CA1061502A - Flushing cisterns - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE.
A flushing cistern for use in conjuction with a sanitary appliance or appliances comprises a flush-initiating piston or plunger which is actuated by an electromechanical device in response to operation of a switch or switches.
Facilities are included for controlling the quantity of water discharged and for preventing initiation of the flushing cycle in certain circumstances.

Description

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FI`~LD 0~ THE I~VE~I0~
This invention relates to flushing oisterns and its object is to provide an actuating means for a flushing cistern which requires relativel~ little, if any, effort on the part of the user to initiate the flushing action.

SU~ARY O _THE INVE~ 0~
A siphonic flushing cietern comprising : an inverted U-shaped siphonic unit whose down leg is connected to the outlet of the cistern and whosa up leg includes an enlarged ohamber in which a flush-initiating piston i5 displaoeable; a solenoid having an armature whioh is linked to the piston so that when the solenoid is energised the piston is drawn upwardly to initiate the siphonio flushing aotion; means for breaking the siphonio action to prevent further disoharge from the oistarn; and eleotrioal oontrol oirouitry inoluding user-actuable switoh means fox energising said solenold, said switch means being seleotively operable such that, in one mode of operation3 said means for breaking the siphonic aotion is rendered operable before the;oistern empties to limit the quantity of water disoharged and, in a seoond mode of operation,~said means for breaking the ~iphonio aotion i~ not operated.

Preferably said~user-aotuable switoh means oomprise~
- ~ two awitches eaoh of whioh is operable to enexgise said solenoid and . ~ : ~ , .
~ ~ ~aid mean~ for breaking the siphonio aotion oomprises an electrioally-.. ...
operable valve oontrollin~ oommunication between the interior of said 25~ ohamber and atmosphere,~the valve normall~ being closed, and timing ; means opaxabLa, in respo~se~to~aotuation of one of said swibohes but not the other, to time out & predetermined time interYal and then open~said~val~e tQ break~the siphonic aotion.

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DESCRIPTION OF TIIE DRAWINGS
. The invention will now be described with reference to the accompanying drawings, in which:-Figure l is a diagramr,latic sectional view of a . siphon-controlled flushing cistern equipped with an electrical control unit for initiating the siphon action;
- Figure 2 is a diagrammatic sectional view of a flushing ~ cistern which is controlled by means of a piston-type valve : which is operated by an electrical control unit;
Figure 3 is an enlarged perspective view showing : the control unit in detail; and ; Figure 4 is a circuit diagram~
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Figures l and 2, the cister~s l0 illus-~ trated are both of known design in which discharge of the water through the cistern outlet 12 lS controlled by a flush-initiating member in the form of a piston 16 having the usual one way valve means~such as valve 17 therein. In Figure l, the piston or plunger 16 forms part of an inverted U-shaped siphon unit 14, the downleg : 20 of which is connected to the cistern outlet and the u~leg of which .
.~ is for~ed with an enlarged chamber 18 in which t~e piston 16 is . ver~t1cally movable. The siphon act1on is initiated by drawing the . ~ piston 16 upwardly via its stem 22 and flow continue:s through valve 17 un~l broken by ~entry of air into the sipho~ unit.
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. ~ ~ . In Figure 2, the piston 20,which may be a rubber disc, : ~; ~ norma11y:closes the cistern outlet 12 and is attached to a stem 22 : carry1ng a float 24, the piston being movable within~a cylindrical . ~ guide 26 which~has:holes 28 in 1tS wall so that when the piston is .:

. ~ ~drawn~upwardly away from tbe~cistern out1et 12,:the c~ntents of the ~ cister~n discharge through the outlet via the holes 28. Other forms of the~cist~ern:shown;in F1gure 2 are envisaged in whiQh the float is

