39
IPC codes: D06F39