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 port 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-port frame and its upper part connected to the frame of the hinged fume-extraction flap covering said port. 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. P-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.

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 has a vertically positioned fixed beam with its upper end provided with yoke and in pivot joint with one end of a tie rod that is connected with the clamping ring of the lower end of servo actuator, whereas the lower end of the beam is in pivot joint with one end of the lever the other end of which is in pivot joint with the end of said servo actuator. The upper end of the vertical beam mounts the fixed part of a lock, which has its movable part connected, together with the end of the actuator rod, with one end of movable connector the other end of which is in pivot joint with holder fixed to the frame of fume-extraction flap. Moreover, said mechanism is provided with at least one blocking cord with one end connected to the holder fixed to the frame of fume- extraction flap and the other end connected with the holder of roof port frame. Preferably, the upper face of vertical beam has a slant surface provided with a yoke that serves as the tie rod holder. Also favorably, the movable part of the lock is provided with tensioning spring. It is also favorable that the other end of the lever be provided with servo actuator holder having a profiled end and the other end of the tie rod be provided with the holder of the actuator clamping ring having a side profile cutout of similar shape to that of the actuator holder end. Also favorably, the mutually engaging ends of the fixed part and the movable part of the lock

have shape resembling the letter ,,V" turned by 90 deg. Other favorable feature is that the tensioning spring is hitched at its one end with the movable part of the lock while its other end is connected with the movable connector. Also favorably, the end of the actuator rod and one end of the movable part of the lock are connected with movable connector through a pin.

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 hazard. The design of the mechanism 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 a set of levers in pivot joint with the lower part of the servo actuator enables keeping open flap at fixed position at 140°. Besides, fitting the lock mechanism with tensioning spring, connected at one end with the movable connector, improved the functionality of the lock considerably.

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 roof port covered by fume-extraction flap in vertical cross-section with flap opening and closing mechanism installed and its lock closed, fig. 2 is the same fragment of the roof port covered by fume-extraction flap and the opened lock of the flap opening and closing mechanism, fig. 3 shows the fume-extraction flap at maximally opened position with flap opening and closing mechanism at that flap position, fig. 4 shows the detail ,,A" from fig. 2 of opened lock of flap opening and closing mechanism, and fig. 5 shows the detail ,,B" from fig. 3 of the connection of pneumatic actuator with the actuator beam and its tie rod at maximum opening of the fume-extraction flap.

The middle part of the of the frame I of roof port 2, in pivot joint with the fume-extraction flap 3, mounts a cross bar 4 with beam 5 _. , fixed at right angle to it and having a slanting upper surface that is provided with yoke 6, and a fixed part 8 of the lock 9, with its end shaped as a letter ,,V" turned by 90 deg., is bolted with bolts 7 to the external side surface of that beam. The lower end of the beam 5 is in pivot joint on pin K) with one end of the lever H, while its other end with chamfered upper edge is joined with holder 12 with rounded end 1_3, which is in pivot joint on pin L4 with the lower end of pneumatic actuator L5 positioned in clamping ring 16, whereas the yoke 6 of the beam 5 _. is in pivot joint on pin 17 with one end of the tie rod J_8, the other slanted-face end of which is fixed to the holder U^ having side circular recesses 20 of similar radius as that of the end of the holder 12, which is bolted with bolts 2_1 with the clamping ring 16 of that actuator. In turn, the end of the actuator rod 22 of

the pneumatic actuator JJ5 is connected with one end of the movable connector 23 using pin 24 _> to which one end of the movable part 25 of the lock 9, provided with tensioning spring 26, is also connected, whereas the other end of the movable connector 23 is in pivot joint with its holder 2T ₁ fixed to the frame 28 of the fume-extraction flap 3. Besides, two holders 29 are mounted to the middle section of the frame 28 and two holders 30 are mounted to the frame 1_ of the roof port 2, whereas the end loops 32 of two blocking cords 33 are connected with holders 29 and 30 by means of pins 3_L