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~' ' . ' ;. ' separate from the piston and is arranged to co-operate with it through the agency of a detent or catch so that, when the piston is lifted, it is coupled by the detent to a lever carrying the float and remains coupled thereto un-til the float during its descent effects release of the detent or catch to allow the piston to return to the closure position. As is usual, admis-sion of water into the cistern, either from the mains supply or via a pump from a reservoir, is controlled by a valve 30 which in turn is controlled by a float-carrying arm 32, the valve 30 being closed when the water level reaches a level predetermined by adjustment of the float. ~ ;
In the conventional cisterns of the kind described above, displacement of the piston is effected purely mechanically by a handle or like connected to the piston via a linkage. In accordance with the present invention, displacement of the pis-ton is effected electromechanically in response to actuation of an electrical switch (not shown) which may be manually-operable e.g. a pushbutton switch, or operable indirectly e.g., a proximity switch. The electromechanical control unit for oper-ating the piston is indicated generally by reference numeral 35 in Figures 1 and 2 and is shown 1n greater detail in Figure 3 to which reference is now made The control device is housed within a container, which is shown in outllne in Figure 3, and includes a base 36 pro-vided with depending flanges 37 to facilitate mounting of -the control unit partially within and projecting above the open top of the cistern. In the embodiments of Figures 1 and 2, the cisterns are intended to be concealed from view, for example behind partitlon1ng, and connected to a lavatory basin or bowl on the oth~er side of the partitioning via a flush pipe~
However, it will be understood that the control unit may be used~in-conjuctlon;~with cisterns which are exposed to view, in , . .
~ which case the unit may be dimensioned and arranged to fit L5~
within a lid of -the cistern or alternatively the unit may be enclosed within a waterproofed casing immersed in the cistern or it may be located externally of the cistern .
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in for example a depression in the rear wall of the cistern.
It will be appreciated that some modification of the linkage shown in Figure 3 for connecting the electro-mechanical device to the flush-initiating pis-ton may be necessary in these latter-mentioned modifications.
Reverting to Figure 3, a suppor-t plate 3 8 extends up-wardly from the base 36 and a solenoid assembly 39 is mounted centrally on the plate 38 with its armature 40 pro-jecting vertically downwardly. The lower end of the armature 40 is connected to a lever 42 pivoted at one end to a boss 44 ~ -attached to the plate 38 so that the lever 42 pivots in a plane containing the axis of the armature 40. A universal joint assembly 46 couples the arma-ture 40 to the lever at a position intermediate its ends. the free end of the lever 42 carries a stud 47 which is received in a slot 48 provided in the upper end of a link 50 which extends vertically through an opening 57 in the base ~6, its opposite end being connected to a rod 52 whose en~ are hook-shaped. the lower hook of the rod 52, in use, engages with the stem 22 carrying the flush-initiating piston 16 or 20. Downward travel of the armature 40 under gravity 1S limited by a bolt 54 screw-threadly engaged with its upper end which cooperates with the link 42 and may be capped with resilient material, e.g. a suitalbe plastics, to act as a buffer.
In Figure 3, the control unit is shown in a condition -in which the armature 40 is midway between the lowermost and uppermost positions, the solenoid having been energised by operation of the electrical switch associated with it, the arm-.
ature 40 in its upward movement serving to pivot the lever 42 clockwise, as seen in Figure 3, and to lift the piston 16 or 20 via the link 50, rod 52 and stem 22 to initiate the flushing action.
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: ' / ' ; ;' ' Preferably the electrical circuitry associated with the solenoid assembly 39 is so arranged that the solenoid is maintained "'.
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energised for a short interval of time for example be-tween 1 second and 2 second, after which the solenoid de-energises, allowing the arma-ture 40 to descend together with the flush-initiating piston 16 or 2~. The slot 48 affords lost motion between the armature 40 and the piston 16 or 20 so that the latter is capable of return movement independently of the armature 40 within limits governed by the length of the slot 48. The solenoid assembly 39 is conveniently designed so that the rate of ascent of the armature 40 is relatively slow when attached to the piston a~d the latter is submerged in water, e.g. between 1/2 second and l second in moving from its lowermost position to its uppermost position.
The control unit may include means for disabling further actuation of the flush-initiating piston for a certaih interval of time after it has been actuated so as to prevent any attempt to initiate a fresh flushing cycle before the pre-vious cycle has been completed. The disabling means may, for this purpose, be arranged to respond tQ t~e level of water in the cistern so that a fresh flushing cycle may only be initiated after thç water level has reached a predetermined -level.
In the embodiment illustrated in Figure 3, the disabling means comprises a microswitch 56 mounted on the rear face of the plate 38 and provided with a spring-loaded actuating arm 58 carrying a roller 60, the roller 60 being arranged in the path of travel of a vertically-movable member 62 in the form of a rod passing through an aperture in the base 36 and an apertured ~-lug 64 secured to the plate 38. The upper end of the rod 62 carries a cam 66 having a conical tip which is arranged to coact with the roller 60 in such a way that the microswitch 56, which forms part of the electrical control circuitry, is operated as the rod 62 rises. The lower end of the rod 62 ~ 6 carries a nylon cap 68 which is adjustably connected to the rod 62 to enable its position to be varied lengthwise of the rod.

