The present invention relates to a damper-regulating arrangement for an apparatus provided with cooling and heating batteries, especially an induction apparatus, by means of which preprocessed primary air, such as ventila¬ tion air, is supplied to an enclosed locality or room in which the apparatus is located. The primary air is supp¬ lied at a relatively high velocity at the interior of the apparatus and, in the course of this process, co-ejects secondary air in the form of room air, which is permitted to flow into the casing of the apparatus from the enclosed locality and can, during this process, be caused to pass ^■ "hrough the cooling or heating battery in order to be coo¬ led or heated.

An induction apparatus of the general type here concerned is primarily intended to be used as a facade or surface apparatus (window apparatus) for supplying air at a facade wall. Such a surface apparatus is used for ventilation and heating or cooling, respectively, of air-conditioned pre¬ mises such as offices. To this end, it is necessary for the apparatus to supply, on the one hand, preprocessed primary air (ventilation air), while, on the other hand, being capable of bringing about preprocessing of the room air in the enclosed locality by causing it to flow through the apparatus so that, as a result, it is heated or cooled as it passes through the heating or cooling battery in the apparatus.

Primary air is introduced therefore at relatively high velocity at the interior of the apparatus, the flow of primary air being also used to induce, by co-ejection, a flow of room air (secondary air) into and through the

apparatus for reprocessing by heating or cooling. The new¬ ly supplied ventilation air is thus mixed with co-ejected room air in the apparatus and then blown out of the appa¬ ratus through one or several openings, which are normally arranged in the upper side of the apparatus casing.

The need to reprocess room air (by heating or cooling) varies of course in accordance with, inter alia, the heat generated in the enclosed locality/room, the degree of ventilation, solar radiation in the enclosed locality, ambient air temperature etc.

It must therefore be possible to regulate heating or cool¬ ing of the room air as it flows through the apparatus. With induction apparatus of the kind beforementioned, this is achieved by providing in the enclosed locality a room thermostat which senses the prevailing temperature of the room air and causes the regulating equipment of the appa¬ ratus, which with the aid of damper-controlled electric motors regulates the damper arrangement by which the room air can be guided through the heating or cooling battery in the apparatus, to be controlled in respect of a requi- rec set-point value. This electrical regulating equipment presupposes therefore an electric current supply and is, in addition, relatively complicated and expensive, and it also necessitates wiring. Another disadvantage consists in the fact that the electrical regulating equipment, in par¬ ticular the servomotors, do not operate noiselessly, but often produce irritating buzzing or humming sounds in the course of switching the dampers.

Accordingly, the prime object of the present invention consists in providing for the kind of induction apparatus intended a technically uncomplicated and therewith in¬ expensive purely mechanical damper-regulating arrangement

of a new kind which can replace the above-mentioned known electrical regulating equipment.

According to the invention, this is achieved by attach¬ ment, on a side of the apparatus accessible to the room air, of an memory metal-spring, one end of which is secured to the casing of the apparatus and the other end of which is secured to a first point of a lever device which is rotatably mounted on the casing of the apparatus and which, in addition, is acted upon by, on the one hand, a counterforce spring attached between the casing of the apparatus and another point of the lever device and, on the other hand, a regulating wire extending between a third point on the lever device and one end of a return spring, the other end of which is secured to the casing of the apparatus, and in that attached to the regu¬ lating wire are control means which, when the wire moves, can act on damper spindles pertaining to dampers which serve to control the passage of the co-ejected room air through the apparatus, either via one of the batteries for cooling cr heating and/or through an inlet duct in which the flow of room air does not pass through any of the batteries.

By means of a damper-regulating arrangement of this con¬ struction an installation is achieved which is simpler throughout (without electrical components and wiring), which virtually does not require any care or any mainte¬ nance, which is more reliable in operation (no danger of non-operation due to power failures) and which operates in an entirely noiseless manner.

The memory metal-spring may, for instance, be made from an alloy consisting predominantly of brass (copper and zinc) and contains, in addition, a few per cent of aluminium. The purpose of the counter-force spring is to maintain the

bias of the memory metal-spring within its. entire given operating range, in order to avoid undesirable hysteresis in the operating curve of the memory metal-spring (i.e. a curve showing how the length of the spring changes as a function of the spring material's temperature). By changing the biassing force exerted by the counterforce spring it is also possible to displace the operating curve of the metal storage-spring in the temperaturelength variation diagram.

The return spring has the function of providing the force necessary for resetting the damper.

A memory metal-spring is a spring which "remembers" the form that it had at a certain temperature. When returned to this temperature, the memory metal-spring requires its original form. The memory metal-spring is advantageously a helical spring constituting a tension spring mounted at the front side of the casing of the apparatus facing towards the interior of the enclosed locality/room. Since the emery metal-spring is designed as a tension spring, it is not necessary to provide appropriate lateral guides for such spring, which would otherwise be necessary if the spring were a compression spring.

