A DEVICE FOR PREVENTING RATS AND THE LIKE ANIMALS FROM PENETRATING THROUGH A DRAINING OUTLET

Abstract: The device comprises two flaps (2) which are rotatably and mirror-symmetrically arranged relative to one another as well as preloaded by the gravity towards a closing position in such a manner that they can turn into an open position when water flows through the outlet. Each flap (2) is shaped as a sectional surface of a cylinder, said surface being substantially defined by a first plane (P1) perpendicular to the cylindrical axis, and a second inclined plane (P2) extending through a diameter and forming an acute angle ( alpha ) with the first plane. Each flap is arranged about an axis (A2) adjacent the dividing line between said planes, whereby the edges (4) coinciding with the inclined planes of said flaps (2) substantially abut one another in the closing position.

Description: Title: A device for preventing rats and the like animals from penetrating through a draining outlet. Technical Field The invention relates to a device to be arranged in a vertical section of a draining outlet so as to prevent rats and the like animals from penetrating through said draining outlet, where said device comprises two flaps which are rotatably and mirror-symmetrically arranged relative to one another as well as preloaded by the gravity towards a closing position in such a manner that they can turn into an open position when water flows through the outlet. Background Art EP 0 655 536 discloses a device for retaining rats or the like in a draining outlet. A pipe section is inserted in a vertically extending portion of the draining outlet, where a plurality of blocking bars form the outline of a funnel. Downwardly, the funnel is narrowed, and at the outlet of said funnel an opening is provided which is sufficiently small for preventing rats and the like from passing. The blocking bars extend through a plurality of openings in the wall of the pipe section and are rotatably arranged in an annular cavity surrounding said pipe section. The blocking bars are preloaded for instance by means of counterweights in such a manner that the funnel-shaped outline inside the pipe section is maintained as long as nothing but fluid flows through the draining outlet. When solid ingredients, such as faeces, paper etc. exceeding the size of the opening, follow the drainage water, the blocking bars are pressed outwards while suppressing the above preload. This device is encumbered with the draw-back that the draining outlet must be provided with said pipe section, which can present a problem to the room available. In addition the pipe section presents a large outer diameter due to the cavity, which presents a further problem to the room available. Another draw-back is found in the fact that said solid ingredients may stick to the openings in the wall of the pipe through which the block- ing bars extend, or said ingredients may accumulate in the annular cavity in which said blocking bars are positioned and preloaded. In both cases the latter may imply that the movability of the blocking bars is reduced or prevented completely, and in turn this may imply that the pipe section is completely or partially clogged up. Another possibility is that the blocking bars are stuck in a position in which rats or the like animals can pass the pipe section. Finally, the blocking bars arranged in the cross section of the pipe present an increased flow resistance. US 5,323,804 discloses a blocking device comprising two pivotally suspended flaps which keep the outlet closed by means of counterweights when no water passes. This device is encumbered with the draw-back that the inner cross section of the outlet has been considerably reduced with the effect that inter alia the flow resistance is substantially increased. Brief Description of the Invention The object of the invention is to provide a device of the above type which ensures an essentially free passage of water with or without solid ingredients without risking a clogging up, and which furthermore is simple and inexpensive to manufacture and mount. The device according to the invention is characterised in that each flap is shaped as a sectional surface of a cylinder, said surface being substantially defined by a first plane perpendicular to the cylindrical axis, and a second inclined plane extending through a diameter and forming an acute angle with said first plane, and that each flap is arranged about an axis adjacent the dividing line between said planes, whereby the edges coinciding with the inclined planes of said flaps substantially abut one another in the closing position. As a result a simple and inexpensive device is obtained where the risk of clogging up has been eliminated because together the flaps form a substantially circular opening in the open position of the device, said circular opening being of a diameter only insignificantly smaller than the inner cross section of the draining outlet with the effect that an essentially free passage is ensured. The device is especially suited for toilet outlets, but it can, of course, also be used in connection with other outlets, such as an outlet in the floor of a bathroom. According to a first preferred embodiment, the flaps are shaped as sections of a cylindrical surface of a substantially circular cross section. The resulting device is particularly suited for outlets of a circular cross section. According to a second embodiment, the flaps are arranged in an annular holder with a circumferential groove for receiving the edges of said flaps coinciding with said first plane. In this manner it is ensured that solid ingredients following the draining water are not retained by the edges of the flaps coinciding with the first perpendicular planes, which might prevent the movability of the flaps and cause a clogging up of the device. According to a further embodiment, the mutually abutting edges of the flaps coinciding with the inclined planes are provided with notches. As a result, small amounts of water can flow through the device in its closing position. According to yet another embodiment, the notches are shaped such that tooth-like projections are provided in the edge of the flaps. As a result, rats or the like animals trying to press themselves between the flaps keep off doing so due to the effect of the pointed teeth. Brief Description of the Drawing The invention is explained in greater detail below by means of embodiments illustrated on the drawings, in which Fig. 1 is a side view of a device according to the invention in the closing position, Fig. 2 is a side view of the device according to the invention in the open position, Fig. 3 is a vertical sectional view through a portion of the device, and where the positioning of a flap appears, Fig. 4 is a diagrammatic view of the device mounted in a lavatory sleeve, and Fig. 5 is a front view of a flap provided with notches. Best Mode for Carrying Out the Invention The blocking device 1 shown in Figs. 1 to 3 for preventing rats or the like animals from penetrating through a draining outlet comprises an annular holder 10 and two flaps 2, each flap being rotatably arranged about a horizontal axis A2. Each flap 2 is manufactured from a thin bent plate, and after the bending procedure each flap can be described as a section of a circular cylindrical surface. The latter surface is substantially defined by a first plane P1 perpendicular to the cylindrical axis A1 , and a second inclined plane P2 extending through a diameter and forming an acute angle a with the first plane P1 , cf. Fig. 2. The terminal edge of each flap 2 is defined by the first plane P1 and designated the general reference numeral 3, and the side edge is defined by the second plane P2 and designated the general reference numeral 4. Each flap 2 is provided with two openings 14 allowing said flap to be rotatably arranged about two journal pins 9. The journal pins 9 are permanently connected to the annular holder 10 and extend transverse to a circumferential groove 1 1 in the holder 10, cf. Fig. 3. The journal pins 9 are received in openings, such as by way of inter- ference fit, and these openings are shaped substantially diametrically opposite one another in the holder 10. The flaps 2 are of a triangular shape when seen in a direction parallel to the axis of rotation A2, cf. Figs. 1 and 2. The gravity has the effect that the device 1 is in the closing position shown in Fig. 1 as long as water does not flow through said device. In the closing position the flaps 2 abut one another along their side edges 4. When water flows through the outlet, the device 1 enters its open position, cf. Fig. 2. In this position, each flap 2 is turned so much outwards that they form a circular opening in axial direction. The latter circular opening is of a diameter only slightly smaller than the inner diameter of the draining outlet. The device 1 can, of course, enter all positions between the one shown in Fig. 1 and the one shown in Fig. 2 in response to the amount of passing water. The holder 1 0 is of a modest height whereby the device can be mounted in existing installations, if any, without requiring additional pipe sections or the like. Each flap 2 is, as mentioned, pivotally arranged by means of two journal pins 9, at least one of said journal pins appearing from Fig. 3. The terminal edges 3 of the flaps 2 are substantially arranged in the circumferential groove 1 1 of the holder 10, whereby solid ingredients, such as faeces, toilet paper etc. are not retained by said terminal edges, which might otherwise cause a clogging up of the device. The holder 10 comprises furthermore an inclined surface 1 2 extending obliquely upwards and outwards. The latter surface 1 2 is adapted to abut an inner surface of a lavatory sleeve 20 known per se, cf. Fig. 4. In Fig. 4 the device 1 shown in Figs. 1 to 3 is mounted in a lavatory sleeve 20. As illustrated, the device 1 according to the invention requires very little room and can be inserted from the top in the lavatory sleeve 20 usually made of soft PVC and therefore deformable. As mentioned, the device 1 takes up very little room in the lavatory sleeve 20, and accordingly it does not prevent the usual positioning of the spout 21 of a bowl in the lavatory sleeve 20, cf. Fig. 4. Fig. 5 illustrates a second embodiment of a flap 2 for a blocking device 1 according to the invention. The side edge 4 of the flap is provided with notches 30. These notches 30 are shaped such that a kind of pointed teeth 31 are provided along the edges of the flap, said pointed teeth 31 preventing rats or the like animals from trying to press themselves between the flaps 2 due to the effect of said pointed teeth 31 . The notches 30 have furthermore the effect that small amounts of water can pass through the device 1 without said device being opened. The flaps are preferably made of steel, especially acid-resisting stainless steel optionally coated with a material presenting a low friction coefficient, such as teflon. The holder 10 is preferably made of plastics, but it can also be made of metal. The invention is not limited to the embodiments shown in Fig. 1 to 5. The flaps may for instance be shaped such that in an open position they form a slightly oval opening or a quadrangular opening. The latter possibility is, of course, advantageous in connection with outlets of a quadrangular cross section. In general, the flaps should substantially be shaped such that in an open position they form an opening being substantially con ¬ gruent with and of the same size as the opening of the draining outlet.

