Abstract:
A device for regulating the airflow in an air damper including a twist sleeve of flexible material, the cross section of which substantially conforms to, an outer tube in which the flow takes place, one end of the twist sleeve being disposed on the inner side of the outer tube and the other end of the twist sleeve being disposed in a tube sleeve which can be rotated under an axial displacement controlled in relation to the rotation. The tube sleeve may be provided with a helical slot. A guide pin is arranged on an inner side of the outer tube, which guide pin goes down into the helical slot. The operating apparatus comprises two cords, which cords are provided with fastenings against the tube sleeve and run along opposite circumferential directions of the tube sleeve between the outer tube and the tube sleeve.

Description:
This application is a divisional of U.S. application Ser. No. 12/998,101, filed Mar. 17, 2011, which is a National Phase of PCT/SE2009/051089 filed Sep. 30, 2009, which claims priority to S.E. Application No. 0802050-5 filed Sep. 30, 2008, S.E. Application No. 0900496-1 filed Apr. 15, 2009, and S.E. Application No. 0802178-4 filed Oct. 13, 2008, the contents of each of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a device for, from the outer side of an air duct, achieving regulation of the airflow in an air damper, comprising a twist sleeve of flexible material, the cross section of which substantially conforms to the duct in which the flow takes place, one end of the twist sleeve being disposed arranged in relation to the duct and the other end being arranged in relation to a tube sleeve which can be rotated under an axial displacement controlled in relation to the rotation. 
     BACKGROUND 
     Various devices for transmitting motions, both in the axial direction and in the direction of rotation, between an outer tube and an inner tube are previously known. The majority are realized as a thread between the tubes, either the outer tube or the inner tube being used to achieve the rotation. These devices are often used in table legs, white goods and other applications in which there is a need to make a height adjustment and effect levelling against the floor. This works well when dealing with small tube dimensions. Where larger dimensions are involved, it creates problems. A type of “drawer effect” is then obtained, which increases the greater the dimensions of the tubes. There are an endless number of devices for converting a rotary motion into a linear motion. Likewise, there are an endless number of devices for converting a linear motion into a rotary motion. These are not made to achieve simultaneous linear and rotary transmission. Air dampers comprising a twist sleeve of flexible material, the cross section of which substantially conforms to the duct in which the flow takes place, are previously known. One end of the twist sleeve is fixed in relation to the duct and the other end can be rotated, whereupon the free area in the centre decreases in relation to the original state. 
     There are some known solutions for rotating the twist sleeve, but when it is a matter of, from the outer side of an outer tube, achieving an axial and, at the same time, rotary motion of the twist sleeve, there is currently no solution for this. The motion should also be able to be indicated for fine adjustment. Likewise, no flow in the outer tube must leak out. It is especially difficult to achieve this when larger tube diameters are involved. 
     In addition, there are some known solutions for rotating the twist sleeve from the outer side of the outer tube with cords. There are also known solutions for rotating damper valves with cords from the inner side of an outer tube. But where it is a matter of achieving in an outer tube an axial and, at the same time, rotary motion of the twist sleeve with cords from the outside, there is currently no solution for this. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an improved device for, preferably from the outside but also from the inside, achieving rotation under an axial displacement of a twist sleeve, which displacement is controlled in relation to the rotation. One end of the twist sleeve is arranged in relation to the outer tube of the duct and the other end is arranged in relation to a tube sleeve. The outer diameter of the tube sleeve is only somewhat smaller than the inner diameter of the outer tube, so that the tube sleeve slides easily in the outer tube. The tube sleeve has a helical slot in its shell surface. According to the invention, the rotation can be achieved in a variety of ways with the aid of some form of operating apparatus, which can be variously configured, e.g. with the aid of an operating spindle which cooperates with the slot. The rotation can be realized with the aid of two cords from the inner side of the outer tube. The rotation can be realized by, from the outer side of the outer tube, rotating a cord reel in cooperation with cords in such a way that the cords pull round the tube sleeve. 
