DOSING DEVICE FOR LIQUIDS

Abstract: According to the invention a plastic dosing device for liquids is realized, suited to be applied to the output hole of a container, consisting of only three parts, namely an upper element (10) to which a cap (19) is connected for closing the device, an intermediate element (20) which cooperates with the upper element and which connects the device to the neck (41) of the container, and a sliding dosing element (30) which allows the preselected dose collected inside to be discharged outside. The predosing chamber (50) and the output duct (13) are defined by the upper element (10), which realizes an annular space which is comprised between two essentially cylindrical surfaces and which cooperates with the intermediate element (20) connected to said upper element. The dosing element (30) ends with a frustum-shaped rim (32) which widens towards the predosing chamber and which presents an annular hollow (34) which closes the shaped rim (18) of the output duct (16) when the container is turned upside down.

Description: DOSING DEVICE FOR LIQUIDS The invention concerns a dosing device for liquids suited to be applied to the output hole of containers and to be used for the dosing of liquids, mostly for domestic usage like detergents, oils and chemical products to be used in predeterminate amounts. The need for the chemical industry to produce containers equipped with dosing devices is due to the necessity to optimize the performances of the product contained therein and also to avoid a misuse of the product which, on the one hand, could lead to worse results than those obtainable with a controlled dose, and on the other hand could lead to ecological problems due to environmental pollution. For these reasons dosing devices for liquids are a more and more frequent industrial choice. Dosing devices are known consisting of outlets provided with channels inside which a sphere slides, immersed in the liquid to be dosed and running along a predeterminate distance. When the container is turned upside down from the upright position to the liquid output position, the liquid keeps outflowing as long as the sphere moves toward the output hole until the sphere closes it. The main disadvant- age arising from such devices is that the stroke of the spheres depends on the density of the liquid in which the spheres are immersed, thus the weight of said spheres must be changed according to the density of the liquid to be poured out. Therefore, it is necessary either to change the material the spheres are made of, or to change the size of the spheres, with the obvious disadvantages arising from the realization of dosing devices of different sizes. Further, it must be noted that these types of dosing de- vices are not very precise, because the speed of the sphere in the closing phase depends also on the liquid head which overhangs it, and therefore, as the container is dis- charged, the amount of liquid which is delivered by the dosing device varies itself. The international patent application PCT/EP90/02106 filed by the same inventor concerns a dosing device comprising an essentially tubular external body, a sliding dosing element inserted in the external body, a co-axial output duct placed inside the external body and a predosing chamber for the liquid placed between the internal surface of the external body and the external surface of the output duct. After the preselected dose has reached the sliding dosing element, the reversal of the container from the upright position to the overturned position makes the dosing ele- ment to slide toward the outside, so as to close the commu- nication between the inside of the container and the output duct, while the liquid contained in the dosing element is ejected outside and the liquid contained in the container enters the predosing chamber. This device overcomes the above mentioned disadvantages, but it presents some difficulty in the construction, be- cause to the three above mentioned elements, i.e. the internal body, the external body, and the sliding dosing element r a connection element is necessarily required between the external body and the neck of the container, which comprises the cap too. Basically, the dosing device of the above mentioned invention consists of four parts separately moulded and then assembled. The constant need to reduce the production costs, by ain- taining the same quality, has induced the inventor to realize a dosing device for liquids, the main purpose of which is to maintain the dosing precision already known in the patent application PCT/EP/9002106 and, at the same time, to simplify the construction by realizing a dosing device equipped with a cap consisting of only three parts rather than four, thus leading to advantageous savings in materials and assembly time. Another goal of the invention is that the dosing device can operate correctly without there being the necessity for the container to be turned upside down in a completely vertical position each time. Also, there is the need that a perfect closing is realized when the sliding dosing element reaches the fixed part of the dosing device, so as to avoid that the predosed liquid can mix with the liquid present in the container, altering the dosage. All the above mentioned goals and others which will be better understood hereafter are reached by realizing a dosing device for liquids, made of plastic material, suited to be applied on the exit hole of a container which, ac- cording to the first claim comprises: - a predosing chamber for the liquid in the container circumscribed by at least two annular walls; - a dosing element sliding with respect to the fixed wall of said device, which collects the selected dose when the container is in the upright position and delivers * said dose when the container is turned upside down; -an essentially cylindrical output duct, co-axial with the predosing chamber and with the dosing element; - a cap which closes said output duct, and is characterized in that the predosing chamber and the output duct are defined by an upper element realizing an annular space comprised between two essentially cylindrical surfaces and superiorly ending with a centrally drilled frustum-shaped part, cooperating with an intermediate element connected to said upper element, said upper element being moulded in only one part and comprising also the cap which closes the output duct, the intermediate element presenting means for the connection to the output hole of the container and below ending with a series of longitudi- nal wings which guide the dosing element. The advantage of the dosing device of the invention is obvious, because it consists of only three