EP1517100A1

EP1517100A1 - Adjustable diffuser for air conditioning plants

Info

Publication number: EP1517100A1
Application number: EP04102918A
Authority: EP
Inventors: Ennio Malaspina
Original assignee: Tecnoelettra Srl
Current assignee: Tecnoelettra Srl
Priority date: 2003-09-12
Filing date: 2004-06-23
Publication date: 2005-03-23
Also published as: ITMI20031753A1

Abstract

An adjustable diffuser for air-conditioning plants comprises at least one fixed portion (2) and at least one movable portion (4) adapted to define at least one duct (6) between them for passage of the conditioned air, and at least one actuator (8) active on the movable portion (4) to carry out displacement of said movable portion. The actuator (8) comprises at least one spring (9) made of a shape-memory material and adapted to become longer reaching an extended position or get contracted to a shorted position, depending on the temperature of the air flow.

Description

The present invention relates to an adjustable diffuser for air conditioning plants.
It is known that diffusers for air conditioning plants, in particular circular diffusers installed in false-ceiling structures, generally contemplate the possibility of at least partly modifying orientation of the air flow emitted by them so as to optimise air circulation in the surrounding environment.
Practically, in summer the air flow from the air conditioning plant which normally has a temperature lower than about 17°C is mainly conveyed by the diffusers in a direction substantially parallel to the ceiling so that said air can then descend, because it has a greater density than the air of higher temperature already present in the environment.
On the contrary, in winter the conditioned-air flow that has a higher temperature than in summer, i.e. of about 23°C for example, is conveyed mainly downwards by the diffusers so that it can subsequently rise, due to the density difference with respect to the surrounding atmosphere, and thus create a suitable circulation of hot air from bottom to top.
To create the above-mentioned two different orientations of the conditioned-air flow, the circular diffusers for ceilings generally have, inside a fixed portion substantially of truncated conical form, at least one pair of movable portions also of substantially frustoconical conformation and disposed inside each other so that altogether they form an outer annular duct of conical shape and a more inward annular duct of conical shape as well.
The movable portions of truncated conical form, known in the art as "adjustable cones" are shiftable relative to the fixed portion or outer cone, so that the conformation of the outer cone and consequently the orientation of the air flow emitted therefrom, can be varied.
In particular, if the adjustable cones are shiftable downwards, i.e. they are caused to slightly project relative to the contour of the fixed portion, the air flow passing through the outermost annular duct is conveyed almost horizontally.
On the contrary, if the adjustable cones are moved upwards so as to remain slightly recessed relative to the fixed-portion contour, the air flow emitted by the outer duct is conveyed downwards substantially vertically.
In a first known type of the diffusers briefly described above, adjustment of the position of both the movable cones relative to the fixed outer cone and of the mutual position of said movable cones is carried out manually since said movable cones are in engagement with a micrometric screw which, in turn, is coupled with a nut centrally positioned and locked with respect to the fixed outer cone by means of radially-disposed support elements. Manual rotation of the micrometric screw allows both the movable cones to be moved relative to the fixed cone, whereas rotation of one of the movable cones around the screw enables the distance of one cone relative to the other to be varied.
To overcome the existing drawback consisting in that at each change of season manual adjustment of each individual diffuser is to be carried out, which operation is rather long when there are many diffusers, diffusers equipped with actuators capable of carrying out shifting of the movable cones relative to the fixed portion are known.
In particular, a second type of diffuser is known which has a structure similar to that of the above mentioned first type in which rotation of the micrometric screw causing shifting of the movable cones is carried out by an electric motor.
The mentioned second type of diffuser however has some drawbacks connected with the presence of the electric motor itself, i.e. a greater cost, the possibility of failures and the necessity of electric connection lines.
Also known is a third type of diffuser equipped with a cylinder-and-piston actuator containing a mixture of alcohol and wax that is very sensitive to variations of the air temperature on season changing and that, due to the thermal expansion of the mixture, is adapted to create a sufficient force to shift the movable cones.
The last-mentioned type of diffuser is however of complex construction and important bulkiness and is rather heavy since for the return stroke of the piston disposed within the cylinder when the alcohol and wax mixture is contracted, the presence of suitable counterweights is required.
Under this situation the technical task underlying the present invention is to devise an adjustable diffuser for air-conditioning plants capable of substantially obviating the mentioned drawbacks.
Within the scope of this technical task it is an important aim of the invention to devise a diffuser for air-conditioning plants provided with an automatic adjustment, which is at the same time of simple construction, high reliability, reduced weight and limited manufacturing costs.
The technical task mentioned and the aims specified are substantially achieved by an adjustable diffuser for air-conditioning plants that is characterised in that it comprises one or more of the technical solutions hereinafter set out.
The description of a preferred but not exclusive embodiment of an adjustable diffuser in accordance with the invention is now given by way of non-limiting example with the aid of the accompanying drawings, in which:

