HK1187581B - Suction coupling - Google Patents

Description

Suction type coupling

Technical Field

The invention relates to a suction device for discharging a mixed fluid, in particular excrement, from a collection container, in particular an excrement tank of a railway vehicle, comprising: a mixed fluid inlet port for receiving a mixed fluid, the mixed fluid inlet port being fluidly connectable to the interface of the collection container; a mixed fluid outflow port for discharging a mixed fluid, the mixed fluid outflow port being connectable to a suction duct; and a flow channel extending between the inflow port and the outflow port. The invention further relates to a suction station for sucking the mixed fluid and to a method for sucking the mixed fluid.

Background

Vehicles, in particular rail vehicles or also other goods-carrying and people-carrying vehicles (for example campers or yachts), usually have a collecting container for collecting the excrement. The collection vessel must be emptied periodically. For this purpose, the collecting container usually has a connection piece, for example on the outside of the vehicle, to which a hose coupling of a suction hose can be connected, so that the excrement located in the tank can be sucked in by means of the underpressure.

Conventional suction couplings or suction devices usually have a ball valve on the hose side of the suction device in order to close the hose after the end of the suction process, so that the drawn-off waste cannot flow out of the hose again. However, such a ball valve is arranged between the connection piece and the suction connection at a distance from the connection surface, depending on the design, so that mixed fluid (for example excrement) can collect in the dead space between the connection surface and the ball valve, which mixed fluid can flow out after closing the ball valve and uncoupling the connection part from the connection piece. In conventional suction couplings, this outflow amounts to up to about 0.5 l. Such an outflow of the mixed fluid (for example of excrement) is not only undesirable due to unpleasant odours, but also leads to contamination of the suction station and is likewise classified as dangerous from the point of view of health protection and water resource protection.

In order to solve this problem, DE202004019308U1 proposes that the suction hose between the coupling and the receiving container be suspended elevated in the central region, and that the hose region between the coupling and the elevated point be designed with a small diameter so that an elevated flow velocity is produced in said region. However, in this solution, it is shown that mixed fluid residues or waste residues remain in the coupling and flow out after decoupling.

DE102007011210B3 proposes another solution. Although the proposed hose coupling has a sealing element arranged directly on the parting plane of the coupling, mixed fluid residues or waste residues can also flow out of the nipple after uncoupling. In order to prevent this, DE102007011210 proposes that a membrane be provided in the connector, which membrane prevents the excrement from flowing out of the connector after the disconnection, in such a way that it forms a wall, so that excrement residues remain in the connector. Although direct outflow of waste after uncoupling is thus prevented, waste residues can freeze in the connection in winter, thus hindering or at least making it more difficult. Furthermore, it is disadvantageous that such a diaphragm must be attached to each connection piece. Such an installation is expensive and extremely costly.

Another solution for railway vehicles is proposed in DE4335945C 2. This solution provides an additional shut-off valve for each collection tank container in the rail vehicle, which shut-off valve must be opened by the operator after consideration at the beginning of the suction process and closed after the end of the suction process. Whether the coupling can be removed without dripping depends on the skill of the operator. Thus, in this embodiment, an outflow of excrement is often caused. In addition, the additional shut-off valve disadvantageously leads to an increased weight, complexity and cost of the suction coupling.

Disclosure of Invention

It is therefore an object of the present invention to provide a suction coupling which is improved with respect to at least one of the mentioned disadvantages.

In a suction device of the type mentioned at the outset, the object of the invention is achieved by a narrowing body for reducing the cross section of the flow channel partially or along its entire length. The present invention utilizes the following facts: when the liquid level drops, air flows through the flow channel, which air can be manipulated to empty the mixed fluid. Preferably, the narrowing body is for selectively narrowing the flow passage. Thus, according to the invention, an increased flow velocity of the air is achieved in the narrowed section, as a result of which the mixed fluid or the excrement residue located in the region of the flow channel is sucked in. In addition, turbulence is generated by local flow acceleration during the transition from the slow-flow-dominant connection to the fast-flow-dominant flow channel, which turbulence ensures that solid or highly viscous components of the mixing fluid are also entrained and drawn off. The effect of this flow is not only limited to the flow channel but also at least partially restricts the coupled connection so that the mixed fluid or excrement in the coupled connection is also removed. Preferably, the narrowing is adapted to selectively reduce the cross-section of the flow passage partially or along its entire length. It is particularly preferred that the flow channel is formed in the housing of the suction device. Furthermore, a coupling element is preferably provided on the mixed fluid inflow opening in order to couple the suction device to a connection piece of the vehicle. Preferably, the coupling is designed as a lever-arm coupling (so-called quick coupling).

According to a first preferred embodiment, the narrowing body at least partially forms a wall of the flow channel. Accordingly, in a first alternative, the flow channel is at least partially configured as a recess, channel or bore in the narrowing body. In a further alternative, the flow channel is formed between a housing wall and a narrowing body of the suction device. According to this alternative, the narrowing body can be configured as a separate body which can be inserted into the housing of the suction device. For example, a channel is formed in the housing, which channel is formed to substantially correspond to the diameter of a connecting piece that can be connected to the mixed fluid inflow opening. The channel can extend from the mixed fluid inlet port all the way to the mixed fluid outlet port. The narrowing body can then be inserted or already inserted into the channel, such that the narrowing body at least partially constitutes a wall of the flow channel.

According to a further preferred embodiment, the narrowing body can be moved into a first and a second position relative to the inflow opening and/or the outflow opening, wherein the cross section of the flow channel in the second position is smaller than in the first position. It is therefore possible according to the invention to vary the diameter of the flow channel, preferably during the suction process. The suction process can therefore start with a large flow channel cross section first, so that a high volume flow is achieved. At the end, the narrowing body can be moved into the second position, as a result of which the flow cross section is narrowed and the above-mentioned effects of fluid acceleration and suction are enhanced. In a preferred embodiment, the cross-section of the second location is half as large as the cross-section of the first location. In a further preferred embodiment, the ratio of the cross section of the second location to the cross section of the first location is one of the following: 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.05. In a further preferred embodiment, the cross section decreases at the second point along the flow direction of the flow channel. In an alternative embodiment, the narrowing body is designed as a partition. Such a partition is preferably designed such that the size of the partition opening is variable. In a further alternative, the suction device has a section which is designed according to a pinch valve and in which the flow channel is designed. Thus, the inner wall of the pinch valve constitutes the narrowing. By means of the squeezing of the squeeze valve, the cross section of the flow channel can be reduced.

