Claims
- 1. A fire door control system comprising a latch having a first part adapted to be mounted on a door and a second part adapted to be mounted in a fixed position relative to the door for cooperation with the first part when the door is in an open position, the second part including holding means operative, when actuated, to engage with the first part to inhibit closing movement of the door and pneumatically operated actuating means for actuating the holding means when a gas pressure differing from atmospheric pressure is applied thereto, the system further comprising a gas pressure source connected to the actuating means and valve means for establishing communication between the actuating means and atmosphere.
- 2. Retaining means for controlling displacement of an object from a predetermined position relative to another object, comprising a first part for mounting on one of the objects and a second part for mounting on the other object and having holding means for latching engagement with the first part to inhibit relative displacement between the two objects and pneumatically operated means operative when a first pressure differential is applied thereto to inhibit operation of the holding means and operative when a second pressure differential is applied thereto to permit operation of the holding means, the first part being moveable into engagement with the holding means during times when the second pressure differential is applied.
- 3. A fire door control system comprising a latch having a first part adapted to be mounted on a door and a second part adapted to be mounted in a fixed position relative to the door for cooperation with the first part when the door is in an open position, the second part including holding means operative, when actuated, to engage with the first part to inhibit closing movement of the door and pneumatically operated actuating means for actuating the holding means when a gas pressure differing from atmospheric pressure is applied thereto, the system further comprising a gas pressure source connected to the actuating means and valve means for establishing communication between the actuating means and atmosphere, and a smoke and/or fire detector for opening the valve means.
- 4. A fire door control system comprising a plurality of latches, each latch having a first part adapted to be mounted on a door and a second part adapted to be mounted in a fixed position relative to the door for cooperation with the first part when the door is in an open position, the second part including holding means operative, when actuated, to engage with the first part to inhibit closing movement of the door and pneumatically operated actuating means for actuating the holding means when a gas pressure differing from atmospheric pressure is applied thereto, the system further comprising a common gas pressure source connected to all of said actuating means and common valve means for establishing communication between all of said actuating means and atmosphere.
- 5. Retaining means for controlling displacement of an object from a predetermined position relative to another object, comprising a first part for mounting on one of the objects and a second part for mounting on the other object and having holding means for latching engagement with the first part to inhibit relative displacement between the two objects and pneumatically operated means operative when a first pressure differential is applied thereto to inhibit operation of the holding means and operative when a second pressure differential is applied thereto to permit operation of the holding means, the first part being movable into engagement with the holding means during times when the second pressure differential is applied, the pneumatically operated means comprising an intermediate actuating member movable into a first position in which operation of the holding means is inhibited and pneumatic pressure sensing means operative to displace the release means into the second position in which operation of the holding means is not inhibited.
- 6. Retaining means according to claim 5, wherein the intermediate actuating means is spring biased into its first position.
- 7. Retaining means according to claim 5, wherein the holding means is so arranged that, when the intermediate member is in its second position, the first part disengages from the holding means on application of a displacing force exceeding a threshold value.
- 8. Retaining means for controlling displacement of an object from a predetermined position relative to another object, comprising a first part for mounting on one of the objects and a second part for mounting on the other object and having holding means for latching engagement with the first part to inhibit relative displacement between the two objects and pneumatically operated means operative when a first pressure differential is applied thereto to inhibit operation of the holding means and operative when a second pressure differential is applied thereto to permit operation of the holding means, the first part being movable into engagement with the holding means during times when the second pressure differential is applied, the pneumatically operated means including a chamber, one wall of which is formed by a diaphragm having the holding means operatively coupled to a central region thereof whereby establishment of a pressure differential across the diaphragm causes the release means to be moved from said first position to said second position.
- 9. Retaining means for controlling displacement of an object from a predetermined position relative to another object, comprising a first part for mounting on one of the objects and a second part for mounting on the other object and having holding means for latching engagement with the first part to inhibit relative displacement between the two objects and pneumatically operated means operative when a first pressure differential is applied thereto to inhibit operation of the holding means and operative when a second pressure differential is applied thereto to permit operation of the holding means, the first part being movable into engagement with the holding means during times when the second pressure differential is applied, the holding means comprising a holding member which is angularly movable between a first position in which it is operative to engage with the first part and a second position in which such engagement is inhibited, the retaining means further comprising spring-biasing means for urging the holding member into its second position and the pneumatically operated means being operative to displace the holding member into its first position.
- 10. Retaining means according to claim 9, wherein the holding member is so arranged that, when it is in its first position, the first part disengages with the second part on application of a displacing force exceeding a threshold value.
- 11. Retaining means according to claim 9, wherein the first part comprised a member which cooperates with the holding member to form a spring catch.
- 12. Retaining means according to claim 9, wherein the first part as a detent surface and the holding member comprises a plate mounted for angular movement about an axis perpendicular to its surface and having an edge shaped to engage with the detent surface when the plate is in its first position.
- 13. Retaining means according to claim 12, wherein the pneumatically operated means is adapted to hold the plate in a position in which the detent surface can freely move past the said edge.
- 14. Retaining means according to claim 9, wherein the first part comprises a plate containing an aperture, said plate being mounted parallel to the direction of relative movement between the first and second part, the detent surface being an edge of the aperture.
- 15. Retaining means for controlling displacement of an object from a predetermined position relative to another object, comprising a first part for mounting on one of the objects and a second part for mounting on the other object and having holding means for latching engagement with the first part to inhibit relative displacement between the two objects and pneumatically operated means operative when a first pressure differential is applied thereto to inhibit operation of the holding means and operative when a second pressure differential is applied thereto to permit operation of the holding means, the first part being movable into engagement with the holding means during times when the second pressure differential is applied, the pneumatically operated means comprising a chamber, one wall of which is formed by a diaphragm, and a coupling member one end of which is secured to a central region of the diaphragm and the other end of which is connected to the holding member whereby establishment of a pressure differential across the diaphragm causes the holding means to be urged from its second position to its first position.
Priority Claims (2)
Number |
Date |
Country |
Kind |
19352/76 |
May 1976 |
GBX |
|
3787/78 |
Jan 1978 |
GBX |
|
Parent Case Info
This application is a continuation-in-part of Ser. No. 793,433, filed May 3, 1977, now U.S. Pat. No. 4,121,319.
US Referenced Citations (11)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2422205 |
Dec 1974 |
DEX |
1043198 |
Sep 1960 |
GBX |
1253553 |
Nov 1971 |
GBX |
1341667 |
Dec 1973 |
GBX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
793433 |
May 1977 |
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