GB2076143A

GB2076143A - Roof Ventilators

Info

Publication number: GB2076143A
Application number: GB8115701A
Authority: GB
Original assignee: Wilhelm Gebhardt GmbH
Current assignee: Wilhelm Gebhardt GmbH
Priority date: 1980-05-21
Filing date: 1981-05-21
Publication date: 1981-11-25
Also published as: DE3019267A1; NL8101871A; FR2483059A1; FR2483059B3

Abstract

A roof ventilator comprises a base, an upwardly open housing, and two shutters (8, 9) pivotally mounted at their lower edges to the base and coming together at their upper edges, when shut, to form a ridge roof-like structure. For normal ventilation, while at the same time keeping out rain, each shutter (8, 9) has an opening closable by a door (15, 16) hinged to the respective shutter (8, 9) at the top edge thereof. When the shutters (8, 9) are moved into the fully open position, the doors (15, 16) are shut. <IMAGE>

Description

SPECIFICATION A Roof Ventilation Unit The present invention is with respect to a roof ventilation unit on a roof at the top of a shaft within the building to be ventilated, and having an upwardly opening housing with a base-frame positioned at the top of said shaft, and having furthermore a roof-like structure for covering over the top end of the shaft and made up of two shutters hinged at their lower edges to the baseframe and coming together when shut at their top edges like the ridge of a roof.

For the ventilation of large rooms, for example open spaces in buildings used for trade purposes, there has been a development of late of roof ventilation units and the like which, on the one hand, make certain of ventilation without any danger of rain making its way into the building while, on the other hand, in the case of a fire in the building or other serious event, the largest possible cross-section may be made free for letting off smoke and gases produced by the fire.

Known systems on these lines are to be seen for example in German patents 1,276,880 and 2,018,949 but, however, so far such systems have been complex in structure and further not completely trouble-free and certain in function, while on the other hand, some of such prior art systems may not be fully opened so as to be equal to the full cross-section of the shaft because of parts of the shutters, support parts, gutters or the like being in the way of an upwardly moving air current. Putting it differently, in these prior art systems, the relation between the cross section which is aerodynamically free and the geometrically free opening, that is to say when the shutters are opened, is poor.

One purpose of the present invention is to take care of these shortcomings and to make certain of a design which, while of generally simple structure may be opened without any trouble in case of fire so as to give the greatest possible cross-section of the opening, the relation between the aerodynamically free cross-section and the geometrically free one being as nearly 1 to 1 as possible.

In the present invention, a roof ventilation unit on a roof at the top of a shaft within the building to be ventilated, and having an upwardly opening housing with a base-frame positioned at the top of said shaft, and having furthermore a roof-like structure covering over the top end of the shaft and made up of two shutters hinged at their lower edges to the base-frame and coming together when shut at their top edges like the ridge of a roof, is characterized in that the shutters take the form of a structure fully shutting off and covering over the top end of the shaft and in that each shutter has an opening and a ventilation door for shutting the opening and which may be opened when the shutters are shut.The design may more specially be such that the free ends of the shutters, when in the open position, are without an imaginary prism or cylinder with vertical sides running upwardly from said frame-base as its outline, the shutters being so placed in the open position that their planes are at an angle to each other such that the distance between the planes becomes greater in an upward direction, that is to say out of the space to be ventilated. In this respect the design may be well such that the shutters, when in the open position, make an acute angle with the axis of the cross-section and of the base-frame, that is to say so as to have an upwardly increasing distance between each plane and the axis.In this respect, the design may, for example, be such that the ventilation door is positioned against its shutter, for example resting against its outer face and so as to be parallel to it, the ventilation door being best made part of the shutter and hinged thereto. With these design measures, the outcome is a unit which is simple to put up, may be produced at a low price and, in case of fire, may be opened without any trouble so as to give the greatest possible cross-section, there being no parts of the structure then running into the freed cross-section in the way of the upward smoke or other current. The main sizes of the unit may then be made so as to be clearly smaller than other units designed on the same general lines.

