GB1564619A - Sound insulating door construction - Google Patents

Description

(54) SOUND INSULATING DOOR CONSTRUCTION (71) We, INGEMANSSONS INGEN JORSBYRA AB., a Swedish Body Corporate of Box 53037, S-400 14 Goteborg 53, Sweden, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to door casings and combinations of door casings and doors having improved sound deadening characteristics.

It is known to use composite doors com- prising a basic door panel with certain constructional elements so that the composite door gives a higher degree of sound insulation than the basic door itself, and including means to reduce the sound leakage between the edges of the door and the door frame or casing.

In most standard door constructions (door to door casing) it is the sound leakage through the gap between the door and casing which results in the sound insulation being at most 20 dB (mean reduction in the frequency range 100 - 3150 Hz).

By applying sound insulation in the form of thin-walled "trailing strips" or tubes or rubber or plastics it is possible in the construction to achieve a mean sound reduction (reduction number) of about 35 dB, provided that the door itself has a higher reduction number. With small tolerances, i.e. a narrow gap between the door and its casing, values up to 40 dB can be achieved with one or at the most two sound insulations of the above type. For higher insulation extremely narrow tolerances are required and several repeated sealings.

If one, in accordance with Swedish patent No. 193738, makes the part of the door which lies adjacent the casing completely or partly sound absorbing the gap leakage can be substantially reduced and door constructions made with very high mean reduction numbers. In such a construction the tolerances are less critical from the point of view of reducing the sound intensity.

However, the design according to the said patent has certain drawbacks which will be described further below. The said drawbacks have been reduced in severity in the novel casing construction according to the present invention.

According to the present invention a door casing has a hollow interior filled with sound absorbing material, the wall of the casing which will, in use, be juxtaposed to the edge of the door when the door is closed being provided with perforations. The thickness of the outer wall of the casing may be less than 10% and is preferably between 1 and 3% of the transverse thickness of the casing.

The invention also embraces the combination of such a door casing with a sound insulating door, the door comprising a main door panel and connected to it a subsidiary door panel parallel to and spaced from the main door panel, sound absorbing material being located in the space between the two door panels, the space in the area between the edges of the door panels being substantially free of rigid constructional elements forming sound transmitting bridges between the two panels.

The invention may be put into practice in various ways and certain embodiments of the prior art and certain embodiments according to the present invention will be described by way of example with reference to the accompanying drawings all of which are horizontal cross sections through the doors and their associated door casings, and in which Figures 1 to 3 show cross sections through previously known door constructions and Figures 4 to 8 show the corresponding cross sections of door constructions according to five different specific forms of the present invention.

Figures 1 and 2 show a section through a door construction according to Swedish patent No. 193738.

Referring to Figure 1 the construction consists of a main door panel 1, with a subsidiary door panel 2 arranged parallel to it and spaced from it. The panels are made of a stiff, rigid material such as solid wood, chip board, or plywood. A soft sound-absorbing material, e.g. mineral wool, is located in the space 5 between the panels. The panels are held apart by side walls 3, only one of which is shown in Figures 2 and 3. The side wall 3, which faces the door casing 9, is perforated with holes 20 and the gaps at both ends of the slit 6 between the panels 1 and 2 and the door casing are sealed by sealing strips 7 and 8.

Referring now to Figure 2, the arrows A, B and C represent the three different principal sound transport routes through the door construction. In constructions which high reduction numbers it has been found that the majority of the sound travels along the sound route C in the figure. It has been proposed to eliminate this effect by forming a special "absorbing chamber" in the door as shown in Figure 3. This can be achieved by the provision of a rigid separating wall 10 connecting the panels 1 and 2 of the door and locating a special sound absorbent material 11 in the space between the walls 10 and 3 as shown in Figure 3. The extra separating wall 10 is however not wholly satisfactory since it forms a sound-transmitting or acoustic bridge between the panels 1 and 2. Further, the cost of manufacture is increased.