According to a further preferred embodiment, the narrowing body can be moved into a third position in which the narrowing body closes the flow channel. Thus, according to the invention, an additional non-return valve is dispensed with, whereby the structure of the suction device is significantly simplified. The weight of the suction device according to the invention is thus also reduced. Alternatively, the constriction body can be moved into the third position to activate a closure element, which serves to close the flow channel.

According to a further preferred embodiment, the narrowing body has a recess which is connected in fluid-conducting manner to the inflow opening and the outflow opening in the second position of the narrowing body. Such a recess can be configured, for example, as a through-hole or through-channel in the narrowing body. The flow duct is therefore preferably delimited by the housing in the first position. In the second position, the flow duct is preferably partially or completely delimited by the narrowing body, while in the third position the flow duct is completely closed by means of the narrowing body.

According to a further preferred embodiment, the recess is formed on the circumferential surface of the narrowing body. Preferably, the recess is configured as a groove. The recess is formed as a groove on the circumferential surface, for example, which is a particularly effective solution for forming the recess on the narrowing body. Alternatively, the narrowing body has a section on the circumferential surface, which is intended to correspond to the housing wall and thus form a narrowed flow duct, in particular a gap. For example, the recess is configured as a flattened portion on the narrowing body. A recess shall here mean various shapes of the narrowing body that open or open a gap as a flow channel between the narrowing body and, for example, a wall of the housing.

According to a further preferred embodiment, the narrowing body is designed as a piston. It is particularly preferred if the narrowing body is designed as a movable piston. The piston is preferably movable along its piston axis in a cavity of the housing of the suction device. In particular, it is preferred that a recess is formed on the piston circumference of the piston, which recess at least partially forms a wall of the flow channel in the second position of the piston.

According to a further preferred embodiment, the narrowing body is cylindrically configured and has an actuating mechanism, by means of which the narrowing body can be moved between the first, second and/or third position by sliding and/or rotating along or about its cylinder axis. The narrowing body can thus be moved, for example, by sliding from the first position into the second position and by pivoting from the second position into the third position. Alternatively, the piston can be moved by sliding from the first position into the second position and by sliding from the second position into the third position. Furthermore, it is alternatively possible for the piston to be moved by rotation from the first position into the second position and by sliding from the second position into the third position. Furthermore, it is alternatively possible for the piston to be moved by rotation between all three positions. By configuring the narrowing body as a cylindrical piston, a movement in these two degrees of freedom (rotation, sliding) is possible, thereby enabling a simple actuation of the suction device according to the invention. Alternatively, the operating mechanism preferably includes, for example: handles, sliders, levers, push rods, cable drives, pinions and racks, and the like.

According to a further preferred embodiment, the suction device has an air inlet opening into the flow channel, which opening can be opened or closed in order to selectively convey air into the flow channel. The turbulent flow created in the flow channel is further exacerbated by the delivery of air into the flow channel. More turbulence occurs due to the turbulent flow, so that the flow channel and thus the faecal residue in the suction device is removed more effectively. In this case, the air can be selectively supplied so that the air inlet preferably remains closed during the suction process and can be opened at the end. The air inlet can be configured, for example, as an opening in the housing, which can be closed and opened by means of a valve, a slide, a plug, etc. In one alternative, the air inlet can be opened by means of a pivotable valve in the housing, so that the valve can be pivoted towards or into the flow channel. Thus, the opening of the inlet port is coupled with the narrowing of the flow channel. Alternatively, the suction device has a mechanism that provides automatic opening of the air inlet if a certain result occurs. Such a result can be, for example, a specific liquid level of the collecting container or a specific pressure in the suction device. In a further alternative, the air inlet can be opened and closed, so that the volume flow of the air can be regulated. The air inlet is then preferably dimensioned such that fluid residues in the suction device and/or the adjoining connection piece are removed, whereas no additional fluid or additional waste is drawn off from the adjoining collection container.

According to a further preferred embodiment, the air inlet is configured as a recess in the narrowing body and is connected to an openable or closable air channel in the narrowing body. Accordingly, the intake opening is correspondingly movable together with the narrowing body relative to the mixed fluid inflow opening and the mixed fluid outflow opening. Due to the positioning of the air inlet, air can be introduced into the flow channel in a targeted manner and, as a result, residual fluid can be removed from the suction device effectively. Preferably, the gas inlet is arranged adjacent to a recess in the narrowing body which delimits the flow channel. Thus, the air can be better guided into the flow channel. In an alternative, the air duct can be opened or closed by means of the above-mentioned actuating mechanism. The provision of an openable or closable air inlet is particularly advantageous in particular if the suction process carried out by means of the suction device is to be ended before the collecting container of the vehicle is completely emptied, so that in each case a mixed fluid is still preferentially conveyed through the flow channel and no or only an insufficient amount of air is conveyed. The air inlet is advantageous even in the case of a completely empty collecting container of the vehicle. Although the removal of the mixed fluid residues is successfully carried out even without the air inlet when the tank is emptied, the additional provision of an air inlet according to the invention constitutes a further development since additional air is provided for removing the mixed fluid residues or the waste residues.

