The present invention relates to a cover adapted for placing over an opening in a building or similar structure, such as in particular an attic opening, which is readily removable and yet provides both insulating and sealing capabilities. More particularly the cover of the present invention employs magnetic forces to not only keep the cover in place over the opening, but also to seal the opening against air passage. The cover of the present invention can be readily adapted to any opening design and is adjustable in its attachment and removal strength.
The prior art has concerned itself principally with removable covers for building openings that are attic hatches or openings. The purpose of such openings is to provide access to the attic or may be used for the placement of a fan or other device in the ceiling of a room. The devices of the prior art either are not readily removable or if removable provide inadequate sealing ability to prevent either undesirable air from penetrating into a building or desirable air from escaping from the building. Furthermore those that are capable of providing both insulating and air tight seals are expensive, difficult to install, or difficult to remove and place back over the opening. Frequently when used the covers interfere with the existing insulation above the opening or require the placement of separate insulating material.
The cover of the present invention is adapted to provide both sealing and insulating properties. It can be used for any type of opening and can be adjusted as to the force applied to adhere or remove the cover from the opening.
More specifically the cover of the present invention in a preferred embodiment comprises (1) a ferrous metal frame, capable of attracting a magnet, surrounding the an opening in the surface of a structure to which the frame is attached in a permanent manner (2) a solid, rigid cover extending on all sides beyond the opening and the attached metal frame, (3) flexible sealing material, generally in the form of a gasket, permanently attached to the interior surface of the cover in a position to removably contact the surface of the structure to which the metallic frame is attached and (4) magnets permanently attached to the interior surface of such cover, in a position to engage the metallic frame with sufficient spacing to allow the flexible sealing material attached to the cover to removably come into contact with the surface having the frame attached thereto when the magnets are in contact with the frame. In order to provide an airtight seal it is also preferred to employ a sealing material between the frame and the surface to which it is attached. The magnets and the flexible sealing material are positioned such that the magnets exert sufficient pressure on such sealing material to provide an airtight seal against the surface of the structure. The cover itself can be any rigid solid material but is generally solid wood, ply wood, wood composite but is not limited to such materials.
In a preferred embodiment, particularly where the cover is used as an attic hatch, the inside of the cover containing the magnets and sealing gasket also contains a rigid insulating block fitting within the opening to be covered to provide an improved thermal barrier when the cover is attached to the opening. The magnets used are preferably well-known commercially available rare earth magnets because of their greater strength, although standard ferrite magnets, if used in sufficient number to provide the required attraction to the frame, may also be used. Preferably the sealing gasket on the cover is a continuous strip, in the form of a flexible material, around the circumference of the opening and placed between the actual opening and the magnets attached to the cover. Although in a preferred embodiment the magnets are attached to the cover and the frame to the finished or interior building side it is equally possible to reverse the placement of the frame on the cover and magnets and sealing gasket on the surface such that the magnets and sealing gasket are permanently attached to the building surface at the opening and the cover has the continuous metal frame attached on its interior side. The cover of the present invention is not limited for use inside a building or structure but it can similarly used on openings in the exterior surfaces of structures such as a cover for windows and doors. The number and type of magnets to be used can be adjusted to provide the degree of contact of the cover with the surface containing the opening However the number should be adequate to keep the cover in place when placed against the opening.
If access to the opening is desired a user simply grabs the edges of the cover, and applies outward pressure on the cover until it exceeds the attaching force of the magnets thereby releasing the cover. If desired it is possible to attach handles or other means of removing the cover from the to the opening. The foregoing description will make it obvious that the magnetic cover of the present invention can find many applications in the construction of buildings as well as other structures such as boats, house trailers, trains and airplanes.