Different aspects of preferred embodiments of the inven¬ tive damper-regulating arrangement are set forth in the following independent claims.

Claim 3, for instance, discloses that the memory metal- spring and the counterforce spring are advantageously arranged with a parallel-epipedic apparatus casing.

Claim 5 discloses a suitable comfort-dependent temperature range in respect of the memory storage interval of the

memory metal-spring as regards longitudinal change within the intended operating range of the spring.

Claim 6 discloses how the memory metal-spring should advantageously be constructed so that the spring will res¬ pond also to small changes of temperature. Using an opti¬ mal helical memory metal-spring it is possible to achieve a spring mobility in the order of magnitude of 10 mm/"C, i.e. the memory metal-spring converts a sensed temperature change of one degree to an axial longitudinal change (at the movable end of the spring) of the order of magnitude of 10 mm.

Finally, claim 7 discloses how the "levers" of the lever device are to be fashioned so that the tensile force in the memory metal-spring will remain fairly constant irres¬ pective of its temperature-related longitudinal change. Such a constant tensile force is important and necessary, lest the spring "moves about" in different bias positions, which must be avoided.

The invention will now be described in more detail with reference to an exemplifying embodiment thereof illustra¬ ted in the accompanying drawings, in which

Fig. 1 shows, in vertical projection, the front side of an inventive induction apparatus (facade apparatus) provided with a damper-regulating arrangement;

Fig. 2 shows one end face of the induction apparatus shown in Fig. 1 ;

Figs. 3, 4 and 5 show one and the same schematic cross- section (along section III-III in Fig. 1) through the apparatus shown in Fig. 1, whereby Fig. 3 shows the air flow with max. cooling in and through the apparatus,

Fig. 4 shows the air flow with max. heating, and Fig. 5 shows the apparatus in its neutral state, in which the co-ejected room air is neither cooled nor heated.

Induction apparatus 2 shown in Figs. 1 and 2 is construc¬ ted as a facade or surface apparatus for attachment to a wall in the room in which the apparatus is mounted. The basic principle is that the ventilation requirements of the room are met by supplying preprocessed primary air through the apparatus 2 or, when the need is found, seve¬ ral such apparatus connected in series. The induction apparatus also ensures that secondary air in the form of room air, which is co-ejected owing to the supply of primary air, is reprocessed by cooling or heating in the apparatus. Hence the apparatus is provided with two built- in plate batteries, one for cooling and one for heating.

As can be seen from Figs. 1 and 2, the induction apparatus 2 comprises a substantially parallelepipedic casing 4 in the front side of which facing the inside of the room there is an oblong air inlet 6 for room air, and in the upper side 8 of which there is an equally oblong air out¬ let 10 for the primary air and the co-ejected room air.

The induction apparatus 2, which with the embodiment shown is assumed to be connected in series with several units of the same type, has on its end faces primary-air connectors 12 in the form of circular duct sections, tubular connec¬ tors 14' and 14" for feeding and discharging the water for a cooling battery 18 in the top of the apparatus, and tubular connectors 16' and 16" for feeding and discharging the water for a heating battery 20 located in the bottom of the apparatus. ^* Room air which is to be cooled flows into the cooling battery 18 through an opening 22 located in the front side of casing 4, whereas air intended to flow through heating battery 20 enters the apparatus

through a lower air inlet 24 (see Figs. 3-5). When the room air flowing into the apparatus is neither cooled nor heated, it enters casing 4 of the apparatus through the air inlet 6 and the inlet duct 26 located within said inlet, said duct in the .neutral position shown in Fig. 5 extending into the apparatus between two rotatably switch- able dampers 28 and 30, the positions of which are con¬ trolled by means of the damper-regulating arrangement according to the invention. In Figs. 3-5 the flow arrows R indicate room air flowing into apparatus 2, whereas the flow arrows P within the interior of the apparatus casing 4 indicate the introduction of primary air, at relatively high velocity, through small nozzles 32. As a result of this influx of primary air, secondary air in the form of room air R is induced, said air being capable of flowing through the battery 18 or 20 or through the inlet duct 26.

We now go on to a more detailed study of the damper-regu¬ lating arrangement according to the present invention, said regulating arrangement being a purely mechanical arrangement replacing previously known regulating arrange¬ ments with electric motors for controlling and switching the dampers 28 and 30. The components forming part of the damper-regulating arrangement can be seen in Figs. 1 and 2.