According to a further preferred embodiment, the suction device has a housing with a recess which is connected in fluid communication with the air inlet in the second position of the narrowing body. Preferably, the recess in the housing is connected in fluid communication with the gas inlet only in the second position of the narrowing body. The air inlet is thus closed in the first position. Furthermore, it is preferred that the cross-sectional area of the fluid channel is maximal at the first position of the narrowing body. It is thus possible to effectively utilize the vacuum applied to the mixed fluid outflow in order to empty the collection container. If the narrowing body is disposed at the second position, the air inlet is opened. Additional air can reach into the flow channel and assist in carrying and thus removing residual fluid from the suction device by means of turbulence and/or flow acceleration. Preferably, the recess in the housing is configured as a bore. In an alternative, the housing comprises a plurality of recesses with different cross sections, preferably configured as bores, so that the amount of air which can be fed through the air inlet to the flow channel can be adjusted. The air channels formed in the narrowing body can then be connected in fluid-conducting manner to the respective recesses by a movement of the narrowing body. In a further alternative, the recess is configured as an elongated hole with a variable width, and the air channel has a substantially circular cross section in the narrowing body, so that the amount of air that can be delivered to the flow channel through the air inlet can be adjusted via a corresponding movement of the narrowing body relative to the elongated hole.

According to a further preferred embodiment, the suction device has a closing body for selectively opening or closing off the air inlet, which closing body can be moved back and forth between an open position and a closed position. Such a closure is preferably designed as a slider. This is a particularly simple solution to provide opening and blocking of the air inlet. Such a slide is preferably movable in different intermediate positions so as to be able to adjust the amount of air delivered to the flow channel through the air inlet.

In a preferred development of the invention, the closing body is arranged in a stationary manner relative to the housing of the device. Thus reducing the number of movable parts. Preferably, the narrowing body is movable relative to both the housing and the closing body. The positional fixation relates to the outer dimensions of the closure. Here, the position fixing includes: the closing body can be moved, in particular rotatable, about an axis of symmetry.

Preferably, the closing body is at least partially arranged in a recess of the narrowing body. Preferably, the closing body is at least partially integrated into the narrowing body. Thus, the closer is better protected from external influences. Since the closure is to have a sealing effect, it is advantageous for the functionality of the device that the closure is as little affected externally as possible. Preferably, the closing body is arranged completely and/or integrated in the narrowing body.

It is also preferred that the longitudinal axis of the closing body is arranged substantially coaxially to the longitudinal axis of the narrowing body. The closing body is therefore particularly preferably movable relative to the narrowing body, or the narrowing body is movable relative to the closing body. In this case, it is also preferred that the channels in the narrowing body are formed parallel, in particular coaxially, in the narrowing body. The closing body is therefore also coaxial with said passage and is suitable for simply and effectively closing said passage and therefore also the air inlet.

In a particularly preferred embodiment, the closing body is connected to the housing via a retaining element, and the retaining element together with the recess on the narrowing body forms a gate guide for the narrowing body. Preferably, the gate guide is designed such that the narrowing body can also move relative to the housing and the closing body. Alternatively, the gate guide for the narrowing is also preferably combined with one of the above embodiments without the closing body and without the holding element. By connecting the closing body to the housing by means of a holding element (for example one or more screws, pins, ribs, rivets, etc.), the closing body is arranged in a positionally fixed manner relative to the housing. The retaining element preferably extends through a slit-shaped recess of the narrowing body, so that said recess together with the retaining element serves as a gate guide. The narrowing body can therefore always be moved in a predetermined manner relative to the housing also relative to the fluid inflow and fluid outflow and relative to the closing body. That is to say that the closing body occupies a predetermined defined position at each point in time with respect to a specific position of the narrowing body. The handling of the device is therefore significantly simplified.

It is furthermore preferred that the narrowing body and/or the closing body have a sealing mechanism for fluid-sealing, preferably pressure-sealing, the suction device from the surroundings. Such sealing mechanisms can include or have, for example, O-rings, X-rings, and the like. It is also preferred that the mixed fluid inflow opening can be connected to the connection of the collecting container by means of a coupling (preferably a quick coupling), wherein the suction device has a first coupling which engages in a fluid-tight, preferably pressure-tight manner with a second coupling of the connection of the collecting container. Preferably, such a coupling is configured as a lever arm coupling and the first coupling is configured as a female part.

According to another aspect, a suction station for discharging a mixed fluid, in particular excrement, from a collecting container, in particular an excrement tank of a vehicle, of the type mentioned at the outset, wherein the suction station has: a receiving container for mixing a fluid; a suction line for delivering the mixed fluid to a receiving container; a delivery unit for generating a negative pressure in the suction duct and delivering the mixed fluid through the suction duct into the receiving container; and a suction device connected to the suction line for leading the mixed fluid out of the collection container, said object being achieved in that: the suction device is constructed according to one of the previously described preferred embodiments. Such suction stations are provided, for example, on train service stations for railway vehicles or in yacht ports or docks. For example, a vehicle having a collecting container, in particular a waste bin, can thus be driven over at such a suction station, and the collecting container can be emptied by means of the suction device of the suction station. In this case, the delivery unit is preferably designed as a vacuum pump (or rotary piston pump). A rotary piston pump is preferably provided as the vacuum pump. Alternatively, other conventional pump devices for generating a negative pressure are used. For the advantages achieved by the suction station according to the invention, reference is made to the above discussion relating to the suction device according to the invention.

According to a further aspect of the invention, in a method of the type mentioned at the outset for discharging a mixed fluid, in particular excrement, from a collecting container, in particular an excrement tank of a rail vehicle, by means of a suction device, which is preferably constructed according to one of the preferred embodiments of the suction device, the object is achieved by the following steps: coupling a suction device to a mouthpiece of a collection container; sucking the mixed fluid from the collection container by means of negative pressure; reducing the cross-section of the flow channel by means of a narrowing body of the suction device, in particular partially or along the entire length of the flow channel; and decoupling the suction device. By reducing the cross section of the flow channel, a local flow acceleration of the air flowing through the flow channel is caused, whereby mixed fluid residues located in the flow channel are entrained and removed (dragged away). Furthermore, turbulence is caused by local flow acceleration, so that adhering fluid residues can also be removed. Accordingly, the reduced step is also referred to as "drag-away". It is particularly preferred that, when the collecting container is emptied, a step of reduction or dragging is introduced so that the air which can flow in through the ventilation valve of the collecting container is sucked in. The term "emptying" is to be understood in the sense of the present invention as meaning that the liquid level in the collecting container is reduced, so that only air is mainly, preferably only air is, also sucked from the collecting container. The suction device for drawing off the mixed fluid thus removes fluid residues, in particular in the coupling region, according to the invention. The step of reducing or dragging off here preferably takes a shorter period of time than the suction step. Preferably, the reduced state is maintained for about 2 seconds to 30 seconds. The suction device is then uncoupled. In this about 2 to 30 seconds, so much residual fluid is removed from the suction device that it can be uncoupled substantially without dripping after uncoupling. The outflow of excrement is prevented or at least significantly prevented according to the invention.

According to a first embodiment of the method, the method comprises, before the step of decoupling the suction device, a step of closing the flow channel by means of a narrowing body. Thus, the suction device is also more effectively protected against the outflow of fluid residues. The mixed fluid does not flow out even if the suction device is shaken after being decoupled. It is particularly preferred that the closure of the flow channel is achieved by means of a narrowing body. Thus, according to the invention, the implementation of the method is significantly simplified. Preferably, the narrowing body is movable in three positions: for suction, the narrowing body is moved to or held in the first position; for reduction, the narrowing body is moved to a second position; to close the flow channel, the narrowing body is moved into a third position.

According to a further preferred embodiment of the method, the movement of the narrowing body comprises a rotation and/or a sliding of the narrowing body. Rotation and sliding are simple movement processes that can be reliably carried out by the user of the method. Alternatively, the movement comprises pivoting.

According to a further preferred embodiment of the method, reducing the cross section of the narrowing body comprises sliding the narrowing body, and the closing of the flow channel comprises rotating the narrowing body. Thus, the implementation of the method is further simplified. For example, in order to reduce the cross section, the narrowing body must slide against the stop from the first position to the second position. For closing, the narrowing body is rotated about the axis of rotation, wherein the narrowing body in turn rotates against a stop. Thus, the method is simple for the user to implement and can be less error prone. In particular, it is possible to carry out the method with one hand when the narrowing body has an actuating mechanism.

According to another preferred embodiment of the method, the method comprises the step of selectively delivering air into the flow channel by means of opening and closing the air inlet. By supplying air into the flow channel, a stronger turbulence and further flow acceleration are caused, so that residual fluid, in particular also adhering residual fluid, can be removed from the flow channel. In particular, the opening of the air inlet is preferably carried out simultaneously with or during the step of reducing the cross-section of the flow channel.

Drawings

The invention is explained in detail below with reference to the drawings by means of embodiments. Shown in the attached drawings:

fig. 1 is a sectional view of a suction device according to the invention, which is connected to a collection container via a pipe connection;

FIG. 2a is a cross-sectional view of the suction device with a narrowing in a first position;

figure 2b is a front view of the suction device with narrowing in the first position;

FIG. 3a is a cross-sectional view of the suction device with a narrowing in a second position;

figure 3b is a front view of the suction device with narrowing in the second position;

FIG. 3c is another cross-sectional view of the suction device with the narrowing body in a second position;

FIG. 3d is another front view of the suction device with the narrowing body in the second position;

FIG. 4a is a cross-sectional view of the suction device with a narrowing in a third position;

figure 4b is a front view of the suction device with narrowing in a third position;

fig. 5a is a plan view of a suction device with a suction pipe connection according to a first embodiment;

fig. 5b shows a further plan view of the suction device with a suction pipe connection according to the second embodiment;

FIG. 6a is a front view of a first alternative of the narrowing body;

FIG. 6b is a front view of a second alternative of the narrowing body;

FIG. 6c is a front view of a third alternative of the narrowing body;

FIG. 6d is a front view of a fourth alternative of the narrowing body;

figure 7 is a cross-sectional view of a suction device according to another embodiment in a first position;

FIG. 8 is a cross-sectional view of the suction device of FIG. 7 in a second position;

figure 9 is a cross-sectional view of the suction device of figures 7 and 8 in a third position;

fig. 10a corresponds to a perspective view of the narrowing body according to the embodiment of fig. 7 to 9;

FIG. 10b is another perspective view of the narrowing body of FIG. 10 a; and

fig. 10c is another perspective view of the narrowing body of fig. 10a and 10 b.

Detailed Description

According to fig. 1, a suction device 1 for discharging a mixed fluid, in particular excrement, from a collecting container 2 has a mixed fluid inflow 4 and a mixed fluid outflow 8. The mixed fluid inflow 4 is connected to a pipe connection 6 by means of a coupling 5. The pipe connection 6 is connected to the collecting container 2 via a suction line 7. The collecting container 2 furthermore has a ventilation valve 3. The coupling 5 is preferably designed as a positive-locking lever-arm coupling, wherein the male part of the coupling 5 is designed on the pipe connection 6 and the female part of the coupling 5 is designed on the mixing fluid inlet 4. A flow channel 14 extends between the mixed fluid inflow 4 and the mixed fluid outflow 8, said flow channel being delimited by the housing 12 of the suction device 1 and the narrowing body 10 movably arranged in the housing 12. The mixed fluid outflow 8 is connected to a suction connection 16, which can be connected to a hose (not shown), which preferably leads to a receiving container and is connected to a vacuum pump (both not shown). According to this embodiment, the narrowing body 10 is configured as a piston and is arranged in the housing 12 so as to be movable in translation coaxially to its longitudinal axis 11. In particular the narrowing body 10 is arranged coaxially to the central axis of the mixed fluid inflow 4. The mixed fluid outflow 8 is arranged substantially radially with respect to the narrowing body 10.

An air inlet 18 for feeding air into the flow channel 14 is provided on the side of the narrowing body 10 facing the mixed fluid inflow opening 4. The air inlet 18 is connected via an air channel 20 to a channel inlet 19, which is formed in the narrowing body 10. Furthermore, the narrowing body has an actuating device 24 on the side facing away from the mixed fluid inflow opening 4 in order to move the narrowing body 10 relative to the mixed fluid inflow opening 4 and the mixed fluid outflow opening 8 or relative to the housing 12. According to this embodiment, the steering mechanism 24 includes a push rod 26 that is connected to a handle 28. Furthermore, the narrowing body 10 has a recess 22 on the outer circumferential surface, which is configured as a towing groove 22.