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In use, the rod 62 is arranged so that it extends into the cis-tern and the nylon cap 68 rests on the float arm 32.
The cap 68 is adjusted so that when the float arm 3Z occupies a position corresponding to the predetermined water level within the cistern, the microswitch 56 is operated but, as soon as the water level falls with conse~uent descent of the float arm 32, the microswitch 56 is changed to a condition (which may correspond to closure or opening of its contacts) in which it prevents energisation of the solenoid assembly in response to operation of the flush-initiating electrical switch (not shown), In addition, to controlling energisation of the solenoid assembly 39, the microswitch 56 may also control other functions -~
associated with operation of the cistern. For example when the microsmith is in its operated condition, i.e. when the water level is at a predetermined level, the electrical circuitry may be effectice to illuminate a ligh-t source associated with -:
the flush-initiating electrical switch to indicate that the cistern is ready for operation. The light source may be incorporated within the electrical switch or it may be separate from the switch. Also, when the cistern is supplied with water from a nearby source by means of an electrically-operable pump, the microswitch 56 may be included in an electrical circuit associated wlth the pump so as to cause operation of the pump when tha water level in the cistern falls below the predetermined level.
The control unit 35 may also include means governing the amount of water discharged in a given flushing cycle so as to provlde a multiple-flush facility. Multiple flush cisterns are well known in which the user may control the quantity of water dlscharged by appropriate control of -the flush-initiating handle,~for example, a full flush may be obtained by actuating the handle and immediately releasing it and a part-flush can 7 ~
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be obtained by actuating the handle and holding it in the actuating position, or vice versa. In accordance with this aspect o~ the invention, two or more flush-initiating ,:

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electrical switches are provided and the electrical circuitry is arranged so that the time interval of the flushing action varies according to the par-ticular switch operated. Thus, for dual flush operation, the switches may be provided for actuation by the user, one switch giving full flush and the other part-flush.
To achie~e this, a valve may be associated with the siphon of Figure 1 so as to admit air into the unit and termin-ate the siphon action, the valve being controlled by -the electri-cal control circui-try either directly or indirectly via the stem of the piston 16. In the former case, the siphon unit may have an opening in one of its walls at a position above the mouth of its upleg, for example, either in the crown of the chamber of the upleg or in the base of the U, and the opening may have a small bore, vertically-extending pipe 70A or 70 respectively connected to it which extends into the control unit and has a spool valve 73 associated with its upper end. -The spool 73 is biassed to the left, as seen in Figure 3, by a tension spring 72 and has a through aperture (not shown) which can be brought into alignment with the pipe 70 or 70A by being displaced to the right by solenoid 71, which is energised via connections 74. The con-trol circuitry may, in this instance, cause the spool valve 73 to oepn after the expiry of a predetermined time interval following actuation of the "part-flush" switch to connect the interior of the siphon chamber to atmosphere via the upper end of the pipe 70 or 70A
thereby terminating the siphon action. In another embodiment, the stem of the piston 16 may be hollow with i-ts lower end opening into the siphon chamber and may have an aperture adja-cent the upper end so that,~ if the p1s-ton 16 is maintained in it upper position, when the water level drops to the level of sa1d aperture the slphon action is terminated. In this case, the control circuitry will be arranged so that, when part-~l~3~

