Fire door and operator therefor

• US 4,147,197 A
• Filed: 06/20/1977
• Issued: 04/03/1979
• Est. Priority Date: 06/20/1977
• Status: Expired due to Term

• Current Assignee: Overhead Door Corporation (Sanwa Holdings Corp.)
• Original Assignee: Overhead Door Corporation (Sanwa Holdings Corp.)
• Inventors: Bailey, Morris W., Luby, John J., Carlton, Donald G.
• Primary Examiner(s): Kannan, Philip C.
• Application Number:
  US05/807,926
• Time in Patent Office: 652 Days
• Field of Search: 160/7, 160/8
• US Class Current: 160/7
• CPC Class Codes: E06B 9/68 Operating devices or mechanisms, e.g. with electric drive
• CPC Class Codes: E06B 9/74 adapted for selective electrical or manual operation
• CPC Class Codes: E06B 9/82 automatic

Abstract

There is provided a roll-type door having horizontally positioned slats which is normally held by operator means in an open position against gravity. Said operator means includes fusible means responding to a predetermined heat level for releasing said door and permitting same to move under gravity in a closing direction. Said operator means includes a device for initiating said door movement immediately after the response of said fusible means to said heat level and further includes a connection to braking means for insuring against too rapid a descent by the door. The door may be manually opened if desired or mechanical means, power driven if desired, may be provided for opening or assisting in opening such door. In the latter case, clutch means are provided for disconnecting same immediately upon breakdown of said fusible means whereby said door will be enabled to close freely in response to gravity subject only to control by the above-mentioned braking means.

Claims

1. In a control device for a fire door having a roll with a flexible panel wrappable therearound, wherein said control device includes energy storage means releasable in response to a signal, such as the melting of a fusible link, for initiating unwrapping rotation of said roll, and wherein said roll after such initiating will continue to rotate in response to the gravitational effect on the panel unwrapping therefrom, the improvement comprising:

shaft means coaxially affixed to said roll;

actuating means connected to said shaft means for rotating same in a panel wrapping direction;

frictional means operably connected to said shaft means for limiting the rate at which said panel is unwrapped from said roll;

clutch means releasably connecting said frictional means to said actuating means, said clutch means having a pair of separable parts and resilient means urging said parts into driving engagement;

disconnect means for disengaging said clutch means in response to said melting of said fusible link, said disconnect means including cam means operable to separate said parts, whereby to disengage said clutch means so that said shaft means is disconnected from said actuating means; and

torque means mounted to move under the force of gravity to operate said cam means to disengage said clutch means, said movement of said torque means being responsive to said melting of said fusible link.

2. A device according to claim 1, wherein said frictional means is a centrifugal brake axially parallel with and radially spaced from said shaft means.

3. A device according to claim 1, wherein said actuating means is a plurality of chains and sprockets connected in series.

4. A device according to claim 1, including positive drive means drivingly connected between said roll and said frictional means, said positive drive means including at least one pair of sprockets and a drive chain connecting same, the center-to-center distance between said sprockets being approximately 7.76 inches.

5. In combination, a flexible door primarily for use as a fire door, a horizontally elongated rotatable roll upon which said flexible door may be wrapped, a first horizontally elongated shaft projecting outwardly from one end of said roll and being rotatably supported relative to said roll, a second horizontally elongated shaft coaxially alinged with said first shaft and projecting outwardly from the other end of said roll, said second shaft being supported for rotation relative to a stationary housing but being nonrotatably connected to said roll, and control means for controlling the rotation of said roll to thereby control the wrapping and unwrapping of the flexible door, said control means comprising:

torsion spring means coacting between said first shaft and said roll for rotatably urging said roll in a direction tending to wrap the flexible door thereon so as to at least partially counterbalance the weight of said door when in a partially unwrapped condition;

initiating means coacting between said stationary housing and said first shaft for positively initiating rotation of said first shaft, and said roll, in a door unwrapping direction whereby further rotation may then continue in response to gravity;

said initiating means including a rotatable member secured to and rotatable with said first shaft and spring means for rotatably urging said rotatable member and said first shaft in said door unwrapping direction, said initiating means also including releasable means for normally preventing rotation of said rotatable member but permitting release and hence rotation of said rotatable member in response to a signal, such as the melting of a fusible link, and stop means cooperating with said rotatable member for permitting only a single revolution thereof;

over-running means coacting between said first shaft and said roll for drivingly rotatably connecting said roll to said first shaft during the initial rotation of said first shaft to thereby initiate unwrapping of said door, said over-running means permitting continued rotation of said roll and over-running thereof relative to said first shaft after said first shaft is stopped by said stop means;

speed responsive means actuatable in response to rotation of said roll for limiting the rotational speed of said roll to a predetermined value to thereby control the rate at which the door unwraps in response to gravity, said speed responsive means including speed-sensitive frictional braking means and positive drive means connected between said second shaft and said braking means, said positive drive means defining a substantial speed ratio so that said braking means is rotatably driven at a rate several times faster than the rotation of said roll;

wind-up means drivingly connected to said second shaft for permitting driving rotation of said second shaft in a direction to permit wrapping of said door onto said roll, said wind-up means including normally-engaged clutch means for drivingly coupling said wind-up means to said second shaft; and

disconnect means for disengaging said clutch means in response to the melting of said fusible link to thereby disconnect said wind-up means from said second shaft during the gravity-urged unwrapping of said door from said roll.

6. A combination according to claim 5, wherein said braking means is associated with a third rotatable shaft which is positioned in parallel relationship to said second shaft, said positive drive means including a chain-and-sprocket drive arrangement drivingly coupled between said second and third shafts, and said wind-up means being drivingly connected directly to said third shaft, said clutch means being associated directly with said third shaft.

7. A combination according to claim 6, wherein said braking means includes a rotatable friction braking element fixedly connected to said third shaft for rotation therewith.