In this present invention a specially designed door casing is used instead.

In all the specific examples shown in Figures 4 to 8 the door casing is hollow. It can be made of metal plate or plastics material. The wall 12 adjacent to the gap between the door and the door casing is perforated over its entire area and the interior of the door casing is entirely filled with a sound-absorbing material 13 such as mineral wool. In the design according to Figures 4 and 5 the door case is, in transverse cross-section, a closed profile.

In Figure 4 it is cast into a construction wall 14 and is thus sound-proofed to the wall. In Figure 5 the door casing is sealed to the wall with calking material 15 and jointing material 16.

In the embodiment shown in Figure 6 the casing is a closed profile which in addition to having perforations in the wall facing towards the gap between the door casing and the door, also has perforations in its wall which faces towards the construction wall 14.

The connection with the wall can in this case be sound-proofed solely with seaming or jointing compound 16. Thus the calking 15 can be omitted because the sound absorbing material in the hollow casing replaces the function of the calking.

The embodiments shown in Figures 7 and 8 have an open profile which in the Figure 7 arrangement is cast into the wall 14 or in the Figure 8 arrangement overlaps the edges of the wall opening and is attached thereto, supplemented with jointing material 16.

The side wall 3' of the door which faces towards the casing is not perforated but if desired could be perforated e.g. as shown in Figures 1 to 3.

WHAT WE CLAIM IS: 1. A door casing having a hollow interior filled with sound absorbing material, the wall of the casing which will, in use, be juxtaposed to the edge of the door when the door is closed being provided with perforations.

2. A casing as claimed in Claim 1 which is formed as a closed profile in cross section.

3. A casing as claimed in Claim 1 or in Claim 2 in which the portion of the casing which will be juxtaposed to the wall defining the door opening, is provided with perforations.

4. A casing as claimed in Claim 1, 2, 3 or 4 which comprises an outer wall whose thickness is less than 10% of the transverse thickness of the casing.

5. A casing as claimed in Claim 4 in which the outer wall is 1 to 3% of the transverse thickness of the casing.

6. A casing as claimed in any one of the preceding claims in which substantially the entire cross-section of its hollow interior is filled with sound absorbing material.

7. A casing as claimed in any one of the preceding claims formed of metal plate or plastics material.

8. A casing as claimed in Claim 1 substantially as specifically described herein with reference to any one of Figures 4,5, 6,7 or 8.

9. A combination of a sound insulating door and a door casing as claimed in any one of the preceding claims, the door comprising a main door panel and connected to it a subsidiary door panel parallel to and spaced from the main door panel, sound absorbing material being located in the space between the two door panels, the space in the area between the edges of the door panels being substantially free of rigid constructional elements forming sound transmitting bridges between the two panels.

10. A combination as claimed in Claim 9 including sealing strips so as to seal the gap between the door and the casing when the door is closed.

11. A combination as claimed in Claim 9 or Claim 10 in which the said wall of the casing is provided with perforations over substantially the entire proportion of its area which will be juxtaposed to the edge of the door when the door is closed.

12. The combination as claimed in Claim 9 substantially as specifically described herein with reference to any one of the accompanying Figures 4, 5, 6, 7 or 8 or Fig

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (12)

