Automatic opening bolt for evacuation passage double-leaf fireproof door
By applying a spring-slider linkage mechanical design to the latch, the connection structure and movement trajectory of the latch are changed, realizing the automatic opening and closing of the latch of the fire door in the evacuation passage. This solves the problem that the existing technology cannot meet the new standard, and has automation function and complies with national standards.
Patent Information
- Application Number
- CN202520662654.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2026-03-17
- Estimated Expiration
- 2035-04-09
AI Technical Summary
The existing fire door latches in evacuation routes cannot be opened automatically, which fails to meet the requirements of the new national standard GB12955-2024.
It adopts the mechanical design principle of spring slider linkage, and by changing the internal connection structure and movement trajectory of the latch, the latch can be automatically opened when the door is opened and automatically locked when it is closed.
It achieves automatic opening and closing of the latch, meets the requirements of the new national standard, has a simple and practical structure, is widely used and easy to operate.
Smart Images
Figure CN224002518U_ABST
Abstract
Description
(I) Technical Field:
[0001] This utility model relates to an automatic opening latch for a double-leaf fireproof door in an evacuation passage. Based on existing manual opening and closing latches, it modifies the internal connection structure and movement trajectory of the latch, thereby changing the opening method and achieving automatic opening. It is installed on the secondary door leaf (the side without the fireproof lock) of a double-leaf fireproof door in a building evacuation passage. Its function is to lock when the door is closed and automatically open when the door is opened. When the main door leaf (the side with the fireproof lock) is closed, the vertical side of the main door leaf (the side with the fireproof lock) presses against the latch's vertical side assembly, causing the latch rod to lock the secondary door leaf (the side without the fireproof lock). When the main door leaf (the side with the fireproof lock) is opened, the vertical side of the main door leaf (the side with the fireproof lock) releases the latch's vertical side assembly, allowing the latch rod to exit the door frame, enabling the secondary door leaf (the side without the fireproof lock) to open freely. (II) Background Technology:
[0002] Currently, fire doors are important fire protection products for building fire safety in my country. They are widely used in fire separation in industrial and civil buildings. Double-leaf fire doors installed on evacuation routes play a vital role in ensuring the safety of people's lives and property during a fire, as long as both leaves can be fully opened to provide sufficient evacuation width for evacuees.
[0003] The new standard for fire doors is the national standard GB12955-2024 "Fire Doors," which was released on October 28, 2024, and will be implemented on May 1, 2026. Clause 6.4.7.2 of the new standard's 6.4 accessory performance clause explicitly requires that "the latches installed on fire doors in evacuation routes should be able to open automatically when the door leaf is opened." However, the latches used in domestically manufactured fire doors for evacuation routes are all manually closed and manually opened, which cannot meet the new national standard's requirement that the latches automatically open when the door leaf is opened.
[0004] This utility model—an automatic opening latch for a double-leaf fireproof door in an evacuation passage—effectively solves the above problems. It utilizes a spring-slider linkage mechanical design principle. The horizontal linear movement of the spring-slider mechanism assembly, where the door leaf on the side with the fireproof lock is installed, compresses / releases the latch. This movement drives the latch linkage mechanism assembly, resulting in a vertical linear movement of the latch pin, thus achieving the function of closing and opening the latch. (III) Utility Model Content:
[0005] The purpose of this invention is to design an automatic opening latch for a double-leaf fireproof door in an evacuation passage. Based on existing manual opening and closing latches, it modifies the internal connection structure and movement trajectory of the latch, thereby changing the opening method and achieving automatic opening. It is installed on the secondary door leaf (the side without the fireproof lock) of a double-leaf fireproof door in a building evacuation passage. Its function is to lock when the door is closed and automatically open when the door is opened. When the main door leaf (the side with the fireproof lock) is closed, the vertical side of the main door leaf (the side with the fireproof lock) presses against the latch's vertical side assembly, causing the latch rod to lock the secondary door leaf (the side without the fireproof lock). When the main door leaf (the side with the fireproof lock) is opened, the vertical side of the main door leaf (the side with the fireproof lock) releases the latch's vertical side assembly, allowing the latch rod to exit the door frame, enabling the secondary door leaf (the side without the fireproof lock) to open freely.
