Fume-Extraction Flap Opening and Closing Mechanism

The subject of this invention is the fume-extraction flap opening and closing mechanism.

A fume-extraction flap opening and closing mechanism known from Polish patent application No. P-342350 has a lever with one end in pivot joint with the beam of the flap support structure and the other end, also pivot joint with the actuator cylinder having the cylinder rod in pivot joint with the flap lug, together with one end of a tie rod, the other end of which in connected with the lock of said mechanism, said lever being also in its middle part in pivot joint with a tie rod. The other end of said lever is connected with a lug of said flap. Besides, said mechanism has an additional electric actuator fixed to the support structure of the fume extraction flap and provided with a catch, the other end of which is located in the stub pipe of the lock affixed to the fume-extraction flap. In turn, the lock of said mechanism consists of plate element integrally connected with the stub pipe having a sleeve fixed perpendicularly to its side wall. Said sleeve contains a piston valve inside it, whereas the stub-pipe wall is provided with a hole for one end of the piston valve and the other end of the piston valve is connected with one end of the tie rod, the other end of which, together with actuator rod, is in pivot connection with the lug yoke of the fume-extracting flap.

In turn, the fume-extraction flap opening and closing mechanism revealed by Polish patent application No. P-338203 has a system of levers provided with gas springs, the lower part of said system being in pivot connection with ventilation-hole frame and its upper part connected to the frame of the hinged fume-extraction flap covering said hole. Besides, the mechanism contains a lever in pivot joint with one end to adjustable holder on a fixed beam. Its other end is in pivot joint with connector, the other end of which is in pivot joint with the adjustable holder fixed on the fume- extraction flap, said connector and said lever being in pivot joint with the actuator cylinder and actuator piston rod of at least one gas spring.

Another Polish patent application No. F-336399 reveals a lock of fume-extraction flap opening mechanism having a tie rod of adjustable length with one end in pivot joint with permanent connectors fixed together with movable catches to an axle held in clamping rings, and the other end of said tie rod is, together with pneumatic actuator rod, in pivot joint with movable connector that is in articulated joint with the body of fume-extraction flap frame. Besides, the lock is provided with stationary catches fixed to he upper part of the fume-extraction flap body. Said catches constitute snap fasteners with movable catches.

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Polish patent application No. P-368264 reveals fume-extraction flap opening mechanism consisting of a holder fixed to the front part of the fume-extraction flap base and in pivot joint with one end of the lever, the other end of which is in pivot joint with the lower part of pneumatic actuator provided with shiftable clamping ring which is in pivot joint with one end of a tie rod, the other end of which is in pivot joint with the upper end of a holder. The end of piston rod of that actuator, as well as one end of movable connector, are in pivot joint with the clamping ring fixed to the front part of the hinged frame of fume-extraction flap. In its middle part, said connector is in pivot mounting on bolt that is mounted in said clamping ring, while the lower end of the movable connector is in articulated joint with one end of the tie rod of movable catch, the other end of which is connected with lower end of fixed connector provided with movable catch, and the other of said connector is pivotally mounted in the middle clamping ring fixed to the to the front part of the hinged frame. The objective of his invention was to develop a simple and compact design of the fume-extraction flap opening and closing mechanism, ensuring reliable functioning of fume-extraction flaps, for their opening even to 155°, as well as permitting maintaining of constant flap position at any set angle of its opening. The fume-extraction flap opening and closing mechanism of the present invention consists of a rocking lever, with its horizontal beam in pivot joint with one end of the roof-port frame element, and of two gas springs. Lower end of one of the gas springs is in pivot joint with the other end of the horizontal beam and its upper end is in pivot joint with a holder fixed to the frame of the fume-extraction flap. The upper end of the other gas spring is in pivot joint with the upper end of vertical beam of the rocking lever while the lower end of that gas spring is in pivot joint with the holder fixed to the lower part of the frame. Said holder is also connected to one end of the tensioning spring, the other end of which is connected to lower end of a (limiting) stop and, moreover, the middle part of the frame of the fume-extraction flap and the upper part of the roof-port frame are provided with holders connected to each other with at least one blocking cord. Favorably, the roof-port frame contains a horizontal crossbar element located in the lower part of the frame. It is also favorable that the (limiting) stop in the upper part has a vertically situated bracket for the vertical beam of the rocking lever, whereas the middle part of the (limiting) stop rests against a retainer that is perpendicular to the horizontal element of the frame. Also, favorably, the front part of the roof- port frame and that of the fume-extraction flap frame have rotating rollers mounted on them and bound with cord having the other end hitched to the lower part of the (limiting) stop that cooperates with the tensioning spring. The fume-extraction flap opening and closing mechanism of this

invention has a simple and compact design that meets all requirements related to functional reliability of fume-extraction flaps in case of a fire

