BACKGROUND OF THE INVENTION

The present invention relates to a hydraulic connecting unit, intended in particular to be applied to cooling and heating plants.

PRIOR ART

Hydraulic units to be applied to cooling and heating plants are known that provide a thermal generator of heat-conveying fluid, a supply network supplying the heat- conveying fluid, and a series of terminal units, for example fan coil units, that uses the heat-conveying fluid.

The hydraulic unit connects the supply network to a terminal unit and performs several functions, including connecting function, bypassing function, filtering function and fluid intercepting functions of different types for intercepting the fluid to perform maintenance, cleaning and washing.

Normally, known hydraulic units each consist of different separate shut-off valves and of a filter that are sealingly assembled together.

This requires different connections to be made during assembly and thus increases production costs.

Further, such connections are sealed and thus require the use of sealing gluing or sealing rings. In view of the necessary number of seal connections, the risk of leaks and loss of water through the seals during use of the hydraulic unit is high.

It must be added that known valve units are bulky and thus require a certain space to be installed and to allow the manual operation of the various valves. OBJECT OF THE INVENTION

The object of the present invention is to propose a hydraulic connecting unit that is able to overcome the drawbacks indicated above.

BRIEF DESCRIPTION OF THE INVENTION

This object is achieved by a hydraulic connecting unit in accordance with claim 1. BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention, a description is given below of a non- limiting exemplary embodiment thereof, illustrated in the attached drawings, in which:

fig. l is a perspective view of a hydraulic connecting unit according to the invention;

fig.2 is a plan view of the hydraulic unit of fig. 1;

fig.3 is a view according to arrow ΠΙ of the hydraulic unit of fig. 1;

fig.4 is a view according to arrow Γ of the hydraulic unit of fig. 1;

fig.5 is an exploded perspective view of the hydraulic unit of fig. 1;

figs 6-12 show seven types of functions of the hydraulic unit of fig. 1, combining for each figure a plan section of the hydraulic unit and a section of the hydraulic unit along a plane X-X perpendicular to the plane of the plan section;

fig.13 shows in a perspective view a different version of a component of the hydraulic unit of fig. 1.

DETAILED DESCRIPTION OF THE INVENTION

The hydraulic connecting unit illustrated is generally indicated by 10.

For the detailed description of the hydraulic unit 10, reference is made particularly to fig. 5. The hydraulic unit 10 provides a one piece body 11 in which two through cylindrical seats 12 and 13 are obtained that are crossed at 90°, one through cylindrical seat 14, and (fig.5) a bypass conduit 15 that connects the crossed seats 12 and 13 to the seat 14. The axis of the seat 12 and the axis of the conduit 15 are parallel, and the axes of the seats 13 and 14 are parallel to one another and perpendicular to the axes of the seat 12 and of the conduit 15; further, all the aforesaid axes lie on the same plane.

Into the seat 12 a hollow ball shutter 16 is inserted that has two coaxial opposite holes 17 (only one of which is visible in fig.5), one hole 17' (clearly visible in fig.13) with an axis that is perpendicular to the axis of the holes 17 and parallel to the conduit 15, and a further hole 18, of smaller diameter, with axis tilted with respect to the axis of the holes 17 and 17' and directed towards the centre of the ball shutter 16; this shutter 16 is provided with a hollow stem 19 to which annular seal washers 20 are fitted. The shutter 16, with the stem 19 thereof, is held in the seat 12 by a ring nut 21 that screws tight in the seat 12 of the body 11. Onto the ring nut 21 an indicator ring 22 is fitted that couples with the body 11 in a predetermined position. Into the ring 22 a handle 23 is inserted, provided with one through axial hole 24, that is connected in rotation by shape coupling with the stem 19 of the shutter 16. A filter 25 is lastly provided consisting of a hollow cylindrical body 26 with a nut head 27; the cylindrical body 26 has on one side a wall formed by a filtering mesh 28 and on the opposite side an opening 29; the head 27 provides one through hole 30 that makes the inside of the body 26 communicate with the outside and which is sealingly closed by a removable cap 31 that is screwed into the hole 30. The filter 25 is sealingly inserted into the hole 24 of the handle 23, in the ring 22, into the ring nut 21, into the stem 19, and into the ball shutter 16, and is screw coupled with the stem 19; when the filter 25 is inserted into and fixed in the shutter 16 the mesh 28 and the opposite opening 29 are located at the holes 17.