Fig. 1 is a perspective view of an adjustable diffuser in accordance with the invention;
Fig. 2 is a section of the device in Fig. 1 in which the movable portions provided therein are in a position for emitting cold air (summer setting); and
Fig. 3 shows the section of the device in Fig. 1 in which the movable portions provided therein are in a position for emitting hot air (winter setting).

With reference to the drawings, the diffuser in accordance with the invention is generally identified with reference numeral 1.
It comprises a fixed portion 2, to be installed on the structure of a false ceiling 3 for example, which has a shape preferably in the form of a truncated cone terminating, at the minor base thereof; with a first cylindrical stub pipe 2a to be connected with a conditioned air-conveying pipeline and, at the major base, with a second cylindrical stub pipe 2b the outer edge 2c of which is aligned with the plane of the false ceiling 3.
The diffuser 1 further comprises at least one movable portion 4 adapted to define, between the fixed portion 2 and the movable portion itself, at least one duct 6 for passage of the conditioned air to be admitted into a room or the like. Advantageously the movable portion 4 is shiftable relative to the fixed portion 2 so that the section and conformation of duct 6 can be varied and the orientation of the air flow emitted therefrom can be modified. The movable portion 4, in accordance with an alternative embodiment not shown, can be movable between two end positions corresponding to opening and closure of duct 6, respectively.
In the preferred embodiment herein illustrated, disposed internally of the fixed portion or fixed outer cone 2, are two movable portions or movable cones and more specifically a first movable portion 4 and a second movable portion 5 disposed internally of the first one 4.
The first movable cone 4 forms a first duct 6 of annular shape with the outer cone 2 for passage of the conditioned air and a second annular duct 7 with the second movable cone 5, said second duct being in an inner position with respect to said first duct 6.
Also provided is an actuator 8 active on the movable portion 4 to carry out displacement of the latter.
As shown in the accompanying drawings, actuator 8 is active on the movable cones 4, 5 for the purpose of shifting them relative to the fixed cone 2, so that the section and conformation of the first duct 6 can be varied and the orientation of the air flow emitted therefrom can be modified.
In an original manner, actuator 8 comprises a spring 9 made of a shape-memory material, the main feature of which is to be able to recover the preset shape by effect of a mere temperature change. Spring 9 is adapted to become longer reaching an extended position or to get contracted reaching a shortened position, depending on the temperature of the air flow impinging on it, through exploitation of the different modulus of elasticity of the material in case of high and low temperatures.
Practically, if the spring 9 is of the cylindrical compression type, it takes a configuration of more reduced length when the temperature is low, lower than about 17°C for example, whereas it recovers the shape corresponding to its elongated setting, when the temperature is higher, 22-23°C for example, the outer load to which it is submitted being the same in both cases.
In more detail, actuator 8 comprises, in addition to spring 9, a support pin 10 adapted to engage the movable cones 4, 5 and slidable in a vertical direction internally of a guide bush 11 disposed centrally of the fixed cone 2 and rigidly secured to the latter by means of radially oriented support elements 12.
The support pin 10 in turn comprises a first end section 10a at the upper part thereof, which is inserted in the cylindrical cavity of the spring 9, which spring is interposed between the guide bush 11 and an abutment head 13 rigidly connected with the free end of said end section 10a.
In addition, the support pin 10 comprises, at the lower part thereof, an end section 10b which is at least partly threaded and is adapted to engage a connecting element with an inner thread 14 which is rigidly connected with the first movable cone 4.
The second movable cone 5 is on the contrary fastened to a free end of said second end section 10b.
Operation of the adjustable diffuser described above mainly as regards structure is as follows.
When cold air is conveyed, i.e. during summer, spring 9 takes a shortened conformation. Consequently, the distance between the abutment head 13 and guide bush 11 is minimum and the support pin 10 and movable cones 6, 7 engaged therewith take a lowered position slightly projecting from the lower edge 2c of the fixed cone 2 (Fig. 2).
Under this situation, the first duct 6 is widened and the air flow is directly substantially parallel to the surface of the false ceiling 3 (see Fig. 2).
If hot air is conveyed, i.e. during winter, spring 9 takes an elongated conformation and the abutment head 13 is moved away from the guide bush 11 so that the support pin 10 is raised together with the movable cones 6, 7 associated therewith which take a slightly recessed position relative to the lower edge 2c of the fixed cone 2.
Under this situation, the first duct 6 becomes narrower and the conditioned air flow is substantially directed downwards (see Fig. 3).
Obviously, as in the known art, a manual intervention on the second duct 7 too is always possible, so as to adjust the distance between the first movable cone 4 and the second movable cone 5.
The invention achieves important advantages.
In fact, first of all, the diffuser in accordance with the invention not only can be always adjusted in an automatic manner on varying of the conditioned-air temperature, but it is also of very simple construction as it is made of a very reduced number of mechanical components.
It will be further recognised that said components are of high operating reliability, which will make the diffuser adjustment very reliable too.
It will be also appreciated that since the actuator enabling displacement of the movable cones is of very reduced sizes and weight, it makes the diffuser to which it is applied less bulky and light-in-weight.

