Abstract:
An electric shower-waste pump and control unit for pumping run-off shower water from a waste outlet to a drain, the unit comprising a housing having a first chamber and a separate second chamber which is water-tightly sealable, a removable housing cover for closing the housing, an electric pump provided in the first chamber, electronic control circuitry provided in the second chamber, and a removable second chamber cover for water-tightly sealing the second chamber against ingress of water leakage from the pump.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an electric shower-waste pump and control unit. Self-contained shower-waste pump and control units are known, and can be obtained from Autumn (UK) Limited of Ashton-under-Lyne, Lancashire, United Kingdom, Impey (UK) Limited of Ilton, Somerset, United Kingdom, and Digital Pumps Limited of Blackpool, Lancashire, United Kingdom. 
     Prior art examples of such units  1  are shown in  FIGS. 1 to 3 . Each unit  1  comprises a water-tightly sealable housing  2  in which is housed a shower-waste pump  3  and appropriate electronic control circuitry  4 . An external mains AC electricity supply, typically of 230 or 240 volts, is connected via a connector  5  to a power transformer  6  forming part of the electronic control circuitry within the housing. The power transformer converts the mains voltage to a lower voltage suitable for operating the pump and the control circuitry. 
     Such a unit  1  is typically connected to a shower  7  as shown in  FIG. 4 . The shower head  8  is provided above a shower tray  9  having a waste outlet  10 . The shower head is connected to a, typically wall-mounted, shower unit  11 , which in turn is connected to a mains water supply  12 . 
     A flow sensor  13  or sensors is/are connected to the shower-waste pump and control unit  1  and monitor operation of the shower unit. The shower-waste pump and control unit itself is connected to a mains power supply  14 . 
     The waste outlet of the shower tray is connected to one port  15  of the pump  3  of the shower-waste pump and control unit, and another port  16  of the pump discharges to a drain pipe  17  and then to a soil pipe  18  of the building. 
     The problem with such prior art arrangements is that, should the pump leak, the water-tightly sealed box can fill with water. This leads to direct contact with the electrically energised control circuitry. The water leaking from the pump thus forms a conduction path back to the floor of the shower tray or base presenting a serious and potentially fatal risk of electrocution. 
     The pump utilised in such units is often of a diaphragm variety, and this kind of pump is well known to fail through diaphragm wear. Leakage of water through a worn diaphragm frequently occurs. The water can thus pass out of a pump housing and into the housing of the unit by flowing through an air vent hole intentionally provided for venting air from behind the diaphragm. 
     This is a known problem which has not heretobefore been addressed, and the present invention seeks to provide a solution. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an electric shower-waste pump and control unit for pumping run-off shower water from a waste outlet to a drain, the unit comprising a housing having a first chamber and a separate second chamber which is water-tightly sealable, a removable housing cover for closing the housing, an electric pump provided in the first chamber, electronic control circuitry provided in the second chamber, and a removable second chamber cover for water-tightly sealing the second chamber against ingress of water leakage from the pump. 
     The present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 to 3  show first to third prior art electric shower-waste pump and control units; 
         FIG. 4  shows a known standard installation of the electric shower-waste pump and control unit; 
         FIG. 5  shows a perspective view of a first embodiment of an electric shower-waste pump and control unit, in accordance with the invention and with a housing cover and a second chamber cover removed; 
         FIG. 6  is a view similar to  FIG. 5 , but with a shower-waste pump removed; 
         FIG. 7  is a plan view of the unit shown in  FIG. 5 , but with the second chamber cover in place; 
         FIG. 8  is a perspective view of the unit shown in  FIG. 5 , but with the housing cover in place; 
         FIG. 9  is diagrammatic side view of a second embodiment of an electric shower-waste pump and control unit, in accordance with the invention; and 
         FIG. 10  is a perspective view of a third embodiment of an electric shower-waste pump and control unit, in accordance with the invention and with the front housing cover and pump removed for clarity. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 5 to 8 , there is shown a first embodiment of an electric shower-waste pump and control unit  110  which comprises a, typically moulded plastics, housing  112  having a first pump chamber  114  and a second control-circuitry chamber  116 , a removable housing cover  118  for closing the housing  112 , and a removable second chamber cover  120  for closing the second chamber  116 . 
     An electric shower-waste pump  122  is provided in the first chamber  114 , and electronic control circuitry  124  is provided in the second chamber  116 . The electronic control circuitry  124  includes a power transformer  126 , and user-controls  128  for controlling and setting characteristics and/or parameters of the pump  122 , such as ramp-up and ramp-down times, delay times, and pumping rate. 
     The second chamber  116  is separate of the first chamber  114 , and is defined by a continuous wall  130  which is provided within the first chamber  114 . The continuous wall  130  of the second chamber  116  is typically integrally moulded as part of the housing  112 . 