A specially useful effect is produced if the ventilation doors are hinged at the free outer ends of their shutters, the design being then such, more specially, that the turning motion of the ventilation doors into their open positions and the turning motion of the shutters take place in opposite directions. The shutters and the ventilation doors are best designed with separate driving systems which are automatically kept in step with respect to the order of opening and shutting operations. A specially useful effect is produced if the one of the two shutters has, at its free outer edge, a rain-water gutter stretching across the housing for generally the full size thereof, the gutter taking up a position between the shutters, when the same are shut, between their top or outer free edges.In such a system, for completely dry ventilation, that is to say without any rainfall into the building under the ventilation unit, the ventilation doors may be lifted till about 50% of the cross-section is freed and uncovered, there then still not being any chance of rain making its way into the building. For ventilation in good weather conditions, and, on the other hand, in the event of a fire, the shutters, together with the gutter may be folded back away from each other so that, generally speaking, 100% of the cross-section is uncovered and freed.The control system for causing such two motions is so designed that, in the case of fire, the fluid power line for the actuator or actuators of the doors has a locking system, as for example a valve therein, stopping opening of the ventilation doors when the shutters are open while on the other hand the ventilation doors are automatically shut when the shutters are to be opened.On opening the shutters, this system makes certain that firstly the door without a gutter is moved completely open and then the shutter with the gutter is moved into the open position, while on shutting the ventilation unit, the order of events is changed round, this system offering the useful effect that in the case of a fire or the like the cross-section uncovered is, generally speaking, 100% of the shaft or of the housing, the last-named being used for guiding the air so that, with this design, in the case of a fire or the like, one is able to be certain that the smoke is fully let off from the building.A further useful effect is to be seen that if, as part of a further useful development of the invention, the housing and the shutters are of such a size and so in relation to each other that the opening motion of the shutters is not stopped, slowed down or in other way dependent on air currents so that the power needed for operation of the system is kept at a low level. The base-frame may have a glass dome in place of the housing, it then having the purpose of lighting, while if it has a driving system and a control system, it may be used for ventilation in good weather and for opening in the case of a fire. The base-frame may be furthermore used in connection with two different forms of apparatus of the sort in question here.

An account of one working example of the invention will now be given within the Figures acc mpanying the specification.

Figure lisa diagrammatic side view of the ventilation unit of the invention with the shutters in the shut position.

Figure 2 is a view of the unit of Figure 1 in a position in about which 50% of the cross-section is uncovered for dry ventilation.

Figure 3 is a diagrammatic side view of the unit of Figure 1 in the completely open condition (in case of fire).

The working example of the invention to be seen in the figures is in the form of a roof ventilating unit having a superstructure 1 placed at the top end of a shaft in the roof of the building 2 to be ventilated. The unit is made up of a baseframe 3 placed in or on the shaft and a housing 4 on the frame, the housing being open at its top end. Over the top end of the shaft there is a covering structure 5 which may be folded back as will become clear from the account now to be given of the structure of this cover.The housing is open at its lower end, its side walls being made up of part-walls 6 and 7 which are at an angle (L (alpha) to each other In a known way, the covering structure is made up of two shutters 8 and 9 hinged at their lower and outer edges at 10 and 11 to the base-frame 3 and which, when shut (see Figure 1) take the form of a roof with a roof ridge at the top, the top and inner edges 12 and 13 being next to each other but having a space 14 therebetween. The shutters 8 and 9 are the main shutters or doors and, as part of the invention, have the effect of fully covering over the cross-section "a" of the shaft when shut, the breadths "b" together naturally being greater than the breadth of the opening "a" of the shaft.As a further part of the invention, the shutters each have an opening, which may, for example, be a rectangular opening able to be shut by ventilation doors 1 5 and 16 which may be opened when the shutters are in the shut position. In Figure 2 it will be seen that, when the shutters 8 and 9 are shut, the ventilation doors 1 5 and 1 6 are open, such opening best being to such a degree that about 50% of the overall cross-section of the greatest possible opening at the top end of the shaft is freed or uncovered. When the shutters 8 and 9 are fully opened (see Figure 3), the ventilation doors 1 5 and 16 are placed against the outer faces of the shutters, and parallel thereto, so that the openings are shut off.It will be seen from the account given so far that in the form of the i invention in the present case, each door takes the form of part of the shutter on which it is hinged.