Claims

An adjustable diffuser for air-conditioning plants, comprising:

at least one fixed portion (2) and at least one movable portion (4) adapted to define at least one duct (6) between them for passage of the conditioned air to be admitted into a room or the like, said at least one movable portion (4) being shiftable relative to the fixed portion (2) so that the section and conformation of said at least one duct (6) can be varied and the orientation of the air flow emitted therefrom can be modified,

and at least one actuator (8) active on said movable portion (4) to carry out displacement of the latter,

characterised in that said actuator (8) preferably comprises at least one spring (9) and is at least partly made of a shape-memory material adapted to become longer reaching an extended position or get contracted reaching a shortened position, depending on the temperature of the air flow.
A diffuser as claimed in claim 1, characterised in that said actuator (8) further comprises a support pin (10) which is adapted to engage said at least one movable portion (4) and is slidable internally of a guide bush (11) rigidly connected with said fixed portion (2), and in that said shape-memory spring (9) is active on said support pin (10) and causes displacement of the latter on passing from said extended position to said shortened position and vice versa.
A diffuser as claimed in claim 2, characterised in that said shape-memory spring (9) is of the cylindrical compression type and said support pin (10) comprises, at the upper part thereof, a first end section (10a) inserted into the spring (9), said spring (9) being interposed between said guide bush (11) and an abutment head (13) rigidly connected with said first end section (10a) of the support pin (10).
A diffuser as claimed in claim 3, characterised in that said fixed portion (2) and movable portion (4) have a conformation substantially in the form of a truncated cone and define an outer wall and an inner wall respectively of said duct (6) for air passage, said guide bush (11) being positioned centrally of said fixed portion (2) and connected thereto by support elements (12) having a radial arrangement.
A diffuser as claimed in claim 4, characterised in that said support pin (10) comprises, at the lower part thereof, a second end section (10b) at least partly threaded and adapted to engage a connecting element (14) with an inner thread which is rigidly connected with said movable portion (2).
A diffuser as claimed in claim 5, characterised in that two said movable portions (4, 5) are provided, which substantially are in the form of a truncated cone and comprise a first outer movable portion (4) and a second inner movable portion (5), said first movable portion (4) defining a first duct (6) and a second duct (7) for air passage with said fixed portion (2) and said second movable portion (5) respectively, and in that said first movable portion (4) is in engagement, by said internally-threaded connecting element (14), with said second end section (10b) of the support pin (10) and said second movable portion (5) is connected with the free end of said pin.
A circular diffuser with adjustable cones for air-conditioning plants, comprising:

a fixed outer cone (2) and at least one movable cone (4) disposed within the space formed by the fixed outer cone (2) and defining, in cooperation with the latter, at least one duct (6) for passage of the conditioned air to be admitted into a room or the like, said movable cone (4) being shiftable relative to the fixed cone (2) so that the section and conformation of said duct (6) can be varied and the orientation of the air flow emitted therefrom can be modified,

and at least one actuator (8) active on said movable cone (4) to carry out displacement of the latter,

characterised in that said actuator (9) comprises at least one spring (9) made of a shape-memory material and adapted to become longer or to get contracted to a shortened position, depending on the temperature of the air flow.