     The first embodiment of the invention comprises an improved device, which allows a rotation to be achieved from the outside under an axial displacement of a twist sleeve, which displacement is controlled in relation to the rotation. Control dampers of the type which are to be regulated by the device are used to regulate the airflow in air treatment installations and ventilation systems by causing a fall in pressure and in order to control the airflow to individual spaces and in relation to other spaces within the zone of the same ventilation system. In order to attain this, control dampers are installed at a number of different locations within a system. 
     One end of the twist sleeve is fixed in relation to the outer tube of the duct and the other end is fixed to a tube sleeve. The rotation is made, preferably through 180 degrees, to and fro, at the same time as the tube sleeve moves axially to and fro. The outer diameter of the tube sleeve is only somewhat smaller than the inner diameter of the outer tube, the tube sleeve being able to slide easily in the outer tube. The tube sleeve has a helical slot in its shell surface. The slot can be configured, for example, with teeth along one edge. From the outside and through a hole, at right angles to the outer tube, an operating spindle is seated, so that its lower part, configured as a gearwheel, goes down into the slot in the tube sleeve. When the operating spindle is rotated, the gearwheel pulls round the tube sleeve, which at the same time moves axially, whereupon the twist sleeve moves in accompaniment and its free area in the centre decreases in relation to the original state. 
     Between the outer tube and the tube sleeve and in the slot in the tube sleeve there is a runner which slides in the slot. The lower part of the operating spindle passes through the runner, which guides the gearwheel of the operating spindle in correct position towards the slot in the tube sleeve. The top of the operating spindle is arranged such that it can be rotated manually or with a motor. When the operating spindle is rotated, the gearwheel pulls round the tube sleeve in a controlled axial displacement. A simple construction is hereby attained, which, with a low torque upon the operating spindle, moves the tube sleeve. The operating spindle seals the outer tube, so that no fluid can leak out. The operating spindle is provided with a worm screw which actuates a display wheel. On the display wheel, the position of the tube sleeve can be read, so that the flow in the duct can be finely adjusted. The operating spindle and the display wheel are enclosed in an operating hood fixed against the outer tube. In the upper part of the operating hood there is a window for reading of the display wheel. The operating spindle is mounted in the outer tube and in the top part of the operating hood. 
     The second embodiment of the invention has a device which allows a rotation to be achieved from the inside with two cords under an axial displacement of a twist sleeve, which displacement is controlled in relation to the rotation. A control damper of the type which shall be regulated by the device is used to regulate the airflow in air treatment installations and ventilation systems by causing a fall in pressure and in order to guide the airflow to individual spaces and in relation to other spaces within the zone of the same ventilation system. 
     One end of the twist sleeve is fixed in relation to the outer tube of the duct and the other end is fixed to a tube sleeve. The rotation is effected with two cords, preferably through 180 degrees, to and fro, at the same time as the tube sleeve moves axially to and fro. The outer diameter of the tube sleeve is only somewhat smaller than the inner diameter of the outer tube, the tube sleeve sliding easily in the outer tube. There is also space for the cords between the outer tube and the tube sleeve. The tube sleeve has a helical slot in its shell surface. In the outer tube there is a guide pin, which goes down into the slot in the tube sleeve. The guide pin holds the tube sleeve in place and guides the tube sleeve in the axial direction when it is rotated. Between the tube sleeve and the outer tube, on the inner side of the outer tube and directly in front of the tube sleeve, sits an eye, through which the two cords run. The cords are accommodated between the outer tube and the tube sleeve. The cords change direction in the eye, so that they, on the one hand, follow the outer tube in the axial direction and, on the other hand, are angled to run round the tube sleeve on either side. In the outer tube sits a guide pin, which goes down into the slot in the tube sleeve. The cords pull round the tube sleeve, which at the same time moves axially, the central, free area of the twist sleeve decreasing or increasing in relation to the original state. A simple construction is hereby attained, which, with a small force upon the cords, moves the tube sleeve. The cords are marked such that it is known which cord has to be pulled on for opening or shutting of the control damper. The cords are pulled up to an air handling unit, beneath which they are protected against unauthorized influencing of the adjustment of the control damper. 
