Dual function security/fire locking mechanism for fire rated devices

Patent metadata

Field	Value
Publication number	US-10577832-B2
Application number	US-201615342196-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Nov 3, 2016
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

An exit device located in a door frame having a door strike including a latchbolt assembly, a pushbar assembly, and a link assembly. The latchbolt assembly includes an extended position configured to engage the door strike, and a retracted position configured to move past the door strike. The pushbar assembly moves from a released position to a pressed position to move the latchbolt assembly from the extended position to the retracted position. The link assembly is operatively connected to the pushbar assembly and includes a security link having an elongated aperture and a pin configured to extend through the elongated aperture about which the security link rotates. A keeper surrounds the pin and supports the security link for rotation. In the event of extreme heat, the keeper melts and the security link moves to a position to substantially prevent opening of the door.

First claim

What is claimed is:

1. An exit device for a door located in a door frame having a door strike, comprising:
a latchbolt assembly including a latchbolt having an extended position configured to engage the door strike and a retracted position configured to allow the door to move past the door strike;
a pushbar assembly including a pushbar connected to an actuating mechanism, the pushbar assembly having a released position and a pressed position, wherein movement of the pushbar from the released position to the pressed position moves the latchbolt assembly from the extended position to the retracted position; and
a link assembly operatively connected to the actuating mechanism of the pushbar assembly, wherein the link assembly includes a latchbolt link operatively connected to the latchbolt and a security link, the security link including a void, an elongated aperture, a pin configured to extend through and be displaced along the elongated aperture to allow the security link to be displaced from a first position to a second position, and a keeper engaged with a shoulder defined on the elongated aperture;
wherein, in normal operation, when the latchbolt is moved to the retracted position, the void receives the latchbolt link; and
wherein the keeper is configured to melt at a designated temperature, and wherein melting of the keeper allows the pin to pivotably displace along the elongated aperture, allowing the security link to move from the first position to the second position, thereby blocking movement of the latchbolt link and preventing the latchbolt from moving toward the retracted position.

2. The exit device of claim 1 , wherein the elongated aperture defines a rotational axis about which the security link rotates between the first and second positions.

3. The exit device of claim 1 , wherein the pin includes a portion having an outer diameter to fit within an opening in the keeper and to fit within an end portion of the elongated aperture.

4. The exit device of claim 3 , wherein the keeper includes an outer diameter sized larger than the end portion of the elongated aperture.

5. The exit device of claim 4 , wherein the elongated aperture includes a center portion at which the shoulder is located.

6. The exit device of claim 5 , wherein the elongated aperture includes a second end portion disposed adjacently to and on one side of the central portion, wherein the second end portion defines an open space configured to receive a material.

7. The exit device of claim 6 , wherein the link includes a shelf disposed opposite the shoulder, the shoulder and the shelf defining a portion of the elongated aperture having a size sufficient to removably locate the keeper at the central portion of the slot.

8. The exit device of claim 7 , wherein the keeper includes a material having a melting point of approximately 563 degrees Fahrenheit or greater.

9. The exit device of claim 8 , wherein the material comprises nylon.

10. The exit device of claim 9 , wherein the nylon comprises nylon 46.

11. An exit device for a door located in a door frame having a door strike, comprising:
a latchbolt assembly including a latchbolt configured to move between an extended position configured to engage the door strike and a retracted position configured to permit the door to move past the door strike;
a pushbar assembly including a pushbar and an actuating mechanism, the pushbar assembly having a released position and a pressed position, wherein movement of the pushbar from the released position to the pressed position moves the latchbolt assembly from the extended position to the retracted position;
a link assembly operatively connected to the actuating mechanism of the pushbar assembly, wherein the link assembly includes a latchbolt link operatively connected with the latchbolt and a security link defining an aperture engaged with a keeper that is mounted to a pin about which the security link is operable to pivot between a first position in which the security link engages the latchbolt link to prevent retraction of the latchbolt and a second position in which the security link does not prevent retraction of the latchbolt; and
a key operable to move the security link between the first position and the second position;
wherein the keeper is configured to melt at a designated temperature to thereby cause the security link to move to a third position in which the security link engages the latchbolt link to prevent retraction of the latchbolt.

12. The exit device of claim 11 , wherein the keeper includes an outer dimension insufficient to completely fill the elongated aperture.

13. The exit device of claim 11 , wherein the elongated aperture includes a first end portion disposed at the second position and on one side of the central portion, and a second end portion disposed on another side of the central portion.

14. The exit device of claim 13 , wherein the pin includes a cylindrical portion having a size configured to engage one of the first and second end portions, but insufficient to engage the central portion for rotation without the keeper.

15. The exit device of claim 14 , wherein the keeper includes an outer circumference having a size larger than one of the first and second end portions.

16. The exit device of claim 11 , wherein the security link includes an ear configured to engage a housing of the link assembly.

17. The exit device of claim 16 , wherein when the pivot member is located at the second position, the ear is disposed adjacently to the housing to substantially prevent the latchbolt assembly from moving from the extended position to the retracted position.

18. The exit device of claim 11 , wherein the third position is different from the first position.

19. The exit device of claim 11 , wherein the link assembly includes an extending portion operable to drive the security link from the first position to the second position in response to movement of the pushbar from the released position to the pressed position.

20. An exit device, comprising:
a latchbolt having an extended position and a retracted position, wherein the latchbolt is operatively connected with a latchbolt link;
an actuating mechanism operably connected with the latchbolt via the latchbolt link;
a pushbar operably connected with the actuating mechanism such that movement of the pushbar from a projected position to a depressed position moves the latchbolt from the extended position to the retracted position; and
a security link pivotably mounted to a pin via a keeper having a melting point; and
a key operable to pivot the security link about the pin between a first position and a second position;
wherein, with the security link in the first position, a finger of the security link is aligned with the latchbolt link and prevents retraction of the latchbolt, and wherein, with the security link in the second position, the finger is misaligned with the latchbolt link and the latchbolt is operable to move to the retracted position; and
wherein the security link is configured to move to a third position in response to melting of the keeper, and wherein, with the security link in the third position, the finger is aligned with the latchbolt link and prevents retraction of the latchbolt.

21. The exit device of claim 20 , wherein the melting point is at least 400° Fahrenheit.

22. The exit device of claim 20 , wherein the security link further includes a second finger and a void positioned between the finger and the second fing

Assignees

• Schlage Lock Co Llc

Inventors

• Blanchard Walter T
• Lehner Jr Jack R

Classifications

• E05B15/16

  Use of special materials for parts of locks · CPC title

• Y10S292/66

  Thermally controlled mechanism · CPC title

• Y10T292/0908

  Emergency operating means · CPC title

• E05B65/104 Primary

  actuated in response to heat, e.g. with fusible element, bimetal, memory shape or swelling material · CPC title

• E05B65/1093

  Dogging means for holding the actuation means, e.g. the actuating handle · CPC title