At the front of the apparatus casing 4, which is freely accessible to room air, there is attached a memory metal- spring 34 in the form of a helical tension spring, which responds to, and as a result senses, the air temperature prevailing at the bottom of the front side of the appara¬ tus. The left-hand end of the memory metal-spring 34 (as seen in Fig. 1) is attached (at 36) to casing 4 of the apparatus, whereas the other end of spring 34 (on the right in Fig. 1) is attached to a first point 38 of a lever device 40 rotatably located at 41 on the apparatus casing. Although the lever device is shown in Fig. 1 in

the form of a three-armed linkage, ^" it could equally well be a roller or a disc where the engagement points of the levers, such as points 38, constitute mutually separate attachment points. Apart from the tensile force exerted by memory metal-spring 34, the lever device 40 is also in part acted upon by a counterforce spring 42 attached between a temperature-setting knob 44 at the top of casing 4 of the apparatus and another point 46 on the lever devi¬ ce 40. The lever 'device is also subject to the force exer¬ ted by a regulating wire 48, which extends between a third point 50 on the lever device 40 and one end of a return spring 52 arranged within the right-hand end face of the apparatus casing 4 (as seen in Fig. 1). Regulating wire 48 extends from point 50 on the lever device 40 to the counterforce spring 52 via a deflector roll 54 located at the right-hand end face of the apparatus casing 4. The end of the regulating wire 48 located at said end face is secured to the lower end of the return spring 52 at 56. The upper end of the return spring 52 is secured to the apparatus casing 4 in a holder 58 at the right-hand end face of the casing.

The two rotatable switchable dampers 28 and 30, whereof damper 28 permits flow of the room air through the cooling battery 18 while damper 30 permits flow of the room air through the heating battery 20, are each secured on its respective damper spindle 60 or 62, these spindles being rotatably journalled in the two end faces of the apparatus casing 4. So as to enable switching of the dampers, the damper spindles 60 and 62 extend, at one end face of the casing, through the corresponding wall of the casing, as can be seen at the right-hand side of the casing in Fig. 1. So as to prevent the regulating forces required for switching the dampers from becoming excessively large, the aairipe -spindle ends projecting from the casing 4 are pro¬ vided with damper-balancing weights 64 and 66.

Furthermore, each damper spindle 60 and 62 has attached thereto a respective lever 68 or 70 which projects towards the regulating wire 48, said regulating wire 48 either passing through said lever or said lever having actuating parts located immediately adjacent the wire 48.

The wire 48 has attached thereto in the region above the lever 68 and below the lever 70, control means 72 and 74, which, when the regulating wire 48 moves (for instance, in consequence of a temperature-related change in the length of memory metal spring 34) are brought into contact with the appropriate damper-spindle lever, in order to cause thereby the spindle concerned to rotate and thus to switch the damper secured to the spindle.

As indicated above, the memory metal-spring 3 will accor¬ dingly sense the temperature of the room air upstream of the induction apparatus 2, and when this temperature chan¬ ges, the length of the memory metal-spring 34 will also change in consequence thereof, this change in length being transmitted to the regulating wire 48 via the lever device 40, which with the embodiment shown consists in a three- armed linkage in which the regulating wire 48 is connected to point 50 at the end of the central lever.

In order finally to explain the operation of the damper- regulating arrangement, it is assumed that the memory metal-spring is so constructed as to ensure that a lower¬ ing of the room air temperature sensed by the spring will result in lengthening of the memory metal-spring.

With such lowering of the temperature, the regulating wire 48 will then move to the right in Fig. 1, i.e. upward at the right-hand end face of the apparatus casing 4. In the course of this process, the control device 7 is caused to contact the lever 70 of damper spindle 62, and as the wire

48 continues to move upward (In Fig. 2), the damper spind¬ le 62 will therefore turn clockwise in Fig. 2, i.e. anti¬ clockwise in Figs. 3-5, as a result of which the damper 30 is gradually swung up towards a more open position enab¬ ling passage of the room air through the heating battery 20. Consequently, the damper ^' 30 is switched from the posi¬ tion shown in Fig. 5 to the maximum opening position shown in Fig. 4, which causes maximum heating of the room air passing through the apparatus. This causes heating of the volume of air in the room concerned, which in turn brings about a gradual rise of the air temperature in the vicini¬ ty of the memory metal-spring 34, thus causing the length of the memory metal-spring to be reduced and, accordingly, causing the regulating wire 48 to move to the left in Fig. 1 and, therefore, downward in Fig. 2. This causes the dam¬ per 30 to be gradually closed from the position shown in Fig. 4 to the position shown in Fig. 5, and if the tempe¬ rature of the room air now continues to be higher than the required temperature, the control device 72 will gradually come into contact with the lever 68 of the damper spindle 60, which if the wire 48 continues to move downward initi¬ ates counter-clockwise rotation of the spindle 60 in Fig. 2, i.e. clockwise rotation in Figs. 3-5. This leads to a gradual opening of the damper 28 from the position shown in Fig. 5 to the position shown in Fig. 3, in which room air flows in through the cooling battery 18 and causes, accordingly, maximum cooling of the room air sucked into the apparatus through co-ejection. Cooling of the room air sucked in continues thereafter until the memory metal- spring 34 senses that the temperature of the room air has dropped and, as a result, increases its length, which in turn gradually leads to throttling of the flow of room air through the cooling battery and switching of the damper 28 to the neutral position shown in Fig. 5, in which the room air flowing through air inlet 6 and the inlet duct 26 is neither cooled nor heated.