Device driving vent covers, especially for smoke extractor flap

Abstract

 Device includes a link mechanism of the drive mounted inside the venting opening between the fixed frame and the swinging frame, having an arm (7) connected by the base articulation (8) with the fixed frame at the side of the hinge (5) and a piston actuator (9) mounted in an articulating way between the arm (7) and the swinging frame. The arm (7) of the drive mechanism consists of many links, which are connected by chain articulations (15) and are provided by bottom and upper stops. The bottom stops limit the relative downward deflection of the links to keep the rectilinear form of the arm (7), and the upper stops limit the upward deflection of the links, letting the arm (7) to assume the form of an open polygon. The piston actuator (9) is firmly fixed to the end link of arm (7), and is located below and at a distance from the pins of the chain articulations (15) in which its cylinder adheres to all of them when the arm (7) is rectilinear. When the venting cover is being opened and is partly open in position II at approximately 45° from level, the first link of the arm (7) leans against the base element of the fixed frame, while in the fully open position (III) determined by the upper stops of the links when the piston rod is completely extended, the end link assumes a position which is above (b) and outside (c) the axis of the hinge (5).

Description

[0001] The subject of the invention is a device driving vent covers, especially for smoke extractor flap, i.e. covers of openings connecting the inside of buildings with the open atmosphere for venting purposes or to let out smoke and gases during a fire.

[0002] Known smoke extractor flap driving devices consist of a fixed frame arranged on the edge of the venting opening, and a swinging frame to which the vent cover is fixed. The swinging frame is connected with the fixed frame by hinges the axis of which is parallel to one side of the fixed frame and is driven by a link mechanism arranged inside the venting opening between the fixed and the hinged frames.

[0003] In the solution presented in FR 2 878 883, the driving mechanism has an arm connecting its upper end by a base articulation with the fixed frame. The bottom end of the arm is connected by an articulation with the piston head of the actuator. The piston rod end is connected with the swinging frame by an articulation of the cover, which is fixed close to its side opposite to the hinge. A moving support is fastened to the axle of the base articulation serving to stop the cylinder of the actuator at the end of cover opening phase.

[0004] At the beginning of opening the cover, the arm is resting on the base element of the fixed frame. Then the piston rod is moving out, the articulator swings open to an approximately vertical position at which its cylinder touches the moving support. From then on, when the piston rod moves further out and the cover is being opened, the cylinder tilts together with the arm rotating about the base articulation. When the cover is completely opened, almost half of the actuator cylinder remains inside the venting opening, which situation during a fire can lead to damaging the seals of the actuator.

[0005] The solution presented in this invention is specific by the structure of the link mechanism of the drive. The arm of the mechanism consists of many links connected together by chain articulations, the links being fitted with bottom stops limiting the relative downward swinging of links to a straight form of the arm, and with upper stops limiting the swinging up of the links, and causing the arm to take the form of an open polygon.

[0006] The piston actuator is fixed at the end link of the arm in a position reaching down and placing the actuator cylinder close to the arm so as to adhere to all pins of the chain articulations when the arm links are straight, and also so that the cylinder axis meets the axis of the base articulation.

[0007] The first chain link, when the cover is being opened partly to an angle of approximately 45° above horizontal, rests on the base element of the fixed frame. When the cover is completely open, which is determined by the upper link stops and full extension of the piston rod, the end link position is above and outside the hinge axis. The piston actuator, which is fastened to the end link, is located sideward from the upper edge of the venting opening and much higher than it, thereby considerably easing the outflow of gases to the atmosphere and reducing the thermal load on the actuator.

[0008] It is preferable to shape the cross section of external and internal links of the arm in form of the letter C and with different spacing of their arms, arranging the links alternately. The links have their web cut-out at the ends and their arm wings mate in and out in the subsequent links. The links are connected by articulation pins arranged symmetrically between the edges of the webs being joined. The bottom stops are formed by the upper edges of the internal link arm wings, which in the straight position of the arm rest on the internal surface of the next external link. The upper stops are formed by the adjacent edges of the webs of external and internal links.

[0009] A further development of the invention consists in fixing the piston actuator to the end link by an actuator articulation on the piston rod cylinder head and by a band hanging on the chain articulation pin of the end link.

