Sectional fire door assembly

Claim 2

A door assembly for covering an opening in an upright wall, comprising: door means having plural, horizontally hinged sections; brace means secured to said wall adjacent the opening therein and defining a pair of upright channels opening toward each other and arranged to receive opposite edge portions of said door; a pair of L-shaped track means rigidly held with respect to said brace means, said track means having upright portions adjacent said brace means and parallel, horizontal portions extending away from said brace means in the same direction, said horizontal portions and upright portions having adjacent, arcuate portions; roller means on said door sections and engaged with said track means for guiding movement of said door means between a closed position within said channels and a horizontal, open position; spring-biased counterbalance means mounted on said wall above said openiNg and having drum means supporting cable means connected to the lower part of said door means, and spring means continuously resiliently urging said drum means to rotate in a cable-winding direction whereby said door means is continuously resiliently urged toward said open position; and fusible link means connected to said spring means for maintaining a predetermined minimum tension thereon whereby rupture of said link means permits release of at least a part of the tension in said spring means to enable said door means to move by gravity from said open position into the closed position.

Claim 3

A door assembly according to claim 1, wherein said door means and said brace means are fire resistant; wherein said counterbalance means includes horizontal shaft means supported upon said wall means, said drum means being mounted upon and rotatable with said shaft means, and said spring means being a spiral spring having one end thereof secured to said shaft means; and including pawl means pivotally mounted upon said wall means and engageable with the other end of said spiral spring for holding same against rotation, said pawl means being releasably held in said position of engagement by said fusible link means.

Claim 4

A door assembly according to claim 1, wherein said counterbalance means includes shaft means to which said drum means is secured, and said spring means includes a spiral spring having one end secured to said shaft means and the other end thereof releasably held with respect to said wall means; including sprocket means rotatably supported upon said wall means near one end of said shaft means; chain means engaged with said sprocket means for rotating same; arm means having one end pivotally supported upon said wall means adjacent to and coaxial with said sprocket means; gear means connecting said sprocket means to said shaft means, said gear means including a first gear on said shaft means and a second gear supported on said arm means for movement with said arm means into and out of engagement with said first gear; and wherein said fusible link means holds said arm means in a position for engagement between said first and second gears.

Claim 5

A door assembly for covering an opening in an upright wall, comprising: door means having plural, horizontally hinged sections; brace means secured to said wall adjacent the opening therein and defining a pair of upright channels opening toward each other and arranged to receive opposite edge portions of said door means; a pair of L-shaped track means rigidly held with respect to said brace means, said track means having upright portions adjacent said brace means and parallel, horizontal portions extending away from said brace means in the same direction, said horizontal portions and upright portions having adjacent, arcuate portions; roller means on said door sections and engaged with said track means for guiding movement of said door means between a closed position within said channels and a horizontal, open position; spring-biased counterbalance means mounted on said wall above said opening and having drum means supporting cable means connected to the lower part of said door means, said counterbalance means including shaft means to which said drum means is secured, and spring means resiliently urging said drum means to rotate in a cable-winding direction, said spring means including a spiral spring having one end secured to said shaft means and the other end thereof releasably held with respect to said wall means; sprocket means rotatably supported upon said wall means near one end of said shaft means; chain means engaged with said sprocket means for rotating same; arm means having one end pivotally supported on said wall means adjacent to and coaxially with said sprocket means; gear means connecting said sprocket means to said shaft means, said gear means including a first gear on said shaft means and a second gear supported on said arm means foR movement with said arm means into and out of engagement with said first gear; and fusible link means connected to said spring means for maintaining a predetermined tension thereon whereby rupture of said link means permits release of at least a part of the tension in said spring means to enable said door means to move by gravity into the closed position, said fusable link means holding said arm means in a position for engagement between said first and second gears.

Claim 6

A door assembly for covering an opening in an upright wall, comprising: door means having plural, horizontally hinged sections; brace means secured to said wall adjacent the opening therein and defining a pair of upright channels opening toward each other and arranged to receive opposite edge portions of said door means; a pair of L-shaped track means rigidly held with respect to said brace means, said track means having upright portions adjacent said brace means and parallel, horizontal portions extending away from said brace means in the same direction, said horizontal portions and upright portions having adjacent, arcuate portions; roller means on said door sections and engaged with said track means for guiding movement of said door means between a closed position within said channels and a horizontal, open position; spring-biased counterbalance means mounted on said wall above said opening and having drum means supporting cable means connected to the lower part of said door means, said counterbalance means including shaft means to which said drum means is secured, and spring means resiliently urging said drum means to rotate in a cable-winding direction, said spring means including a spiral spring having one end secured to said shaft means and the other end thereof releasably held with respect to said wall means; sprocket means rotatably supported upon said wall means near one end of said shaft means; chain means engaged with said sprocket means for rotating same; arm means having one end pivotally supported on said wall means adjacent to and coaxially with said sprocket means; gear means connecting said sprocket means to said shaft means, said gear means including a first gear on said shaft means and a second gear supported on said arm means foR movement with said arm means into and out of engagement with said first gear; and fusible link means connected to said spring means for maintaining a predetermined tension thereon whereby rupture of said link means permits release of at least a part of the tension in said spring means to enable said door means to move by gravity into the closed position, said fusable link means holding said arm means in a position for engagement between said first and second gears.

