Abstract: A locking mechanism to be applied to an inactive door of a set of active and inactive double doors coordinated so that the inactive door closes first relative to a frame followed by the closing of the active door. Adjustable drive means is employed capable of either lengthwise contraction upon the application of a force between first and second separated locations on the adjustable drive means exceeding a threshold value, or linear movement without substantial contraction upon the application of a force less than the threshold value. A door-lock actuating element is coupled to the adjustable drive means at the first location. A door-locking element is coupled to the adjustable drive means at the second location. The adjustable drive means, the door-lock actuating element, and the door-locking element are supported at an upper or lower corner of the inactive door.

Abstract: An electromagnetic lock including an armature and an electromagnet with the armature adapted for floating attachment to a door by a plunger-bolt assembly fixed to the door, and an electromagnet adapted for fixed attachment to a door frame. A door-movement alert switch structure comprising a pushbutton switch supported on the electromagnet, a plunger supported on the plunger-bolt assembly, and a spring force-biasing the plunger into mating contact with the switch when the door is electromagnetically locked to establish a first switch-actuation state. The force-biased spring maintains the switch in its first state while the armature is magnetically restrained. When the door is opened a door-movement distance slightly less than the armature float distance, the plunger is partially drawn into a plunger housing fixed on the plunger-bolt assembly. The switch responds by transferring to a second switch actuation state indicating an attempt to open the magnetically locked door.

Abstract: A door control comprising a heat-actuated door latch and a combination door-closing-arm holder and release. An optional smoke detector is located within a holder-release housing. During normal conditions, the door-closing arm is set at a hold-open angle free of the door to permit an easy door swing. In response to an emergency or smoke condition, the closing arm is released to pick up and close the door. In the event of excessive heat, the door is latched in response to the separation of fusible link segments. Heat from the side of the door opposite the latch housing is conducted through the door by a heat conducting rod.

Abstract: A pivot hinge comprising a reed switch embedded in the leaf of a nonmagnetic pivot-jamb portion. The reed switch is located in the jamb leaf at an attitude to miss the mounting holes. A round permanent magnet is adjustably mounted on the pivot-door portion perpendicular to the door leaf. When both the door and jamb leaves are together, the magnet is positioned over the reed switch contacts. A threaded, nonmagnetic rod (adjusting screw) with a head the shape of a mounting screw is positioned adjacent the magnet in a mounting hole of the door leaf and retained in position by a retainer ring. The adjusting screw is, in turn, coupled to the magnet with a nonmagnetic link. When the adjusting screw is turned, the magnet can be moved closer to or away from the reed switch in order to actuate the switch with an adjustable sensitivity as indicated by a change in the degree of door opening or closing required to operate the switch.

Abstract: This disclosure relates to an electrically actuated door holder and release for the multi-point holding of a pivoted door at selected door opening angles, and for the release of a held door either electrically or in response to manual override. The door holder and release includes a rotatable spindle adapted to be connected to a pivoted door which is either push or pull-side mounted. The holder and release comprises a spindle gear assembly having a pair of male spline gears with each gear having a circular ring of splineways forming a series of male projecting keys. A pair of cams, each having cam lobes defining detent segments with each cam having a circular hole internally grooved to mate with the projecting keys of spline gear, is mounted on the shaft. A pair of springs yieldingly hold the cams into mating positions with associated spline gears to rotate therewith. A double lever having a common pivot or fulcrum carries a roller which follows the cams.

Abstract: A combination door chime and detector responsive to the particulate products of combustion passing through multiple passageways formed in the chime cover. The door chime includes conventional spaced tone bars each cooperating with a tuned resonator chamber. A tone bar striker mechanism capable of single-note, two-note, and sustained-repetitive note striking of the tone bars is disposed between the tone bars. A photoelectric particulate products of combustion detector is also disposed between the tone bars. The conventional low-voltage door and chime transformer serves as a power supply for both the combustion detector and the striker mechanism. The closing of a first remote door chime switch generates a single-note signal; the closing of a second remote door chime switch generates a two-note signal; and the detection of the particulate products of combustion generates a sustained-repetitive note which serves as an intense audible alarm.

Abstract: A photocell smoke detector comprising a housing defining a dual section smoke chamber having a first smoke sensing chamber and a second compensating chamber, a smoke sensing photocell coupled to the smoke sensing chamber and a compensating photocell coupled to the second chamber, a light source coupled to the compensating chamber and transmitting a beam of light generally parallel and away from the photosensitive surfaces of the two photocells, and a light trap communicating with the smoke sensing chamber and fabricated of layers of corrugated media sandwiched between relatively flat liners whereby light is absorbed in the flutes of the corrugated media and smoke is enabled to pass freely into and out of the smoke sensing chamber.