GB2160249A

GB2160249A - Door sealing mechanism

Info

Publication number: GB2160249A
Application number: GB08515301A
Authority: GB
Inventors: David Seed
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-16
Filing date: 1985-06-17
Publication date: 1985-12-18
Also published as: GB8515301D0; GB2160249B

Abstract

A mechanism for blocking the gap between the bottom edge of a door leaf, and the adjacent threshold, when the door is closed comprises an elongate bar 16 housed above a sealing strip 17 in the bottom of the door both of which carry respective magnets. One end 16a of the bar protrudes from an edge of the door adjacent the door frame, such that, with the door open, the sealing strip of material is magnetically attracted to the bar and raised clear of the threshold; as the door closes, the bar is moved longitudinally to take the two sets of magnets out of line repulsing the strip of material to block the threshold. <IMAGE>

Description

SPECIFICATION Door sealing mechanism Field of the Invention The invention relates to a mechanism for sealing or at least blocking the gap between the bottom edge of a hung and openable and closable door leaf and the adjacent threshold.

Review of the Prior Art Draft excluders which fix directly along the bottom edge region of a door are known.

They comprise strips of material which extend along essentially the whole of the length of the bottom edge of the door leaf. Although they can flex relative to the door leaf they do not otherwise move in relation to it. For this reason they have drawbacks in that they rub against the surrounding carpet or other floor covering, causing wear, and making it difficult to open and close the door without effort to overcome the frictional resistance of the strip against the carpet.

Lever-action draft excluders are known in which the draft excluding strip is automatically raised from the carpet as the door swings about its hinges, and is progressively lowered into place as the door closes. These are not wholly reliable and are expensive and relatively complicated to fit to the door leaf.

Neither of the known general forms of sealing or blocking strip just outlined has been specifically developed as a fire-resistant sealing strip.

Summary of the Invention The present invention seeks to provide a means for automatically blocking off the gap along the bottom edge of the door leaf when the door is closed, and unblocking that gap as the door opens, which is without the drawbacks of known sealing strips and which can be adapted to form a fire-resistant strip.

In its broadest aspect the invention provides a mechanism for automatically blocking the gap between the bottom edge of a door leaf, hung to open and close within a surrounding frame, and the adjacent threshold, when the door is closed; and automatically unblocking that gap when the door starts to open again; the mechanism comprising a) A strip of material housed at the bottom edge of the door leaf, extending along essentially the whole of the length of the bottom edge, and movable up and down from a first position (in which it protrudes from the door edge to contact the threshold) into and out of a second position (in which it is held clear of the threshold); b) An elongate bar, also housed at the bottom edge region of the door leaf and extending adjacent the said strip, the bar being movable back and forth along or across its axis and with one end of the barr with a member operatively connected to said one end-terminating adjacent an upright of the door frame or adjacent the threshold; c) At least one magnet fixed to the bar or to the strip of material;; d) At least one piece of material which is either positively attracted to the magnet or is positively repelled by it and is fixed to the strip or to the bar (according as to whether the magnet itself is fixed to the bar or to the bar or to the strip respectively) in the vicinity of the magnet; e) The arrangement of components being such that when the magnetically attracted or repelled piece comes within the effective range of action of the magnet, the strip of material is either pushed to protrude from the bottom edge of the door and contact the threshold or alternatively is raised clear of the threshold towards (but not necessarily wholly withdrawn into) the bottom edge of the door; whilst the opposite happens when the said piece is moved out of the effective range of the magnet; f) With means on the upright of the door frame or on the threshold which, with the door closed, co-operates with the said bar to move the said piece and the magnet in a sense which causes the strip of material to contact the threshold and which, when the door opens, co-operates with the bar in the opposite sense to raise the strip of material clear of the threshold.

In practical embodiments of the invention it is envisaged that the strip-raising movement will be consequent upon a positive attraction of the magnetically-attractable piece to the magnet, as there is then a positive holding force acting on the strip throughout the time the door swings about its hinges. Although in theory a positive force of repulsion could push the strip upwards into the door and hold it there, it is surer as well as simpler to arrange for the strip to be positively attracted to the magnet when the door opens and then allowed to drop (or positively repulsed) and contact the threshold under gravity when the door is closed.

The magnetically attractable piece of material may conveniently comprise another magnet. Since opposite magnetic poles attract, and corresponding poles repel, the forces lifting and letting fall the strip of material can be made that much more positive using such components.

Preferably the bar or the strip of material (or both) carry more than one magnet, and such magnets are aligned and spaced so that the necessary forces of attraction and repulsion are produced depending on whether the door is open or closed.