**WARNING** start of CLMS field may overlap end of DESC **. patent No. 193738. Referring to Figure 1 the construction consists of a main door panel 1, with a subsidiary door panel 2 arranged parallel to it and spaced from it. The panels are made of a stiff, rigid material such as solid wood, chip board, or plywood. A soft sound-absorbing material, e.g. mineral wool, is located in the space 5 between the panels. The panels are held apart by side walls 3, only one of which is shown in Figures 2 and 3. The side wall 3, which faces the door casing 9, is perforated with holes 20 and the gaps at both ends of the slit 6 between the panels 1 and 2 and the door casing are sealed by sealing strips 7 and 8. Referring now to Figure 2, the arrows A, B and C represent the three different principal sound transport routes through the door construction. In constructions which high reduction numbers it has been found that the majority of the sound travels along the sound route C in the figure. It has been proposed to eliminate this effect by forming a special "absorbing chamber" in the door as shown in Figure 3. This can be achieved by the provision of a rigid separating wall 10 connecting the panels 1 and 2 of the door and locating a special sound absorbent material 11 in the space between the walls 10 and 3 as shown in Figure 3. The extra separating wall 10 is however not wholly satisfactory since it forms a sound-transmitting or acoustic bridge between the panels 1 and 2. Further, the cost of manufacture is increased. In this present invention a specially designed door casing is used instead. In all the specific examples shown in Figures 4 to 8 the door casing is hollow. It can be made of metal plate or plastics material. The wall 12 adjacent to the gap between the door and the door casing is perforated over its entire area and the interior of the door casing is entirely filled with a sound-absorbing material 13 such as mineral wool. In the design according to Figures 4 and 5 the door case is, in transverse cross-section, a closed profile. In Figure 4 it is cast into a construction wall 14 and is thus sound-proofed to the wall. In Figure 5 the door casing is sealed to the wall with calking material 15 and jointing material 16. In the embodiment shown in Figure 6 the casing is a closed profile which in addition to having perforations in the wall facing towards the gap between the door casing and the door, also has perforations in its wall which faces towards the construction wall 14. The connection with the wall can in this case be sound-proofed solely with seaming or jointing compound 16. Thus the calking 15 can be omitted because the sound absorbing material in the hollow casing replaces the function of the calking. The embodiments shown in Figures 7 and 8 have an open profile which in the Figure 7 arrangement is cast into the wall 14 or in the Figure 8 arrangement overlaps the edges of the wall opening and is attached thereto, supplemented with jointing material 16. The side wall 3' of the door which faces towards the casing is not perforated but if desired could be perforated e.g. as shown in Figures 1 to 3. WHAT WE CLAIM IS:

1. A door casing having a hollow interior filled with sound absorbing material, the wall of the casing which will, in use, be juxtaposed to the edge of the door when the door is closed being provided with perforations.

2. A casing as claimed in Claim 1 which is formed as a closed profile in cross section.

3. A casing as claimed in Claim 1 or in Claim 2 in which the portion of the casing which will be juxtaposed to the wall defining the door opening, is provided with perforations.

4. A casing as claimed in Claim 1, 2, 3 or 4 which comprises an outer wall whose thickness is less than 10% of the transverse thickness of the casing.

5. A casing as claimed in Claim 4 in which the outer wall is 1 to 3% of the transverse thickness of the casing.

6. A casing as claimed in any one of the preceding claims in which substantially the entire cross-section of its hollow interior is filled with sound absorbing material.

7. A casing as claimed in any one of the preceding claims formed of metal plate or plastics material.

8. A casing as claimed in Claim 1 substantially as specifically described herein with reference to any one of Figures 4,5, 6,7 or 8.

9. A combination of a sound insulating door and a door casing as claimed in any one of the preceding claims, the door comprising a main door panel and connected to it a subsidiary door panel parallel to and spaced from the main door panel, sound absorbing material being located in the space between the two door panels, the space in the area between the edges of the door panels being substantially free of rigid constructional elements forming sound transmitting bridges between the two panels.

10. A combination as claimed in Claim 9 including sealing strips so as to seal the gap between the door and the casing when the door is closed.

11. A combination as claimed in Claim 9 or Claim 10 in which the said wall of the casing is provided with perforations over substantially the entire proportion of its area which will be juxtaposed to the edge of the door when the door is closed.

12. The combination as claimed in Claim 9 substantially as specifically described herein with reference to any one of the accompanying Figures 4, 5, 6, 7 or 8 or Fig

ure 1 and Figure 4, 5, 6, 7, and 8 or Figure 3 and Figure 4, 5, 6, 7 or 8.