Title:
RETRACTABLE HIDEAWAY CHIMNEY DAMPER CAP
Kind Code:
A1


Abstract:
An apparatus for a damper cap for a chimney flue includes a top plate having dimensions conforming to a top of the chimney flue. A bird and animal screen is joined to and extends from a bottom of the top plate. The screen has dimensions for insertion into the chimney flue. A rod joined to a center of the top plate extends downward into the chimney flue. A support structure is secured to an interior of the chimney flue. A mechanism is joined to the support structure and the rod for moving the rod in a vertical direction. In an open position the top plate is above the chimney flue to allow smoke to exit and the screen restricts birds and animals from entering. In a closed position the top plate is proximate the chimney flue restricting airflow into and out of the chimney flue and the apparatus is retracted into the flue.



Inventors:
Thomas, Daniel Paul (Louisville, KY, US)
Application Number:
12/351775
Publication Date:
07/16/2009
Filing Date:
01/09/2009
Primary Class:
Other Classes:
454/4, 454/29, 110/163
International Classes:
F23L17/10; F23L13/00; F23L17/12
View Patent Images:
Related US Applications:



Primary Examiner:
PROBST, SAMANTHA A
Attorney, Agent or Firm:
Daniel Paul Thomas (Louisville, KY, US)
Claims:
What is claimed is:

1. An apparatus for a damper cap for a chimney flue, the apparatus comprising: a top plate being configured with dimensions conforming with a top opening of the chimney flue; a bird and animal screen joined to and extending from a bottom surface of said top plate, said bird and animal screen being configured with dimensions suitable for insertion into the top opening of the chimney flue; a rod joined to a center of said top plate for extending downward into the chimney flue; a support structure configured to be secured to at least two sides of an interior surface of the chimney flue, said support structure constraining horizontal movement of said rod; and a mechanism joined to said support structure and said rod for moving said rod in a vertical direction, where, in an upward open position, said top plate is at a sufficient distance above the top opening of the chimney flue to allow smoke to exit the chimney flue and said bird and animal screen extends downward to at least the top opening of the chimney flue substantially restricting birds and animals from entering the chimney flue, and where, in an downward closed position, said top plate is proximate the top opening of the chimney flue substantially restricting airflow into the chimney flue and the apparatus is substantially retracted within the flue.

2. The apparatus as recited in claim 1, wherein said mechanism further comprises at least one pulley and a cable in engagement with said pulley, said cable being joined to a distal end of said rod and extending downward through the chimney flue to a firebox where, when said cable is pulled, said rod is raised to said upward open position, and, when said cable is released, said rod is lowered to said downward closed position.

3. The apparatus as recited in claim 2, further comprising a hook positioned within the firebox for securing said cable when said rod is in said upward open position.

4. The apparatus as recited in claim 2, further comprising a cable retainer for retaining said cable in a groove of said at least one pulley and allowing said at least one pulley to freely rotate.

5. The apparatus as recited in claim 1, further comprising a sealing flange joined to the top opening of the chimney flue, said sealing flange comprising an opening dimensioned to receive said bird and animal screen where, when said rod is in said downward closed position, said top plate rests on a top of said sealing flange.

6. The apparatus as recited in claim 5, further comprising a gasket disposed between said sealing flange and said top plate to provide a seal in said downward closed position.

7. The apparatus as recited in claim 5, further comprising a cap stop angle joined to a distal edge of said bird and animal screen where, when said rod is in said upward open position, said cap stop angle contacts a lower surface of said sealing flange.

8. The apparatus as recited in claim 2, wherein said support structure further comprises at least two lower arms, each of said lower arms comprising an engaging end configured for engaging said interior surface of the chimney flue, a lower pivot point and an upper pivot end, said lower arms joined at said lower pivot point for rotation about said pivot point; and at least two upper arms, each of said upper arms comprising a lower pivot end pivotally joined to one of said lower arms upper pivot end and a pivoting end, each of said pivoting ends pivotally joined to said at least one pulley where, when a downward force is applied to said pivoting ends, said engaging ends move outward engaging said interior surface of the chimney flue and thus securing the apparatus.

9. The apparatus as recited in claim 8, wherein said support structure further comprises flue cleats joined to said engaging ends for providing addition friction on said interior surface of the chimney flue.

10. The apparatus as recited in claim 8, wherein said support structure further comprises a rod guide for constraining horizontal movement of said rod.

11. An apparatus for a damper cap for a chimney flue, the apparatus comprising: means for damping the chimney; means for restricting birds and animals from entering the chimney flue; means for supporting the apparatus in the chimney flue; and means for moving said damping means and said restricting means to an open position for allowing smoke to exit the chimney flue and substantially restricting birds and animals from entering the chimney flue, and to a closed position for substantially restricting airflow into the chimney flue where the apparatus is substantially retracted within the chimney flue.

12. The apparatus as recited in claim 11, further comprising means for operating said moving means from a firebox.

13. The apparatus as recited in claim 11, further comprising means for sealing said damping means to the chimney flue.

14. An apparatus for a damper cap for a chimney flue, the apparatus comprising: a top plate being configured with dimensions conforming with a top opening of the chimney flue; a bird and animal screen joined to and extending from a bottom surface of said top plate, said bird and animal screen being configured with dimensions suitable for insertion into the top opening; a cap stop angle joined to a distal edge of said bird and animal screen; a sealing flange joined to the top opening of the chimney flue, said sealing flange being configured with an opening dimensioned to receive said bird and animal screen; a rod joined to a center of said top plate for extending downward into the chimney flue; a support structure configured to be secured to at least two sides of an interior surface of the chimney flue, said support structure constraining horizontal movement of said rod; and a mechanism joined to said support structure and said rod for moving said rod in a vertical direction, said mechanism comprising at least one pulley and a cable in engagement with said pulley, said cable being joined to a distal end of said rod and extending downward through the chimney flue to a firebox where, when said cable is pulled, said rod is raised to an upward open position where said cap stop angle contacts a lower surface of said sealing flange and said top plate is at a sufficient distance above the top opening of the chimney flue to allow smoke to exit the chimney flue and said bird and animal screen substantially restricts birds and animals from entering the chimney flue, and, when said cable is released, said rod is lowered to a downward closed position where said top plate rests on a top of said sealing flange substantially restricting airflow into the chimney flue and the apparatus is substantially retracted within the flue, whereby said top plate and bird and animal screen can be raised easily under severe weather conditions and when retracted said bird and animal screen is hidden from view.

15. The apparatus as recited in claim 14, further comprising a hook positioned within the firebox for securing said cable when said rod is in said upward open position.

16. The apparatus as recited in claim 14, further comprising a cable retainer for retaining said cable in a groove of said at least one pulley and allowing said at least one pulley to freely rotate.

17. The apparatus as recited in claim 14, further comprising a gasket disposed between said sealing flange and said top plate to provide a seal in said downward closed position.

18. The apparatus as recited in claim 14, wherein said support structure further comprises at least two lower arms, each of said lower arms comprising an engaging end configured for engaging said interior surface of the chimney flue, a lower pivot point and an upper pivot end, said lower arms joined at said lower pivot point for rotation about said pivot point; and at least two upper arms, each of said upper arms comprising a lower pivot end pivotally joined to a one of said lower arms upper pivot end and a pivoting end, each of said pivoting ends pivotally joined to said at least one pulley where, when a downward force is applied to said pivoting ends, said engaging ends move outward engaging said interior surface of the chimney flue and thus securing the apparatus.

19. The apparatus as recited in claim 18, wherein said support structure further comprises flue cleats joined to said engaging ends for providing addition friction on said interior surface of the chimney flue.