The end of the bar terminating adjacent the door upright or adjacent the threshold may positively project from the edge of the door so as to contact, and effectively be "triggered" by, the upright or the threshold as the door closes and opens.

Alternatively or additionally the terminating end of the bar may be magnetically operated i.e. may be positively attracted to or repulsed from a co-operating magnet in the door upright or the threshold as the door closes and opens.

Preferably the bar is spring-loaded in a way which assists its operation in raising the strip from the threshold.

Preferably also the strip of material, whilst being held against any undue lengthwise movement in the door, is not restricted in its up and down movement other than by its lengthwise constraints and the threshold which it contacts. In other words the strip is free to "float" and effectively find its own level once it contacts the threshold.

The bar may conveniently comprise an elongate bar which, like the strip, extends essentially across the whole of the length of the bottom edge of the door leaf and with a substantially constant vertical gap between it and the top edge of the strip. This makes it possible for the bar and the strip to accommodate lines of multiple magnets for maximum effectiveness of operation.

It also makes it possible for the bar to ride in a continuous shelf of plastics or other suitable non-magnetic material, which shelf can separate the bar from the strip whilst not impeding the efficient operation of the magnet and the magnetically attracted piece or pieces irrespective of whether such pieces comprise magnets themselves.

The strip of material may be a fire-resistant strip but it could simply be a draft excluder.

As such it could be made of inherently flexible material consistent with the need for the mechanism to operate.

The bottom edge of the strip, the one that contacts the threshold when the door is closed, could be faced with rubber or other resilient material for a good draughtproof seal.

The door leaf and door frame could be found in situations other than internal or external access doors in buildings. For example they could comprise the door of a food freezing cabinet.

If the strip of material were suitably waterproofed then the invention provides a potential means of blocking off flood water from external doors of buildings. In practice the water might eventually find its way through but nevertheless the very large amounts of debris which do as much if not more damage than the incoming flood water would be kept out by such a mechanism.

One mechanism embodying the invention is shown in the accompanying drawings and will now be described with reference to those drawings. It is currently the best way known to the applicants of putting the invention ito practice.

Brief description of the Drawings Figure 1 shows the bottom edge region of a door leaf when viewed flat-on and with parts broken away to show the door blocking strip held clear of the threshold; Figure 2 corresponds to Fig. 1 but with the strip contacting the threshold; Figure 3 is an edge-on view of the door leaf sectioned to show the parts of the mechanism.

Description of the Preferred Embodiment A rectangular door leaf is referenced 11 and is of conventional construction in all but its bottom edge region. It is hung, in use, conventionally inside a door frame to swing open and closed above a threshold 12. The door frame itself can be conventional and is not shown in the drawings.

A channel is routed out along the bottom edge of the door leaf 11 and extends along substantially the whole of the length of the bottom edge. This channel 13 accommodates a plastics extrusion 14 which is glued or force-fitted into the channel 13 before the door leaf 11 is hung.

As Fig. 3 shows, the extrusion 14 is essentially rectangular in cross section and is Ashaped when so viewed. The cross piece 15 of the A extends along the whole of the length of the extrusion and acts as a bearing surface on which an elongate bar 16 can slide axially back and forth. The portion of the extrusion below the cross piece 15 forms an open-ended channel in which a strip of material 17 can move up and down towards and away from the underside of the bar 16.

The underside of the bar 16 carries a succession of magnets. The top edge of the strip 17 carries a similar succession of magnets.

The strip 17 is held against anything other than up and down movement in the door leaf 11, by pins 18; but the bar 16 can slide back and forth axially so as to bring its magnets M respectively into and out of the effective range of attraction or repulsion of the other line of magnets M on the top edge of the strip 17.

One end 1 6a of the bar 16 protrudes from the upright edge of the door leaf 11. It is chamfered to give a "lead-in" as illustrated.

The other end of the bar 16 compresses a coiled spring 19 which is initially inserted into the extrusion 14 and held therein by a stud 21.

With the door open, as illustrated in Fig. 1, and the end 1 6a of the bar 16 protruding from the upright edge of the door leaf 11, the two lines of magnets positively attract one another and the strip 17 is raised and held clear of the threshold 12. In this particular embodiment the strip is retracted wholly into the bottom edge of the extrusion 14 and hence into the door leaf. Pressure from the expanded compression spring 19 keeps the bar 16 in the position illustrated in Fig. 1.