85 hazard. Its design enables increasing the opening angle of the fume- extraction flap as well as raising the reliability of lock functioning during both flap opening and closing. Fitting the mechanism with blocking cord and with angular rocking lever enables to keep open flap at fixed position at 140°. Besides, the use of additional cord, located in the front part of the

90 roof port facilitates the closing of the fume-extraction flap as well as enables the regulation of flap opening and closing in the angle range of even 155°.

The subject of this invention is shown in one of its embodiments on the accompanying illustrative drawings, where fig. 1 is a fragment of the

95 roof port covered by fume-extraction flap in vertical cross-section with simplified flap opening and closing mechanism installed in closed position, fig. 2 is the same fragment of the roof port frame with opened fume-extraction flap and the flap opening and closing mechanism, fig. 3 shows the same fragment of the roof port frame with closed fume-

100 extraction flap and a more detailed flap opening and closing mechanism in vertical cross-section, and fig. 4 shows the same fragment of the roof port frame with opened fume-extraction flap and a more detailed flap opening and closing mechanism.

The lower part of the frame 1 of the roof port 2, in pivot joint with

105 the fume-extraction flap 3 _. , mounts a cross bar 4 with its middle section in pivotal connection on pin 5_ with one end of longer horizontal beam 6 of the rocking lever 7 and the other end the beam 6 being provided with perpendicular shorter beam 8 of said rocking lever. The other end of the horizontal beam 6 is in pivot joint, on pin 9, with the lower end of the gas

110 spring 10, the upper end of which is in pivot joint, on pin ϋ, with the holder JL2 mounted on the frame j_3 of the fume-extraction flap 3 _. - In turn, the upper end of the vertical beam 8 of the rocking lever 7 is in pivot joint, on pin 14, with the upper end of the other gas spring 15 _. , the lower end of which is in pivot joint, on pin 16, with the holder J/7 fixed to lower part of

115 the frame 1 of the roof port 2. The pin 16 is also connected with one end of the tensioning spring 18 _. having the other end hitched to the lower end of (limiting) stop _. 19.

The (limiting) stop 19 is provided in its upper part with bracket 20 that is perpendicular to it and supports the vertical beam 8 of the rocking

120 lever 7 in the opened position of the fume-extraction flap 3 _. . The rocking lever 7 is supported in its middle part on the retainer 21 that is mounted perpendicular to the cross bar 4. Moreover, two holders 22, provided with pins 23, are mounted to the middle part of the frame 13 of the fume- extraction flap 3, and two holders 24, provided with pins 25, are mounted

125 to the upper part of the frame 1 of the roof port 2, whereas the end loops

26 of blocking cords 27 that limit the opening of fume-extraction flap 3 _. to 140°, are hitched to pins 23 and 25. In turn, the front part of the frame JJ3 of the fume-extraction flap 3 is provided with catch 28 of the cord of a winch with thermal safety device not shown in the drawing. In the other embodiment on the invention, not shown in the drawing, the opening and closing mechanism for fume-extraction flap 3 has one holder 22 fixed to the middle part of the frame JJ3 and one holder 24 mounted to the upper part of the frame i of the roof port 2 and both holders are connected to each other with one blocking cord 27. In another embodiment on the fume-extraction flap opening and closing mechanism, shown in Fig. 3 and 4, the front part of the frame i of the roof port 2 and the frame 13 of the fume-extraction flap 3 are equipped with rotating rollers 29, 30 and 31 bound with cord 32 that serves for flap closing, with one end hitched to lower part of the (limiting) stop 19 cooperating with the tightening spring JjS.