20. The apparatus as recited in claim 18, wherein said support structure further comprises a rod guide for constraining horizontal movement of said rod.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Utility patent application claims priority benefit of the U.S. provisional application for patent Ser. No. 61/020,707 filed on Jan. 12, 2008 under 35 U.S.C. 119(e). The contents of this related provisional application are incorporated herein by reference for all purposes.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER LISTING APPENDIX

Not applicable.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever.

FIELD OF THE INVENTION

The present invention relates generally to chimney caps. More particularly, the invention relates to a retractable chimney damper cap that cannot be seen on the outside of the chimney.

BACKGROUND OF THE INVENTION

Homeowners who have one or more masonry fireplace flues in their home are loosing energy from their furnace through these chimney flues. Dampers mounted above the fireboxes are not airtight, and even if the dampers are closed much energy is still lost up the flues. When the wind is blowing, the wind often comes down the flue and makes the home much colder, requiring the furnace to kick on needlessly. In the warm months, the air conditioner is pulling warm air down the flue unintentionally. This puts a heavy demand on the compressor, using more energy and causing wear and tear on the compressor. Fireplace flues may also allow rain to enter the system. Virtually, there is a square foot hole in the roof where the flue is. Furthermore, rain, birds, raccoons, snakes, rats, squirrels and other pests can enter the open flue at the top and cause problems.

There are chimney damper caps available to seal flues. However, current chimney caps sit on top of the flue. These caps often have a cold industrial look and resemble a birdcage, which is a look that some people do not like. Also, currently known chimney damper caps are spring loaded and require a lot of force to pull the cap closed. Elderly people in particular may have trouble manipulating these designs. Other currently known chimney caps require driving four heavy screws, two on each side, into the flue tile to mount these caps on top of the flue. This is troublesome since terracotta flue tile has a surface glaze from being fired in a kiln. This glaze should never be drilled or altered in any way since a crack or hole in this glaze may enable freezing rain to seep into the flue and cause the flue to crack and weaken and fails to prevent wind from blowing the cap off. The two leading damper caps in the United States require the purchase of a lid and screen in order to prevent birds, squirrels, raccoons, and other pests from entering the flue, making it necessary to purchase two separate products to solve all of the problems incurred with chimney flues.

One specific prior art damper cap, which is one of the leading commercially successful chimney damper caps on the market, has no bird and animal screen. Raccoons are the most notorious animal to break into houses via open chimney flues, and the springs around the perimeter of this cap cannot keep desperate raccoons from entering the flue and nesting in the bottom smoke chamber. Therefore a separate rain cap with a bird and animal screen design is often required to be used with this damper cap. Also this design is difficult or impossible to open in severe ice and snow. The springs in this cap are not strong enough to lift the load. Another similar prior art damper cap uses a second product, a rain cap with a screen, to go over top of the cap to prevent failure when ice and snow mount on top and to prevent animal intrusion. Another exemplary prior art damper cap also has no bird and animal screen, and, if a homeowner forgets to close the lid, an animal has plenty of room to enter the home via this damper cap design. Also the present damper cap does not function properly in severe ice and snow, and may fail from the load. To resolve this, the inventor offers a lid and screen in a separate unit, as in the previous prior art example. Therefore, two products must be purchased to meet the total needs of the homeowner. The need for a second cap unit in these prior art examples is not ideal. In another similar prior art damper cap, a lever device is provided for attempting to hammer the lid open when frozen shut from ice. This mechanism works in light frost; however, if the lid is completely filled with rain, held on top of the lid by the outer perimeter of the outer walls, thick ice forms, and the lid typically does not open. Furthermore, this design has no bird and animal screen and sits on top of the flue, which is unsightly to many.

