GB2104836A

GB2104836A - A sound absorbtive door

Info

Publication number: GB2104836A
Application number: GB08223595A
Authority: GB
Inventors: Hans Gunnar Strom; Bror Ivar Fries
Original assignee: SVENSKA DOERR AB
Current assignee: SVENSKA DOERR AB
Priority date: 1981-09-02
Filing date: 1982-08-17
Publication date: 1983-03-16
Also published as: DK391282A; FI822765L; SE443603B; FI71973C; GB2104836B; NO822663L; SE8105207L; FI71973B; SE443603C; DK155683C; DK155683B; FI822765A0

Abstract

During manufacture of the door, laminae 13, 14 which may comprise hard and porous wooden fibre respectively, are cut to form grooves 21. In the finished door, the laminae are loosely arranged with respect to each other and an optional centre plate but are fixed to cover plates 29, 30. <IMAGE>

Description

SPECIFICATION A door The present invention relates to sound absorbtive doors, and particularly to doors of the type identified as "double constructions lacking mechanical interconnections".

By forming the body of a door of the type mentioned as a laminar construction, for instance as in Swedish laid-open Patent Specification No.

330 250, comprising laminae of, for instance, wooden fibres, there is obtained a certain construction absorbing lateral resonance.

A further step towards improved sound absorption is obtained, if the known door is arranged with a divided frame according to, for instance, Swedish laid open Patent Specification No. 349 093.

The known technique, however, does not provide an optimum solution of the sound absorption problem with certain available material combinations and weights, respectively.

Therefore, the object of the present invention is to provide such a solution with due consideration of manufacturing possibilities from a practical and economic point of view.

In the broadest sense thereof, the invention provides a door comprising a frame and body construction with a laminar arrangement and cover plates arranged at both sides of frame and body, the characterising feature of the door being the tight arrangement of the laminae in the body, and the fact that the laminae are discontinuous in the longitudinal direction, at least across the major part of the cross-section thereof.

Basically, the laminae may be arranged either in the height direction of the door or in the lateral direction.

Consecutive laminae preferably consist of alternating porous and hard material, respectively, for instance a wooden fibre material.

In principle, the body of the door consists of a so-called double construction lacking mechanical interconnection (contrary to what is identified as "a solid door" within the art). In this case the laminar arrangement is doubled and each set of laminae is attached to a supporting element or similar structure.

Preferably, the supporting element forms part of a cover plate arrangement consisting of a pair of plates, for instance plates of hard wooden fibre material.

The discontinuities of the laminae preferably are obtained as kerfs or similar structures extending from the side of the laminae, facing away from the support and cutting through the major part of each lamella.

The lamella parts preferably have about the same length; being less than half of the height of the lamella.

The invention also provides a method of manufacturing the door. According to one version, the door body is manufactured by placing at least one set of laminae tight against each other onto a support and attaching the set thereto, whereafter the set of laminae is cut through by means of, for instance, a laminae saw or similar device for forming the said discontinuities.

In another version, the frame is cut through, preferably in the plane of existing gasket grooves, for a so-called double construction lacking mechanical interconnection, whereafter the laminae set in each door half is cut through by a saw or similar device.

The invention will now be clarified in the following description with reference to the accompanying drawings, where:~ Figure 1 is a perspective view showing a door body or section of such a body, Figure 2 is a broken vertical section view showing a door having a body according to Figure 1, Figure 3 schematically, partially in a broken view, shows the method of manufacture of a body section for a double construction, and Figure 4 is a partial view showing how the body according to Figure 3 is arranged in a frame and also indicates the manner in which a "double construction" is cut through.

In Figure 1 there is shown in a partially-broken away perspective view a door body 10, in the embodiment disclosed comprising two layers 11 and 12, each one constituting an arrangement of wooden fibre laminae or similar structure cut out from wooden fibre plates. Consecutive pairs of laminae, for instance 14 and 13, alternatively consist of a porous and a hard wooden fibre material, respectively. The sets of laminae are separated at the centre thereof by a plate 15 of, for instance, a hard wooden fibre material, but not fixed to the plate.The plate as such is not absolutely necessary, but from a fire-protection point of view and also with regard to sound absorption point of view and also with regard to sound absorption the plate has certain qualities, On the other side of each arrangement of laminae, there is an arrangement of cover layers; each one consisting of hard wooden fibre plates 16, 17 or similar structure glued together or interconnected in any other way.

