GB2462998A

GB2462998A - A door seal

Info

Publication number: GB2462998A
Application number: GB0811159A
Authority: GB
Inventors: Ian Geoffrey Stalker
Original assignee: WINTUN ACOUSTIC SEALS Ltd
Current assignee: WINTUN ACOUSTIC SEALS Ltd
Priority date: 2008-06-18
Filing date: 2008-06-18
Publication date: 2010-03-03
Also published as: GB0811159D0

Abstract

A seal 1 for a door bottom with an upper portion 3 of a first substantially rigid material and lower portion 2 of a second substantially flexible material. The upper portion includes a base and the lower portion includes at least one sealing element that projects substantially downward with respect to the plane of base 4. The first material may be PVC, the second material may be nitrile butadiene rubber compound, have a deflection recovery value of more than 40% and a Shore A hardness of around 61. The first and second materials may be co-extruded. The upper portion may have side elements 4' for retention in a holder 6 which is attached to the bottom edge of the door. A strengthening element (10, Figures 3, 4) may be provided in the upper portion.

Description

Door Bottom Seal

Field of the Invention

The invention relates to a seal; in particular to a threshold seal for the bottom of a door.

Background of the Invention

Door seals are fitted for a number of purposes. For example, they may function as acoustic seals, fire seals or weather seals.

Threshold seals such as seals that are fitted to door bottoms, co-operate with threshold plates located under the door, such that when the door is closed the sealing element engages with a groove in the threshold plate, to form a tight seal.

There are a number of different types of door bottom seals.

Some door bottom seals include a mechanism which causes a seal to automatically drop down towards a floor and seal upon closing of a door. Upon opening, the seal is lifted so that it does not obstruct movement of the door.

Alternative door bottom seals include blades or flaps that flex on movement of the door.

These types of seals may be secured into a recess made in the bottom of the door or attached via a metal housing screwed to the bottom of the door.

U52949651 (Hill) describes a flexible weather strip with fins or flaps. It is said to be made of rubber or neoprene, and is retained in an aluminium housing on the bottom of the door, without fastening. The document states that the strip can be easily removed by puffing it from the housing. The ends of the strip include beads or rims that are held in troughs in the housing. The fins are able to flex back and forth and a channel between the lower surface of the housing and the upper surface of the weather strip allows displacement of the main body of the weather strip.

Although there are door bottom seals having flexible blades, they require some rigidity in order to function properly and seal tightly against a threshold plate or floor. This may lead to unnecessary force being required to open or close a door.

It would therefore be desirable to provide an improved seal.

Summary of the Invention

One aspect of the invention provides a seal as specified in Claim 1.

A further aspect of the invention provides a door as specified in Claim 17.

Preferred aspects of the invention are specified in the claims dependent on Claims I and

17 and the description which follows.

The invention provides a seal for a door bottom comprising an upper portion of a first substantially rigid material and a lower portion of a second substantially flexible material wherein the upper portion includes a base and the lower portion includes at least one sealing element projecting substantially downward with respect to the plane of base.

Advantageously, the lower portion comprises at least one sealing element.

In a preferred embodiment, the first material is polyvinyl chloride.

Advantageously, the second material has a deflection recovery value of more than 4O%.

Preferably, the second material has a Shore A hardness of around 61.

In a preferred embodiment, the second material is a nitrile butadiene rubber compound.

In a preferred embodiment, the first material and the second material are co-extruded.

Advantageously, the upper portion comprises side elements for retention in a holder.

Preferably the upper portion comprises a substantially U shaped portion.

Advantageously, the substantially U shaped portion defines a channel with the holder.

In one embodiment the upper portion may comprise a top portion that defines a channel with the substantially U shaped portion.

The upper portion may comprise at least one strengthening element.

In a preferred embodiment, at least one sealing element depends from the upper portion at an angle of substantially 90 degrees.

The seal may comprise a plurality of sealing elements.

Each sealing element may be of equal length.

The sealing elements may be parallel.

Another embodiment of the invention comprises a door including a seal.

The invention provides an improved seal, which has sufficient rigidity in an upper portion to facilitate insertion and retention in a holder and has a lower portion that does not add unnecessary resistance to the opening or closing of a door.

The lower portion can be used with a variety of threshold plates and need not seal against a specific form of threshold plate. It can also compensate for doors fitted too low or high in a door frame as the level of flexibility in the lower portion allows bending of the sealing elements.

The improved seal has a greater usable life than prior art seals as the flexible lower portion is less prone to breakage.

Brief Description of the Drawings

In the drawings, which illustrate preferred embodiments of the invention by way of

example:

Figure 1 shows a schematic representation of an embodiment of the invention with a holder.

Figure 2 shows a schematic representation of an embodiment of the invention of Figure 1.

Figure 3 shows a schematic representation of an alternative embodiment of the invention.

Figure 4 shows schematic representation of an embodiment of the invention of Figure 3.

Detailed Description of the Preferred Embodiments

As shown in Figures 1 and 2, the seal I comprises an upper portion 3 and three blades 2 depending from the upper portion 3, which form a lower portion of the seal 1.

The upper portion 3 is preferably made from cross hatch rigid PVC (polyvinyl chloride).

The upper portion 3 includes base 4 and side elements 4'. In use the base 4 is substantially parallel to the bottom of a door. The base 4 and its side elements 4' form a substantially rectangular channel 5 when the seal I is located in a holder 6. The holder 6 is preferably made from aluminium and is secured to the door by screws.

Two strengthening elements 7 extend from the base 4 of the upper portion 3. In Figures I and 2, the strengthening elements are shown as projections extending into the channel 5. However alternative or additional strengthening elements such as ribs are envisaged.