[0006] The technical solution of this utility model is as follows: An automatic opening latch for a double-leaf fireproof door in an evacuation passage, characterized in that it mainly comprises screws, a latch plate, a latch rod guide frame, a compression post, a short spring, a telescopic rod, a pin shaft, a cotter pin, a connecting rod, a fixing connecting rod bolt post, a nut, latch rod a, an extended latch rod connecting lock nut, latch rod b, a long spring, a latch front cover plate, a cover plate positioning block, a cover plate fixing screw, a latch rear cover box, a door leaf anti-collision protection plate, and a door leaf anti-collision protection plate fixing screw; two automatic opening latches are respectively installed on the double-leaf fireproof door in the evacuation passage. The automatic opening latch of the secondary door leaf (the side without the fireproof lock) is connected to the secondary door leaf (the side without the fireproof lock) of the double-leaf fire door of the evacuation passage via screws in a threaded manner at the upper and lower ends of its thickness direction. Two door leaf anti-collision protection plates are respectively installed on the main door leaf (the side with the fireproof lock) of the double-leaf fire door of the evacuation passage at the upper and lower ends of its thickness direction. The door leaf anti-collision protection plates are connected to the main door leaf (the side with the fireproof lock) of the double-leaf fire door of the evacuation passage via screws in a threaded manner. The pin guide bracket and the cover plate positioning block are welded to the pin plate. The short spring is installed on the extrusion column, which passes through the round hole of the pin plate and is connected to the telescopic rod by threads. The telescopic rod and the connecting rod are connected by the pin and the cotter pin. The connecting rod can rotate around the fixed connecting rod bolt column. The fixed connecting rod bolt column passes through the front cover plate and the rear cover box of the pin and is connected to the nut. The other end of the connecting rod is connected to the pin a by the pin and the cotter pin. The pin a passes through the pin guide bracket and is connected to the extended pin connecting nut by threads. The long spring is installed on the pin b. The pin b passes through the guide hole of the rear cover box of the pin and is connected to the extended pin connecting nut by threads. The rear cover box of the pin is connected to the cover plate positioning block by the cover plate fixing screw. The front cover plate of the pin is connected to the cover plate positioning block by the cover plate fixing screw.
[0007] The assembly process of this utility model is as follows: (1) Weld the pin rod guide frame and the cover plate positioning block to the pin plate fixing position; (2) Put the short spring on the extrusion column; (3) Put the threaded end of the extrusion column with the short spring on it through the round hole on the pin plate and screw it onto the telescopic rod; (4) Use the pin shaft and cotter pin to install the two ends of the connecting rod onto the telescopic rod and the pin rod a respectively; (5) Put the pin rod a through the pin guide frame and tighten it with the pin rod connecting lock nut; (6) Put the pin rod b through the guide hole of the pin rear cover box and the long spring and screw it onto the pin rod connecting lock nut; (7) Put the fixing connecting rod bolt column through the pin front cover plate, the connecting rod, the pin rear cover box and screw it onto the nut; (8) Use the cover plate fixing screw to screw onto the pin front cover plate and the pin rear cover box; (9) After adjusting the position of the fixing connecting rod bolt column, the pin front cover plate and the pin rear cover box, tighten the cover plate fixing screw and nut.
[0008] The automatic closing and opening process of this utility model is as follows: (1) Tighten the assembled automatic opening latch to the upper end of the secondary door leaf (the side without the fireproof lock) with screws; (2) Tighten the door leaf anti-collision protection plate to the upper end of the main door leaf (the side with the fireproof lock) with the door leaf anti-collision protection plate fixing screws; (3) Close the main door leaf (the side with the fireproof lock), the door leaf anti-collision protection plate collides with the latch and squeezes the column, compresses the short spring, and the telescopic rod slides horizontally inward; (4) The telescopic rod drives the connecting rod to move around the fixed connecting rod bolt column; (5) (6) When the main door leaf (the side with the fireproof lock) is opened, the short spring and the long spring release the spring force, and the compression column and telescopic rod slide horizontally outward; (7) The telescopic rod drives the connecting rod to move around the fixed connecting rod bolt column; (8) When the other end of the connecting rod pulls the pin a, the pin a is connected to the lock nut, and the pin b moves vertically downward, disengaging from the upper door frame, thus achieving the function of automatic opening.
[0009] The advantages of this utility model are: (1) It is a type of automatic closing and opening mechanism achieved by partially modifying the existing manual latch; (2) The original mold of the manual latch can still be used; (3) The structure is simple and practical, and there is no change in the connection method and connection size of the manual latch and door leaf on the market; (4) It is widely used, simple and convenient to use, and easy to master; (5) It fully meets the functional requirements of the new national implementation standard for latches. (iv) Description of the attached drawings:
[0010] Figure 1 This is a vertical sectional view of an automatic opening latch for a double-leaf fire door in an evacuation passage, as described in this utility model.