[0010] A still further invention improvement incorporates priority locks between the external and internal links. Each link is provided with a locking pin sliding in an elongated hole made at the center, between the chain articulations in the arms of the external and internal links. The position of the locking pin in the elongated hole is determined by cams grasping it on both sides. The cams, made on the face edges of the arm wings, have bottom cams made on the link ends at the side of the base articulation, and upper cams on the opposite link ends.

[0011] In order to increase the stiffness of the arm being bent into the form of an open polygon over the hinge, a side support is fastened to the fixed frame, the abutment face of which comes into contact with the web of the adjacent link. The position of this link is determined by the upper stops of links connecting it with the first link, which is resting on the rigid element of the fixed frame.

[0012] The description of an embodiment of the smoke extractor flap driving device shown in the drawings fully illustrates the invention. Fig. 1 shows the vertical section of the device in closed flap position, fig. 2 presents the same section of the device in partly open position of the flap, fig. 3 is the side view of the arm unit with the piston actuator, fig 4 shows the arm elements in exploded view, figures 5, 6 and 7 are successively the cross-sections of the arm in the section lines marked in fig.4 by A-A, B-B, and C-C, figures 8 to 12 present one after the other the characteristic phases of bending the arm in the course of opening the flap after the position shown in fig.2, and fig.13 depicts the vertical section of the device in fully open flap position.

[0013] In a roof of a big building, above two shafts or halls, are made the venting openings 1 closed by covers 4, which are turned aside by the link mechanism of the driving unit A.

[0014] The cover 4 is fixed to the swinging frame 3, which is connected by the hinge 5 with the fixed frame 2 set on flange structure of the venting opening 1. The hinge axis 5 is parallel to one side of the fixed frame 2.

[0015] The link mechanism of the drive A consists of the arm 7 fixed at the side of the hinge by the base articulation 8 to the fixed frame 2, and of the piston actuator 9 mounted between the end of the arm 7 and the swinging frame 3.

[0016] The construction of the arm 7 consists of many links: the first link 12, the external links 13a and 13b, the internal links 14a and 14b, and of the end link 16, which are connected together by the chain articulations 15. The cross section of all links - 12, 13a, 13b, 14a, 14b, and 16 - has the shape of the letter "C", the web of which is situated horizontally and pointing up, and the spacing of the arms is alternatively d1 and d2. The web of the links is cut-out at their ends, the arm wings 17 resulting from the cut-outs grasp or penetrate in each other in an alternating way, and are connected together by the chain articulations 15 in the overlapping areas.

[0017] The chain articulations 15 are symmetrically located between the edges of the webs of the connected links, for example in the center of the spacing between the edges of external link edge 13a and the internal link 14a. The edges of the adjoining webs of the external links 13a, 13b and internal links 14a, 14b form the upper stops 20. The upper stops 20 determine on all link connections the relative upward break angle β between links, which in this example is β = 25°. All links have also their bottom stops 19, which are formed by the upper edges of the arm wings 17 of the internal links 14a and 14b resting in the vertical position of the arm 7 on the internal surface of the webs of the adjacent external links 13a and 13b. The bottom stops 19 restrict the relative downward swing of the links 12, 13a, 13b, 14a, 14b, 16 to the rectilinear form of the arm 7.

[0018] The piston actuator 9 is rigidly fastened to the end link 16 by its articulation 10 on the piston rod head of the cylinder and by the band 18 hanging on pin of the chain articulation 15 of the end link 16.

[0019] When all links 12, 13a, 13b, 14a, 14b, and 16 of the arm 7 are set rectilinearly, the piston actuator 9 is situated below and at the distance a from the chain articulation pins 15, its cylinder abutting on all of them. The axis of the piston actuator 9 meets then the axis of the base link 8. The first link 12 of the arm 7, during the opening phase of the cover 4 in the partial opening position II at an angle of approximately 45° to horizontal, rests on the base element 6 of the fixed frame 2 in point P. When the cover 4 is fully open in position III and the piston rod is completely extended, the arm 7 assumes the shape of an open polygon with the angle β between its links, which is determined by the upper stops 20 of the links. The end link 16, to which the piston actuator 9 is rigidly fastened, assumes then a position above and outside the axis of the hinge 5 - which in fig.13 is indicated by the dimensions b and c respectively.