The upper portion 3 has side members 8, which slot into generally U-shaped edges 9 of the holder 6.

Multi blades of the same length mean that air becomes trapped between the blades 2 to aid in sealing. The air pockets between the blades 2 give improved heat sealing and acoustic sealing.

The blades 2 depend from the base 4 at substantially 90 degrees to the base 4 of the upper portion 3. They are tapered and in a preferred embodiment taper from around 0.6mm near the base 4 to around 0.4mm at the tip of the blade 2.

The upper portion 3 is substantially rigid and is preferably formed of standard grade PVC with a smooth finish. This aids in fitment of the seal I to the holder 6 as the rigid upper portion 3 slides easily into the holder 6. It is held in place using thin end plates (not shown) which are pinned to the door, one at each end of the seal I. The blades 2 are formed from very flexible material and they are thin so that they allow improved range of motion and flexibility.

They are preferably made from a PVC/NBR (nitrile butadiene rubber) compound having the properties listed below in Table 1.

Table 1

Property Units Value Test Method (British Standard) _________ _______ g/cc 1.33 Relative Density-S.G. BS2782 620A Softness-BSS Number BS2782 365A _________ _______ Softness-Shore A Hardness MN/m2 11 Tensile Strength MN/m2 B52782 320A _________ _______ Extension at Break -% B52782 320A _________ _______ MN/m2 Modulus at 100% -MN/m2 B52782 320A ________ _______ °C -36 Cold Flex Temperature B52782 I 50B _________ _______ The PVC/NBR compound further has a deflection recovery value of more than 40% when tested using the British Standards Institute (BSI) deflection recovery test BSEN 12365-3:2003 "Building hardware. Gasket and weatherstripping for doors, windows, shutters and curtain walling".

This BSI test involves compression of a sample between two plates at 55°C for 22 hours.

It is then allowed to cool for 2 hours, removed from the plates and measured. The difference between height before compression and after compression is expressed as a percentage. The PVC/NBR compound scores more than 4O% on this test.

In a preferred embodiment the seal I is manufactured by co-extrusion of the upper portion 3 and the blades 2.

The rigid upper portion 3 and flexible blades 2 of the seal I result in greatly improved functionality over prior art seals. The rigid upper portion 3 helps to maintain the integrity of the seal I in use, by preventing buckling or bending. The blades 2, being of flexible and easily deformable material, allow effective sealing without increasing resistance against opening and closing of the door.

The easily deformable blades 2 allow the seal I to be fitted even where there is limited space underneath a door. In these circumstances, blades having less flexibility would need to be made shorter, otherwise they would cause resistance against opening or closing of the door.

The high deflection recovery value of the blades 2 not only prevents unnecessary resistance against opening and closing of the door, but also extends the life of the seal I and allows sealing with a variety of shapes of threshold plates or floors.

Figures 3 and 4 show an alternative embodiment of the seal I. In the embodiment shown, the upper portion 3 includes a top member 10, which extends between side members 8. In this embodiment, the channel 5 is formed between the top member 10 and the base 4. As shown in Figure 3, when the seal I is in the holder 6, the top member is substantially parallel with the top of the holder 6.

As in the embodiments of Figures 1 and 2, the upper portion 3, including the top member 10, may be formed from substantially rigid PVC and the blades 2 formed from a PVC/NBR compound. The top member 10 strengthens the upper portion 3 such that additional strengthening elements 7 may not be required.

In an alternative embodiment the top member 10 and side members 8 are formed of substantially rigid PVC and the base 4 and blades 2 are formed from a PVC/NBR compound. This allows the entire lower portion, which includes the side elements 4' of the base, the base 4 and the blades 2 to flex.

Claims

Claims 1. A seal for a door bottom comprising an upper portion of a first substantially rigid material and a lower portion of a second substantially flexible material wherein the upper portion includes a base and the lower portion includes at least one sealing element projecting substantially downward with respect to the plane of base.
2. A seal as claimed in Claim 1, wherein the lower portion comprises at least one sealing element.
3. A seal as claimed in Claim 2, wherein the first material is polyvinyl chloride.
4. A seal as claimed in Claim 3, wherein the second material has a deflection recovery value of more than 4O%.
5. A seal as claimed in Claim 4, wherein the second material has a Shore A hardness of around 61.
6. A seal for a door bottom as claimed in Claim 5, wherein the second material is a nitrile butadiene rubber compound.
7. A seal as claimed in any of Claims I to 6, wherein the first material and the second material are co-extruded.
8. A seal as claimed in any preceding claim, wherein the upper portion comprises side elements for retention in a holder.
9. A seal as claimed in Claim 8, wherein the upper portion comprises a substantially U shaped portion.
10. A seal as claimed in Claim 9, wherein in use the substantially U shaped portion defines a channel with the holder.
11. A seal as claimed in Claim 9, wherein the upper portion comprises a top portion that defines a channel with the substantially U shaped portion.
12. A seal as claimed in any preceding claim, wherein the upper portion further comprises a strengthening element.
13. A seal as claimed in any preceding claim, wherein the at least one sealing element depends from the upper portion at an angle of substantially 90 degrees.
14. A seal as claimed in Claim 13, comprising a plurality of sealing elements.
15. A seal as claimed in Claim 14, wherein each sealing element is of equal length.
16. A seal as claimed in Claim 15 or 16, wherein the sealing elements are parallel.
17. A door comprising a seal as claimed in any of Claims I to 16.
18. A seal as substantially as shown in and described with reference to the drawings.