Magnetic threshold construction

BACKGROUND OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS

A threshold assembly is usually associated with doors, especially exterior doors, to exclude drafts, dust, water and insect pests. One form of conventional threshold assembly includes an extruded threshold plate, usually of aluminum, which receives a hollow resilient member or bubble, usually of vinyl material, which resiliently engages the bottom of the door when the threshold plate is mounted on the doorsill. With this type of construction it is usually necessary to bevel the lower surface of the door so that it may slide easily over the surface of the vinyl bubble when the door is closed. Additionally, it will be readily apparent that the bubble is in a position in which it will be subjected to constant wear and could easily form an obstruction which could cause a person passing through a doorway to trip.

In another type of construction, as shown in the U.S. Pat. to Gregory, No. 2,611,158, a series of slots are formed in the lower edge of the door and a bar magnet mounted in each of the slots. A movable threshold plate is then pivotally mounted on the doorsill so that when the door is positioned over the sill the bar magnets will attract the pivotally mounted member and bring it up against the lower edge of the door. Aside from the fact that the milling of slots in the lower edge of the door, installation of the magnets therein with their attaching plates and cover plate will require several operations, it will be seen that with this type of construction there still remains an obstruction in the doorway which is both subject to wear and provides a possible obstruction over which a person passing through the doorway could trip.

SUMMARY OF THE INVENTION

A threshold assembly according to the present invention incorporates a lower, stationary threshold plate for attachment to the doorsill and a resiliently mounted sealing member which is attached to the lower edge of the door and is magnetically attracted to the threshold plate when the door is closed. The magnet may be mounted in either the threshold plate or the sealing member. In either case because the movable sealing portion of the assembly is mounted on the lower edge of the door, it is not subjected to wear by traffic through the doorway nor does it present an obstruction over which a person passing through the doorway could trip.

The planar lower surface of the sealing member is positioned at a slight angle to the surface of the threshold member so that closing of the door will cause the lower edge of the sealing member to come in contact with the threshold first and then rock down to complete the seal over its entire surface. In this regard, the magnet is conveniently formed of an extruded flexible material so that if it is mounted in the sealing member it can deform with the resilient sealing member to compensate for unevenness of the door lower edge.

It will also be seen that the usual bubble is completely eliminated as well as the necessity of bevelling the lower surface of the door to accommodate the bubble.

Additionally, the cost of materials utilized in the threshold assembly are relatively inexpensive and installation is simplified, both because the number of components which must be attached to the doorway are minimal and also because the dimensions, such as the gap between the lower edge of the door and the sill, are no longer as critical as with prior types of threshold assemblies.

It will also be seen that a ferrous strip may be associated with the magnet as a backing plate to concentrate the magnetic flux lines and increase the pulling power of the magnet. If the magnet is mounted in the sealing member and the threshold plate is made of extruded aluminum, as is common, or some other nonferrous material, a channel may be formed on the interior of the threshold plate for the reception of a second ferrous strip to which the magnet of the sealing section will be attracted when the door is closed. Alternatively, if the ⁵ FIG. 1 is a cross-sectional elevation showing the components of a threshold assembly in accordance with one embodiment of the invention; and

FIG. 2 is a view similar to FIG. 1 showing a second preferred jq embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As seen in FIG. 1, a door 10 may have a drip plate 11 mounted thereon by means of screws 12 passing through slotted apertures 13 in an upstanding vertical leg 14 to which the drip plate is attached. The lower horizontally extending leg 15 extends beneath the lower edge of the door and carries a pair of downwardly extending, oppositely facing, substantially L-shaped members 16 which together define a substantially Tshaped channel 17. In this regard it will be noted that the base 18 of the slot 17 is angularly disposed with respect to the horizontal for a purpose to be presently explained.

Positioned beneath the lower edge of the door 10, is a sealing member 20 having a mounting flange 21 snugly received in the slot 17. Extending in spaced relationship to the mounting flange 21 is a pocket 22 receiving an elongated flexible magnet 23 and a strip of ferrous material 24 overlying the magnet in laminar relationship. A pair of resilient, reversely pleated connecting members 25 extend between and interconnect the mounting flange 21 and the pocket 22 and resiliently urge the pocket 22 upwardly toward the mounting flange.

A doorsill 30 is positioned beneath the lower edge of the door 10 and has affixed thereto by means of screws or the like 31 a stationary threshold plate 32. Alternatively, and in some cases, in addition to, the fasteners 31, strips of pressure sensitive tape 33 may be attached to oppositely extending feet 34 of the threshold plate. A pair of downwardly and oppositely facing flanges 35 define a longitudinally extending groove 36 beneath the upper surface of the threshold plate and received in the groove 36 and extending longitudinally of the threshold plate is a strip 37 of a ferrous material.

With the above construction it will be apparent that as the door is moved from an open position to the closed position shown in FIG. 1, the trailing edge 40 of the sealing member will be brought into proximity to the threshold plate to an extent such that the magnetic attraction between the magnet 23 and the ferrous strip 37 is sufficient to overcome the resilient pull of the pleated members 25 which are urging the magnet upwardly towards the lower edge of the door 10. As the trailing edge 40 is brought into contact with the threshold plate 32, the remainder of the sealing element pivots about the lower right-hand corner as seen in FIG. 1, and completes the seal with the threshold plate. Because of the ferrous strip 24 the lines of magnetic flux are concentrated and increase the pulling power of the magnet.

While in the above embodiment the magnet is positioned in the sealing member, it will be apparent that the magnet could , be mounted in the threshold and a ferrous strip positioned in the sealing member instead. Thus, as seen in FIG. 2, a strip 50 of ferrous material may be mounted in a pocket 51 similar to the pocket 22 and a magnet 52 mounted in a groove S3 formed by oppositely facing flanges 54 in the threshold plate 65 55. As in the previous embodiment, a strip of ferrous material 56 may be mounted in laminar relationship to the magnet to increase its magnetic pull.

In either of the above embodiments, the sealing member can conveniently be made of a resilient material such as 70 polyvinylchloride and the ferrous strips of a mild steel. The magnet, particularly if it is mounted in the resilient sealing member may be any conventional flexible magnet which will usually be of extruded construction. The drip member 11 and the threshold plate may conveniently be formed of extruded 75 aluminum, although it will be apparent that the threshold

3,604,152 plate, for example, could be made of a ferrous material and the strip 37 eliminated.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention.