Closure arrangement

Abstract: A connection arrangement for a toilet system having an emptying tube (1) connected to a closed sewage collection tank is described. The emptying tube (1) has an end portion that extends through a wall (5) and has a free end that projects from the wall (5) for reception in a socket of a coupling hose. A cover (6) is attached to the wall (5) and is moveable relative to the wall (5) between an open position, in which the cover (6) allows free access to the free end of the emptying tube (1) for emptying the sewage collection tank, and a closed position, in which the cover (6) protects the free end of the emptying tube (1) against contamination and damage. A plug (101) is attached to the cover (6) and engages the free end of the emptying tube (1) when the cover (6) is in the closed position and is disengaged from the free end of the emptying tube (1) when the cover (6) is moved from the closed position to the open position. When the cover (6) is in its closed position, it defines with the wall (5) a space that is substantially larger than the space occupied by the free end of the emptying tube (1), whereby the free end of the emptying tube (1) is reliably protected from contamination and damage.

Description: This invention relates to a closure arrangement for a toilet system including a closed sewage collection tank, i.e. a collection tank in which the sewage is stored until the tank can conveniently be emptied. This type of toilet system has been used for several years, for instance in stationary installations in sparsely populated areas where there is no municipal sewer system, and in mobile installations, in particular on trains and boats. US 5 056 678 describes an access port sealing device for use in connection with aircraft human waste systems. The device utilises a sealing plug which expands to occludingly seal the interior of the conduit when compressed between an exterior latching cover and the exterior of the inner conduit closure. A toilet system having a closed sewage collection tank may be provided with an emptying tube that is connected to the tank and has a free end that can be connected to a hose for emptying the sewage collection tank. The free end of the emptying tube is closeable by means of a cap or plug which is removed from the end of the emptying tube in order to allow the collection tank to be emptied. In a toilet system of this kind it is essential that the free end of the emptying tube be sealed effectively by means of a sealing element, and further that the tube end should be protected against contamination and damage. The present invention seeks to provide a closure arrangement which ensures effective sealing of the free end of the emptying tube and which protects the free end against contamination and damage. In accordance with the invention there is provided a closure arrangement for a toilet system including a closed sewage collection tank having an emptying tube that extends through a wall for emptying the collection tank the emptying tube being provided with a free end, wherein the closure arrangement includes: a cover which in operation of the closure arrangement is attached to the wall and moveable relative to the wall between an open position in which the cover allows free access to the free end of the emptying tube, and a closed position; and a first sealing member attached to the cover, the sealing member being adapted to engage the free end of the emptying tube when the cover is in the closed position and to become disengaged from the free end of the emptying tube when the cover is moved from the closed position to the open position; characterised in that the cover, when in the closed position, defines with the wall a closed space that is substantially larger than the space occupied by the free end of the emptying tube, whereby the free end of the emptying tube is reliably protected from contamination and damage. A closure arrangement according to the invention may be applied with particular advantage to a toilet system, in particular a vacuum toilet system, on a railway train. In a vacuum toilet system, otherwise known as a vacuum sewer system, a normally-closed discharge valve is connected between the outlet of the toilet bowl and the sewer pipe, and a blower, ejector, or the like, is used to establish a considerable partial vacuum (typically about 0.3 to 0.5 below atmospheric pressure, i.e. 0.7 to 0.5 absolute pressure) in the sewer pipe immediately downstream of the discharge valve while the discharge valve is still closed. When the discharge valve is opened in response to a flush command, the contents of the toilet bowl are forced almost instantaneously into the sewer pipe and are propelled at high speed along the sewer pipe towards a sewage collection tank. In some instances, the sewage collection tank itself is placed under vacuum, and in others it is not. A vacuum toilet system with a closed sewage collection tank may have an air supply cube for supplying air to aid in emptying the sewage collection tank and a supply tube for rinse water. The free ends of the air and water supply tubes are suitably arranged parallel and close to the free end of the emptying tube, and all three of the tubes cooperate with respective sealing elements, which are secured to the cover. In this way, all three tubes are sealed by closing the cover. For a better understanding of the invention, and to explain in more detail how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:- FIG. 1a is a partial section of an embodiment of closure arrangement according to the invention with the cover shown in closed position (and, ghosted, in open position); FIG. 1b is a partial section of the Fig. 1a embodiment with the cover in fully open position, and also illustrates hoses for servicing the vacuum toilet system; and FIG. 2 is a front view of a portion of the closure arrangement of Figs. 1a and 1b, taken from the left of FIG. 1b. showing, at line 1a, the line along which the sections of Figs. 1a and 1b are taken. FIGS. 1a and 1b illustrate a wall 5 having a through hole through which an end portion of an emptying tube 1 for a closed sewage collection tank (not shown) extends. The tank is part of a toilet system, which may be a gravity toilet system although it is preferred that it be a vacuum toilet system. The toilet system may be installed in a passenger carriage of a railway train, in which case the wall 5 is an exterior wall of the passenger carriage, at which service persons attend to emptying the tank and other service functions. The toilet system also includes (not shown) a rinse water container for supplying rinse water to the toilet bowl in response to a flush command. During servicing of the toilet system, it is necessary to drain the sewage collection tank and replenish the rinse water supply tank. The free end of the emptying tube 1 is provided with a spigot element 1a of a bell-and-spigot joint. A mating bell element 1b is provided on the free end of a hose, whose other end (not shown) may debouch into a municipal sewer. The spigot element projects sufficiently beyond the wall 5 to allow the bell element 1b to fit securely over the spigot element 1a. The spigot element is formed with an annular recess 1c at its exterior, which engages a portion of the interior of the bell element to obtain secure and leakproof operation. Similarly, an air inlet tube 2 and a rinse water feeding tube 3 also have end portions that extend through respective holes in the wall 5 and are equipped with spigot elements 2a and 3a for mating engagement with bell elements 2b and 3b of the free ends of, respectively, an air supply hose and a water supply hose. The air supply hose is used to supply air, preferably under pressure, to the collection tank to aid in draining of the collection tank. The rinse water feeding hose supplies water for replenishing the rinse water container (not shown). As shown in FIG. 1b, the bell elements 1b, 2b and 3b may be attached to a mounting plate 24, so that all three bell elements can be applied simultaneously to the respective spigot elements and to ensure that each bell element is applied to the proper spigot element. A cover 6 is pivotally mounted to the wall 5 for movement about an axis 7 that is disposed outside the cover and is spaced from the outer surface of the wall 5. The cover 6 is pivotable between a closed position (FIG. 1a) and an open position (FIG. 1b). The cover is held in its closed position by means of a latch 8 engaging a pin 11. The latch 8 includes a hook 10 which is released from the pin 11 by turning a handle 9 in the clockwise direction seen in FIG. 1a. When the cover is turned from its open position to its closed position, surface 10a of the end portion of hook 10 engages the pin 11 as the hook 10 is pivoted in the counterclockwise direction in Fig. 1a, and when the cover is fully closed, the hook is retained behind the pin 11, holding the cover in the closed position. Because the pin 11 is slightly below the turning axis of the hook 10, the closing mechanism is self-locking. The cover 6 is circular and has a peripheral wall 6a that terminates in an inturned lip 6b. The wall 5 has an annular groove that receives a sealing ring 5a. When the cover is in its closed position, the lip 6b engages the sealing ring 5a for effectively sealing the space 4 defined between the cover 6 and the wall 5. The sealing ring 5a is compressed when the cover is in the closed position. Three sealing plugs 101, 102 and 103 are secured to the cover 6, and are positioned for entering the spigot elements 1a, 2a and 3a of the tubes 1, 2 and 3 respectively when the cover 6 is in its closed position. Thus, when the cover 6 is in its closed position, the tubes 1, 2 and 3 are effectively sealed by the respective plugs, whereas when the latch 8 is released by pulling on the handle 9, and the cover is pivoted to its fully open position, the plugs are automatically removed allowing ready access to the spigot elements of the tubes 1, 2 and 3. Because the plugs are attached to the cover 6, there is no danger of a service person misplacing a plug or forgetting to install a plug in the proper spigot element. It will be noted that the interior surfaces of the spigot elements 1a, 2a and 3a flare slightly at their outer ends and that the sealing plugs have tapered leading edges 101a, 102a and 103a. The combination of this flaring and tapering allows the plugs to be inserted in the respective spigot elements even though the plugs move towards the sealing position along a curved path rather than a rectilinear path. Also, the sealing plugs are formed with respective peripheral grooves 101b, 102b and 103b in which 0-rings 101c, 102c and 103c are respectively placed. The O-rings abut the interior surface of the respective spigot elements, ensuring a tight seal. It will be seen that the volume of the interior space of the cover 6 is substantially larger than the minimum volume required to enclose the free ends of the tubes 1, 2 and 3, so that there is substantial clearance between the peripheral wall 6a and the spigot elements. The connection arrangement shown in the drawings thereby allows the ends of the tubes 1, 2 and 3 to be protected from contamination and damage in a reliable fashion, yet when the cover is turned to its fully open position, the spigot elements are immediately accessible. When the cover is returned to its closed position, the ends of the tubes are automatically sealed. The invention is not limited to the embodiments disclosed, but several variations thereof are feasible, including variations which have features equivalent to, but not necessarily literally within the meaning of, features in any of the attached claims. In particular, the invention is not restricted to the cover 6 being provided in conjunction with the emptying tube 1, the air inlet tube 2 and the rinse water feeding tube 3. For example, a tube for supplying cleaning liquid to the sewage collection tank could be provided inside the cover, in addition to the connections for the tubes 1, 2 and 3.