[0020] The external links 13a, 13b and the internal ones 14a, 14b are interconnected by the priority locks 21. Their task is forcing on the links successive bending of each other according the sequence: 12 -14a - 13a - 14b - 13b - 16 in the opening phase of the cover 4 and the reversed sequence in the closing phase. Each priority lock 21 has a locking pin 22, which is sliding in the elongated hole 23 made centrally between the chain articulations 15 in the arms of the external links 13a, 13b and internal links 14a, 14b. The lengthwise position of the locking pin 22 in the elongated hole 23 is determined by the cams 24 enclosing it from both sides, which are made in the face edges of the arm wings 17. At the side of the base articulation 8, the cams 24 have bottom seats 25 made in the ends of the links 13a, 14b, 13b, and 16, while the ends of the links 12, 14a, 13a, 14b are provided with the upper seats 26.

[0021] The stiffness of the arm 7 being bent upwards in the vertical plane into an open polygon is enhanced by the side support 27, which is fixed to the upper surface of the fixed frame 2. The abutment edge K of the side support 27 comes into contact with the web of the link 13a, which adjoins it sidewise in its position determined by the upper stops 26 of the links 12, 14a, and 13a connecting it with the first link 12 leaning against the base element 6 of the fixed frame 2. To meet that condition in practice, it is useful to provide an adjustment of the projection distance of the side support 27.

[0022] The "opening signal" of the cover 4, initiated manually lub automatically by a smoke or heat sensor, controls the supply valve of the piston actuator 9. In the opening sequence of the cover 4 occurr three characteristic phases of its movement:

• the first phase, including the range from the closed position I to the partly open cover position II when the first link 12 leans against the fixed frame 2 in point P, which is shown in the figures 1 and 2 of the drawing,
• the second phase, from the partly open position II to the position characterized by resting of the external link 13a on the side support 27, which is shown in the figures 8 and 9, and
• the third phase, from the position shown in fig.9 to the fully open position III of the cover, shown in fig.13.

[0023] During the first phase, the arm 7 is rectilinear; the cylinder of the piston actuator 9 leans against all pins 15 of the chain articulations. When the arm 7 reaches position II, the first link 12 is blocked due to meeting the fixed frame 2 in the point P. That moment occurs when the axis of the piston actuator 9 is inclined at an angle α of about 60° from a horizontal line, and determines the reference line I, which corresponds to the inclination of the cover 4 of about 45°. Starting from passing the reference line I, begin the phases 2 and 3, when the links of arm 7 start to bend on the chain links 15.

[0024] In the second phase further extension of the piston rod causes first the deflection of the internal link 14a on the chain articulation 15 from the line of the first link 12. During that deflection, the locking pin 22 is initially held in the elongated hole 23 of the internal link 14a in the position of the bottom seat 25 of the external link 13a, and at the end of the deflection, when the edges of the upper stops 20 come closer to each other, the locking pin 22 falls down into the upper seat 26 of the first link 12. The position of the elements at that time is shown in fig 8, at which the cylinder of the piston actuator 9 still adheres to all chain articulation pins 15. Further extension of the piston rod during phase 2 causes the external link 13a to deflect from the line of the internal link 14a. The deflection by the next angle β determined by the upper stops 20 of the internal link 14a and the external link 13a causes the external link 13a web to meet the edge K of the side support 27. The locking pin 22 in the elongated hole 23 of the internal link 14a is getting locked in the upper seat 26 of the first link 12 by the cam 23 on the bottom wing of the arms 17 of the internal link 14a, and at the same time the locking pin 22 in the elongated hole 23 of the external link 13a falls into the upper seat 26 of the internal link 14a.

[0025] In the third phase, the consecutive deflections of the links by the angle β are shown in fig. 10, 11, and 12. During the deflections of the links in the phase 2 and 3, the center line of the piston actuator 9 follows the line of the end link 16. Full opening of the cover 4 in position III shown in fig.13 is achieved upon swinging it by the angle γ = 160° from its closed horizontal position I.
When the cover 4 is being closed, the "straightening" deflections of links and the opening of the priority locks 21 occur in reversed sequence.

