GB2112282A - Improvements in or relating to fire-safety systems - Google Patents

Abstract

The invention provides a smoke vent which can be automatically opened when smoke is detected, and which can be closed by the application of air pressure to a pneumatic system. in one embodiment, the pneumatic system includes a cylinder (8) pivotally connected to a frame, and a piston (9) pivotally connected to a glazed sash mounted to pivot about a horizontal axis in the frame. In another embodiment, the pneumatic system includes a rotary actuator (41), the output member of which is connected to the glazed sash through a lever (47) and an operating arm (48). In both embodiments, the glazed sash is locked in the closed position by a pneumatic lock comprising a ball (16) in a pneumatic cylinder (17). The ball (16) cooperates with a recess in a latch member (15) on the glazed sash. <IMAGE>

Description

SPECIFICATION Improvements in or relating to fire-safety systems This invention relates to smoke vents for use in fire-safety systems.

Such smoke vents have been described, for example, in United Kingdom Patent Specifications Nos. 1326 1 13 and 1417 579. The smoke vents described in these two Patent Specifications are arranged so that they can be controlled by a firesafety system in such a way that they open when smoke is detected in the building in which they are instalied.

The smoke vents described in Patent Specification No. 1 326 1 13 are particularly suitable for use in positions in which they are within convenient reach to enable them to be manually closed after they have been opened under the control of the fire-safety system. The vents described in Patent Specification No.

1 417 579 are also suitable for use in such positions but, in addition, they may be used where the vents are located at a height which is a short distance above that which can normally be reached. Thus these vents are provided with a flexible member which is adapted to limit the outward pivoting of the panel and which, in addition, can be used for closing the vent. In particular, the flexible member may be provided with a ring which can be engaged by a hooked pole for closing the vent.

It is an object of the present invention to provide a smoke vent which can be closed even when it is located at a position in a building which is normally completely inaccessible, or is so high that it cannot be reached by means of a pole of reasonable length.

From one aspect the invention consists in a smoke vent including a panel adapted to close an aperture in a building, said panel being mounted to pivot about a horizontal axis; spring means urging the panel to pivot about said axis outwardly with respect to the building; pneumatically operated means capable of causing said panel to pivot about said axis towards a closed position; and remote controlled locking means capable of holding said panel in the closed position against the action of said spring means, said locking means being arranged so that they are in the tucked condition when air pressure is applied to said pneumatically operated means to cause them to urge the panel towards the closed position.

The panel may be adapted to close an aperture in a wall of the building or it may be adapted to cover an aperture in the roof of the building. In the latter case the invention may be used in connection with so-called fire-flaps. The term "fire-flap" is used herein to describe a panel mounted to pivot about a horizontal axis located substantially along one edge of the panel, the panel normally being held in a substantially horizontal position to cover an aperture in the roof of a building, said panel being capable of pivoting about said axis into a substantially vertical position in which smoke can pass upwardly through the aperture.

The locking means may be pneumatically controlled and, in this case, the pneumatically controlled locking means may include a ball which cooperates with a recess provided in an edge of the panel, the ball being urged into the recess by air pressure. However, it is to be understood that the ball could be urged into the recess eiectromagnetically, for example, by means of an armature rod slidably mounted in a solenoid.

Alternatively, the ball could be replaced by a slidable latch, similarly engaging in a recess in an edge of the panel.

From a second aspect the invention consists in a smoke vent including a panel adapted to close an aperture in a wall of a building, said panel being mounted to pivot about a horizontal axis located below the centre of gravity of the panel; spring means urging the panel to pivot about said axis outwardly with respect to the building; pneumatically operated lifting means capable of causing said panel to pivot about said axis towards a closed position; and pneumatically controlled locking means capable of holding said panel in the closed position against the action of said spring means, said locking means being arranged so that they are in the locked condition when air pressure is applied to said lifting means to cause them to urge the panel towards the closed position.

From a third aspect the invention consists in a smoke vent including a panel adapted to cover an aperture in the roof of a building, said panel being mounted to pivot about a horizontal axis located in the vicinity of one edge of the panel; means urging the panel to pivot about said axis towards a vertical position; pneumatically operated means capable of causing said panel to pivot about said axis towards a substantially horizontal position in which it covers said aperture; and electromagnetically controlled locking means capable of holding said panel in said substantially horizontal position.

Preferably the pneumatically operated means are in the form of a piston and cylinder, one pivotally mounted on the panel, and the other pivotally mounted on a member which is fixed relatively to the building. This member may be a structural member of the building, or may be a part of, or connected to, a framework on which the panel is pivotable. Preferably the integer mounted on the frame is displaced inwardly with respect to the frame by means of a bracket, or the like, so that the piston and cylinder are disposed at a small angle with respect to the plane of the frame even when the vent is closed. In the case of a smoke vent in accordance with the second aspect of the invention, the length of the cylinder will normally be such that it will allow the panel to move outwardly with respect to the building to an angle of about 450 with respect to the frame.In the case of a smoke vent in accordance with the third aspect of the invention, the length of the cylinder will be such that it will allow the panel to move upwardly into a substantially vertical position, and to pivot downwardly into a position in which it is inclined to the horizontal at an angle of about 5 . In either case, if air is admitted to the piston rod side of the piston, the pneumatically operated means will be operative to rotate the panel about its pivot axis towards the closed position. Normally it will be most convenient to mount the cylinder on the frame and to mount the piston rod on the panel. It will, therefore, be assumed in the following description that this arrangement is adopted but it is, of course, to be understood that the piston rod may be attached to the frame, and the cylinder to the panel.

It is to be understood that the pneumatically controlled locking means serve to maintain the vents securely closed against the action of wind and other pressure changes inside and outside the building when the panel is moved into the closed position by pneumatic means in accordance with the present invention. It has been found that electromagnetic locking means of the kind described in Patent Specifications Nos. 1 326 11 3 and 1 41 7 579 are not always satisfactory because of the speed at which the panel is travelling when it reaches the closed position. In some cases, bouncing may occur so that the vent is then maintained in a semi-closed position.

When pneumatically controlled locking means are provided in accordance with the present invention, on the other hand, it has been found that bouncing will not occur.

As already stated, the locking means may comprise a ball located in the upper part of the frame and urged downwardly by pneumatic means. The ball cooperates with a recess provided in the upper edge of the panel or in a latching member attached to the panel. It will be understood that air pressure is provided to urge the ball downwardly at the same time as the air pressure is provided to cause the piston to enter the cylinder, and thus to retract the piston rod and move the panel towards the closed position. Thus the locking means are already in the locked condition when the panel is moving towards the closed position. However, the use of a bail as the locking member enables the panel to force the ball upwardly when it first comes into contact with the ball.As has already been stated, the panel is moving at a relatively high speed at this stage of operation, and its momentum is sufficient to overcome the air pressure on the upper side of the ball and force it upwardly so that the panel can continue its inward movement until the ball can enter the recess on the top of the panel.

In a particular embodiment of the invention, the ball is located in a cylinder housing which is divided into two compartments by a membrane.

The lower compartment contains the ball and the upper compartment is connected to the same air supply which is connected to the end of the cylinder containing the piston rod.

Preferably the spring means urging the panel to move outwardly with respect to the building are located in the cylinder on the opposite side to the piston rod. Thus these spring means will normally act to extend the piston rod from the cylinder, and thus move the panel outwardly. However, under normal circumstances, the air pressure on the piston rod side of the piston will be high enough to at least balance the spring pressure. Thus the panel will be held in the closed position by the locking means. However, if the air pressure is removed from the locking means and from the piston rod side of the piston, the spring will act to open the vent.

Normally it will be found that air can be exhausted from the piston rod side of the cylinder at only a relatively slow rate so that, with the arrangement so far described, the panel will open only relatively slowly. Accordingly, in a preferred embodiment of the invention, a double-acting piston and cylinder is used. In such an arrangement, when air is allowed to exhaust from the piston rod side of the cylinder, it is admitted under pressure to the other side. Thus, with an arrangement of this kind, the vent is opened positively by pneumatic pressure when the pressure is changed over from one side of the cylinder to the other. Under these circumstances, the spring acts merely as a fail-safe device.

Preferably a system incorporating a plurality of smoke vents in accordance with the invention includes a change-over valve located in the vicinity of each piston and cylinder. The main air supply is provided to this change-over valve, and is admitted either to the piston rod side of the cylinder or to the other side of the cylinder in dependence on the state of the valve. The state of the valve is controlled by means of a secondary air supply which is provided from a central control panel. When air is supplied through the secondary supply, each valve is maintained in the state in which it allows the main air pressure to be applied to the piston-rod side of each cylinder and hence also to the locking means.However, when the secondary air supply is cut off, each of the changeover valves automatically changes to the state in which it allows the main air pressure to be applied to the opposite side of the respective cylinder and causes it to be cut off from the locking means.

The secondary air supplies are normally controlled from the panel by manually operated valves, but they are preferably also controlled automatically by means of a fire-safety system such as that described in Patent Specification No. 1 326 112.

It is to be understood that, in some cases, it will be desirable to provide two pneumatic cylinders and pistons for each panel, the two pistons being respectively pivotally attached to opposite vertical sides of the panel and the two cylinders being respectively pivotally attached to brackets secured to opposite vertical sides of the frame.

In yet another arrangement a single cylinder and piston will be used with the piston pivotally mounted on the vertical median line of thq panel.

When the panel is a glazed sash, this arrangement may necessitate the provision of a special vertical or horizontal member on the panel to receive the pivoted in connection to the piston.

Normally smoke vents in accordance with the third aspect of the invention will include a pair of panels adapted to cover respective apertures in the roof of the building. The two panels will be pivotable about parallel axes located along the outer edges of the two panels. A central fixed channel member will be provided between the adjacent edges of the two panels remote from their pivot axes. The arrangement will be such that, when the adjacent edges of the two panels engage with the channel member, they will both be inclined downwardly from the centre at an angle of about So. Preferably, in an arrangement of this kind, the remote controlled locking means serve to retain the respective panels in contact with the central channel member.

It is to be understood that spring means may be used to urge each panel to pivot about its pivot axis into the substantially vertical position when the remote controlled locking means are released.

Further it is to be understood that the pneumatically operated means are used to cause the panels to pivot about their respective axes into the substantially horizontal positions. However, a double-acting piston and cylinder may be used with each panel. In this case the piston and cylinder may constitute both the spring means and the pneumatically operated means, although it will usually be desirable to provide separate spring means acting to move the panel into the vertical position as a fail-safe device. It is to be understood that, when a double-acting piston and cylinder is used, means are provided to admit air under pressure to one side of the piston, and to allow it to exhaust from the other side. Thus air will normally be provided to the side of the cylinder remote from the piston rod in order to urge the panel towards the vertical position.The air will be effective to move the panel into the vertical position if the remote controlled locking means is released. In order to return the panel to the substantially horizontal position, air is admitted to the piston rod side of the cylinder, and is allowed to exhaust from the other side. As already stated, the locking means are in the locked condition in these circumstances and, accordingly, they must be in the form of a spring latch so that the latching member can move to allow the panel to adopt the substantially horizontal position, whereupon the latching member will enter the recess in the edge of the panel. This action is similar to that described above in connection with the ball and recess.

In one particular embodiment of the third aspect of the invention, the locking means for a pair of panels include two pins located in the central channel and urged outwardly into the corresponding recesses in the adjacent edges of the two panels by respective springs. The outer ends of the two pins are chamfered or radiused so that the pins will be moved inwardly by the panels when they are approaching the closed position.

Thereafter they will move outwardly into their respective recesses. In addition, they are capable of being held in their inward positions in which they are disengaged from their respective recesses by a cam which is movable into engagement with lugs on the adjacent ends of both pins to draw them together. The cam may be located at the end of a rod which is capable of being held electromagnetically in a position in which the cam is disengaged from the lugs so that the pins are free to be urged by their respective springs into the recesses in the edges of the panels. However, further spring means are provided to move the rod into a position in which the cam engages the lugs and withdraws the pins from their recesses when ever the electro-magnet is de-energised. Thus the electro-magnet is normally energised so that the panel is locked in the closed position.However, if a fire occurs, the electro-magnet is de-energised and the panel is unlocked and swings into the vertical position. If the electro-magnet has been inadvertently de-energised, for example, by a false alarm, the panel may be returned to the closed position by the pneumatically controlled means.

When air is admitted to the pneumatic means to close the vent, the electro-magnet is energised so that the panel will be locked in the closed position.

For this purpose the pneumatic means are preferably controlled by an electro-magnetically controlled valve connected in the same electrical circuit as the electro-magnet which controls the locking means.

Methods of performing the invention will now be described with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side view partly in section of a smoke vent in accordance with the invention located in a wall of a building; Figure 2 is a side view on an enlarged scale of the smoke vent illustrated in Figure 1: Figure 3 is a side view partly in section of a smoke vent in accordance with the invention arranged in a roof light:: Figure 4 illustrates a plurality of smoke vents as shown in Figure 1 arranged side-by-side in the wall of the building; Figure 5 is a sectional side view of one of the smoke vents shown in Figure 4; Figure 6 is a perspective view of a modified smoke vent in accordance with the invention; Figure 7 is a side view of the smoke vent illustrated in Figure 6; Figure 8 is a scrap view of a part of the control apparatus for the smoke vent illustrated in Figures 6 and 7; Figure 9 is a side view of a different version of the smoke vent illustrated in Figures 6 and 7; Figure 10 is a side view of two smoke vents as illustrated in Figures 6 and 7 arranged in roof lights; and Figure 11 is a front view of two smoke vents as shown in Figure 10 arranged side-by-side.

The smoke vent illustrated in Figures 1 and 2 is fitted into an opening 1 in the wall 2 of a building.

The smoke vent includes a frame 3 which is fixed in water-tight fashion within the opening 1.

Pivotally mounted in the frame 3 is a glazed sash 4. As can be seen from Figure 1, the horizontal pivot axis of the sash is located slightly below the centre of the sash. Fitted near the lower end of one side of the sash is a strut 5 projecting inwardly into the building. The strut 5 is provided with a plurality of holes 6. A trunnion 7 is fitted to the frame 3 on the same side of the sash as the strut 5 near the upper end thereof. A pneumatic cylinder 8 is pivotally connected to the trunnion 7 and the piston rod 9 of the cylinder 8 is pivotally connected to the strut 5 by means of a pin 10 passing through one of the holes 6. In addition, a spring 11 extends between the trunnion 7 and another one of the holes 6 in the strut 5.

The pneumatic motor including the cylinder 8 and the piston rod 9 is single-acting and air is supplied to the end qf the cylinder remote from the piston rod 9 by a supply line 12 through a T-junction 13 and an adjustable restrictor valve 14. Thus, if air is supplied under pressure to the supply line 12, the piston rod 9 is driven out of the cylinder 8. The sash 4 is shown in the closed position in full lines and, in the open position, in broken lines. Thus it can be seen that extension of the piston rod 9 causes the sash to rotate about its pivot axis from the open position to the closed position. On the other hand, it will be seen that, in the absence of air under pressure in the supply line 12, the spring 11 acts to rotate the sash 4 from its closed position to its open position.The travel of the piston in the cylinder 8 is arranged to be such that opening of the sash is limited to approximately 450.

A latch member 1 5 is secured to the sash frame in the centre of the top rail thereof. This latch member includes a depression adapted to receive a ball 1 6 located in a cylinder housing 17.

The cylinder is connected by a pipe 18 to the T-junction 13.

The cylinder housing 1 7 is divided into two compartments by a membrane (not shown). The lower compartment contains the ball 16, and the upper compartment is in communication with the pipe 18. Thus, if air under pressure is supplied to the pipe 18, the ball 1 6 is forced downwardly with respect to the cylinder housing. Downward travel of the ball is limited by the diameter of the hole in the bottom of the cylinder housing so that the ball cannot be forced out of the housing by the air pressure on the membrane.

Since the pipe 18 is connected to the supply line 12 through the T-junction 13, the ball 1 6 will be urged downwardly whenever air under pressure is supplied to the cylinder 8. Thus, when the glazed sash 4 is moved from the open position to the closed position by the air pressure, the ball will protrude from the lower side of the cylinder housing 1 7 to its fullest extent. As can be seen particularly from Figure 2, the latch member 1 5 is provided with a chamfered leading edge 19 and, when this edge contacts the ball 16, it will force the ball upwardly into the cylinder housing against the air pressure.As rotational movement of the sash continues, the ball 1 6 will be forced by the air pressure into the recess in the top surface of the latch member 1 5. Thus, so long as air pressure is maintained in the supply line 12, the sash will remain locked by the ball 1 6 in the closed position. On the other hand, if the air pressure in the supply line 12 is removed and this line is connected to exhaust, the locking action of the ball 1 6 will be released and the sash will be opened by the action of the spring 11.

The operation of the smoke vent to clear smoke from the building will be as explained in U.K.

Patent Specifications Nos. 1 326 112 and 1 326 113, and the release of the air pressure in the supply line 12 may be controlled by the detection of smoke in the same manner as described in these Patent Specifications. However, when smoke has been cleared, the glazed sash 4 may be returned to the closed position by restoration of air pressure in the line 1 2 so that it is not necessary to close the sash manually.

Figure 3 shows a smoke vent similar to that illustrated in Figures 1 and 2 except that it is mounted in a roof light. An opening 21 is formed in a flat roof 22 of a building, the opening being defined by an upstanding cill 23. A frame generally similar to the frame 3 of Figure 1 is secured in water-tight fashion in one vertical face of the roof light, the top of which is closed by a glazed pitched roof 24. The use of a smoke vent in accordance with the present invention is particularly advantageous in these circumstances since a large number of vents will normally be provided in the roof of the building and closing such panels after they have been opened, for example, for testing or as a result of a false alarm, is a relatively arduous task unless the pneumatic closing means in accordance with the invention are provided.

Figure 4 shows a plurality of smoke vents 31, 32 and 33 of the kind illustrated in Figures 1 and 2 mounted side-by-side in a wall of a building. It will be seen that the supply lines 12 are connected through respective T-pieces 34 to a common air line 35 so that all the vents can be opened and closed in dependence on the air pressure in the line 35.

Figure 5 is a cross-sectional view of one of the smoke vents illustrated in Figure 4.

Figures 6 and 7 show a modified smoke vent in accordance with the invention in which the pneumatic cylinder 8 is replaced by a rotary actuator 41. The rotary actuator is mounted on the frame 3 of the vent by means of a mounting plate 42. The rotary actuator is connected to a supply line 43 through a variable restrictor valve 44 and serves to rotate its output member through a predetermined angle from a rest position when air under pressure is supplied to the line 43. When the air pressure is removed and the line 43 is connected to exhaust, a spring in the rotary actuator serves to restore its output member to the rest position.

The output member has a square socket which receives the square end 45 (Figure 8) of a shaft 46. The shaft extends across the full width of the frame 3, and is shown continuing to the adjacent smoke vent. Obviously, if desired, a releasable coupling may be included in the shaft between the two vents.

Located on the square end 45 of the shaft 46 is an operating lever 47. The end of this lever remote from the shaft is pivotally connected to one end of an arm 48. The other end of this arm is pivotally connected to a trunnion 49 mounted on the glazed sash 4. The shaft 46 passes through a bearing 50 on the left-hand upright of the frame 3.

A further square section is provided on the shaft 46 in the vicinity of the bearing 50, and a further lever 51 and arm 52 connect the shaft to a trunnion 53 on the left-hand upright of the glazed sash 4.

The operating sense of the rotary actuator 41 is such that, when pressure is supplied to the air line 43, the levers 47 and 51 are rotated in the direction necessary to close the vent. When pressure is removed from the line 43, the spring in the rotary actuator 41 rotates the levers 47 and 51 in the direction necessary to open the vents.

The angle through which the output member of the rotary actuator rotates is such that, in the open position of the vent, the glazed sash 4 s inclined at an angle of approximately 450 with respect to the frame 3.

As can be seen from Figure 6, the shaft 46 passes through a further bearing 54 on the righthand upright of the frame of the adjacent vent, and is connected to the sash of this vent by a lever 55 and an arm 56.

It will be seen from Figures 6 and 7 that the rotary actuator 41 is mounted on the outside of the building. This is possible because the rotary actuator is fully weatherproof. However, if weather conditions are particularly severe, the rotary actuator can be mounted within the building by the arrangement shown in Figure 9.