[0011] Figure 2 This is a schematic diagram of the elevation transition of an automatic opening latch for a double-leaf fire door in an evacuation passage, as described in this utility model.
[0012] Figure 3 This is a cross-sectional schematic diagram of an automatic opening latch door leaf anti-collision protection plate for a double-leaf fire door in an evacuation passage, which is related to this utility model.
[0013] Figure 4 This is a plan view of an automatic opening latch door leaf anti-collision protection plate for a double-leaf fire door in an evacuation passage, which is a part of this utility model.
[0014] Figure 5 This is a flowchart illustrating the assembly process of an automatic opening latch for a double-leaf fire door used in an evacuation passage, as described in this utility model.
[0015] Figure 6 This is a flowchart illustrating the automatic closing process of an automatic opening latch for a double-leaf fire door used in evacuation routes, as described in this utility model.
[0016] Figure 7 This is a flowchart illustrating the automatic opening process of an automatic opening latch for a double-leaf fire door used in an evacuation passage, as described in this utility model.
[0017] Among them, 1 is a screw, 2 is a pin plate, 3 is a pin rod guide bracket, 4 is a pressing column, 5 is a short spring, 6 is a telescopic rod, 7 is a pin shaft; 8 is a cotter pin, 9 is a connecting rod, 10 is a fixing connecting rod bolt column, 11 is a nut, 12 is pin rod a, 13 is an extended pin rod connecting lock nut, 14 is pin rod b, 15 is a long spring, 16 is a pin front cover plate, 17 is a cover plate positioning block, 18 is a cover plate fixing screw, 19 is a pin rear cover box, 20 is a door leaf anti-collision protection plate, and 21 is a door leaf anti-collision protection plate fixing screw. (V) Specific Implementation Methods:
[0018] Example: An automatic opening latch (e.g., for a double-leaf fire door in an evacuation passage) Figure 1 , Figure 2 , Figure 3 , Figure 4The device is characterized by comprising: a screw 1, a pin plate 2, a pin rod guide frame 3, a pressing column 4, a short spring 5, a telescopic rod 6, a pin shaft 7, a cotter pin 8, a connecting rod 9, a fixing connecting rod bolt column 10, a nut 11, a pin rod a 12, an extended pin rod connecting lock nut 13, a pin rod b 14, a long spring 15, a front cover plate 16, a cover plate positioning block 17, a cover plate fixing screw 18, a rear cover box 19, a door leaf anti-collision protection plate 20, and a door leaf anti-collision protection plate fixing screw 21; two automatic opening pins are respectively installed on the secondary door leaf (the side without fireproof lock) of the double-leaf fire door in the evacuation passage. The automatic opening latch is connected to the secondary door leaf (the side without the fireproof lock) of the double-leaf fire door in the evacuation passage via screws 1 in a threaded manner at the upper and lower ends of the thickness direction of the main door leaf (the side with the fireproof lock installed). The two door leaf anti-collision protection plates 20 are respectively installed at the upper and lower ends of the thickness direction of the main door leaf (the side with the fireproof lock installed) of the double-leaf fire door in the evacuation passage via door leaf anti-collision protection plate fixing screws 21 in a threaded manner. The latch rod guide bracket 3 and the cover plate positioning block 17... The short spring 5 is welded to the pin plate 2 and mounted on the compression post 4. The compression post 4 passes through the round hole of the pin plate 2 and is connected to the telescopic rod 6 by threads. The telescopic rod 6 and the connecting rod 9 are connected by the pin 7 and the cotter pin 8. The connecting rod 9 can rotate around the fixing connecting rod bolt post 10. The fixing connecting rod bolt post 10 passes through the pin front cover plate 16 and the pin rear cover box 19 and is connected to the nut 11. The other end of the connecting rod 9 is connected to the nut 11 by the pin 7 and the cotter pin 8. The pin a12 is connected, passing through the pin guide bracket 3 and connected to the extended pin connecting nut 13 by threads. The long spring 15 is installed on the pin b14, which passes through the guide hole of the pin rear cover box 19 and is connected to the extended pin connecting nut 13 by threads. The pin rear cover box 19 is connected to the cover plate positioning block 17 by the cover plate fixing screw 18, and the pin front cover plate 16 is connected to the cover plate positioning block 17 by the cover plate fixing screw 18.