In each of the laminar arrangements 1 1 and 12 there are interruptions, in the embodiment disclosed in the shape of kerfs 21, extending the whole way to a corresponding cover layer 16 from the centre plane of the body 10. The interruptions or discontinuities of the laminae 13, 14 may also be obtained in any other manner, for instance by cutting through the laminae partially, which might be of advantage from a handling point of view. There is also the possibility of placing in advance cut lamina parts tight against each other and putting them into the door frame between the cover plates by any feasible method.

The laminae 13, 14 are loosely arranged relative each other and the centre plate 15, but are fixed to the cover plate, over the entire surface thereof or partially. The "free" relatively short lamella parts obtained in this manner give an unexpectedly high contribution to the sound absorbtive characteristics of the material due to the degree of freedom of the lamella parts. This has, for instance, resulted in that at one and the same sound absorption level, it has been possible to lower quite substantially the total weight of the door.

The laminae 13 and 14 are divided by the kerfs 21, preferably in parts of equal lengths. There might be applied a rule of thumb saying that the cut length should be less than twice the height of the lamella (the height is measured in the plane of a corresponding wooden fibre plate; in laminae shape the plate is placed perpendicularly to the cover plates).

The orientation of the laminae 13, 14 of the ready-made door preferably is such that the laminae are orientated in the height direction of the door, but an orientation in the lateral direction basically is not impossible.

The body construction 10 is intended to be inserted into a door frame 18 shown in vertical section in Figure 2 and at the top and the bottom thereof provided with reinforcing elements 19, 20. In a known manner, the door has a groove 22 for accommodating a gasket 23 giving the required sealing against a door case 26 and sill 27 together with further gaskets 24, 25.

In Figure 3 it is shown, how a section of a door body 10 may be manufactured by placing tightly and attaching laminae 13, 14 to a supporting element 29 between a pair of wooden cross-bars 28. Thereafter, the entire package is cut through by a saw for forming intersecting grooves 21 and finally covered by a further plate 30 for forming a finished door body package, which may be inserted into a door case 26 (Figure 4) with or without a centre plate 15. The plates 29, 30 form the inner plates corresponding to the plates 16, 1 7 of the cover layer arrangement in Figure 1.

In Figure 4 it is shown by dotted lines 31 a method of extending the existing gasket groove 22 to pass the whole way through the frame.

Such an operation allows separation of an ordinary type of door of "double construction" by cutting the laminae 13, 14 with a saw into desired lengths. Thereafter, the door halves may be assembled, for instance as in the Swedish laidopen Patent Specification No. 340 093.

Claims

1. A door, comprising frame and body constructions with a laminar arrangement within the body construction and covering layers on both sides of the frame and body, characterised in that the laminae of the body are arranged generally tight against each other and are discontinuous in the longitudinal direction thereof, at least across the major part of the cross-section thereof.

2. A door as claimed in claim 1, characterised in that consecutive laminae alternatively consist of a hard and a porous material, respectively.

3. A door as claimed in claim 1 or claim 2, wherein basically the door body is a so-called double construction lacking mechanical interconnection, and wherein the arrangement of laminae is doubled, characterised in that each set of laminae is attached to a supporting element or similar structure.

4. A door as claimed in claim 3, characterised in that the supporting element forms part of a covering layer arrangement consisting of a pair of plates, for instance of a hard wooden fibre material.

5. A door as claimed in claim 4, characterised in that the discontinuities are obtained as kerfs or similar structures, extending from the side of the laminae facing away from the supporting element and cutting through the major part of each lamella.

6. A door as claimed in claim 5, characterised in that the discontinuous laminae consists of lamella pieces of generally the same length; being less than twice the height of the lamella.

7. A door as claimed in claim 6, characterised in that a hard wooden fibre plate or similar structure is loosely arranged between the two sets of the discontinuous laminae.

8. A door as claimed in claim 1 substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

9. A method of manufacturing a door as claimed in any one of the preceding claims comprising a frame and body construction with an arrangement of laminae in the body construction and arrangements of covering layers on both sides of the frame and body, characterised in that the body is manufactured by placing at least one set of laminae generally tight against each other on a support and attaching them thereto, whereafter the package of laminae is cut through by a saw or similar device for forming the said discontinuities.

10. A method of manufacturing a door as claimed in any one of claims 1 to 8 comprising a frame and body construction with an arrangement of laminae in the body construction and arrangements of covering layers on both sides of the frame and body, characterised in that the frame of a door of a so-called double construction lacking mechanical interconnection is cut through, preferably in the plane of existing gasket grooves, and that thereafter the set of laminae of each door half is cut through by a saw or similar device.

1 1. A method of manufacturing a door as claimed in claim 9 or claim 10 substantially as hereinbefore described with reference to the accompanying drawings.