Dual function security/fire locking mechanism for fire rated devices

An exit device, comprising:

• a latchbolt assembly;
• a pushbar assembly connected with the latchbolt assembly;
• a security link comprising an elongated aperture through which a pin extends, wherein the security link during normal operation occupies a home position in which the security link is pivotable about the pin between a retaining position, in which the security link prevents retraction of the latchbolt assembly, and a releasing position, in which the security link permits retraction of the latchbolt assembly;
• and
• a keeper mounted to the pin and engaged with the security link, wherein the keeper is configured to melt at a designated temperature;
• wherein the security link is configured to move from the home position to a blocking position in response to melting of the keeper;
• and
• wherein the security link in the blocking position is configured to prevent retraction of the latchbolt assembly.

An exit device, comprising:

• a latchbolt assembly;
• a pushbar assembly operably connected with the latchbolt assembly;
• a security link having a first operating state and a second operating state, wherein the security link in the first operating state selectively prevents retraction of the latchbolt assembly, and wherein the security link in the second operating state prevents retraction of the latchbolt assembly;
• and
• a keeper engaged with the security link and configured to retain the security link in the first operating state;
• wherein the security link is configured to move from the first operating state to the second operating state in response to melting of the keeper;
• and
• wherein, with the security link in the first operating state, the security link is pivotable between a retaining position which prevents retraction of the latchbolt assembly and a releasing position which permits retraction of the latchbolt assembly.

An exit device, comprising:

• a latchbolt assembly;
• a pushbar assembly operably connected with the latchbolt assembly;
• a security link having a first operating state and a second operating state, wherein the security link in the first operating state selectively prevents retraction of the latchbolt assembly, and wherein the security link in the second operating state prevents retraction of the latchbolt assembly;
• and
• a keeper engaged with the security link and configured to retain the security link in the first operating state;
• wherein the security link is configured to move from the first operating state to the second operating state in response to melting of the keeper;
• and
• wherein the security link in the first operating state is configured to pivot about a pivot axis.