~lush operation is required, the solenoid assemb~ 39 is energised for a leng-th of time :`:

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sufficient for the water level to fall to the level of the aperture in the piston stem.
It will be understood that control of the quantity of water discharged from the cistern of Figure 2 may be controlled in similar fashion by designing the control circuitry so -that the piston 20 is returned to the closed position either on completion of the discharge or, for example~ after one half or some other preselected proportion, of the cistern contents have been discharged.
The base 36 and the support plate 38 of the unit are designed so that the linkage comprising the lever 42, its mount-ing boss 44, ~he link 50 and the rod 52 can be mounted either ~-for left-hand operation in the manner indicated in Figures l and 2 or for right-hand operation as in Figure 3 when, for l example, the siphon unit 14 in the cistern of Figure l is assem-bled the other way round, there being a second opening 57 on the right-hand side of the base 36. Similarly, the microsmith 56 and the rod 62 can be mounted on the right-hand side of the plaie 38.
The flush-initiating electrical switch or switches may be located~in any one of a number of positions, for example on the partitlonlng between the cistern and the lavatory basin or bowl, or on a nearby wall, or where the cistern is not concealed, on the ci~stern itself, e.g. on the lid.
In the embodlment~ o~ Figure 3, the solenoid armature 40 is linked~to the piStoA 16 or ciO~via a lever system so that the stroke of~the armature may~be les~s~than~that of the piStoA 16 ~; or 20.~ However~, in an alternative embodiment, the lever may be coupled directly to the piston stem 22 ~ia linkage means, ;the armature in this case having a stroke equal to the required piston stroke.
Referring now;to Flgure 4, the control circuit comprises a step-down~transformer ao for supplylng power from an a.c. source to .

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-the circuit. The switch 56 is connected in series with a normally open "full flush" initiating switch 82, a first timing relay TRl and a normally closed -timing contact pair TRl/2, across the circuitry of the transformer 80. The switch 56 is shown in its open condition corresponding to the case where the water level within the cistern is below the predetermined level. When the water level rises to -the predetermined level, the switch 56 closes. A lamp 84 is connec-ted in parallel across switch 82, contact pair TRl/2 and relay TRl and, when energised (i.e. when switch 56 is closed), serives to ill~mina-te the switch 82 and also a normally-open , "par-t-flush" switch 86.
Two lamps 84 may be provided, each being incorpora-ted in a respective one of the switches 82 and 86.
The switch 56 is also connected in a series circuit with the "part-flush" switch 86, a second timing relay TR2 and normally closed timing contact pair TR2/3 or relay TR2. The switches 56 and 82 are shunted by a parallel combination o~
normally open contact pairs TRl/l and TR2/2 associated with re-lays TRl and TR2 respectively. The solenoid of the assembly 39 is connected in series with normally open contact pair TRl/3 of relay TRl across the secondary of the transformer 80. The solenoid 71 associated with the spool valve 73 is connected in series with normally open contact pairs TR2/2 and TR2/4 of relay TR2 across the transformer secondary and the junction , ,: .
between the latter contact pairs is connected via line 88 to the junction between switch 86 and contact pair TR2/3. ~ -Operation o~ the control circuit will now be described for the case where "fu11 flush" operation is required. In this event, the "full slush" switch 82, which may be a pushbutton, ::
is operated and provided switch 56 is closed, timing relay TRl is energised vla contact pair TRl/2 and causes closure of con- -~- tact pairs TRl/l and TRl~3. Contact pair TRl/l enables the relay TRl to maintain 1 0 . ' ''~ ' s~3~