Claims: Claims 1. A device to be arranged in a vertical section of a draining outlet so as to prevent rats and the like animals from penetrating through said draining outlet, where said device comprises two flaps (2) which are rotat- ably and mirror-symmetrically arranged relative to one another as well as preloaded by the gravity towards a closing position in such a manner that they can turn into an open position when water flows through the outlet, c h a ra c t e r i s e d in that each flap (2) is shaped as a sectional surface of a cylinder, said surface being substantially defined by a first plane (P1) perpendicular to the cylindrical axis, and a second inclined plane (P2) extending through a diameter and forming an acute angle (σ) with the first plane, and that each flap is arranged about an axis (A2> adjacent the dividing line between said planes, whereby the edges (4) coinciding with the inclined planes of said flaps (2) substantially abut one another in the closing position. 2. A device as claimed in claim 1, c h a ra cte r i s e d in that the flaps (2) are shaped as sections of a cylindrical surface of a substantially circular cross section. 3. A device as claimed in claim 1 or2, ch a racte ri s ed in that the flaps are arranged in an annular holder (14) with a circumferential groove (11) for receiving the edges (4) of said flaps (2) coinciding with said first plane (P1). 4. A device as claimed in claim 1 or 2, c h a ra ct e ri s ed in that the mutually abutting edges (4) of the flaps (2) coinciding with the inclined planes (P2) are provided with notches (30). 5. A device as claimed in claim 4, c h a ra cteri s ed in that the notches (30) are shaped such that the edge (4) comprises pointed tooth- like projections (31).

Inventors: HAMMERICH JOERN, HAMMERICH SOEREN, HAMMERICH, JOERN, HAMMERICH, SOEREN
Applicants: HAMMERICH JOERN, HAMMERICH SOEREN, HAMMERICH, JOERN, HAMMERICH, SOEREN
Application year: 1997
Main classification: E03F7
IPC codes: E03F7