On opposite openings of the cylindrical seat 13 two respective ring nuts 32 and 33 are screwed with the interposition of two respective sealing rings 34 and 35. The two ring nuts 32 and 33 constitute connecting ports of the hydraulic unit 10, whereas the two sealing rings 34 and 35 are part of the seats for the ball shutter 16. Into the seat 14 a further hollow ball shutter 36 is inserted that has two coaxial opposite holes 37 (only one of which is visible in fig.5) and a groove 38 that runs along the outer surface of the shutter 36 for a circumferal portion. The shutter 36 is connected to an outer handle 39 through a control rod 40 by a fixing screw 41. An indicator ring 42 is interposed between the handle 39 and the body 11.

On opposite openings of the cylindrical seat 14 two respective ring nuts 43 and 44 are tightened with the interposition of two respective sealing rings 45 and 46. The two ring nuts 43 and 44 constitute further connecting ports of the hydraulic unit 10, whereas the two sealing rings 45 and 46 are part of the seats for the ball shutter 36.

The rotation axes of the two shutters 16 and 36 are parallel and thus the components 16, 21-23, 26, 31 and 39-42 are arranged along the same two parallel axes coinciding with the rotation axes of the shutters 16 and 36.

The ball shutter 16 can be rotated to three positions by the handle 23. In a first position, the axis of the holes 17 of the ball shutter 16 is aligned with the axis of the cylindrical seat 13, placing the connecting port 32 in communication with the connecting port 33. In a second position, by rotating the handle 23 by 90° in one direction, the axis of the holes 17 of the ball shutter 16 is perpendicular to the axis of the cylindrical seat 13, closing the communication between the connecting port 32 and the connecting port 33, whereas the hole 18 of the ball shutter 16 faces the connecting port 32, placing the latter in communication with the inside of the ball shutter 16. In a third position, by rotating the handle 23 by 90° from the first position in a direction opposite the previous direction, the axis of the holes 17 of the ball shutter 16 is always perpendicular to the axis of the cylindrical seat 13, closing the communication between the connecting port 32 and the connecting port 33, whereas the hole 18 of the ball shutter 16 faces the connecting port 33, placing the latter in communication with the inside of the ball shutter 16. These three positions are identified by suitable marks on the ring 22.

The ball shutter 36 can likewise be rotated to three positions by the handle 39. In a first position, the axis of the holes 37 of the ball shutter 36 is aligned with the axis of the cylindrical seat 14, placing the connecting port 43 in communication with the connecting port 44. In a second position, by rotating the handle 39 by 90° in one direction, the axis of the holes 37 of the ball shutter 36 is perpendicular to the axis of the cylindrical seat 14, closing the communication between the connecting port 43 and the connecting port 44, whereas the groove 38 of the ball shutter 36 is arranged so as to place the port 44 in communication with the conduit 15. In a third position, by rotating the handle 39 by 90° from the first position in a direction opposite the previous direction, the axis of the holes 37 of the ball shutter 36 is always perpendicular to the axis of the cylindrical seat 14, closing the communication between the connecting port 43 and the connecting port 44, whereas the groove 38 of the ball shutter 36 is arranged so as to place the port 43 in communication with the conduit 15. These three positions are identified by suitable marks on the ring 42.

The hydraulic unit 10 is intended to be applied to a cooling and heating plant that provides a thermal generator of heat-conveying fluid, a supply network supplying the heat-conveying fluid, and a series of terminal units, for example fan coil units, which use the heat-conveying fluid. Figs 6- 12 show seven operating conditions of the hydraulic unit 10, according to the position of the handles 23 and 39. With a block A, the supply network is indicated and with a block B a terminal unit is indicated. The hydraulic unit 10 connects the supply network A to the terminal unit B.

Fig. 6 shows the normal operating condition of the hydraulic unit 10. The handles 23 and 39 are in the first position. The heat-conveying fluid coming from the supply network A enters the connecting unit 10 through the connecting port 32, passes through the ball shutter 16, where it is filtered by the mesh 28, and exits the connecting port 33 to reach the terminal unit B. The fluid exiting the terminal unit B enters the connecting unit 10 through the connecting port 43, through the ball shutter 36, and exits the connecting port 44 to return to the supply network A. In this normal operating condition, the bypass conduit 15 is shut, preventing entering and exiting flows from mixing.