As the door closes, the chamfered lead-in on the protruding end 1 6a of bar 16 contacts an upright (not illustrated) of the door frame; and the bar is pushed axially to the left when viewed as in Figs. 1 and 2, against the action of spring 19. This movement, which continues as the door leaf 11 closes fully into its frame, moves the line of magnets on the bar 16 in such a way that instead of opposite magnetic poles being vertically in alignment, like magnetic poles are now aligned and positively repel one another.

As a consequence the strip 17 falls under gravity to contact the threshold 12.

When the door is subsequently opened, the compression spring 19 expands to push bar 16 back into its Fig. 1 position. The vertical gap between the two lines of magnets in the Fig. 2 position is sufficiently small. when the door opens, for the strip 17 to be pulled back up against the underside of shelf 15 due to the force of attraction between the two lines of magnets in the Fig. 1 position.

The opposite upright edges of the door leaf 11 will of course conventionally close inside their respective door frame uprights. For that reason it is not necessary for the strip 17 to extend literally the whole length of the bottom edge of the door leaf as long as it at least reaches and preferably overlaps the two opposite door frame uprights.

The required means on the upright of the door frame or on the threshold (integer (f) of the broadest aspect of the invention) may comprise a surface of the upright or of the threshold, therefore. as in the above embodiment.

Claims

1. A mechanism for automatically blocking the gap between the bottom edge of a door leaf, hung to open and close within a surrounding frame, and the adjacent threshold, when the door is closed: and automatically unblocking that gap when the door starts to open again; the mechanism comprising: a) A strip of material housed at the bottom edge of the door leaf. extending along essentially the whole of the length of the bottom edge, and movable up and down from a first position (in which it protrudes from the door edge to contact the threshold) into and out of a second position (in which it is held clear of the threshold);; b) An elongate bar. also housed at the bottom edge region of the door leaf and extending adjacent the said strip, the bar being movable back and forth along or across its axis and with one end of the barr with a member operatively connected to said one end-terminating adjacent an upright of the door frame or adjacent the threshold; c) At least one magnet fixed to the bar or to the strip of material; d) At least one piece of material which is either positively attracted to the magnet or is positively repelled by it and is fixed to the strip or to the bar (according as to whether the magnet itself is fixed to the bar or to the strip respectively in the vicinity of the magnet;; e) The arrangement of components being such that when the magnetically attracted or repelled piece comes within the effective range of action of the magnet, the strip of material is either pushed to protrude from the bottom edge of the door and contact the threshold or alternatively is raised clear of the threshold towards (but not necessarily wholly withdrawn into) the bottom edge of the door; whilst the opposite happens when the said piece is moved out of the effective range of the magnet; f) With means on the upright of the door frame or on the threshold which, with the door closed, co-operates with the said bar to move the said piece and the magnet in a sense which causes the strip of material to contact the threshold and which, when the door opens, co-operates with the bar in the opposite sense to raise the strip of material clear of the threshold.

2. A mechanism according to Claim 1 and in which the strip-raising movement occurs consequent upon a positive attraction of the magnetically-attractable piece to the magnet.

3. A mechanism according to Claim 1 or Claim 2 and in which the magnetically-attractable piece of material comprises another magnet.

4. A mechanism according to any of the preceding Claims and in which the bar or the strip of material (or both) carries more than one magnet. and such magnets are aligned and spaced so that the necessary forces of attraction and repulsion are produced depending on whether the door is open or closed.

5. A mechanism according to any of the preceding Claims and In which the said end of the bar terminating adjacent the door upright or adjacent the threshold (or the said member operatively linked thereto) positively projects from the edge of the door so as to contact, and effectively be triggered into action by, the upright or the threshold as the door closes and opens.

6. A mechanism according to any of the preceding Claims and in which the said end of the bar terminating adjacent the door upright or adjacent the threshold (or the said member operatively linked thereto) is magnetically operated.

7. A mechanism according to any of the preceding Claims and In which the bar is spring loaded In a way which assists its operation in raising the strip from the threshold.

8. A member according to any of the preceding Claims and in which the strip Is free to float and find its own level once it contacts the threshold.

9. A mechanism according to any of the preceding Claims and in which the bar comprises an elongate bar which extends essentially across the whole of the length of the bottom edge of the door leaf and with a substantially constant vertical gap between it and the top edge of the strip.

10. A mechanism according to any of the preceding Claims and in which the bar rides in a substantially continuous shelf of plastics or other suitably non-magnetic material which separates the bar from the strip.

11. A mechanism according to any of the preceding Claims and in which the strip is a fire resistant strip.

1 2. A mechanism according to any of the preceding Claims and in which the bottom edge of the strip is faced with resilient draught-proofing material.

13. A mechanism as substantially described herein with reference to and as illustrated in the accompanying drawings.