In another prior art chimney damper cap without a bird and animal screen, the lid moves up and down; however, the holding mechanism is spring loaded and not practical for easy fabrication or installation. Also, this damper cap is not universal. In this design the cap is supported by expandable tumbuckles anchored in sockets formed in the chimney liner, and in order to attach this device to a flue, holes must be drilled into the terracotta flue tile. This procedure may cause the flue tile to crack, and if the lid is left open and freezing rain enters, the flue may break. Furthermore, it is very difficult and dangerous to drill down inside a flue, especially when standing on a second or third story ladder. It is also a disservice to the homeowner to form sockets in their flue as freezing rain may enter the sockets themselves and expand and break the flue, causing much damage in time. An experienced professional chimney sweep would never drill into a flue liner to attach a damper cap.

Other prior art damper caps have attached lids and animal screens in one unit. These damper caps sit in a stationary position on top of the flue, and each have a spring-loaded additional lid inside the outer lid and screen. This design is held into place by four spring-loaded levers attached to the four corners. The multiple lids make this design complicated and expensive to manufacture. Another prior art damper cap comprises a damper flap with a bird and animal screen. The damper flap is automatic and electrically controlled, which makes it costly to make and difficult to install. Furthermore, this design is unsightly to many since it sits on top of the flue.

Yet another prior art damper cap is electrically controlled to open and close automatically when sensing smoke in the flue. This design has no bird and animal screen and uses relays and double pull switches, motors and smoke detectors. This design is extremely complicated to manufacture and is expensive. Another very complicated and costly prior art damper cap provides a brake mechanism said to prevent unwanted damper closure. However, this damper cap is impractical in nature and also difficult to install. Furthermore, this design does not include a bird or animal screen.

Yet other prior art damper cap designs are hinged to one side of the flue and open much like a book. In these designs one side of the damper cap is bound and three sides are free. This is a problem in windy conditions where these designs may blow shut and cause smoke problems or blow backwards and bend or break. Furthermore, these designs do not include a bird and animal screen. Another prior art damper cap design has a cross member that holds the lid in place. However, this cross-member prevents the lid from closing tightly, making it impossible to save costly energy. This design allows furnace air to escape, and allows cold wind to blow into the home. Also, this design does not have a bird and animal screen. Yet another prior art damper cap design has a tube that holds a spring that lifts the lid. However, this spring can fail from creosote building up inside the tube. Furthermore, this design does not include a bird and animal screen.

In view of the foregoing, there is a need for improved techniques for providing a chimney or damper cap that cannot be seen on the outside of the chimney, seals tightly, is easy to open and close, is easy to install, and generally prevents pests, rain, snow, and debris from entering the chimney flue.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:

FIGS. 1A, 1B and 1C illustrate an exemplary retractable damper cap, in accordance with an embodiment of the present invention. FIG. 1A is a cross sectional view of damper cap installed in a chimney flue, FIG. 1B is a cross sectional view of a pulley assembly as indicated by section A-A in FIG. 1A, and FIG. 1B is a side view of the damper cap not attached to a chimney flue.

Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.

SUMMARY OF THE INVENTION

To achieve the forgoing and other objects and in accordance with the purpose of the invention, a retractable hideaway chimney damper cap is presented.

In one embodiment, an apparatus for a damper cap for a chimney flue is presented. The apparatus includes a top plate having dimensions conforming with a top opening of the chimney flue. A bird and animal screen is joined to and extending from a bottom surface of the top plate. The bird and animal screen includes dimensions suitable for insertion into the top opening of the chimney flue. A rod joined to a center of the top plate extends downward into the chimney flue. A support structure is configured to be secured to at least two sides of an interior surface of the chimney flue. The support structure constrains horizontal movement of the rod. A mechanism is joined to the support structure and the rod for moving the rod in a vertical direction, where, in an upward open position, the top plate is at a sufficient distance above the top opening of the chimney flue to allow smoke to exit the chimney flue and the bird and animal screen extends downward to at least the top opening of the chimney flue substantially restricting birds and animals from entering the chimney flue. In a downward closed position, the top plate is proximate the top opening of the chimney flue substantially restricting airflow into the chimney flue and the apparatus is substantially retracted within the flue. In another embodiment the mechanism further includes at least one pulley and a cable in engagement with the pulley. The cable is joined to a distal end of the rod and extends downward through the chimney flue to a firebox where, when the cable is pulled, the rod is raised to the upward open position. When the cable is released, the rod is lowered to the downward closed position. A further embodiment includes a hook positioned within the firebox for securing the cable when the rod is in the upward open position. Another embodiment further includes a cable retainer for retaining the cable in a groove of the at least one pulley and allowing the at least one pulley to freely rotate. Yet other embodiment further include a sealing flange joined to the top opening of the chimney flue, the sealing flange including an opening dimensioned to receive the bird and animal screen where, when the rod is in the downward closed position, the top plate rests on a top of the sealing flange and a gasket disposed between the sealing flange and the top plate to provide a seal in the downward closed position. Still another embodiment further includes a cap stop angle joined to a distal edge of the bird and animal screen where, when the rod is in the upward open position, the cap stop angle contacts a lower surface of the sealing flange. In another embodiment the support structure further includes at least two lower arms. Each of the lower arms includes an engaging end configured for engaging the interior surface of the chimney flue, a lower pivot point and an upper pivot end. The lower arms are joined at the lower pivot point for rotation about the pivot point. At least two upper arms are included. Each of the upper arms includes a lower pivot end pivotally joined to a one of the lower arms upper pivot end and a pivoting end. Each of the pivoting ends is pivotally joined to the at least one pulley where, when a downward force is applied to the pivoting ends, the engaging ends move outward engaging the interior surface of the chimney flue and thus secures the apparatus. Various other embodiment further include flue cleats joined to the engaging ends for providing addition friction on the interior surface of the chimney flue and a rod guide for constraining horizontal movement of the rod.

In another embodiment an apparatus for a damper cap for a chimney flue is presented. The apparatus includes means for damping the chimney, means for restricting birds and animals from entering the chimney flue, means for supporting the apparatus in the chimney flue and means for moving the damping means and the restricting means to an open position for allowing smoke to exit the chimney flue and substantially restricting birds and animals from entering the chimney flue, and to a closed position for substantially restricting airflow into the chimney flue where the apparatus is substantially retracted within the chimney flue. Yet other embodiments further include means for operating the moving means from a firebox and means for sealing the damping means to the chimney flue.

In another embodiment an apparatus for a damper cap for a chimney flue is presented. The apparatus includes a top plate having dimensions conforming to a top opening of the chimney flue. A bird and animal screen is joined to and extends from a bottom surface of the top plate. The bird and animal screen has dimensions suitable for insertion into the top opening. A cap stop angle is joined to a distal edge of the bird and animal screen. A sealing flange is joined to the top opening of the chimney flue. The sealing flange has an opening dimensioned to receive the bird and animal screen. A rod is joined to a center of the top plate for extending downward into the chimney flue. A support structure is configured to be secured to at least two sides of an interior surface of the chimney flue. The support structure constrains horizontal movement of the rod. A mechanism is joined to the support structure and the rod for moving the rod in a vertical direction. The mechanism includes at least one pulley and a cable in engagement with the pulley. The cable is joined to a distal end of the rod and extends downward through the chimney flue to a firebox. When the cable is pulled the rod is raised to an upward open position where the cap stop angle contacts a lower surface of the sealing flange and the top plate is at a sufficient distance above the top opening of the chimney flue to allow smoke to exit the chimney flue and the bird and animal screen substantially restricts birds and animals from entering the chimney flue. When the cable is released the rod is lowered to a downward closed position where the top plate rests on a top of the sealing flange substantially restricting airflow into the chimney flue and the apparatus is substantially retracted within the flue. The top plate and bird and animal screen can be raised easily under severe weather conditions and when retracted the bird and animal screen is hidden from view. Various other embodiments further include a hook positioned within the firebox for securing the cable when the rod is in the upward open position and a cable retainer for retaining the cable in a groove of the at least one pulley and allowing the at least one pulley to freely rotate. Yet another embodiment further includes a gasket disposed between the sealing flange and the top plate to provide a seal in the downward closed position. In another embodiment the support structure further includes at least two lower arms. Each of the lower arms includes an engaging end configured for engaging the interior surface of the chimney flue, a lower pivot point and an upper pivot end. The lower arms are joined at the lower pivot point for rotation about the pivot point. At least two upper arms are included. Each of the upper arms includes a lower pivot end pivotally joined to a one of the lower arms upper pivot end and a pivoting end. Each of the pivoting ends is pivotally joined to the at least one pulley. When a downward force is applied to the pivoting ends, the engaging ends move outward engaging the interior surface of the chimney flue and thus secures the apparatus. Various other embodiments further include flue cleats joined to the engaging ends for providing additional friction on the interior surface of the chimney flue and a rod guide for constraining horizontal movement of the rod.