Fig. 7 shows the bypass condition of the hydraulic unit 10. The handles 23 and 39 are in the second position. The heat-conveying fluid coming from the supply network A enters the connecting unit 10 through the connecting port 32, enters the ball shutter 16 through the hole 18, passes through the bypass conduit 15, goes through the passage 38 of the ball shutter 36 and exits the connecting port 44 to return to the supply network A. In this manner, the terminal unit B is excluded from the operation of the plant.

Fig. 8 shows the condition of total shut-off and filter maintenance. The handles 23 and 39 are in the third position. The ball shutters 16 and 36 are in the closed position and thus the connections between the supply network A and terminal unit B are interrupted. In this condition, it is possible to proceed to clean the filter 25 by detaching the filter 25 by unscrewing from the stem 19 and extracting the filter 25 from the body 11.

Fig. 9 shows a first direct washing condition of the terminal unit B. The handles 23 and 39 are in the first position. The fluid coming from the supply network A enters the connecting unit 10 through the connecting port 32, passes through the ball shutter 16 where it is filtered by the mesh 28, exits the connecting port 33 and reaches the terminal unit B for washing. The fluid exiting the terminal unit B is evacuated by a drain cock C arranged before the connecting port 43. In this first washing condition the bypass conduit 15 is closed.

Fig. 10 shows a second direct washing condition of the terminal unit B. The handle 23 is in the third position, whereas the handle 39 is in the second position. The fluid coming from the supply network A enters the connecting unit 10 through the connecting port 44, passes through the passage 38 of the shutter 36 and the bypass conduit 15, enters the shutter 16, exits the hole 18 of the shutter 16 in the direction of the connecting port 33, and then reaches the terminal unit B for washing. The fluid exiting the terminal unit B is evacuated by the drain cock C. In this second washing condition, the delivery branch through the connecting port 32 and the connecting port 33 is closed.

Fig. 11 shows a first counterflow washing condition of the terminal unit B. The handle 23 is in the third position, whereas the handle 39 is the first position. Further, the cap 31 is removed from the head 27 of the filter 25. The fluid coming from the supply network A enters the connecting unit 10 through the connecting port 44, passes through the ball shutter 36 and exits the connecting port 43 to reach the terminal unit B. The fluid flows in counter current through the terminal unit B for washing, re-enters the terminal unit 10 through the connecting port 33, enters the shutter 16 through the hole 18 and is evacuated outside through the body 26 of the filter 25. In this counterflow washing condition, the bypass conduit 15 and the delivery branch through the connecting port 32 and the connecting port 33 are closed. Fig. 12 shows a second counterflow washing condition of the terminal unit B. The handle 23 is in the second position, whereas the handle 39 is in the third position. The fluid coming from the supply network A enters the connecting unit 10 through the connecting port 32, enters the ball shutter 16 through the hole 18, passes through the bypass conduit 15, goes through the passage 38 of the ball shutter 36, exits the connecting port 43 and reaches the terminal unit B. The fluid flows in counter current through the terminal unit B for washing and exits the terminal unit B, where it is evacuated through a drain cock D arranged before the connecting port 33. In this condition, the branch returning to the supply network through the connecting port 43 and the connecting port 44 is closed.

With reference to fig. 13, in the shutter 16, instead of a single hole 18, two paired holes 18A and 18B can be provided, each with an axis tilted with respect to the axis of the holes 17 and 17' and directed towards the centre of the ball shutter 16. The hydraulic unit 10 has remarkable advantages.

First of all, the hydraulic unit 10 is made of a one piece body and accordingly during assembly there is no need to connect together separate valves to make the hydraulic unit: this simplifies assembly and lowers production costs.

As the different valves do not have to be connected together, seal connections are avoided and thus there is no risk of leaks and loss of fluid through the seals during use of the hydraulic unit. Lastly, the hydraulic unit 10, owing to the coplanar one piece configuration that incorporates valve and filter elements, is compact and thus requires little space for installation.

It is clear that variations on and/or additions to what has been disclosed and illustrated above can be provided.

In particular, the configuration and the number of the various components of the valve unit can vary according to need.