[0019] The assembly process of this utility model is as follows: (1) Weld the pin rod guide frame 3 and the cover plate positioning block 17 to the fixed position of the pin plate 3; (2) Put the short spring 5 onto the extrusion column 4; (3) Screw the threaded end of the extrusion column 4 with the short spring 5 through the round hole on the pin plate 3 and onto the telescopic rod 6; (4) Use the pin shaft 7 and the cotter pin 8 to install the two ends of the connecting rod 9 onto the telescopic rod 6 and the pin rod a12 respectively; (5) Put the pin rod a12 through the pin guide frame 3 and the pin rod connection lock nut 13. Tighten; (6) Pass the pin rod b14 through the guide hole of the pin rear cover box 19 and the long spring 15 and screw it onto the pin rod connecting lock nut 13; (7) Pass the fixing rod bolt post 10 through the pin front cover plate 16, the connecting rod 9, the pin rear cover box 19 and screw it onto the nut 11; (8) Screw the pin front cover plate 16 and the pin rear cover box 19 onto the cover plate fixing screw 18; (9) After adjusting the position of the fixing rod bolt post 10, the pin front cover plate 16, and the pin rear cover box 19, tighten the cover plate fixing screw 18 and the nut 11 (as shown). Figure 5 ).
[0020] The automatic closing and opening process of this utility model is as follows: (1) Tighten the assembled automatic opening latch to the upper end of the secondary door leaf (the side without the fireproof lock) with screw 1; (2) Tighten the door leaf anti-collision protection plate 20 to the upper end of the main door leaf (the side with the fireproof lock) with door leaf anti-collision protection plate fixing screw 21; (3) Close the main door leaf (the side with the fireproof lock), the door leaf anti-collision protection plate 20 collidees with the latch and squeezes the column 4, compresses the short spring 5, and the telescopic rod 6 slides horizontally inward; (4) The telescopic rod 6 drives the connecting rod 9 to move around the fixing connecting rod bolt column 10; (5) The other connecting rod (6) Push the bolt a12 and the bolt-connected lock nut 13 to compress the long spring 15. The bolt b14 moves vertically upward and locks the upper door frame, achieving the function of automatic closing; (7) Open the main door leaf (the side with the fireproof lock installed). The short spring 5 and the long spring 15 release the spring force, squeezing the column 4 and the telescopic rod 6 to slide horizontally outward; (8) The telescopic rod 6 drives the connecting rod 9 to move around the fixed connecting rod bolt column 10; (9) The other end of the connecting rod 9 pulls the bolt a12 and the bolt-connected lock nut 13. The bolt b14 moves vertically downward and disengages from the upper door frame, achieving the function of automatic opening (e.g. Figure 6 , Figure 7 ).
Claims
1. An automatic opening latch for a double-leaf fire door in an evacuation route, characterized in that It mainly includes screws, bolt plates, bolt rod guide frames, extrusion columns, short springs, telescopic rods, pins, cotter pins, connecting rods, fixed connecting rod bolt columns, nuts, bolt rod a, lengthened bolt rod connecting lock nuts, bolt rod b, long springs, bolt front cover plates, cover plate positioning blocks, cover plate fixing screws, bolt rear cover boxes, door leaf anti-collision protection plates, door leaf anti-collision protection plate fixing screws; wherein the bolt rod guide frame and the cover plate positioning block are welded on the bolt plate, the short spring is installed on the extrusion column, the extrusion column passes through the round hole of the bolt plate, is coupled with the telescopic rod through threads, the telescopic rod is coupled with the connecting rod through the pin and the cotter pin, the connecting rod can rotate around the fixed connecting rod bolt column, the fixed connecting rod bolt column penetrates the bolt front cover plate and the bolt rear cover box, and is coupled with the nut, the other end of the connecting rod is coupled with the bolt rod a through the pin and the cotter pin, the bolt rod a passes through the bolt rod guide frame, is connected with the lengthened bolt rod connecting lock nut through threads, the long spring is installed on the bolt rod b, the bolt rod b passes through the guide hole of the bolt rear cover box, is coupled with the lengthened bolt rod connecting lock nut through threads, the bolt rear cover box is connected with the cover plate positioning block through the cover plate fixing screw, and the bolt front cover plate is connected with the cover plate positioning block through the cover plate fixing screw.
2. The automatic opening bolt for a double-leaf fire door of an evacuation route according to claim 1, characterized in that The bolt plate is once stamped by a mold, and the bolt rod guide frame and the cover plate positioning block are welded and fixed in position.
3. The automatic latch for a double-leaf fire door of an evacuation route according to claim 1, characterized in that The bolt rod a and the bolt rod b are connected with the lengthened bolt rod connecting lock nut through threads, the length of the bolt rod a is fixed, and the height of the bolt rod b is adjusted according to the door leaf, so that the device is suitable for door leaves with an ultra-high size.