Fig. 2a to 4b show different operating states of the suction device 1 during the suction process. The terms "mixed fluid" and "waste" are used synonymously.

According to fig. 2a, the piston 10 is in the first position. In this first position, the flow channel 14 has a maximum cross section and is therefore maximally permeable, so that the waste stream 30 can flow from the collecting container or waste tank 2 up to the receiving container. In this first position, the channel inlet 19 of the air channel 20 is closed by the housing 2, so that the air inlet 18 is blocked. According to this embodiment, no air is introduced into the flow channel in the first position. The piston 10 is rotationally arranged relative to the housing 12 such that the drag groove 22 is arranged adjacent to the fluid outflow 8. This first position of the piston 10 is also referred to as the "suction position".

According to view a (fig. 2b), the suction device 1 is shown from the direction of arrow a according to fig. 2 a. The coupling 5 between the mixed fluid inflow 4 and the pipe joint 6 is in a coupled state. The intake port 18 is formed around the longitudinal axis 11 of the piston 10 and is arranged on the end face of the piston 10. The drag groove 22 is configured according to this embodiment essentially as a recess with a quarter-circular cross section on the cylindrical circumference of the piston 10. The recess is constituted by the difference between said cylindrical peripheral surface and the corresponding inner surface of the housing 12. The drag groove 22 is arranged adjacent to the mixed fluid outflow 8 (shown in fig. 2 a) or adjacent to the suction connection 16. Alternatively, the towing tank is formed on the housing 12.

According to fig. 3a, 3b, 3c and 3d, the piston 10 is arranged in a second position with respect to the mixed fluid inflow 4, the mixed fluid outflow 8 and the housing 12. This second position is also referred to as the "drag position" of the piston 10. In this second position, the flow channel 14 becomes extremely narrow in such a way that the piston 10 moves translationally in the direction towards the mixed fluid inflow 4. In this state, the towing tank 22 constitutes a wall for the flow channel 14. The flow channel 14 is in this second position substantially defined by the difference between said cylindrical peripheral surface and the inner surface of the housing. The flow is accelerated by making the flow channel 14 extremely narrow, as a result of which residual fluid 38 in the suction device 1 or the pipe connection 6 close to the suction device 1 and/or close to the coupling 5 is entrained and removed (dragged away). To assist the (dragging) process, it is advantageous to introduce additional air into the flow channel 14. In this second position of the piston 10, the passage inlet 19 and the opening 13 in the housing 12 coincide, so that the air inlet 18 is connected in an air-conducting manner to the housing opening 13 and the air flow 40 reaches the flow passage 14. The air flow (drag air) causes strong turbulence in the turbulence zone 36, as a result of which the residual fluid 38 is more effectively removed from the suction device 1 or from the transition region between the end face of the piston 10, the mixed fluid inflow 4, the coupling 5 and the pipe connection 6.

The front view of the mixed fluid inflow opening 4 according to view a (fig. 3b) substantially coincides with the front view a in the first position (fig. 2 b).

Fig. 3a and 3b show the operation of the suction device 1 in the pulled position, in which the collection container 2 to be emptied is not completely emptied. Thus, only the excrement flows from the direction of the pipe connection 6 onto the flow channel 14, while all the dragging air is conveyed through the air channel 20. In contrast, fig. 3c and 3d show the suction device 1 with the piston 10 in the "pulled-in position", in which the collection container 2 to be emptied is emptied according to fig. 3c and 3 d. Thus, both the fluid residues 38 and the additional towing air 41 flow through the suction duct 7 from the direction of the pipe connection 6. The drawing air 41 passes through the ventilation valve 3 into the collection container 2. The thickness of the dashed line representing the dragged air flow 40, 41 also represents the volume flow ratio between the two dragged air flows 40, 41. If the collecting container 2 is emptied, a significantly greater proportion of the entrained air passes through the suction line 7 and the pipe connection 6 to the flow channel 14. Nevertheless, it is also preferable to introduce the dragging air flow 40, since it causes a more intense vortex in the vortex region 36, as a result of which the fluid residues 38 are effectively dragged and removed through the flow channel 14. By forming the air channel 20 in the piston 10 and the intake opening 18 on the end face of the piston 10, the intake opening 18 is close to the fluid inflow opening 4 in the trailing position of the piston, and the trailing air 40 flows in essentially counter to the natural flow in the flow channel 14, so that a stronger swirl is induced in the swirl region 36. By means of the turbulence, it is possible for solid constituents of the mixed fluid which adhere to the inner wall of the housing or to the inner wall of the pipe connection 6 to also be loosened and dragged away.

View a (fig. 3d) also shows a front view from the direction of the pipe connection 6, which is identical to view a (fig. 3 b).

According to fig. 4a, 4 b. In the suction device 1, the piston 10 is arranged in a third position, which is also referred to as "closed position". In this position, the piston 10 is rotated about its longitudinal axis 11 by approximately 180 °. Therefore, the towing tank 22 rotates away from the mixed fluid outflow port 8, and the piston 10 closes the mixed fluid outflow port 8 with its circumferential surface. Accordingly, the channel inlet 19 is not connected in an air-conducting manner to the opening 13 in the housing 12, so that no air or drag air can flow through the channel 20 or the flow channel in the suction device 1. According to the third position, neither the mixed fluid nor the dragging air flows from the direction of the pipe connection 6. By closing the mixed fluid outlet opening 8 with the circumferential surface of the piston 10, the fluid residues 44 deposited in the suction connection piece 16 can no longer flow out of the latter. The translational position of the piston 10 relative to the housing 12 is substantially the same in the second and third positions such that the end face of the piston 10 is disposed adjacent the mixed fluid flow inlet 4. Therefore, the dead space 42 in the suction device 1 is minimized and no mixed fluid residue or excrement residue flows out after decoupling the pipe joint 6 from the suction device 1. By configuring the narrowing body 10 as a piston 10, additional advantages are achieved: by the piston 10 moving from the first position into the second position, the mixed fluid located on the wall is thus swept down towards the mixed fluid inflow 4 and can be dragged away there.

