Pipes and tubular conduits – Flexible – Corrugated
Reexamination Certificate
2000-02-18
2001-04-17
Hook, James (Department: 3752)
Pipes and tubular conduits
Flexible
Corrugated
C138S149000, C138S167000
Reexamination Certificate
active
06216742
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the structure of a heat insulating hose adapted to be used mainly as an air-conditioner drain hose.
A heat insulating hose having a structure in which a belt material of a foamed synthetic resin cut to have a predetermined width is spirally wound on the outer circumferential surface of an inner tube while the cut surfaces of the belt material are made to abut one another and then a synthetic resin tape is spirally wound on the outer surface of the belt material so as to cover the belt material is generally well known and used as a conventional heat insulating hose. Further, a technique of a heat insulating pipe in which a foamed plastic belt material is put longitudinally on the outer circumferential surface of a straight pipe and rolled into a cylinder and the opposite side edges of the rolled belt material are joined in the axial direction to thereby form a heat insulating coating layer is also proposed as a known technique. Further, an inner tube in the form of a bellows tube which has an annular-shaped portion protruded outwardly in a circumferential direction in order to have flexibility is known.
The well-known heat insulating hose of the former type was not always excellent in productivity because the hose had to be formed while a foamed synthetic resin belt material and a coating tape were wound spirally or while parts of the coating tape were laid to overlap each other and adhesively bonded to each other particularly in the case of the coating tape. On the other hand, the heat insulating pipe of the latter type has a merit that the productivity can be improved because the heat insulating pipe is formed in a manner that a heat insulating material is put along a core pipe longitudinally and the opposite ends of the heat insulating material are joined to each other longitudinally. The latter heat insulating pipe, however, has a problem that the heat insulating pipe is poor in heat insulation because the heat insulating material applied on the inner tube is moved relative to the inner tube so as to be separated from the inner tube easily so that a space is produced between the heat insulating material and the surface of the pipe.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention to improve the above-mentioned heat insulating hose. In particularly, it is an object of the present invention to provide a heat insulating hose which can be easily bent at an acute angle for the piping arrangement from the position outside the air conditioning appliance or the like in a discharging direction such as to a hole in a wall and which can provide a piping condition which is not unpleasant in its outer appearance.
The above-mentioned object can be attained by a heat insulating hose according to the present invention which comprises a seamless cylindrical inner tube formed of a synthetic resin, and a cylindrical heat insulating layer formed of a foamed synthetic resin for covering an outer peripheral face of the inner tube. The inner tube is provided at its one end with a cylindrical part for connection with a drain outlet of an air conditioning appliance. The inner tube is formed with a number of ring-shaped protrusion stripes which project toward its outer circumference over an entire length thereof in its axial direction except the cylindrical part. The adjacent ring-shaped protrusion stripes are spaced by a distance W which is wider than an axial width w of each of the ring-shaped protrusion stripes. The inner tube has an area b of a desired range spaced by a determined length a from the cylindrical part which is an area wherein a number of ring-shaped protrusion stripes are formed at smaller distances.
In putting the invention in practice, it is preferable that an axial width ws of the smaller distance s in the area b of the inner tube is substantially the same as an axial width wa of each of the ring-shaped protrusion stripes in said area b.
In addition, it is preferable that the inner tube is provided with at its longitudinal other end with a cylindrical connecting part which has an outer diameter insertable in the cylindrical connecting part.
Further, it is preferable that the heat insulating layer is formed in a tubular shape by cutting the foamed synthetic resin material in a shape of a strip and bonding its longitudinal side edges to each other.
Furthermore, it is advantageous that the foamed material constituting the heat insulating layer is a closed cell foamed material.
Moreover, it is preferable that an area p of a desired range in the heat insulating layer corresponding to the area b of the inner tube is of a structure that a number of annular grooves d are formed at a smaller distance.
In addition, it is preferable that an outer peripheral face of the heat insulating layer is covered with an outer covering layer in a shape of a synthetic resin film.
As material of the inner tube for forming the heat insulating hose according to the invention, an appropriate synthetic resin material such as polyolefin resin including polyethylene (PE), polypropylene (PP), etc. or polyvinyl chloride resin (PVC) can be used. The foamed synthetic resin material composing the heat insulating layer is preferably a closed cell foamed material in order to prevent an intrusion of water and enhance the heat insulating efficiency. Further, at the bent portion of the hose, the heat insulating layer may be embossed or provided with minute asperities so that wrinkles or bending pleats generated on a surface of the heat insulating layer may not be distinguishable.
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patent: 3234969 (1966-02-01), Du Mont
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patent: 3453716 (1969-07-01), Cook
patent: 3858615 (1975-01-01), Weigh
patent: 4637637 (1987-01-01), Adorjan
patent: 4712642 (1987-12-01), Lalikos et al.
patent: 4793384 (1988-12-01), Lalikos et al.
patent: 4819970 (1989-04-01), Umehara
patent: 5311753 (1994-05-01), Kanao
patent: 5324557 (1994-06-01), Lupke
patent: 5964252 (1999-10-01), Simmons et al.
Masui Hiroyuki
Nakanishi Toshihiro
Sato Masaru
Hook James
McGinn & Gibb PLLC
Totaku Industries, Inc.
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