parts, namely an upper element to which a cap is connected for closing the device, an intermediate element co-operating with the upper element and connecting the device to the neck of the con- tainer, and a sliding dosing element which discharges outside the preselected dose contained inside. Further characteristics and details will be better under- stood from the description of a preferred form of execution of the invention, which is only given by way of illustra- tion, but is not meant to limit the scope of the invention, such as it is illustrated in the alleged tables of draw- ings, wherein: - fig. 1 presents an axionometric view of the upper element connected to the cap of said device; - fig. 2 shows an axionometric view of the sliding dosing element; - fig. 3 shows an axionometric view of the intermediate element which co-operates with the upper element and guides the sliding dosing element; - fig. 4 shows a section of the first charge of the dosing element, that is the transfer of the first dose of liquid from the inside of the container to the predosing chamber; - fig. 5 shows a section of the dosing device in its up- right position, during the pouring of the selected dose from the predosing chamber to the sliding dosing element; - fig. 6 represents in section the output phase of the selected dose exiting from the sliding dosing element and a selection of the dose passing from the inside of the con- tainer to the predosing chamber; - fig. 7 shows a section according to the line VII-VII in fig. 6. By referring to the above mentioned drawings, and as can be observed in Figg. 1, 2, 3, the device of the invention is essentially made of only three parts, i.e. the upper part, indicated with 10 in fig. 1, the intermediate element, indicated with 20 and represented in fig. 3, and the sli- ding dosing element, indicated with 30 and represented in fig. 2. More in detail, the upper element, indicated as a whole with 10, consists of a cylindrical external wall 11 and an upper frustum-shaped wall 12, presenting in its center a hole 13 defined by a cylindrical wall 16. The plane part 14 which connects the cylindrical vertical wall 11 and the frustum-shaped wall 12 has an inner width suited to contain the thickness of the rim 21 of the intermediate element 20. The connection between the upper element 10 and the inter- mediate element 20 is obtained by means of a projecting part 15 which engages on a correspondent annular groove 22 that is well visible in fig. 3. In this way the coupling between the upper element 10 and the intermediate element 20 is realized. The intermediate element 20 presents superiorly the cylin- drical wall 23, and below a tapered cylindrical wall, having a smaller diameter, indicated with 24, which guides the intermediate element inside the hole of the container 41. Coaxial with the wall 24 and more externally to it there is another cylindrical wall 241, presenting an annu- lar projecting part 242 which inserts in a correspondent hollow made on the neck of the container 41 and which guarantees the seal between the intermediate element 20 and the container 41. Said intermediate element 20 can be assured to the neck of the container also by means of a thread, or by gluing a wall of the intermediate element with a suitable wall of the container in proximity of the hole. Inside the wall 24 the wings 25 are arranged equally spaced, having a lengthened downward longitudinal shape. Said wings present an essentially smooth and bent wall so that they make the dosing element 30 to slide guided and free in its inside. Since the longitudinal wings 25 are placed between the cylindrical wall 24 belonging to the intermediate element 20 and the cylindrical external wall 31 of the sliding dosing element 30, an interspace is created, i.e. the passage ports 27 which make the inside 40 of the container 41 to communicate with the predosing chamber 50 limited by the connection between the upper element 10 and the inter- mediate element 20. More precisely, said predosing chamber 50 is limited centrally by the cylindrical wall 16, by the upper rim 17, by the conical wall 12, by the cylindrical external part 23 and by a conical-surfaced joint 23a be- longing to the intermediate element. As can be seen in fig. 4, when the sliding dosing element 30 rests on the rim 18 of the cylindrical element 16, the chamber 50 has its upper part open. After the container is turned in its upright position, as shown in fig. 5, the sliding dosing element 30 moves downward and rests on the sloping wall 26 belonging to the wings 25 so that the conical-rim 32 of said sliding dosing element closes the passage ports 27 allowing the predosed liquid in the chamber 50 to flow inside the space 33 which constitutes the collection space for the liquid in the sliding dosing element 30. A further reversal of the container 41, as can be observed in fig. 6, allows the chamber 50 to be recharged with the liquid 40 , and allows the liquid contained in the chamber 33 of the sliding dosing element 30 to flow outward through the output duct 13. In order to avoid the mixing of the predosed liquid collec- ted in the chamber 33 with the liquid coming from the inside of the container 40 and flowing toward the dosing chamber 50, the sliding dosing element 30 is provided with an annular groove 34, realized in correspondence of the variation between the cylindrical surface 31 and the con- ical surface 32, said hollow receiving the shaped rim 18 of the wall of the output duct 16 belonging to the upper element 10. In this way a perfect seal can be obtained between the sliding dosing element and the output duct, so avoiding the mixing between the preselected liquid and the liquid to be preselected. The upper element is also provided with a cap 19 made of plastic material and moulded together with the upper ele- ment itself and which closes the hole 13 when the container 41 does not deliver the liquid. So, all the purposes of the invention are reached, i.e. the realization of a very simple dosing device for liquids which consists of only three parts to be assembled. Also a dosing device accurate with respect to the dosed amount is obtained, because the sliding dosing element slides on shorter but precise guides, so that jams are avoided; in this way it opens and closes the predosing' chamber 50 which connects the output duct and it is avoided that the duct touches the other liquid to be predosed. However, to the device of the invention could be applied variations and modifications in the construction phase. It is understood, however, that all said variations and mod- ifications do not exceed the scope of the present inven- tion, as specified in the following claims.

