Background of the Invention
It is well known that rain, insects, animals, and birds often enter a home or other building through an open chimney. Further it is well known that severe heat loss occurs through an open chimney during the winter when a damper or other means is not provided to close off the chimney opening when there is not fire in the associated fireplace.
Various means have been provided for closing a chimney or flue when not in use such as the well known fire box damper, and various other prior arrangements. Some such prior arrangements are illustrated in U.S. Pat. No. 2,704,502, RAINEY; and U.S. Pat. No. 2,856,839, SODERBERG, as well as U.S. Pat. No. 3,267,832, HINKLE.
Such prior arrangements have certain disadvantages and it is an object of the present invention to overcome many of the difficulties encountered in the use of the prior art arrangements.
Specifically, such previous arrangements have permitted wind blown rain to enter the chimney even though the damper located at the top of the chimney is closed. Moreover in most such arrangements it has been provided for the damper to be normally closed so that when the means to secure the damper are not functioning the damper is in a closed position and if a fire is built in the fireplace, when the damper is closed, the associated rooms are filled with smoke.
Summary of the Invention
The present invention provides a damper arrangement to be received by the top of a chimney where a generally rectangular frame is provided defining an opening from the chimney and having a substantially U-shaped inwardly turned channel member around a portion of the opening defined by the frame to receive an upstanding lip of an associated damper flap which is pivotably mounted on the frame. The arrangement prevents wind blown rain from entering the chimney and likewise prevents a common difficulty encountered with previous arrangement namely the situation where the damper flap is frozen closed during cold weather and cannot be opened. Furthermore the present invention provides an arrangement where the damper flap is pivotably mounted on the frame member to be retained in a normally opened position so that in the event of failure of the means provided to close the damper flap, the damper flap moves to an open position.
Moreover, the present invention can provide the chain means connected to the damper flap by means of a spring. By pulling the chain when the damper flap is closed a selected tension can be securely retained to provide the damper flap when the chimney is not in use.
Likewise, the present invention can advantageously provide a cooperative hammer means which can be carried by the chain so that when the spring is extended the chain is released the force of the spring causes the hammer means to abruptly strike the damper flap to release the flap in the event it is lodged in closed position.
Brief Description of the Drawing
FIG. 1 shows a perspective view partly in section of one example of a damper in accordance with the present invention as described hereinafter.
The example of the present invention shown in the FIGURE, includes a generally rectangular frame member 1 which is provided to rest on the top at the outlet of the flue of a chimney (not shown) in which the damper arrangement is installed. A depending flange 2 can be provided to extend downwardly from frame 1 over the outer surface of the chimney flue. Frame 1 likewise includes an upstanding generally rectangular flange 4 provided with an inverted channel member 6 at the top edge thereof, which extends partially around the periphery of flange 4 as shown. A sleeve 3 can be provided, as shown, to extend downwardly into the flue liner adjacent the walls of the chimney.
As shown, damper flap 7 is provided to be pivotably mounted in cooperation with flange 4 for example by means of a pivot 9. Pivot 9 is advantageously journaled, for example in flange 7 so that when damper flap 7 is unrestrained, the damper flap is rotatable in a clockwise direction out of engagement with channel 6 to open generally vertical position exposing the opening defined by flange 4 and opening the chimney flue, a weight 17 can be provided to provide additional force tending to open flap 7.
As shown, damper flap 7 includes a downwardly extending lip 5 which can, advantageously extend substantially around a portion of damper flap 7 which extends beyond the limits of flange 4. An upstanding flange 8 is provided around a portion of the periphery of flap 7 to be received in channel 6 to provide a seal between flange 4 and damper 7 extending substantially around flange 4 and the periphery of damper 1 from one end of pivot 9 to the other.
An arm 12 can be provided on the underside of flap 7 to be connected to a chain 11 by means of a spring 13. Chain 11 extends downwardly to the chimney to fireplace associated with the chimney for closing damper 7 and can be retained therein by latch means (not shown).
Spring 13 is provided among other purposes to provide a selected tension when chain 11 is pulled after damper 7 is closed, to provide additional basis to hold damper 7 in a closed position and securely fasten damper 7 when chain 11 is pulled to extend spring 13.
In accordance with another advantageous feature of the present invention a hammer means, for example a cup 15, can be provided adjacent the upper end of chain 11. In the example shown the end of spring 13 extends through a slot 16 provided in cup 15 and the end of spring 13 extending through slot 16 is adapted to be attached to chain 11. Cup 15 can advantageously, be of a selected weight so that when chain 11 is pulled, to extend spring 13, and then released, cup 15 abruptly strikes the underside of damper flap 7 to urge damper 7 in a clockwise direction (as view in the drawing) to disengage damper flap 7 from flange 4.
This arrangement is particularly useful in cold weather when moisture may have accumulated between damper 7, and flange 4 and particularly between upstanding lip 8 and channel lip 6 and frozen to damper 7 in a closed position.
In accordance with another feature of the present invention a sealing compound 14 can be provided on the underside of frame 1 between flange 2 and sleeve 3 to seal the underside of flange 1 to the top of the chimney to which the apparatus is placed. In the alternative bolts (not shown) can be provided to extend through cooperative openings in sleeve 3 and fastened to the chimney flue to secure the damper arrangement in place.
In operation, frame 1 is received on the chimney to which the damper arrangement to be installed, with flanges 2 extending downwardly along the outer surface of the chimney while sleeve 3 is received by the flue defined within the chimney.
Damper flap 7 is previously described is normally open, and is closed by pulling spring 11 and fastening the spring to suitable fastener means and which is located within the fire box in the fireplace (not shown).
As further previously described, chain 11 can then be pulled further to extend spring 13 to provide a resultant force urging damper flap 7 into closed position.
Upon release of chain 11 damper flap 7 is then rotated by gravitational force resulting from the location of pivots to an open position extending generally vertically into collar 3 and the chimney flue so that the flue is open and ready for use. It will be noted that in the event spring 11 breaks damper flap 7 will always "fail safe" by rotating to an open position so that the chimney is available for use. In arrangements where the damper is opened by pulling a chain or similar means considerable difficulty is experienced when the chain breaks so the damper return to normally closed position. Extreme difficulties arise when the opening means break after a fire is already set in the associated fireplace.
It will be further noted that the arrangement described herein in accordance with the present invention provides an arrangement, most notably lip 5 and cooperative flange 8 received by channel 6 to prevent air blown water from entering the chimney by leakage around the outer surfaces of the flange 7.
Moreover in the event water accumulates on the upper surface of flange 7 and freezes damper flap closed, chain 11 can be drawn to extend spring 13 where the chain is then released so hammer 15, as previously described strikes the underside of damper flap 7 to urge the damper flap to open position. On some occasions, successive repetition of the procedure may be required to break the damper flap loose.
It will be recognized that various other arrangements in accordance with the present invention will occur to those skilled in the art upon reading the disclosure set forth hereinbefore. Accordingly, the scope of the present invention is to be limited only by the claims appended hereto.