It will be seen from the three accompanying Figures that the ventilation doors 1 5 and 1 6 are each hinged at the free inner ends (top ends) of their doors 8 and 9 at 17 and 18, the design being such as part of the invention (see specially Figures 1 to 3) that the turning motion of the ventilation doors into the open position (as marked by arrows 15a and 16a) and the opening motions of the doors into the open positions (arrows 8a and 9a) are opposite while shutting motion is in the opposite direction to the opening motion. Putting it differently, the shutting motions of the shutters and their doors are opposite.

For producing the useful effects noted of the invention, the shutters and their ventilation doors each have a driving system, the driving systems of the shutters and doors being so designed and so matched that, on opening the shutters the ventilations doors are automatically shut and when the shutters are opened, the ventilation doors thereof are stopped from being opened. It is possible for example to have, as a driving system for each door and shutter, a pneumatic or hydraulic actuator, as numbered 19 and 20 in Figure 2 for the ventilation doors and 21, 22 in Figure 3 for the shutters. Such actuators are controlled using valves.On looking at the system of Figures 1,2 and 3, that is to say the present working example of the invention, in three different stages of operation -- completely shut position in Figure 1, normal ventilation position in Figure 2 and completely open position in case of fire or other catastrophe in Figure 3, the reader will quickly see that, on changing over from the completely shut-up position into the normal ventilation position, it is oniy necessary for the ventilation doors 15, 16 to be opened as marked by arrows 15a and 1 6a in such a way that about 50% of the overall cross-section is uncovered or freed while, on changing over into the completely opened position, to be seen in Figure 3, the shutters 8 and 9 are completely opened (as marked by arrows 8a and 9a) while at the same time the ventilation doors 1 5 and 1 6 are shut by being moved in the direction opposite to arrows 1 5a and 1 6a so that such doors come to rest against the outsides of shutters 8 and 9. In this respect, it will be seen that the free ends of the shutters, when the shutters are opened, are completely without an upright prism or cylinder with its base as the top opening of the shaft or opening through the roof, and that the planes of the shutters are at an angle to each other, that is to say so that the distance between them becomes greater in an upward direction out of the space to be ventilated.When completely opened back, shutters 8 and 9 make an acute angle with an upright running through the middle of the opening in the roof, that is to say the opening of the base-frame (see Figure 3) the full crosssection of the base-frame being uncovered. In this position the shutters are still within the housing 4.

One of the two shutters, that is to say the shutter 9 in the Figures has at its free top inner edge 1 3 a rain gutter 23, stretching in the lengthdirection of the housing for generally the full length thereof and when the shutters are shut, it will be seen that the space 14 between their top ends is shut off underneath by this gutter. The free, inner upper end of the shutter 8 without the gutter, that is to say at position 12, has a lip 24 stretching in the length-direction and running down towards the gutter so that there is no chance of rainfall making its way into the room to be ventilated when the shutters are shut.For making certain of trouble-free functioning of the unit and, at the same time, making certain that the opening of the shaft or of the base-frame is kept covered over fully when rain is falling, while on the other hand for completely uncovering and opening up the shaft's top end in the case of a fire or other catastrophe, the operation of the shutters is such that on opening up the shutters, the shutter 8 without any gutter, is firstly moved completely into the opened position and it is only when this motion has been completed that the other shutter 9 is moved into the opened position while on the other hand, when the shutters are shut, the guttered shutter 9 is the first one to be shut and then shutter 8 is moved into its shut position.

For producing a weatherproof join between the base-frame and the main shutters, covering lips are used, which are joined to an L-section or other edge on the base-frame, for example by adhesive, near the other part, that is to say the shutter.

Furthermore, for producing a weatherproofing effect between the shutter and its door, there is, in each case, a lip seal which is fixed on a part of the door which is near the shutter, for example on an L-section part thereof, for example by adhesive. This makes producing the ventilation unit very much more simple.

As will be seen from the account given so far, the important purpose and function of the unit of the invention is to make certain that it may be completely opened in case of fire for uncovering the greatest possible cross-section without any inner parts being in the way of the current through the fully opened ventilation unit. In the case of such a design of the invention, the relation between the aerodynamically free section and the geometrically free section is generally equal to 1, this being a very good Figure; nevertheless, the design is simple and the unit may be produced at a low price.

