A system for connecting valve units for gas water-heaters to tanks belonging to the water-heaters

Abstract: In the system described for connecting a valve unit for gas water-heaters to a tank of the water-heater, a probe belonging to the valve unit is housed in the tank in a leak tight manner. The system comprises a first element belonging to the valve unit and/or fixed thereto, a second element which projects from the tank and can be housed in a seat of the first element, the second element constituting a support and/or cover for the probe and having an outer surface in which there is a transverse groove, and a third element which is restrained axially on the first element and at least a portion of which extends in the seat in an arrangement such as to engage the groove when the second element is housed in the seat so as to clamp the first and second elements to one another axially, the third element being resiliently deformable between a first position in which the said portion projects into the seat and a second position in which the said portion is outside the seat in order to release the groove.

Description: The present invention relates to a system for connecting valve units for gas water-heaters to tanks belonging to the water-heaters. In the specific technical field of the present invention, there is a need to connect gas-valve units to tanks of the type generally used in water-heaters for domestic heating. Typically, in these applications, the tank has a hole into which a tubular body is screwed in a leak tight manner; a regulation probe, for example, a thermostatic bulb, extends through the tubular body and is supported thereby and housed inside the tank. Means are provided on the tubular body and on the valve unit for clamping the valve unit and the tank to one another axially. A connection system of the type indicated is known from United States patent No. 5,261,438. The system described therein provides for the valve unit to be clamped axially by means of a spring ring which is mounted externally on a shank projecting from the valve unit and which can engage an annular groove formed inside the tubular body screwed into the tank. The insertion of the shank into the tubular body from the front causes the resilient ring to be engaged in the groove, connecting the valve unit axially to the tank. One of the problems encountered in this system is that the coupling between the valve unit and the tubular body is irreversible and, once the valve unit is connected to the tank, it can be disconnected only by completely unscrewing the tubular body. This operation therefore renders maintenance operations on the apparatus with which the valve unit is associated rather complex. This system also involves a fairly complex structure as well as a valve unit which is fairly bulky axially, mainly because of the projecting shank provided for the mounting of the clamping spring ring. The technical problem upon which the present invention is based is that of providing a connection system for valve units for gas water-heaters which is designed structurally and functionally so as to prevent all of the problems complained of with reference to the prior art mentioned. This problem is solved by the invention by a connection system formed in accordance with the following claims. The characteristics and the advantages of the invention will become clearer from the detailed description of a preferred embodiment thereof, described by way of non-limiting example with reference to the appended drawings, in which: Figure 1 is a partially-sectioned, perspective view of a system according to the invention for connecting a valve unit to a tank, Figure 2 is a front elevational view of the valve unit of Figure 1 in a first operative position, Figure 3 is a view corresponding to that of Figure 2 with the valve unit in a second operative position, Figures 4 and 5 are partial sections showing the valve unit of the previous drawings from below and in side elevation, respectively. With reference to the drawings mentioned, a valve unit, generally indicated 1, is arranged for mounting on a tank 2, shown only partially, by a connection system formed in accordance with the present invention. The invention is intended for use particularly but not exclusively for connecting valve units for gas water-heaters tb tanks associated with the said water-heaters. The tank 2 has a through-hole 3 in the region of which an internally-threaded connector 4 is fixed to the outer surface of the tank. A regulation probe 5 connected to the valve unit by means of a connection cable 5a is housed in the tank, through the hole 3. The connection system comprises a first element and a second element, indicated 6 and 7, respectively. The first element comprises a plate-shaped element 6a fixed to the valve unit 1 and the second element comprises a tubular body 7a projecting from the tank. The plate-shaped element 6a preferably has a portion 6b for attachment to the valve unit by means of screws or similar fixing means. The tubular body 7a is screwed into the connector 4 in a leak tight manner and has an axial through-hole 8. The hole 8 defines, starting from the end which is screwed into the connector 4, first and second adjacent cylindrical portions, the second portion having a smaller diameter than the first, and a third, conical portion, the diameter of which increases towards the opposite end of the body 7a. A blind tubular element 9 extending coaxially with the body 7a has its open end fixed in a leak tight manner in the second portion and is closed at its opposite end by a base 9a. The tubular element 9 is preferably fixed to the body 7a by being glued to the corresponding cylindrical internal portion of the body 7a in a manner such as to ensure a fluid-tight seal. The tubular element 9 constitutes a support and/or cover for the probe 5. It will be noted that, by virtue of the fluid-tight seal ensured between the tubular element 9 and the body 7a, leakage of liquid from the tank 2 through the hole 3 is prevented and the probe 5 is housed inside the tank without direct contact with the liquid contained therein. The body 7a of the second element 7 has, at the opposite end to the portion which is screwed into the connector 4, a head 10 which can be housed in a seat 11 formed in the plate-shaped element 6a. The head 10 and the seat 11 have respective mating polygonal profiles so as to prevent relative rotation between the body 7a and the plate-shaped element 6a. The head 10 also has a transverse groove 12 in its outer surface. Moreover, the head has holes and/or slots, all indicated 13, through which capillaries for connecting the probe 5 to the valve unit 1 can extend. An end chamfer which is provided on the head 10 and the function of which will be explained in detail in the following description, is indicated 14. The connection system also comprises a third element which is restrained axially on the plate-shaped element 6a of the valve unit and which can engage the groove 12, as will be explained below. The third element comprises a clip 15 mounted for sliding on the plate-shaped element 6a. The clip is substantially U-shaped with two opposed arms 15a, 15b which can be opened out resiliently and are connected by a connecting region 15c constituting an operating appendage for the clip during its movement along an axis transverse the axis of the coupling of the valve unit to the tank. At least a portion of each arm 15a, 15b extends in the seat 11 in an arrangement such that, when the head is housed in the seat, the arms clasp two opposite sides of the head 10 between them and engage the groove 12, consequently clamping the body 7a and the plate-shaped element 6a to one another axially. The arms 15a, 15b are resiliently deformable between a first position in which the said portions project into the seat (Figure 2) and a second position in which the said portions are outside the seat in order to release the groove 12. The arms 15a, 15b are mounted for sliding on the plate-shaped element 6a by means of supports, preferably formed by bending of corresponding portions of the plate-shaped element, all indicated 16. The clip 15 is preferably made of harmonic steel wire. The free end of each arm 15a, 15b is bent to form a projection 17 which can interfere with a respective abutment 18 of the plate-shaped element 6a during the sliding of the clip so as to be opened out from the first position to the second as a result of a movement along the transverse axis. The connection system of the invention provides for the head 10 of the body 7a to be urged axially into the seat 11 of the valve unit, starting with the clip in the first position of (Figure 2). The insertion of the head causes the arms 15a, 15b of the clip to open out resiliently and subsequently to engage in the groove 12 with a snap coupling which restrains the body 7a axially relative to the plate-shaped element 6a. The opening-out of the clip is facilitated by the end chamfer 14 provided on the head 10. In order to disconnect the valve unit 1 from the tank, the clip 15 is moved transversely relative to the axial coupling axis, by means of the operating appendage 15c, until the clip 15 reaches the second position of Figure 3 in which the arms 15a, 15b are opened out resiliently by virtue of the interference of the projections 17 with the abutments 18 so as to release the groove 12 and allow the body 7a to be removed from the seat 11, consequently disconnecting the valve unit from the tank. The operating appendage 15c is housed inside a cover element 19 fixed to the valve unit by screws 19a. As a result, access to the appendage 15c in order to disconnect the valve unit from the tank is possible only after intentional removal of the cover 19, thus avoiding the danger of accidental and unintentional disconnection of the valve unit. The invention thus solves the problem set, achieving many advantages. Amongst these is the relative structural simplicity of the axial clamping means provided on the tubular body fixed to the tank and on the valve unit. Moreover, the connection system is releasable and enables the valve unit to be disconnected quickly and easily from the tank. Not the least important advantage is the axial compactness of the valve unit in comparison with known solutions.

