Door closure device

A door closer mechanism for automatically closing a door in response to a predetermined condition, the improvement comprising, in combination, a housing, a rotatable power shaft mounted in said housing and having a portion extending therefrom, force-producing means within said housing associated with said power shaft for rotatably biasing the latter in a door-closing direction, a door closure arm connected with a door to be controlled, said door closure arm being supported on said power shaft so as to be freely rotatable thereon, crank means fixedly mounted on said power shaft for conjoint rotation therewith, said crank means being engageable by said door closer arm when the latter is initially rotated in a door-opening direction thereby cocking said crank means and associated force-producing means while said door remains freely movable manually to any desired position between its fully open and fully closed positions, normally operable one-way brake means associated with said power shaft for preventing rotation of the latter in a door-closing direction, said brake means including a brake drum fixedly mounted on said power shaft for conjoint rotation therewith, a flexible cable wrapped a plurality of times around the circumference of said brake drum, said cable being fixed at one end, normally operable pulling means connected to the other end of said cable for applying a pulling force thereto tending to tighten said cable around said drum, said pulling force causing said cable to brake said brake drum against rotation in the direction of said pulling force while permitting rotation of said brake drum in an opposite direction when said door closer arm is initially rotated in a door-opening direction, said pulling means comprising pneumatic means operable by a pre-determined air pressure, and means responsive to a pre-determined condition for releasing said air pressure and thereby releasing said brake means enabling said force-producing means to rotate said power shaft and crank means in a door-closing direction whereby said crank means actuates said door closure

A door closer mechanism for automatically closing a door in response to a predetermined condition, the improvement comprising, in combination, a housing, a rotatable power shaft mounted in said housing and having a portion extending therefrom, force-producing means within said housing associated with said power shaft for rotatably biasing the latter in a door-closing direction, a door closure arm connected with a door to be controlled, said door closure arm being actuated from said power shaft, normally operable one-way brake means associated with said power shaft for preventing rotation of the latter in a door-closing direction, said brake means including a brake drum fixedly mounted on said power shaft for conjoint rotation therewith, a flexible cable wrapped around said brake drum, said cable being fixed at one end, normally operable pulling means connected to the other end of said cable for applying a pulling force thereto tending to tighten said cable around said brake drum, said pulling force causing said cable to brake said brake drum against rotation in the direction of said pulling force while permitting rotation of said brake drum in the opposite direction, and means responsive to a predetermined condition for releasing said pulling force thereby releasing said brake means enabling said force-producing means to rotate said power shaft in a door-closing direction to actuate said door closure arm and effect closing