Pipes and tubular conduits – Distinct layers – With intermediate insulation layer
Reexamination Certificate
2000-01-28
2001-06-26
Brinson, Patrick (Department: 3753)
Pipes and tubular conduits
Distinct layers
With intermediate insulation layer
C138S132000, C138S129000, C138S137000, C138S144000
Reexamination Certificate
active
06250339
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a gas transfer duct, and particularly to a gas transfer duct having a heat-insulating effect and a sound-absorbing effect suitable for transferring air-conditioning air which is set to have temperature different from room temperature.
Such a conventional gas transfer duct generally has a structure in which heat-insulating foamed material is spirally wound around an outer circumferential surface of a duct body with no space, a thin film-like resin tape is wound around an outer circumferential of the heat-insulating foamed material and the duct body defines an inner circumferential surface of the duct.
In such a conventional duct having a structure in which a duct body defines an inner circumferential surface of the duct, the duct becomes a guide cylinder through which noise generated from an air-blow source such as an air blower is guided to an opening portion of the duct while gas is transferred. The noise is discharged together with the gas, to thereby give people an unpleasant feeling. There has been a problem that such noise jars on people's nerves because it is generated continuously while the duct is in use, that is, in air-blowing operation.
In order to solve the above-mentioned problem belonging to air-blow ducts of the conventional type, that is, to largely reduce such the unpleasant noise discharged from the opening of the duct though it may be impossible to entirely extinguish such an unpleasant noise, there has been developed and proposed a structure which is taught by Japanese patent unexamined publication No. Hei. 9-89357. In structure, woven cloth having predetermined width is wound spirally, and then, connection edges of the cloths thus wound are bonded to each other with strip-shaped hard resin material, so that an internal surface layer of a duct is defined. A foam strip of open cells is spirally wound on an outer circumferential surface of the woven cloth while adjacent side edges of the adjacent foam strips are brought into contact with each other, so that an open-cell foam layer is formed. A thin film sheet-like strip is spirally wound on an outer circumferential surface of the open-cell foam so as to form an intermediate sheet layer. A foam strip of closed-cell foam is spirally wound on an outer circumferential surface of the intermediate sheet layer so as to form a closed-cell foam layer. A resin tape is spirally wound on an outer circumference of the closed-cell foam so as to form an external surface layer which wraps the outermost circumference thereof.
This air-blow duct is a product having a superior effect to be able to show substantially practically perfect effects of noise-reducing and heat-insulating functions as expected. The duct is therefore an ideal and suitable product for use as an air-blow duct. This product has, however, only one problem that the manufacturing process is complicated and its cost is not satisfied.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a sound-absorbing and heat-insulating duct which is simple, not complicated, in structure, which can achieve both sound-absorbing and heat-insulating functions in spite of its simple structure, which is suitable for use as an air-blow duct, and which is suitable for continuous production so that the duct can be mass-produced inexpensively.
The above-mentioned object can be attained by a sound-absorbing and heat-insulating duct, according to the present invention, comprising a nonwoven cloth layer, a reinforcing core, a foam strip layer, a bonding resin, and a resin-coating layer. The nonwoven cloth layer is formed in such a manner that a nonwoven cloth having a predetermined width is wound spirally into tube-like shape, and then adjacent side edges of the adjacent nonwoven cloths thus wound are brought in abutment against or lapped with each other so as to form a bonding portion. The wire-shaped reinforcing core is made of hard synthetic resin material, and wound spirally on the bonding portion of the nonwoven cloth while a surface of the reinforcing core which is brought into contact with the nonwoven cloth is welded or bonded to the nonwoven cloth. The foam strip layer is formed in such a manner that a foam resin strip having a width approximately equal to the width of the nonwoven cloth is wound spirally so that both adjacent edges of the foam resin strip are disposed on the two adjacent reinforcing cores respectively. The bonding resin is applied to the wound side surface of the foam strip and the wound part of the reinforcing core bonded to a unwound side surface of a foam strip and a unwound side surface of a reinforcing core. That is, a side surface of the foam resin strip which has been already wound spirally and a side surface of the foam resin strip which is to be wound next to the thus wound foam resin strip are bonded by the bonding resin, and a part of the reinforcing core which has been already wound spirally and the side surface of the foam resin strip which is to be wound next are also bonded by the bonding resin. The resin-coating layer is provided to cover an outer circumferential surface of the foam strip layer.
In order to carrying out the present invention, it is preferable that the bonding resin is a half melted resin, such as EVA or PE, extruded from a die of a extruder.
In the above-mentioned construction, it is advantageous that the bonding resin is also bonded to an outer circumferential of the nonwoven cloth layer.
Further, in the above-mentioned construction, it is advantageous that the bonding resin is bonded to an outer circumferential of the foam strip.
Furthermore, in the above-mentioned construction, it is advantageous that the surface of the reinforcing core which is brought into contact with the nonwoven cloth is flat, so that the reinforcing core is surely bonded to the nonwoven cloth thereat.
Moreover, in the above-mentioned construction, it is also advantageous that the resin-coating layer is formed by winding spirally a tape made of polyolefin resin or polyvinyl chloride resin, which has weatherproof and a less aging deterioration.
REFERENCES:
patent: 3916953 (1975-11-01), Nagayoshi et al.
patent: 4172474 (1979-10-01), Stahl
patent: 4620569 (1986-11-01), Von Glanstatten et al.
patent: 5795634 (1998-08-01), Fukui
patent: 5806567 (1998-09-01), Fukui et al.
patent: 6179009 (2001-01-01), Fukui
Ikegami Hiroshi
Okairi Susumu
Brinson Patrick
McGinn & Gibb PLLC
Totaku Industries, Inc.
LandOfFree
Sound-absorbing and heat-insulating duct does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sound-absorbing and heat-insulating duct, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sound-absorbing and heat-insulating duct will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2517945