Claims: CLAIMS 1) dosing device for liquids, made of plastic mater- ial suited to be applied to the output hole of a container comprising: - a predosing chamber (50) for the liquid of the container, circumscribed by annular walls; - a dosing element (30) sliding with respect to the fixed part of said device, which collects the selected dose when the container (41) is in the upright position and delivers said dose when the container is turned upside down; - an essentially cylindrical output duct (13) co-axial with the predosing chamber and with the dosing element; - a cap (19) which closes said output duct, characterized in that the predosing chamber (50) and the output duct (13) are defined by an upper element (10) which forms an annular space comprised between two essentially cylindrical surfaces (11), ending superiorly with a frus- tum-shaped wall (12) drilled in its central part, co-opera- ting with an intermediate element (20) connected to said upper element, said upper element (10) being moulded in only one part together with the cap (19) which closes the output duct, said intermediate element (20) presenting means for the connection with the hole of the container, and below with a series of longitudinal wings (25) which guide the sliding dosing element (30) during its sliding. 2) An output device according to claim 1), character- ized in that the liquid predosing chamber (50) consists of a cylindrical inner wall (16), the upper rim (17), a slop- ing more external wall (12) converging toward the upper rim, all said walls belonging to the upper element (10), the most external wall of said chamber being formed also by a portion of the cylindrical wall (23) and of the conical wall (23a) converging toward the dosing element, said walls belonging to the intermediate element. 3) An output device according to claim 1), character- ized in that the connection between the upper element (10) and the intermediate element (20) is realized by means of the annular projection (15) present on the lower rim of said upper element, said projection being lodged on a correspondent annular groove (22) of the cylindrical sur- face (23) of the intermediate element (20) projecting from the container, or vice-versa. 4) An output device according to claim 1), character- ized in that the longitudinal wings (25) of the intermedi- ate element (20) form, together with the external wall of the dosing element (30) and the wall (24) of the intermedi- ate element which is connected to the hole of the contai- ner, an interspace with passage ports (27) through which the liquid passes from the container to the predosing chamber. 5) An output device according to claim l), character- ized in that the dosing element (30) presents superiorly a frustum-shaped rim (32) which widens toward the predosing chamber where, in correspondence of the variation between the cylindrical surface (31) and the frustum-shaped surface (32) of said dosing element, an annular hollow (34) is present in which the correspondent shaped rim (18) belong- ing to the terminal part of the output duct (16) is housed when the container is turned upside down and the device delivers the liquid. 6) An output device according to claim 5), character- ized in that the annular hollow (34) of the dosing element (30) and the correspondent rim (18) of the output duct (16) have an essentially triangular-shaped profile. 7) A dosing device according to claim 1), character- ized in that the stable connection between said device and the neck of the container (41) to which said device is fixed is obtained by means of an annular projection (242), of the cylindrical wall (241) of the intermediate element, which is inserted in a correspondent hollow made on the neck of the container. 8) A dosing device according to claim 1) , character- ized in that the connection between said device and the neck of the container (41) to which said device is fixed is obtained by means of a thread. 9) A dosing device according to claim 1), character- ized in that the connection between said device and the neck of the container (41) to which said device is fixed, is obtained by gluing a wall of the intermediate element (20) with a suitable wall of the container (41) in proxim- ity of the hole.

Inventors: SANTAGIULIANA EVANS, SANTAGIULIANA, EVANS
Applicants: SANTAGIULIANA EVANS, TAPLAST SRL, SANTAGIULIANA, EVANS
Application year: 1992
Main classification: G01F11
IPC codes: G01F11