List of parts

[0026] 

1

venting opening

2

fixed frame

3

swinging frame

4

vent cover

5

hinge

6

base element

7

arm

8

base articulation

9

piston actuator

10

actuator articulation

11

cover articulation

12

first link

13a, 13b ...

external link

14a, 14b ...

internal link

15

chain articulation

16

end link

17

arm wing

18

band

19

bottom stop

20

upper stop

21

priority lock

22

blocking pin

23

oval hole

24

cam

25

bottom seat

26

upper seat

27

side support

I

closed cover position

II

partly open cover position

III

full open cover position

A

link mechanism of the drive

a

distance of piston actuator from chain pins

b

vertical distance between actuator articulation and hinge axis

c

horizontal distance between actuator articulation and hinge axis

d1

spacing of external link arms

d2

spacing of internal link arms

I

reference line

P

rest point of the first link at the base element of the fixed frame

α

inclination angle of the reference line

β

relative breaking angle of link

γ

full opening angle of cover

K

abutment edge of the side support

Claims

1. Device driving vent covers, especially for smoke extractor flap, comprising

- a fixed frame (2), mounted on the rim of the venting opening (1),

- a swinging frame (3) of the cover (4) connected with the fixed frame (2) by the hinge (5), the axis of which is parallel to one side of the fixed frame (2), and

- a link mechanism of the drive (A) mounted inside the venting opening (1) between the fixed frame (2) and the swinging frame (3), having an arm (7) connected by a base articulation (8) with the fixed frame (2) at the side of the hinge (5), and

- a piston actuator (9) mounted in articulating way between the arm (7) and the swinging frame (3) by means of the cover articulation (11) close to the side opposite to the hinge (5),

characterized in that

- the construction of the arm (7) of the drive mechanism (A) consists of many links (12), (14a), (13a), (14b), (13b), (16) connected together by chain articulations (15), the links being provided with bottom stops (19) limiting the relative downward deflection of these links to a rectilinear form of the arm (7) and with upper stops (20) limiting the upward deflection of these links providing an open polygon form to the arm (7), while

- the piston actuator (9) is rigidly fixed to the end link (16) of the arm (7) being situated below and at a distance (a) at which its cylinder adheres to all chain articulation (15) pins when the links (12), (14a), (13a), (14b), (13b), (16) of the arm (7) are in rectilinear arrangement, and also so that the cylinder axis meets the axis of the base articulation (8), and so that

- the first link (12) of the arm (7), when the cover (4) is being opened to the partly open position (II) at an angle of about 45° from level, leans at point (P) against the base element (6) of the fixed frame (2), and

- the link (16) in fully open position (III), determined when the piston rod is completely pushed out by the upper stops (20) of the links (12), (14a), (13a), (14b), (13b), (16), assumes the position above (b) and outside (c) the hinge (5) axis.

2. Device according to the claim 1 characterized in that the arm (7) consists of external links (12), (13a), (13b) and internal ones (14a), (14b), (16) with a cross-section in form of the letter "C", differing alterantely by the spacing (d1), (d2) of their arms, the web of the links being cut-out, and the so formed arm wings (17) grasping or penetrating in each other in an alternating way, and being connected together by the chain articulations (15) in the overlapping areas, which are located symmetrically between the web edges of the connecting links (13a), (14a), the bottom stops (19) of the links constiting of the upper edges of the arm wings (17) of the internal links (14a), (14b) meeting in the rectilinear position of the arm (7) the web inner surfaces of the adjoining external links (13a), (13b), and the upper stops (20) consisting of the adjoining edges of the webs of external (13a), (13b) and internal (14a), (14b) links.

3. Device according to the claim 1 characterized in that the piston actuator (9) is fixed to the end link (16) by the actuator articulation (10) on its piston rod head, and by a band (18) hanging on the pin of the chain articulation (15) of the end link (16).

4. Device according to the claim 2 characterized in that the external links (12), (13a), (13b) and internal links (14a), (14b), (16) are interconnected by priority locks (21) of which each is provided with a locking pin (22) sliding in a elongated hole (23) made centrally between the chain articulations (15) in the arms of the external links (12), (13a), (13b) and internal links (14a), (14b), (16), the position of which in the elongated hole (23) is determined by the cams (24) grasping it from both sides, the cams being made on the face edges of arm wings (17) and being provided with bottom seats (25) made in the ends of the links (13a), (14b), (13b), (16) at the side of the base articulation (8) and upper seats (26) on the opposite ends of the links (12), (14a), (13a), (14b).

5. Device according to the claim 1 characterized in that a side support (27) of the arm (7) is mounted to the fixed frame (2), the abutment edge of which (K) comes in to contact with the web of the adjoining link (13a) in its position determined by the upper stops (26) of the links (12), (14a), (13a) connecting it with the first link (12), leaning against the base element of the fixed frame (2).

Drawing