For dry ventilation, that is to say in such a way as to fully keep out rainfall, of the spaces under the unit the ventilation doors are lifted till about 50% of the cross-section is opened and in this position it is not possible for any rain to make its way into the space under the ventilator. For ventilation under good weather conditions or in case of fire, the shutters, together with the gutter, are folded fully open so that almost 100% of the cross-section is uncovered. The control of these two motions takes place in such a way that, in case of fire, the lines for powering the actuators of the ventilation doors are shut down, this stopping the ventilation doors being opened when the shutters are open and on the other hand makes certain that the ventilation doors are completely shut when the shutters are to be open.

The housing is used for guiding the air on ventilation inasmuch as, in case of fire, a good draft effect for the smoke is produced.

Furthermore, wind will have no effect on the opening of the shutters so that the power needed for this purpose is not very great, this being because, even in the fully open position, the shutters are still within the housing and do not come to a higher level (see Figure 3).

Claims

1. A roof ventilation unit for mounting on a roof at the top of a shaft within a building to be ventilated, the unit having an upwardly opening housing with a base-frame to be positioned at the top of said shaft, and a roof-like structure for covering over the top end of the shaft and comprising two shutters hinged at their lower edges to the base-frame and coming together when shut at their top edges like the ridge of a roof, the shutters defining a structure fully shutting off and covering over the top end of the shaft and each shutter having an opening and a ventilation door which can shut the opening and which may be opened when the shutters are shut.

2. A ventilation unit as claimed in claim 1, wherein, in the opened position of the shutters their top edges are without an imaginary cylinder with vertical sides running upwardly from said base-frame as its outline.

3. A ventilation unit as claimed in claim 1 or 2, wherein the shutters extend at an angle in relation to each other, in their open position, with the distance therebetween increasing in an upward direction.

4. A ventilation unit as claimed in any of claims 1 to 3 wherein, when the shutters are fully opened, the ventilation doors are placed thereagainst for shutting the openings therein.

5. A ventilation unit as claimed in any of claims 1 to 4, wherein each ventilation door is hinged on its shutter.

6. A ventilation unit as claimed in claim 4, wherein each ventilation door is hinged on its shutter at the top edge thereof.

7. A ventilation unit as claimed in any of the preceding claims, wherein the housing and the shutters are of such a size and so placed in relation to each other that wind or other air currents have no effect on opening motion of the doors.

8. A ventilation unit as claimed in claim 7, which so designed that the shutters, when opened, are still fully within the housing.

9. A ventilation unit as claimed in any of the preceding claims, wherein opening motion of the ventilation doors is in a direction opposite to opening motion of the shutters.

10. A ventilation unit as claimed in claim 9, wherein the shutters and their ventilation doors have separate fluid-powered actuators for opening and shutting motion, the actuators being so placed in circuit with each other that, opening the shutters, the ventilation doors, if opened, are shut, and when the shutters are in their open positions, the ventilation doors are locked in their shut positions.

11. A ventilation unit as claimed in any of the preceding claims, wherein, when the shutters are fully opened, the full cross-section of the baseframe is uncovered.

12. A ventilation unit as claimed in any of the preceding claims, wherein pne of the two shutters has, at its top edge, a gutter extending generally the full distance across the housing while the other shutter, at its top edge, has a lip, which, in the shut position of the shutters, is positioned over and points into the gutter so that downwardly falling rainwater is taken up by the gutter, into which some of the rain is guided by the lip, the shutter with the lip being designed to be lifted clear of the gutter on the opening the shutters, and on shutting the same the guttered shutter is shut before the lipped shutters

13. A ventilation unit as claimed in any of the preceding claims, wherein weatherproofing systems are provided between the base-frame and the shutters, the weatherproofing systems being made up of a lip on the base-frame or on the shutter.

14. A ventilation unit as claimed in claim 137 in which said weatherproofing lip is on an L-section part of the base-frame or on the shutter.

1 5. A ventilation unit as claimed in any of the preceding claims, wherein a weatherproofing system is provided between each ventilation door and its shutter; the latter weatherproofing system having a lip fixed on the shutter or on the ventilation door.

1 6. A ventilation unit as claimed in 15, wherein the weatherproofing lip is fixed to an L-section part on said ventilation door or said shutter.

1 7. A ventilation unit as claimed in any of claims 1 3 to 16, wherein the or each weatherproofing lip is fixed in position by adhesive.

1 8. A ventilation unit substantially as hereinbefore described with reference to the accompanying Figures.

19. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.