     An opening (not shown) is typically provided in the wall of the second chamber  116 , so that the pump  122  can be electrically connected to the control circuitry  124 . A water-tight gland is provided in the opening. 
     The second chamber  116  also includes a second opening or openings  131  for the passage of a mains electricity supply cable (not shown). Again, the or each second opening  131  includes a water-tight gland  131   a.    
     The second chamber cover  120  watertightly seals the second chamber  116  to IPx4 or IPx5 according to British Standard EN 60529. A sealing gasket (not shown) can be provided on a lower surface of the second chamber cover  120  to receive the continuous wall  130  of the second chamber  116 . 
     Spaced-apart screw-port bosses  132  are integrally moulded within the first chamber  114  and are spaced from the continuous wall  130  of the second chamber  116 . However, the continuous wall of the second chamber can include the spaced-apart screw-port bosses. 
     The second chamber cover  120  is thus releasably fastened to an upper edge  134  of the continuous wall  130 , via screw-threaded fasteners  136  received in the screw-port bosses  132 , in order to water-tightly seal the second chamber  116 . 
     An access opening  138  is provided in the second chamber cover  120 . The access opening  138  is positioned to allow simple unhindered access to the user-controls  128  and/or connectors  140  of the control circuitry  124  for use in commissioning purposes. 
     In this embodiment, a removable access cover  142  water-tightly closes the access opening  138 , typically via a sealing gasket (not shown) and screw-threaded fasteners  144 , to maintain the water-tight sealing of the second chamber  116 . 
     Referring to  FIG. 9 , a second embodiment of an electric shower-waste pump and control unit  210  is shown. This embodiment is similar to that of the first embodiment, except a second chamber cover  220  is provided in or on a rear surface of housing  212 . 
     Access cover  242  is spaced from the second chamber cover  220 , and is accessible from the front of the housing  212  by removal of housing cover  218 , as in the first embodiment. 
     As such, electronic control circuitry  224  is positioned within second chamber  216  from the rear of the housing  212  and prior to installation of the unit  210 . Once installed, typically on a wall, access to the control circuitry  224  is only possible via access opening  238 , and even then, only user-controls and/or connectors are typically accessible. 
     As in the first embodiment, the second chamber cover  220  and the access cover  242  water-tightly seal the second chamber  216 . 
     Referring to  FIG. 10 , a third embodiment of an electric shower-waste pump and control unit  310  is shown. This embodiment is again similar to that of the first embodiment, and therefore like parts have like references, except with ‘ 300 ’ added.  FIG. 10  only shows a base of the housing  312  in which can be seen the first pump chamber  314 , the second control-circuitry chamber  316 , and the second chamber cover  320 . 
     In this case, the second chamber  316  provides a bridge-shaped recess  346  for a pump motor (not shown), such that the second chamber  316  straddles the pump motor, when assembled. 
     The access cover  342  of this embodiment cannot be removed, and is instead a waterproof transparent or translucent flexible plastics membrane  348  which seals the access cover against the ingress of liquid. Since the membrane  348  is flexible, a user can manipulate the controls therebeneath through the membrane  348 . 
     As such, with a housing cover removed, but with the second chamber cover  320  in place, the user controls  328  of the control circuitry  324  are only accessible via the access opening  338 , although without requiring removal of the access cover  342 . 
     Although the access cover of this embodiment is provided in the second chamber cover, similar to the first embodiment, it can be provided separately of the second chamber cover, similarly to the second embodiment. 
     The flexible access cover may be opaque with the controls embossed or printed thereon. Alternatively, the access cover can be a waterproof touch-sensitive control panel, such as a capacitative, inductive and/or piezoelectric device. 
     The housing cover of the embodiments described above not only closes the housing, but also closes the first chamber. The housing cover does not water-tightly seal the housing or the first chamber, thereby allowing drainage of water within the first chamber. 
     Screw-threaded fasteners are suggested, and these can be formed to be engagable by hand, instead of or in addition to the use of a tool, in order to simply removal and relocation of the second chamber cover and/or the access cover. 
     Alternatively, a releasable snap-lock fastening device or any other suitable device can be utilised in place of the afore-mentioned screw-threaded fastener. 
     Sealing of the second chamber cover and/or the access cover can alternatively be achieved by a moulded-in flexible gasket material applied to a bottom surface to form a compressible self-bonding sealing element. 
     Although the second chamber is formed integrally as part of the housing, the second chamber can be independent of the housing and simply attached therein when required. 
     It is thus possible to provide of a self-contained electric shower-waste pump and control unit which liquidly-isolates electronic control circuitry from its associated electric shower-waste pump and from water ingress via a misdirected shower head. It is also possible to provide such a unit which still allows simple user access to the control-circuitry. 
     The embodiments described above are given by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention, as defined by the appended claims.