     The third embodiment of the invention has a device which allows a rotation to be achieved from the outer side of an outer tube under an axial displacement of a twist sleeve, which displacement is controlled in relation to the rotation, inside the outer tube with the aid of two cords. A control damper of the type which shall be regulated by the device is used to regulate the airflow in air treatment installations and ventilation systems by causing a fall in pressure and in order to guide the airflow to individual spaces and in relation to other spaces within the zone of the same ventilation system. 
     One end of the twist sleeve is fixed in relation to the outer tube of the duct and the other end is fixed to a tube sleeve. The rotation is realized with two cords, preferably through 180 degrees, to and fro, at the same time as the tube sleeve moves axially to and fro. The outer diameter of the tube sleeve is only somewhat smaller than the inner diameter of the outer tube, the tube sleeve sliding easily in the outer tube. There is also space for the cords between the outer tube and the tube sleeve. The tube sleeve has a helical slot in its shell surface. In the outer tube there is a guide pin, which goes down into the slot in the tube sleeve. The guide pin holds the tube sleeve in place and guides the tube sleeve in the axial direction when it is rotated. On the inner side of the outer tube and at the bottom edge of the tube sleeve two cords are attached, which run on either side between the twist tube and the outer tube. The cords run out through the outer tube via a slide sleeve fixed against the outer tube, whereafter they on the outside change direction in the longitudinal direction of the outer tube, where they are wound onto a cord reel. When the cord reel is rotated round, the cords pull round the tube sleeve, which also at the same time moves axially, whereupon the central, free area of the twist sleeve decreases in relation to the original state. A simple construction is hereby attained, which, with a small force upon the cords, moves the tube sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A number of embodiments of the invention are described below and are illustrated in the appended drawings, in which: 
         FIG. 1  shows a view of a tube sleeve and how the rotation is achieved, 
         FIG. 2  shows a view of an operating spindle and a display wheel, 
         FIG. 3  shows a slit-open view of the operating mechanism for full flow, 
         FIG. 4  shows a slit-open view of the operating mechanism in respect of restricted flow, 
         FIG. 5  shows a slit-open view of the control damper for full flow, 
         FIG. 6  shows a slit-open view of the control damper in respect of restricted flow, 
         FIG. 7  shows a view of the tube sleeve and how the cords are arranged, 
         FIG. 8  shows a diagram of a control damper installed in an air duct, 
         FIG. 9  shows a view of the tube sleeve in the control damper with guide pin, sliding sleeve and fastened cords, 
         FIG. 10  shows a view of the tube sleeve in the control damper with the guide pin and the sliding sleeve fixedly integrated in a base plate and how this is orientated over the tube sleeve, 
         FIG. 11  shows a view of the tube sleeve in the control damper with a cord reel applied to the base plate and how the cords are wound round the cord reel. 
         FIG. 12  shows a view of a control damper installed in an air duct and how the base plate is fixed against the outer tube, 
         FIG. 13  shows a view of a control damper installed in an air duct and how the base plate with the cord reel is covered by a hood which connects to the outer tube. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Three different embodiments of the present invention will be described below with reference to the figures. 
     According to a first embodiment of the invention, an airflow regulating device according to  FIGS. 1, 2, 3 and 4  is shown and this can represent the structural form which is applied in the example referred to here. 
     The airflow regulating device according to  FIG. 1  shows a view of a tube sleeve  1  and how the rotation  12  is achieved. The tube sleeve  1  has at its one end in the casing  2  an inwardly directed beading  3 , which constitutes an edge against which a twist sleeve shall be fixed. The tube sleeve  1  is provided with a helical slot  4 . By the word “helical” is here meant that the slot  4  (see also, for example,  FIGS. 5 and 9 ) extends round the shell surface of the tube sleeve  1  in such a way that also an axial displacement takes place from the point where the slot commences to the point where the slot ends. 
     The helical slot  4  can be variously configured. The slot can have straight edges, see, for example,  FIGS. 5 and 9 , in which the slot has the reference notation  204  and  302  respectively. The slot can have a straight edge  5  along one side and teeth  6  on the other side, see  FIGS. 1 to 4 . It is further shown in  FIGS. 1 to 4  how rotation of the tube sleeve  1  is achieved by an operating apparatus  7 . The operating apparatus  7  can be constituted, for example, by an operating spindle, or can be configured in some other way suitable for the purpose. The operating apparatus  7  is provided with a part  18 , which is arranged to cooperate with the slot  4  in such a way that the operating apparatus  7  pulls round the tube sleeve  1 , at the same time as the tube sleeve  1  moves axially. 
     The part  18  can be constituted, for example, by a gearwheel  18 , which is disposed in the lower part of the operating spindle  7  and is stuck down through a runner  9 , which runs against the edges in the helical slot  4 . The operating spindle  7  actuates a display wheel  10 , from which the rotation can be read. When the operating spindle  7  is rotated according to the arrow  11 , the gearwheel  18  pulls round the tube sleeve  1  according to the arrow  12 , at the same time as the tube sleeve  1  moves axially according to the arrow  13 . 
     Instead of a slot  4  with teeth  6  and an operating spindle with gearwheel  18 , other suitable solutions are conceivable. For example, a smooth-edged slot can be used and the operating spindle  7  can be provided with a sliding element corresponding to the part  18 , which can slide in the slot  4 . 
     The airflow regulating device according to  FIG. 2  shows a view of an operating spindle  7  having a body  14 , which in its upper part has a mounting spigot  15 , as well as a recess  16  fitting a tool or motor for rotation. In the lower part of the body  14 , a mounting spigot  17  and a gearwheel  18  are integrated. The body  14  is provided with an external worm screw  19 , which actuates a display wheel  10  having a base  20  and a rim  21  with recesses  22  for the worm screw  19 . Around the outer side of the display wheel  10  there are a scale  23  and numerals  24  for reading. 
     The airflow regulating device according to  FIG. 3  shows a slit-open view of the operating mechanism in respect of full flow, with outer tube  25  containing the tube sleeve  1 , as well as a mounted operating hood  27 . On the shell surface of the outer tube  25  there is a hole  26 , in which the gearwheel  18  of the operating spindle  7  connects to the teeth  6  of the tube sleeve  1  via the runner  9 . The operating spindle  7  and the display wheel  10  are mounted in an operating hood  27 , in which the upper spigot  19  of the operating spindle  7  juts up out of the operating hood  27 . In addition, the operating hood  27  is provided with a reading window  28  for reading of the display wheel  10 . A twist sleeve  29  is at its one end  30  fixedly connected to the outer tube  25  and at its other end  31  fixedly connected to the tube sleeve  1 . The figure shows when the flow is regulated to full opening by the twist sleeve  29 . The tube sleeve  1  is in this case in its outermost position according to the arrow  32 . 
     An airflow regulating device according to  FIG. 4  shows a slit-open view of the operating mechanism in respect of restricted flow, an outer tube  25  containing the tube sleeve  1 , as well as a mounted operating hood  27 . A twist sleeve  29  is at its one end  30  fixedly connected to the outer tube  25  and at its other end  31  fixedly connected to the tube sleeve  1 . The figure shows how the flow is restricted in the twist sleeve  29 . This is regulated with the operating spindle  7 , the tube sleeve  1  being then rotated according to the arrow  34 , as well as axially displaced according to the arrow  33 . 
     According to a second embodiment of the invention, an airflow regulating device according to  FIGS. 5, 6, 7 and 8  and this can represent the structural form which is applied in the example referred to here. 
     The airflow regulating device according to  FIG. 5  shows a slit-open view of a control damper in respect of full flow. The control damper consists of an outer tube  201  containing a tube sleeve  202  and a twist sleeve  210 . One end  211  of the twist sleeve  210  is fixed in relation to the outer tube  201  of the duct and the other end  212  is fixed to the tube sleeve  202 . The tube sleeve  202  has a helical slot  204  in its shell surface. In the outer tube  201  there is a guide pin  203 , which goes down into the slot  204  in the tube sleeve. The guide pin  203  holds the tube sleeve  202  in place and guides the tube sleeve  202  in the axial direction when this is rotated. Between the tube sleeve  202  and the outer tube  201 , on the inner side of the outer tube  201  directly in front of the tube sleeve  202 , sits an eye  205 , through which run two cords  206 ,  207 . The cords  206 ,  207  are accommodated between the outer tube  201  and the tube sleeve  202 . The cords  206 ,  207  change direction in the eye  205 , so that they, on the one hand, follow the outer tube  201  in the axial direction and, on the other hand, are angled to run round the tube sleeve  202  on either side to more than half the circumference. The cords  206 ,  207  are provided with fastenings  208 , 209  against the tube sleeve  202 . The cords  206 ,  207  pull round the tube sleeve  202 , which also at the same time moves axially, whereupon the central, free area of the twist sleeve  210  decreases or increases in relation to the original state. A simple construction is hereby attained, which with a small force upon the cords  206 ,  207  moves the tube sleeve  202 . The cords  206 ,  207  are marked, so that it is known which cord  206 , 207  has to be pulled on for opening and closing of the control damper. The cords  206 , 207  are pulled up to an air handling unit, beneath which they are protected against unauthorized influencing of the adjustment of the control damper. Moreover, visibly hanging cords are avoided. 
     The airflow regulating device according to  FIG. 6  shows a slit-open view of a control damper in respect of restricted flow, an outer tube  201  containing a tube sleeve  202 , and a twist sleeve  210 . When one cord  206  is pulled on according to the arrow  217 , the tube sleeve  202  is rotated round according to the arrow  215 , at the same time as the tube sleeve  202  moves in the axial direction according to the arrow  216 . This occurs by virtue of the fact that the helical slot  204  guides the tube sleeve  202  via the guide pin  203 . The second cord  207  is then pulled in and round the tube sleeve  202  according to the arrow  218 . Since one end  212  of the twist sleeve  210  is fixedly secured in the tube sleeve  202 , the twist sleeve  210  is also rotated, whereupon the central, free area of the twist sleeve  210  decreases in relation to the original state and the flow is restricted. In order to increase the flow again, the second cord  207  is pulled on, whereupon the process takes place in reverse. 
     The airflow regulating device according to  FIG. 7  shows a view of a tube sleeve  202 , which is provided with a helical slot  204  running outside a guide pin  203 . The outer diameter of the tube sleeve  202  is only somewhat smaller than the inner diameter of the outer tube  201 , so that the tube sleeve  202  can easily slide in the outer tube  201 . There is also room for the cords  206 ,  207  between the outer tube  201  and the tube sleeve  202 . The eye  205  is fixedly mounted in the outer tube  201  and on the opposite side of the guide pin  203 . The eye  205  is shown orientated in relation to the tube sleeve  202 . In addition, it is shown how the cord  207  runs round the tube sleeve  202  in the same helical form as the slot  204 . The cord  206  runs round the tube sleeve  202  in the other direction on the opposite side. 
     The airflow regulating device according to  FIG. 8  shows a diagram of a control damper installed in an air duct, which emerges through a vault  213  into an air handling unit  214 . The cords  206 ,  207  are marked, so that it is known which cord  206 ,  207  has to be pulled on for opening and closing of the control damper. The cords  206 ,  207  are pulled up to the air handling unit  214 , beneath which they are protected against unauthorized influencing of the adjustment of the control damper. 
     According to a third embodiment of the invention, a device for regulating the airflow in a control damper according to  FIGS. 9, 10, 11, 12 and 13  is shown and this can represent the structural form which is applied in the example referred to here. 
     The device for regulating the airflow in a control damper according to  FIG. 9  shows a view of the tube sleeve  301  in the control damper with guide pin  303 , sliding sleeve  304  and fastened cords  305 ,  306 . The tube sleeve  301  has a helical slot  302  in its shell surface. The cord  305  is fixed and runs on the outer side of the tube sleeve  301  beside the slot  302  and directly below where the slot  302  ends on the tube sleeve  301 . The cord  305  follows the same helical form as the slot  302  in the tube sleeve. The cord  305  is then pulled up through the sliding sleeve  304 , where it then, upon exit from the sliding sleeve  304 , is angled in the longitudinal direction of the tube sleeve  301 . By virtue of a precise fit in the sliding sleeve  304 , this seals the cord  305  against air permeation. The same applies to the cord  306  on the opposite side of the tube sleeve  301 . When the cord  305  is pulled on, the tube sleeve  301  will rotate about its centre axis, at the same time as it moves in the axial direction. When the opposite cord  306  is then pulled on, the reverse process is obtained. 
     The device for regulating the airflow in a control damper according to  FIG. 10  shows a view of the tube sleeve  301  in the control damper with the guide pin  303  and the sliding sleeve  304  fixedly integrated in a base plate  307  and how this is orientated over the tube sleeve  301 . The guide pin  303  passes through the base plate  307 , where it on the underside guides up the tube sleeve  301 , so that this is held in place in an outer tube, and also makes the tube sleeve  301  move in the axial direction when this is rotated. The guide pin  303  goes further up out of the base plate  307 , where it constitutes a journal for a cord reel. The sliding sleeve  304  is integrated in the base plate  307  in the same way, so that it juts down on the bottom side and up on the top side. 
     The device for regulating the airflow in a control damper according to  FIG. 11  shows a view of the tube sleeve  301  in the control damper with a cord reel  308  applied to a base plate  307  and how the cords  305 ,  306  are wound round the cord reel  308 . The cords  305 ,  306  are wound up from their respective direction with at least one turn of the cord reel  308 . The end of the cords  305 ,  306  is fixed against the cord reel  308 . The cords  305 ,  306  are wound up at a distance apart, so that there is no tangling together. The cord reel  308  is integrated with a journal  309  in its upper part. The cord reel  308  can be rotated by the journal  309  manually or with motor, so that the tube sleeve  301  is made to rotate and move in the axial direction. The cord reel  308  is provided in its upper part with graduations  313  for reading whenever the airflow is to be regulated. 
     The device for regulating the airflow in a control damper according to  FIG. 12  shows a view of a control damper  301  installed in an air duct and how the base plate  307  with the cord reel  308  is fixed against the outer tube  310 . Drilled in the outer tube  310  are two holes, in which the guide pin  303  and the sliding sleeve  304  are pressed in place with a press fit. The guide pin  303  goes down into the slot  302  in the guide sleeve  301 , so that it secures the guide sleeve  301  in the outer tube  310 . The lower part of the sliding sleeve  304  juts down between the guide sleeve  301  and the outer tube  310 , where a gap is formed, so that the cords  305 ,  306  are accommodated therebetween. 
     The airflow regulating device for regulating the flow in a control damper according to  FIG. 13  shows a view of a control damper installed in an air duct and how the base plate with the cord reel is covered by a hood  311  which connects to the outer tube  310 . The journal  309  juts up through a hole in the top of the hood  311 . The cord reel  308  is provided with graduation  313  for reading in a window  312  on the hood  311  whenever the airflow is to be regulated. 
     The invention has been described in accordance with a preferred assembly and configuration and it is implicit that certain exchanges and changes can be made without deviating from the spirit of the invention. In the embodiments just described, it is shown how the device is used to achieve regulation of the airflow in a control damper. Further alternative embodiments are nevertheless possible, for example the device can be used to close or open other valves or adjust positions in tubes. Likewise, the device can be used when there is a wish to distribute flows. Likewise, the cords can be provided with graduations for reading during adjustment of the airflow. Instead of cords, narrow ribbons can be used. The invention should therefore not be regarded as limited to that which has been shown and described above, but rather similar variants are incorporated in the inventive concept and can be deemed to fall within the scope of the following claims.