Claims: A closure arrangement for a toilet system including a closed sewage collection tank having an emptying tube (1) that extends through a wall (5) for emptying the collection tank, the emptying tube (1) being provided with a free end, wherein the closure arrangement includes: a cover (6), which, in operation of the closure arrangement, is attached to the wall (5) and moveable relative to the wall between an open position in which the cover allows free access to the free end of the emptying tube (1), and a closed position; and a first sealing member (101) attached to the cover (6), the first sealing member (101) being adapted to engage the free end of the emptying tube (1) when the cover (6) is in the closed position and to become disengaged from the free end of the emptying tube (1) when the cover (6) is moved from the closed position to the open position; characterised in that the cover (6) when in the closed position, defines with the wall (5) a closed space (4) that is substantially larger than the space occupied by the free end of the emptying tube (1), whereby the free end of the emptying tube is reliably protected from contamination and damage. A closure arrangement according to claim 1, wherein said emptying tube (1) constitutes a first tube, and said toilet system further comprises a secbnd tube (2, 3) adapted to fulfil a servicing function of said toilet system, and having an end portion extending through said wall (5). A closure arrangement according to claim 2, wherein the cover (6, 6b), when in the closed position, is suitable for engaging the wall (5) along a path that surrounds the free ends of the first and second tubes (1,2,3). A closure arrangement according to claim 3, comprising a second sealing member (5a) suitable for attachment to the wall (5), and wherein the cover (6,6b) engages the second sealing member (5a) when in the closed position. A closure arrangement according to any of claims 2 to 4, wherein the second tube (2) is an air inlet tube connected to the tank for allowing entrance of air during emptying of the tank, and wherein the closure arrangement further comprises a third sealing member (102) attached to the cover (6) and adapted to engage the free end of the air inlet tube (2) when the cover (6) is in the closed position, and to become disengaged from the free end of the air inlet tube (2) when the cover (6) is moved from the closed position to the open position. A closure arrangement according to any of claims 2 to 4, wherein the second tube (3) is a feeding tube for feeding rinse water to a rinse water container, and wherein the closure arrangement further comprises a fourth sealing member (103) attached to the cover (6) and adapted to engage the free end of the rinse water feeding tube (3) when the cover (6) is in the closed position and to become disengaged from the free end of the rinse water feeding tube (3) when the cover (6) is moved from the closed position to the open position. A closure arrangement according to any preceding claim, wherein the cover (6) is attachable to the wall (5) for pivotal movement relative to the wall (5) between the open position and the closed position. A closure arrangement according to claim 7, wherein the pivot axis (7) is disposed outside the space (4) defined by the cover (6) and the wall (5) when the cover (6) is in the closed position. A closure arrangement according to any preceding claim, wherein the first sealing member (101,101a) comprises a tapered plug adapted to fit into the free end of the emptying tube (1) when the cover (6) is moved from the open position to the closed position. A closure arrangement according to claim 9, wherein the tapered plug (101,101a) is formed with an annular groove (101b) and the closure arrangement includes a sealing ring (101c) fitted in the annular groove (101b) and adapted to abut the interior of the free end of the first tube (1) in sealing relationship, when the cover (6) is in the closed position. A closure arrangement according to claim 10, wherein the free end of the first tube flares outwardly. A closure arrangement according to any preceding claim, comprising a self-locking latch mechanism (8, 9, 10, 10a, 11) for securing the cover in its closed position. A closure arrangement according to any of claims 1 to 4, wherein the toilet system further comprises a feeding tube for feeding cleaning liquid to the sewage collection tank, and wherein the closure arrangement further comprises a fifth sealing member attached to the cover and adapted to engage the free end of the cleaning liquid feeding tube when the cover is in the closed position and to become disengaged from the free end of the cleaning liquid feeding tube when the cover is moved from the closed position to the open position.

Inventors: OERJES ANDERS, TUOMELA JARI, OERJES, ANDERS, TUOMELA, JARI, Örjes, Anders
Applicants: EVAC INT OY, EVAC INTERNATIONAL OY
Application year: 1996
Main classification: B61D35
IPC codes: E03D5, B61D35