The locking arrangements for the modified form of smoke vent are the same as those provided for the vent illustrated in Figures 1 and 2. The cylinder 1 7 controlling the ball 1 6 is connected through a line 57 to the same source of air as the line 43 so that, when pressure is applied to close the vent, the ball 1 6 is urged outwardly to engage the latch member 15. Similarly, when the air pressure is released to allow the air vent to open under the influence of the spring in the rotary actuator, the pressure on the ball 1 6 is released to allow the latch member 1 5 to disengage.

it is to be understood that the modified form of smoke vent can be used in the wall of a building or may be used in a roof light generally similar to that illustrated in Figure 3. Figures 10 and 11 are respectively side and front views of modified roof vents of the kind illustrated in Figures 6 and 7 mounted in roof lights. In the particular case illustrated in Figure 11, it will be seen that separate rotary actuators 41 are provided for the two vents illustrated.

Claims (14)

CLAiMS

1. A smoke vent including a panel adapted to close an aperture in a building, said panel being mounted to pivot about a horizontal axis; spring means urging the panel to pivot about said axis outwardly with respect to the building; pneumatically operated means capable of causing said panel to pivot about said axis towards a closed position; and remote controlled locking means capable of holding said panel in the closed position against the action of said spring means, said locking means being arranged so that they are in the locked condition when air pressure is applied to said pneumatically operated means to cause them to urge the panel towards the closed position.

2. A smoke vent as claimed in Claim 1, wherein the panel is adapted to close an aperture in a wall of a building.

3. A smoke vent as claimed in Claim 1, wherein the panel is adapted to close an aperture in a roof light.

4. A smoke vent as claimed in any of the preceding Claims, wherein the locking means are pneumatically controlled.

5. A smoke vent as claimed in Claim 4, wherein the pneumatically controlled locking means include a ball which cooperates with a recess in a latching member in or on the panel, the ball being urged into the recess by air pressure.

6. A smoke vent including a panel adapted to close an aperture in a wall of a building, said panel being mounted to pivot about a horizontal axis located below the centre of gravity of the panel; spring means urging the panel to pivot about said axis outwardly with respect to the building; pneumatically operated lifting means capable of causing said panel to pivot about said axis towards a closed position; and pneumatically controlled locking means capable of holding said panel in the closed position against the action of said spring means, said locking means being arranged so that they are in the locked condition when air pressure is applied to said lifting means to cause them to urge the panel towards the closed position.

7. A smoke vent as claimed in Claim 6, wherein the pneumatically operated lifting means are in the form of a piston and cylinder, one pivotally mounted on the panel and the other pivotally mounted on a member which is fixed relative to the building.

8. A smoke vent as claimed in Claim 7, wherein said member is a bracket secured to the frame of the vent.

9. A smoke vent as claimed in Claim 7 or Clairn 8, wherein the length of the cylinder is such that it will allow the panel to move outwardly with respect to the building to an angle of substantially 450.

10. A smoke vent as claimed in any of Claims 6 to 9, wherein the pneumatically controlled locking means comprise a ball located in a cylinder housing which is divided into two compartments by a membrane, the lower compartment containing the ball, and the upper compartment being connected to the same air supply as the pneumatically operated lifting means.

11. A smoke vent as claimed in Claim 1 or Claim 6, wherein the pneumatically operated means controlling the panel comprise a rotary actuator.

12. A smoke vent as claimed in Claim 11, wherein the rotary actuator includes a spring adapted to move the output member of the actuator in the direction necessary to move the panel towards an open position, and wherein, when air under pressure is supplied to the rotary actuator, the output member is rotated in the direction necessary to move the panel towards a closed position.

13. A smoke vent as claimed in Claim 12, wherein the rotary actuator is mounted on a member which is fixed relative to the building, and wherein its output member is coupled to one end of a lever, the other end of which is pivotally connected to an operating arm which is itself pivotally connected to the panel.

14. A smoke vent including a panel adapted to cover an aperture in the roof of a building, said panel being mounted to pivot about a horizontal axis located in the vicinity of one edge of the panel; means urging the panel to pivot about said axis towards a vertical position; pneumatically operated means capable of causing said panel to pivot about said axis towards a substantially horizontal position in which it covers said aperture; and electro-magnetically controlled locking means capable of holding said panel in said substantially horizontal position.

1 5. A smoke vent substantially as hereinbefore described with reference to, and as illustrated in, the accompanying diagrammatic drawings.

1 6. Any features of novelty, taken singly or in combination, of the smoke vent as hereinbefore described with reference to the accompanying diagrammatic drawings.