itself closed even af-ter the user has released the switch 82.
Contact pair TRl/3 completes the circuit to the solenoid 39 possibly via a rectifier (not shown) thereby initia-ting the flushing action. As the water level in the cistern falls, the switch 56 opens but the relay TRl remains energised for a preselectable interval of time; thereafter the contact pair TRl/2 open causing de-energisation of the relay TRl, re-opening of contact pairs TRl/l and TRl/3 with consequent de-energisation of solenoid 39 and re-closur-e of contact pair TRl/2. During the flushing cycle and refilling of the cistern~
further actuation of the cont~ol circuit is prevented until switch 56 closes.
Where "part-flush" operation is required, the push-button switch 86 is depressed which, provided switch 56 is closed, leads to energisation of relay TR2 via its normally-closed contact pair TR2/3 and closure of contact pair TR2/2 to maintain relay TR2 energised via line 88 and closure of contact pair TR/l to energise relay TRl. Energisation of the latter relay initiates the flushing operation via solenoid 39. Contact pair TR2/4 does not close immediately upon ener-gisation of~relay TR2; instead there is a time delay to allow the flushing cycle to start and proceed to the extent necessary -to dlscharge the requlred proportion of the cistern contents.
After elapse of this time delay, contact pair TR2/4 closes wi-th consequent energisation of solenoid 71 and opening of the valve 73 to communicate the interior of the siphon unit 14 with atmosphere and thereby interrupt the siphon action. Shortly afterwards contact pair TR2/3 opens to de-energise relay TR2, and at the same time, or subsequently, contact pair TRl/2 opens to de-energise relay TRl preparatory to a further flushing cycle after switch 56 has been closed once again.

Although the control circuit illustrated comprises elec-tro mechancial components, it will be understood tha-t an equivalent solid-state circuit may be used.

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~IL06~5~2 It will be under~tood that whilst the invention ha~
been described herein with reference to two preferred embodiment~, the ambit of the invention i~ not limited to -these particular embodiments but is to be ascertained from the appended claims.

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Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows :-

1. A siphonic flushing cistern comprising : an inverted U-shaped siphonic unit whose down leg is connected to the outlet of the cistern and whose up leg includes an enlarged chamber in which a flush-initiating piston is displaceable; a solenoid having an armature which is linked to the piston so that when the solenoid is energised the piston is drawn upwardly to initiate the siphonic flushing action; means for breaking the siphonic action to prevent further discharge from the cistern; and electrical control circuitry including user-actuable switch means for energising said solenoid, said switch means being selectively operable such that, in one mode of operation, said means for breaking the siphonic action is rendered operable before the cistern empties to limit the quantity of water discharged and, in a second mode of operation, said means for breaking the siphonic action is not operated.

2. A cistern as claimed in Claim 1 in which saiduser-actuable switch means comprises two switches each of which is operable to energise said solenoid and in which said means for breaking the siphonic action comprises an electronically-operable valve controlling communication between the interior of said chamber and atmosphere, the valve normally being closed, and timing means operable, in response to actuation of one of said switches but not the other, to time out a predetermined time interval and then open said valve to break the siphonic action.

3. A flushing cistern as claimed in Claim 1, in which means is provided for disabling operation of said solenoid for an interval of time following each operation of the solenoid.

4. A flushing cistern as claimed in Claim 3, in which said disabling means is responsive to the level of the water within the cistern in such a way that operation of said device is prevented until the water level rises to a predetermined level following operation of the solenoid.

5. A flushing cistern as claimed in Claim 4, in which said disabling means comprises an electrical switch forming part of said electrical control circuit, the disabling switch being responsive to movement of a float arm provided in the cistern to control a water-supply valve of the cistern.

6. A cistern as claimed in Claim 1 in which the solenoid armature is linked to the piston via a lost motion coupling such that the armature moves over a limited part of its stroke without accompanying movement of said piston.