Front view a (fig. 4b) shows a front view of the mixed fluid inflow 4, wherein the piston 10 is in the "closed position" and the coupling 5 is disengaged. In this position, the suction connection 16 and the subsequent lines to the receiving container (not shown) are closed, and no fluid residues or foul-smelling vapors or the like can flow out of the suction station.

The function of the suction device 1 according to this embodiment is explained below with the aid of fig. 2a-4 b.

In the shut-down state, the suction device 1 is decoupled from the pipe connection 6. If a suction process is to be carried out, the suction device 1 is therefore first coupled to the pipe connection 6. This is preferably achieved by means of a coupling 5, wherein the coupling 5 is preferably designed as a lever-arm coupling. Furthermore, the piston 10 is set in the third position before the suction process begins. In this position, the mixed fluid outflow 8 is closed and the mixed fluid is not shaken out of the suction connection 16 as a result of the actuation of the suction device (for example, lifting, pivoting or shaking). The piston 10 has a guide groove 34 on the circumference, which is designed to interact with a guide pin 32, which is only indicated schematically in the drawing and is arranged on the housing 12, in order to be able to guide the piston in a specific path. In the figures of this embodiment, the guide grooves 34 are arranged opposite the trailing grooves, i.e. offset by 180 °. Alternatively, the slot is disposed at another angle, for example in the range of 90 ° -175 °, relative to the towing slot. The guide groove 34 is preferably designed such that the piston 10 can be moved purely rotationally from the second position to the third position or vice versa and purely translationally from the second position to the first position or vice versa. In order to carry out the suction process by means of the suction device 1, it is therefore necessary for the piston 10, which is preferably arranged in the third position at the beginning, to be initially brought into the first position. This can easily be achieved by the operator by means of the operating mechanism 24. Thus, in order to bring the piston 10 from the third position into the first position, it is first necessary to rotate the piston 10 about its longitudinal axis 11 and then to pull the handle 28 in order to move the piston 10 translationally into the first position. If the suction connection 16 is now loaded with negative pressure, the suction process begins and the mixed fluid stream 30 flows through the flow channel 14. According to an alternative embodiment, which is not shown, the narrowing of the piston 10 is configured such that it can be moved slightly (for example, by a few degrees) in rotation into the locking position in the first position and/or in the second position and/or in the third position. This latching function is provided, for example, by additional grooves and guide pins or correspondingly configured guide grooves 34. The reaching of the locking position is preferably spring-assisted, so that it is difficult to automatically unlock from the locking position. Furthermore, it is preferred according to an alternative to provide a locking mechanism in order to lock the narrowing body designed as a piston 10 in the closed position.

At the end of the process or if the process is to be interrupted, the piston 10 is brought into a second position, the "trailing position", which serves to clean the suction device 1 from fluid residues. In this position, the flow channel 14 narrows and air is drawn in through the ventilation valve 30 of the collecting container 2 or through the air channel 20. Since the drag air has a significantly lower viscosity than the mixed fluid or the excrement, by placing the piston 10 in the drag position, the excrement flow 30 is substantially interrupted and the drag air 40, 41 creates a vortex 36, as a result of which the fluid residues 38 are dragged away. Waiting in this position during operation until all the residue is dragged away, which typically lasts about 10-30 seconds. Furthermore, the piston 10 can be moved back and forth during the drawing by means of the handle 28 and the push rod 26 during emptying of the collection tank in order to generate a more intensive vortex and to sweep fluid residues from the housing 12 with the piston end face. For this purpose, the piston 10 preferably has sealing elements arranged in the circumferential surface. After waiting a corresponding time and pulling all fluid residues away from the suction device 1, the piston 10 is set into the "closed position" by rotation, so that the mixed fluid outflow 8 and the channel inlet 19 are closed. Subsequently, the suction device 1 is uncoupled from the pipe connection 6.

In a first embodiment of the suction device 1, the suction connection piece 16 is arranged with its central axis 17 parallel to the piston 10 and to the longitudinal axis 11 of the suction device 1 (not shown in fig. 5a) in a plan view from the direction of the mixed fluid outflow 8 to the suction device 1 (fig. 5 a). The suction connection piece 16 is curved essentially in a quarter circle, preferably in the range from 75 ° to 105 ° (fig. 1 to 4), and has a cylindrical cross section. The suction connection piece 16 can be connected at a first end, preferably in a fluid-tight manner, to the mixed fluid outflow 8 and at a second end to a hose. The suction connection piece 16 is fixed to the housing 12 of the suction device 1 by means of fixing means 50a, 50b, 50c, 50 d. Preferably, the suction connection piece 16 is detachably fastened in a reversible manner by means of fastening means 50a, 50b, 50c, 50 d. Furthermore, the fastening means 50a, 50b, 50c, 50d are designed in such a way that the suction connection piece 16 can be arranged in a plurality of positions relative to the mixed fluid outflow 8. In an alternative embodiment, the plurality of positions can be adjusted steplessly or in preset blocking steps. It is particularly preferred that the suction connection piece 16 is designed to be pivotable in a stepless manner, in each case by approximately 90 ° of rotation. According to fig. 5b, the suction connection piece 16 is arranged in a position in which the central axis 17 of the suction connection piece 16 is arranged substantially perpendicular to the longitudinal axis 11 or the longitudinal axis of the suction device 1. It is therefore possible for the operator to always arrange the suction connection piece 16 such that the suction device 1 can be used ergonomically advantageously and that kinks or sharp bends of the hose relative to the receiving container are avoided.

Furthermore, according to fig. 5a and 5b, the suction device 1 has a coupling 5 adjacent to the mixed fluid inflow opening 4, which according to this embodiment is configured as a lever arm coupling for connecting the male part with the female part. For this purpose, the female part of the coupling 5 has two lever arms 46, 48, each of which serves to positively connect the coupling 5 to the male part of the coupling on the pipe connection 6.

