System of polygonal coupling between the body of a butterfly valve and the support of the control spindle

Abstract: The invention relates to the support (2) of the control spindle (5) of a butterfly valve (4), which is produced in such a way that its outer surface has a polygonal configuration with a slight taper; the purpose being to prevent slippage of the support in the valve body (1',1'') and the build-up of deposited matter.

Description: The invention relates to the support of the control spindle of a butterfly valve, which support is held nonrotatably in the two half-bodies of the valve when the latter are brought together and joined rigidly upon completion of the assembly of the said valve. In butterfly valves at present, the support for the control spindle is of circular section, and the corresponding hole in the valve body is of course also circular. The rigidity of this coupling is ensured by pins mounted in the valve body and introduced into special housings formed in the support, or vice versa. These pins not only prevent the support from slipping inside the valve body when the shutter is being opened and closed, but also ensure that there can be no outward axial displacement of the support. There are both technical and hygiene problems with this approach because the action of the twisting moment due to friction of the spindle on the support when the shutter is being operated is absorbed by the pins only, and these can give. Also, the cavities recessed into the support to take the pins are traps for possible deposits which are difficult to completely remove when cleaning the apparatus. The object of the present invention is to eliminate these problems. The invention, as characterized by the claims, solves the difficulty by greatly increasing the lines of opposition to the twisting moment and having no deep housings so that there is almost no possibility of matter being deposited, and what there is can easily be removed when cleaning the valve. All this is made possible by the fact that the outer surface of the support has a polygonal configuration, as has the housing formed in the two half-bodies of the valve. Patents EP 0 105 218A which should be considered as the closest state of the art describes a coupling between the body of a butterfly valve and the support of the relating control spindle which corresponds to the preamble of claim 1 wherein some parts are designed so as to obtain the same results pursued by the present invention, but the shape of many components and their disposition, as it will be explained, are different, and do not allow to reach the same advantages. The invention is described in greater detail below with the help of the drawings, which show an example of an embodiment thereof. Fig. 1 shows a view of the valve with the body (1), the support (2) for the control spindle, the flange (3) and the shutter (4) in evidence. Fig. 2 shows a section through the valve with the two half-bodies (1') and (1''), the support (2), the flange (3), the shutter (4) and the control spindle (5) in evidence. The two half-bodies are held together by, for example, the screws (6). Fig. 3 shows a section through the hexagonal-profile support (2), and an external view of the flange (3), with the holes (3') for attachment to an actuator and the holes (3'') for attachment to a lever for hand operation in evidence. A hexagonal profile is proposed for the support (2) because that is the most likely, but it is perfectly possible for the profile of the support to be triangular or quadrangular, or polygonal in general. Figure 4 depicts a cross section through the valve before assembly, in an enlarged representation compared with that shown in Fig. 2, illustrating not only the already known parts but also the housings (1a) and (1b) in the two half-bodies (1') and (1''), and the taper of the support (2) and of the housings. Operation is obvious because the polygonal configuration of the outer surface of the support (2) prevents any possibility of its slipping inside the valve body; and the taper of the surfaces prevents any possibility of the support (2) coming out. Finally, the absence of cavities prevents the build-up of deposits of matter and makes it easier to clean the support (2) and its housing in the valve body.

Claims: System comprising a polygonal coupling between the body of a butterfly valve (4) and the support (2) of the control spindle (5) which is held nonrotatably in the two half-bodies (1', 1") of the valve when the latter are brought together and joined rigidly upon completion of the assembly of the said valve, the outer surface of the support (2) of the control spindle (5) and the parts of the two half-bodies (1', 1") which hold the support having a polygonal configuration, characterized in that the said support (2) assumes the configuration of a frustum of a polygonal pyramid because of the taper of its lateral surfaces. System according to Claim 1, characterized, in that when the two half-bodies (1', 1") of the valve are assembled, they that it assume the configuration of a frustum of a polygonal pyramid.

Inventors: LARDIERI SALVATORE, LARDIERI, SALVATORE
Applicants: LARDIERI SALVATORE, LARDIERI, SALVATORE
Application year: 2001
Main classification: F16K27
IPC codes: F16K27