Other features, advantages, and object of the present invention will become more apparent and be more readily understood from the following detailed description, which should be read in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is best understood by reference to the detailed figures and description set forth herein.

Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending upon the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive.

The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.

Preferred embodiments of the present invention provide retractable chimney damper caps that seal chimney flues and keep out rain and pests and do not detract from the design of the home. In preferred embodiments, the screen cap drops down inside the flue rather than sitting on top of the flue, hiding the cap from view so that it does not detract from the architectural integrity of the house. Preferred embodiments comprise no springs and use the weight of the cap to close the cap, making them very easy to open and close. Preferred embodiments also comprise a pulley system that lifts the lid and screen very easily and enables the cap to open even in severe ice and snow. Preferred embodiments can be opened easily with only a user's little finger. Preferred embodiments are held securely in place inside the flue without drilling or altering the flue, and require only one hole to be drilled in the firebox for installation.. This makes preferred embodiments much easier to install than some prior art solutions. Also, preferred embodiments combine the damper cap and a bird and animal screen into one unit, which is much cheaper than and easier to install than prior art caps requiring a separate bird and animal screen to seal the flue from generally all unwanted intrusions in the open or closed position. Typically, in preferred embodiments, no ice can form on top of the lid to cause difficulties, as the lid is flat and smooth allowing rain to run off and away from cap and flue before freezing into ice. If ice forms around the perimeter of lid and gasket that is 3/16 of an inch above flange, it is still very easy to open with the pulley mechanism. Furthermore, the damper cap in preferred embodiments will generally not fall shut accidentally.

FIGS. 1A, 1B and 1C illustrate an exemplary retractable damper cap 101, in accordance with an embodiment of the present invention. FIG. 1A is a cross sectional view of damper cap 101 installed in a chimney flue 100 in a raised position, FIG. 1B is a cross sectional view of a pulley assembly 107 as indicated by section A-A in FIG. 1A, and FIG. 1C is a side view of damper cap 101 not attached to a chimney flue. Referring to FIGS. 1A and 1C, damper cap 101 in the present embodiment comprises a sealing flange 102, a cap stop angle 103, and a top plate 105 preferably made of ⅛ inch thick aluminum and a bird and animal screen 104 preferably made of expanded aluminum mesh. Adhered to the underside and outer perimeter of top plate 105 is a 1/16 inch thick×1 inch wide silicone rubber gasket 124, to insure a hermetic seal between top plate 105 and sealing flange 102. However, various different materials may be used to construct the elements of damper cap 101 in alternate embodiments. For example, without limitation, different types of metal may be used, and plastic may be used for some elements such as, but not limited to, bird and animal screen 104 and sealing flange 102. Carbon steel, stainless steel, aluminum and high temperature plastics are ideal materials for construction of present embodiment. Furthermore some alternate embodiments may be implemented without a sealing flange or rubber gasket.

Referring to FIG. 1A, sealing flange 102 is attached to flue 100 with adhesive. Sealing flange 102 is not attached to bird and animal screen 104 to enable bird and animal screen 104 to be raised and lowered through sealing flange 102. In the present embodiment, pulley assembly 107 raises and lowers damper cap 101. Referring to FIGS. 1A and 1B, pulley assembly 107 comprises lower arms 106 with flue cleats 108, upper arms 109, a stationary pivot pin 110, a pulley pivot pin 111, a pulley 112, a cable retainer 113, a push rod guide 114, a push rod 115, a cable 117, and an actuator chain 116. Flue cleats 108 provide additional friction to hold pulley assembly 107 in place. Flue cleats 108 are optional and may not be included in alternate embodiments. Upper arms 109 and lower arms 106 are coupled together at joints 118 so that both sets of arms may rotate around joints 118. In the present embodiment, joints 118 are riveted; however, in alternate embodiments other coupling methods may be used such as, but not limited to, nuts and bolts. In an alternate embodiment, upper arms 109 and lower arms 106 could be the same length and assembled in the shape of a diamond, much the same as a scissor jack, with push rod guide 114 running from the top of the diamond shaped arms to the bottom. At the right and left joints flue cleats may or may not be attached. When nut 119 is tightened the pivot pin mechanism 110 and pulley pivot pin 111 mechanisms spread the diamond shaped scissor jack into the alternate sides of the flue holding assembly in place. One end of cable 117 is attached to actuator chain 116. Then cable 117 is wrapped around pulley 112, and the opposite end of cable 117 is attached to the lower end of push rod 115. This enables a user to raise damper cap 101 by pulling actuator chain 116. Alternate embodiments may have a longer cable without an actuator chain so that a user pulls the cable instead of a chain to raise the damper cap. In the present embodiment, pulley 112 is held in place on pivot pin 111 by cotter pin 120; however, in alternate embodiments various means may be used to hold pulley 112 onto pivot pin 111 such as, but not limited to, screws, caps on the pin, nuts, etc. In the present embodiment, cable retainer 113 must allow pulley 112 to rotate freely around pivot pin 111 and hold cable 117 into groove of pulley so that cable 117 may move rod 115 up and down freely.

Referring to FIG. 1A, in order to install the present embodiment, a user first adheres sealing flange 102 to flue 100 with silicone adhesive and then centers push rod 115 within flue 100. The user may use a setting tool to assist in this. Then the user inserts pulley assembly 107 into flue 100 until the top of push rod 115 is even with the top of flue 100. The push rod is held temporarily in a stationary position in hollow tube rod guide 110 by the cotter pin 125 that is inserted into holes near the top of the hollow tube 114, and then through a hole in push rod 115. It is necessary to line these holes up to allow cotter pin 125 to be inserted. The user then turns nut 119 clockwise, pushing pulley pivot pin 111 down and causing lower arms 106 to extend outward toward the walls of flue 100. When lower arms 106 engage the walls of flue 100, nut 119 is tightened, preferably with a wrench, until pulley assembly 107 is secure. If a setting tool was used to center push rod 115, the user now removes the setting tool and the cotter pin 125 from hollow tube 110 used to hold rod 115 in place for installation and installs cap damper 101 by inserting push rod 115 through a hole in the center of cap top plate 105 and resting cap top plate 105 on a nut 121 at the top of push rod 115. Then the user attaches hitch pin spring clip 122 to the top of push rod 115 to hold cap top plate 105 in place. In alternate embodiments other means may be used to hold cap top plate 105 in place such as, but not limited to, a nut, a cotter pin, a cap, etc. In some applications, the sealing flange could be screwed on to the flue; however, it is often not suitable to drill into terracotta flue tile material. Once damper cap 101 is installed on push rod 115, push rod 115 may be slid up and down within hollow threaded tube rod guide 114 causing cap top plate 105 and bird and animal screen 104 of damper cap 101 to move up and down in and out of flue 100. In an alternate embodiment, the four sided bird screen 104, that is attached to lid 105, could be eliminated, and one piece of screen 104 could be cut to the same size as sealing flange 102 and inserted under sealing flange 102 prior to adhesion. It would be positioned in such a way as to allow push rod 115 to move lid 105 up and down through an existing opening in said screen. The user then drills a hole in the firebox at a mortar joint and installs a hook 123. In some embodiments this hook may be secured in the firebox with a lag shield and lag screw. The hook may be located, or hidden away above the line of sight on the firebox wall in some embodiments to avoid drilling a hole where it would be visible on the firebox wall..