Fig. 6a, 6b, 6c, 6d show four alternative embodiments of the cylindrical piston 110, 210, 310, 410 with the trailing groove 122, 222, 322, 422. Accordingly, in the first embodiment, the trailing groove 122 is configured as a gap in the piston 110. The piston 110 is only partially cylindrical in this case. The piston comprises a first half 111 having a semi-circular cross-section and a second half 112 having an elliptical cross-section. The inner contour of the housing 100 is cylindrically formed. Accordingly, a gap 122 is formed between the piston 110 and the inner wall of the housing 100, and the gap constitutes the dragging groove 122.

According to a second embodiment (fig. 6b), the piston 210 is of substantially cylindrical design, and the inner contour of the housing 200 is likewise cylindrical. According to this embodiment, the towing tank 222 is configured as a partially circular or partially cylindrical tank 222.

According to a third embodiment (fig. 6c), the piston 310 is of substantially cylindrical design and has a flat flattened section on the side parallel to its central axis. The inner contour of the housing 300 is cylindrical. Therefore, the towing groove 322 is formed by a difference between the two shapes.

According to a fourth embodiment (fig. 6d), the piston 410 is of substantially cylindrical design and has a rectangular groove 422. In all four embodiments, the intake ports 118, 218, 318, 418 are configured coaxially with the central axis. In an alternative embodiment, the air inlet 18 is arranged offset in the direction of the trailing slot 122, 222, 322, 422. In a further alternative embodiment, the air inlet 18 is arranged spaced apart from the trailing slots 122, 222, 322, 422. In a further alternative embodiment, a plurality of inlet openings are formed in the piston 10.

Fig. 7 to 10c show a further embodiment of the suction device 1 or the piston 10. Structurally or functionally identical and/or similar components are advantageously provided with identical or similar reference numerals. In this respect, reference is made to the discussion relating to the preceding figures and embodiments.

The suction device 1 (fig. 7 to 9) has a mixed fluid inflow 4 and a mixed fluid outflow 8. A coupling 5 is provided near the mixed fluid inflow port 4. The coupling 5 is fixed to the housing 12 of the suction device 1. A substantially cylindrical piston 10 constituting a narrowing body is movably arranged in a housing 12. According to this exemplary embodiment, the piston 10 has a front section 10a which is, for example, of a shovel-like or beak-like design with an inclination. This inclined portion constitutes a guide for the mixed fluid when it is sucked from the collecting container 2. A recess 62, which is configured substantially cylindrically according to this exemplary embodiment, is provided in the rear section 10b of the piston 10. A closure 60 is disposed in the recess 62. The closing body 60 has a plug-like projection 64 oriented toward the mixed fluid inflow 4, the diameter of which projection is such that it closes the intake opening 18 formed in the piston 10 in the closed position. The closing body 60 is arranged substantially coaxially to the longitudinal axis 11 of the piston 10. Furthermore, the closing body 60 is arranged in a stationary manner in relation to the housing 12 in the recess 62 by means of a screw 68. The recess 62 is closed off on the side of the piston 10 facing away from the mixed fluid inflow 4 by means of a plate 74, to which the handle 28 is fastened. The closing body 60 is therefore substantially integrated into the piston 10, so that it is not accessible from the outside of the suction device 1. The plate 74 is fixed on the hole 73 (see also fig. 10a to 10c) of the piston 10.

In the rear section 10b, the piston has a slot-shaped through-going recess 80 (see in particular fig. 10a to 10 c). The screw 68, which serves as a retaining element and fixes the closure 60 to the housing 12, extends through the recess 80. Thus, the recess 80 together with the screw 68 serves as a chute guide for the piston 10. The slit-shaped recess 80 has notches 81, 82, 83 in three places, which serve as latching points (see fig. 10 a-c). The screws 68 lock in the recesses 81, 82, 83 when the respective position is reached. To assist this locking, a spring 70 is provided between the closure 60 and a retaining section 72 on a plate 74 in a recess in the rear section 66 of the closure 60. By means of said spring 70, which is configured as a compression spring, the piston 10 is loaded away from the mixed fluid inflow 4, so that the screw 68 can be locked into the notch 81, 82, 83. Furthermore, the spring 70 serves to compensate for play in the movement of the narrowing body or piston 10 in the longitudinal direction.

Furthermore, a circumferential groove 86 is provided on the circumferential surface of the piston 10, which serves as a receptacle for an O-ring or other seal. Furthermore, a circular groove 84 is provided, which likewise serves as a receptacle for an O-ring for sealing off the mixed fluid outflow 8 when the piston 10 is in the third position.

The operation of the suction device according to this embodiment (fig. 7 to 10c) is explained below: before coupling, the suction device 1 is closed and the piston 10 is in the third position (as shown in fig. 9). In this position, the screw 68 is locked into the notch 83 and the position of the piston 10 relative to the closing body 60 is such that the air passage 20 is not completely closed. Thus, a certain degree of air compensation is possible, and thus easy connection to the coupling 5 is possible. Alternatively, the air duct 20 can be closed in the 3 rd position by the closing body 60. The piston 10 for opening the mixed fluid outflow 8 is now rotated into a first position (as shown in fig. 7) by means of the handle 28. Here, the screw 68 locks into the notch 81. The mixed fluid outflow port 8 is fully opened, and the flow channel 14 is not narrowed. In this position, the closing body 60 closes the air inlet 18 by means of a plug-like projection 64. Thus, no additional drag air is added in this first position.

If the collection container is nearly evacuated, the piston 10 is brought into a second position (as shown in fig. 8), i.e. a trailing position, by means of the handle 28. In this position, the flow channel 14 narrows and the groove 22 forms the wall of the flow channel 14 on the piston 10. The screw 68 locks into the notch 82. The piston 10 is in a position relative to the closure 60 that fully opens the air inlet 18 and additional drag air flows through the opening 75 in the plate 74, the throughput 65 in the closure and the air passage 20 inside the suction device 1 and thus acts as drag air. This position ideally remains at least 2 seconds, and more preferably about 3 seconds long (or longer). Subsequently, the piston 10 is again set back in the third position by means of the handle 28 until the screw 68 locks into the recess 83. Subsequently, the suction device 1 can be uncoupled.