Claims: A system for connecting a valve unit (1) for gas water-heaters to a tank (2) of the water-heater, in which a probe (5) belonging to the valve unit is housed in the tank in a leak tight manner, comprising: a first element (6) belonging to the valve unit (1) and/or fixed thereto, a second element (7) which projects from the tank (2) and constituting a support and/or a cover for the probe (5) and having an outer surface in which there is a transverse groove (12), a third element (15) which is restrained axially on the first element (6), characterized in that , the first element (6) comprises a seat (11) in which the second element (7) can be housed, and that, the third element (15) comprises at least a portion (15a, 15b) extending in the seat (11), in an arrangement such as to engage the groove (12) when the second element (7) is housed in the seat so as to clamp the first and second elements (6,7) to one another axially, the third element (15) being resiliently deformable between a first position in which said at least a portion (15a, 15b) projects into the seat (11) and a second position in which the said portion is outside the seat (11) in order to release the groove (12). A system according to Claim 1, in which the second element (7) has a tubular body (7a) having, at one of its ends, coupling means, for example threaded coupling means, for coupling with a connector (4) of the tank (2), and having at its opposite end, a head (10) which can be housed at least partially in the seat (11) and in which the groove (12) is formed. A system according to claim 1 or Claim 2, in which means are provided for preventing relative rotation between the first and second elements (6,7). A system according to Claim 3, in which the means for preventing relative rotation are provided between the head (10) and the seat (11). A system according to Claim 4, in which the means for preventing relative rotation comprise respective mating, for example, polygonal profiles. A system according to one or more of the preceding claims, in which the third element comprises a clip (15) which can clasp two opposite sides of the head (10) between its arms (15a, 15b). A system according to one or more of Claims 2 to 6, in which the head (10) has an end chamfer (14) for opening the clip (15) out during its insertion in the seat (11). A system according to Claim 6, in which the clip (15) is slidable along a transverse axis, with respect to the axial direction, opening-out means (17,18) being provided for opening the arms (15a, 15b) out from the first position to the second as a result of a movement of the clip (15) along the transverse axis. A system according to one or more of Claims 2 to 8, in which the head (10) has slots and/or holes (13) for the passage of the capillaries for connecting the probe (5) to the valve unit (1). A system according to one or more of the preceding claims, in which the second element (7) comprises a blind tubular element (9) for protecting the probe (5). A system according to Claim 6 or Claim 8, in which the arms (15a, 15b) of the clip (15) are connected at the opposite end to their free ends, the connecting region (15c) constituting an operating appendage for the movement of the clip (15) from the first to the second position. A system according to Claims 1 and 6, in which the first element (6) comprises a plate-shaped element (6a) fixed to the valve unit (1), the plate-shaped element (6a) having support means for the slidable mounting of the clip (15). A system according to one of more of Claims 6, 8 and 11, in which the clip (15) is made of harmonic steel wire. A system according to Claim 11 in which the operating appendage of the clip (15) is housed in a cover element (19) fixed to the valve unit (1) so as to allow the first and second elements (6,7) to be disconnected only after intentional removal of the cover (19).

Inventors: SARDENA ANTONIO, TONIOLO ALESSANDRO, VERONESE GIUSEPPE, SARDENA, ANTONIO, TONIOLO, ALESSANDRO, VERONESE, GIUSEPPE
Applicants: SIT LA PRECISA SPA, SIT LA PRECISA S.P.A.
Application year: 1999
Main classification: F24H9
IPC codes: F24H9, F23N5, F23N1