Claim 7

A door assembly according to claim 4, including governor means connected between said shaft means and said wall means for limiting the rotational speed of said shaft means; releasable holding means for maintaining said governor means in an inoperative position; linkage means interconnecting said holding means and said fusible link means for releasing said holding means when said fusible link means ruptures, whereby said governor means becomes operative.

Claim 8

A door assembly according to claim 4, wherein said fusible link means includes pawl means releasably engageable with said arm means in said engaging position; and a fusible link connecting said pawl means to said linkage means.

Claim 9

In a fire door assembly having a horizontally sectioned door supported by track means for movement between a substantially upright closed position and a substantially horizontal opened position and spring-biased counterbalance means for holding said door in an open position, said counterbalance means including drum means and cable means extending between said drum means and the lower part of said door, and fusible link means for releasing the tension on said counterbalance means whereby said door can move by gravity from its opened position into its closed position automatically, governor means for controlling the movement of said door, comprising: toothed wheel means secured to and rotatable with said drum means; annular means encircling said wheel means and pivotally supported at a point directly above the axis of said wheel means for movement around an axis parallel with said wheel axis; projection means extending radially inwardly from the inner surface of said annular means and being engageable with the teeth on said wheel means when said annular means is coaxial with said wheel means; pawl means pivotally supported upon said annular means and resiliently urged into engagement with said teeth, whereby said annular means is caused to pivot as said wheel means rotates in a step-by-step movement and said projection means moves into and out of engagement with successive teeth; and pin means releasably holding said annular means eccentric with respect to said wheel means and holding said pawl means out of engagement with said teeth, whereby said wheel means can rotate independently thereof.

Claim 10

In a fire door assembly having a horizontally sectioned door supported by track means for movement between a substantially upright closed position and a substantially horizontal opened position and spring-biased counterbalance means for holding said door in an open position, said counterbalance means including drum means and cable means extending between said drum means and the lower part of said door, and fusible link means for releasing the tension on said counterbalance means whereby said door can move by gravity from its opened position into its closed position automatically, governor means for controlling the movement of said door, comprising: toothed wheel means secured to and rotatable with said drum means; annular means encircling said wheel means and pivotally supported at a point directly above the axis of said wheel means for movement around an axis parallel with said wheel axis; projection means extending radially inwardly from the inner surface of said annular means and being engageable with the teeth on said wheel means when said annular means is coaxial with said wheel means; pawl means pivotally supported upon said annular means and resiliently urged into engagement with said teeth, whereby said annular means is caused to pivot as said wheel means rotates in a step-by-step movement and said projection means moves into and out of engagement with successive teeth; and pin means releasably holding said annular means eccentric with respect to said wheel means and holding said pawl means out of engagement with said teeth, whereby said wheel means can rotate independently thereof.

Claim 11

A fire door assembly mountable upon wall means having a substantially vertically extending opening therein, comprising: door means having a plurality of horizontally hinged sections; track means mountable upon said wall means and supporting said door means for movement between an upright closed position wherein said door means is disposed adjacent said opening and a substantially horizontal opened position, said track means including an elongated track portion disposed substantially horizontally and extending transversely relative to said opening for supporting said door means when same is in said opened position; spring-biased counterbalance means adapted for mounting on said wall means and connected to the lower portion of said door means and including spring means for continuously resiliently urging said door means toward said horizontal opened position; and linkage means including a fusable link connected to said counterbalance means and adapted to rupture at a predetermined temperature to release at least a part of the tension in the spring means to enable said door means to automatically move from its opened position to its closed position under the force of gravity.

Claim 12

A fire door assembly mountable upon wall means having a substantially vertically extending opening therein, comprising: door means having a plurality of horizontally hinged sections; track means mountable upon said wall means and supporting said door means for movement between an upright closed position wherein said door means is disposed adjacent said opening and a substantially horizontal opened position, said track means including an elongated track portion disposed substantially horizontally and extending transversely relative to said opening for supporting said door means when same is in said opened position; spring-biased counterbalance means adapted for mounting on said wall means and connected to the lower portion of said door means and including spring means for continuously resiliently urging said door means toward said horizontal opened position; and linkage means including a fusable link connected to said counterbalance means and adapted to rupture at a predetermined temperature to release at least a part of the tension in the spring means to enable said door means to automatically move from its opened position to its closed position under the force of gravity.

Claim 13

A door assembly according to claim 8, further including power means releasably connected to said door means for permitting powered movement of said door means between said opened and closed positions, and said linkage means being interconnected to said power means for disconnecting said power means from said door means whenever said fusable link ruptures for permitting said door means to freely move from the opened position to the closed position under the force of gravity.

Claim 14

A door operator according to claim 8, wherein said spring-biased counterbalance means includes horizontal shaft means supported on said wall means adjacent the upper edge of said opening, rotatable drum means supported on said shaft means, elongated flexible element means connected between said drum means and the lower edge of said door means, said spring means including a torsion spring disposed adjacent said shaft means and having one end thereof fixedly connected relative to said drum means for continuously resiliently urging same in a rotational direction tending to move said door means to said opened position, and disk means mounted on said shaft means and supported for rotation relative to said wall means, said disk means being fixedly interconnected to the other end of said torsion spring; and said linkage means including movable link means coating between said disk means and said wall means for normally releasably maintaining said disk means stationary relative to said wall means, said link means being automatically disengaged from said disk means on rupture of said fusible link for enabling said disk means to rotate relative to said wall means to at least partially release the tension in said torsion spring.