Alternatively, the blocking position (82) can be omitted or replaced by a deflection which excludes an unimpeded or transitional intake position (second position). This can be achieved, for example, by means of a profile change or an angle change in the slotted link guide, which is designed in such a way that an optimum feedback is produced when the screw 68 moves along the deflection.

Claims (29)

1. A suction device (1) for drawing off a mixed fluid from a collection container (2), having:

-a mixed fluid inflow (4) for accommodating a mixed fluid, which mixed fluid inflow is connectable in fluid communication with an interface of the collecting container (2);

-a mixed fluid outflow (8) for discharging a mixed fluid, the mixed fluid outflow being connectable in fluid communication with the suction duct; and

-a flow channel (14) extending between the mixed fluid inflow port and the mixed fluid outflow port,

characterized in that a narrowing (10) is provided for reducing the cross section of the flow channel (14) partially or along the entire length of the flow channel; the narrowing body (10) can be moved relative to the mixed fluid inflow opening and/or the mixed fluid outflow opening into a first position and into a second position, wherein the cross section of the flow channel (14) in the second position is smaller than the cross section in the first position; and the narrowing body (10) at least partially forms a wall of the flow channel (14).

2. A suction arrangement (1) according to claim 1, characterized in that the collecting container (2) is a waste tank of a railway vehicle.

3. A suction device (1) according to claim 1, characterized in that the mixed fluid is faeces.

4. A suction device (1) according to one of the claims 1 to 3, characterized in that a third position of the narrowing body (10) is provided, in which third position the narrowing body (10) closes the flow channel (14).

5. A suction arrangement (1) as claimed in one of the claims 1 to 3, characterized in that the narrowing body (10) has a first recess (22) which, in a second position of the narrowing body (10), is fluidically connected to the mixed fluid inflow opening and the mixed fluid outflow opening.

6. A suction device (1) according to claim 5, characterized in that the first recess (22) is configured on the circumferential surface of the narrowing body (10).

7. A suction device (1) as claimed in one of the claims 1 to 3, characterized in that the narrowing body (10) is configured as a piston.

8. A suction device (1) according to claim 4, characterized in that the narrowing body (10) is configured as a piston; the narrowing body (10) is configured cylindrically and has an actuating mechanism (24) by means of which the narrowing body can be moved along or about its cylindrical axis between a first, a second and/or a third position by sliding and/or rotating.

9. A suction device (1) according to one of the claims 1 to 3, characterized in that an air inlet (18) into the flow channel (14) is provided, which can be opened or closed in order to selectively convey air into the flow channel (14).

10. The suction device (1) according to claim 9, characterized in that the air inlet opening (18) is configured as a second recess in the narrowing body (10) and is connected to an air channel (20) in the narrowing body (10) which can be opened or closed.

11. A suction device (1) according to claim 9, characterized in that a housing (12) is provided, which has a housing opening (13) which in the second position of the narrowing body (10) is in fluid-conducting connection with the air inlet (18).

12. A suction device (1) according to claim 9, characterized in that a closing body (60) for selectively opening or closing off the air inlet (18) is provided, which closing body can be moved back and forth between an open position and a closed position.

13. The suction device (1) according to claim 12, characterized in that the closing body (60) is fixed in position with respect to the housing (12) of the suction device (1).

14. A suction device (1) according to claim 12 or 13, characterized in that the closing body (60) is at least partly arranged in the third recess (62) of the narrowing body (10).

15. The suction device (1) according to claim 12 or 13, characterized in that the longitudinal axis of the closing body (60) is arranged substantially coaxially to the longitudinal axis (11) of the narrowing body (10).

16. The suction device (1) according to claim 13, characterized in that the closing body (60) is connected to the housing (12) via a holding element (68), and the holding element (68) together with a fourth recess (80) on the narrowing body (10) form a slotted guide for the narrowing body, so that the narrowing body (10) is also movable relative to the housing (12) and the closing body (60).

17. A suction device (1) according to claim 4, characterized in that the narrowing body (10) can be locked into the first position and/or the second position and/or the third position by means of a locking mechanism.

18. A suction station for drawing a mixed fluid from a collection container (2), having:

-a receiving container for mixing a fluid;

-a suction duct for delivering the mixed fluid to a receiving container;

a delivery unit for generating a negative pressure in the suction duct and delivering the mixed fluid through the suction duct into the receiving container; and

-a suction device (1) connected to a suction conduit for withdrawing the mixed fluid from the collection container (2),

characterized in that the suction device (1) is a suction device according to one of claims 1 to 17.

19. A suction station according to claim 18, characterized in that the collecting container (2) is a railway vehicle's excrement tank.

20. A suction station as claimed in claim 18, characterized in that the mixed fluid is excrement.

21. Method for drawing a mixed fluid from a collection container (2) by means of a suction device (1) according to one of claims 1 to 17, comprising the steps of:

-coupling the suction device (1) to the interface (6) of the collection container (2);

-withdrawing the mixed fluid from the collection container (2) by means of negative pressure;

-reducing the cross-section of the flow channel (14) by means of a narrowing (10) of the suction device (1);

-uncoupling the suction device (1).

22. The method according to claim 21, wherein the collecting container (2) is a waste tank of a railway vehicle.

23. The method of claim 21, wherein the mixed fluid is fecal matter.

24. The method according to claim 21, wherein the cross-section of the flow channel (14) is reduced partly or along the entire length of the flow channel by means of a narrowing body (10) of the suction device (1).

25. The method according to one of claims 21 to 24, comprising the steps of:

-closing the flow channel (14) by means of the narrowing body (10) before the step of uncoupling the suction device (1).

26. The method of claim 25, wherein the reduction in cross-section and/or the closing of the flow channel (14) comprises moving a narrowing body (10).

27. The method of claim 26, wherein said moving the narrowing body (10) comprises rotating and/or sliding the narrowing body (10).

28. The method of claim 27, wherein the reduction in cross-section comprises sliding the narrowing body (10) and the closing of the flow channel (14) comprises rotating the narrowing body (10).

29. The method according to one of claims 21 to 24, comprising the steps of:

-selectively delivering air into the flow channel (14) by opening and closing the air inlet (18).