In typical use of the present embodiment, the weight of damper cap 101 forces push rod 115 down through rod guide 114, and bird and animal screen 104 drops down inside flue 100 in the closed position when not in use. Sealing flange 102 helps to form an airtight seal with cap top plate 105 at the top of flue 100. In some embodiments a rubber gasket 124 may be adhered to the under side of cap top plate 105 to further help create an airtight seal; however, this gasket is optional and may not be included in some embodiments. In some embodiments, cap top plate 105 may rest on flue 100 without a sealing flange or a gasket. When the user wishes to open damper cap 101 using the present embodiment, the user pulls actuator chain 116 downward to raise damper cap 101. To hold damper cap 101 in the open position the user hooks actuator chain 116 on hook 123. The pulley system of the present embodiment enables damper cap 101 to be opened very easily even in severe ice and snow. In prior art damper caps, it is important to have tension on the cable to hold the lid closed to prevent incoming and outgoing air movement. However, the present embodiment requires no tension on cable 117 to remain closed; instead, damper cap 101 is closed and held in the closed position by gravity and its own weight.

An alternate embodiment of the present invention may be implemented without a pulley mechanism to lift the damper cap. Instead, in this embodiment, one end of a long spring is attached to the bottom of the push rod and the other end of said spring is attached to a stationary part of a holding mechanism that holds the device in place in the flue. Releasing the cable from the mounted bracket on the firebox wall causes the tension of the spring to lift the rod and at the same time lift the attached damper cap. Pulling down on the cable closes the damper cap.

Other alternate embodiments may comprise various different means for raising and guiding the push rod. For example, without limitation, in one alternate embodiment, the push rod may comprise a worm gear assembly at the pulley that raises and lowers the push rod. In another alternate embodiment, a chain and gear may be used in place of the pulley and cable. In yet another alternate embodiment, the push rod is replaced by a ratcheting rack and the pulley comprises a toothed gear that engages with this rack to raise the rack, which is attached to the damper cap. This embodiment also comprises a second cable attached to a release mechanism on the rack in order to release the gear from the rack and lower the damper cap.

Yet other alternate embodiments may employ various different means for holding the pulley assembly in place. The preferred embodiment illustrated by way of example in FIG. 1A comprises a linkage assembly with two upper arms 109 and two lower arms 106 that expand to fit within a chimney flue. Alternate embodiments may comprise more arms for example without limitation, four upper arms and four lower arms to engage with all four walls within the chimney flue. This embodiment may be more complicated to manufacture yet may provide more stability when installed. Other alternate embodiments may comprise spring-loaded arms to hold the pulley assembly in place. Another alternate embodiment may comprise a sleeve that slides down into the chimney flue onto which various elements of the pulley assembly and damper cap may be attached.

Having fully described at least one embodiment of the present invention, other equivalent or alternative methods of providing chimney damper caps that cannot be seen on the outside of the chimney according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. For example, the particular implementation of the damper cap may vary depending upon the particular type of bird and animal screen used. The bird and animal screens described in the foregoing were directed to implementations that slide into the chimney; however, similar techniques are to provide bird and animal screens made of collapsible materials such as, but not limited to, fine mesh, folding lattices, hinged materials, etc. Collapsible implementations of the present invention are contemplated as within the scope of the present invention. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims.