Plastic and nonmetallic article shaping or treating: processes – Direct application of fluid pressure differential to... – Corrugating
Reexamination Certificate
1999-04-30
2001-05-22
Silbaugh, Jan H. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Direct application of fluid pressure differential to...
Corrugating
C264S514000, C264S516000, C264S171140
Reexamination Certificate
active
06235232
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin hose containing electrically conductive wire adapted for an antistatic hose, an electric cleaner hose, a reservoir water pump hose, and so on, and a method for producing the same.
A conventional synthetic resin hose of this type containing electrically conductive wire is generally configured so that resin-coated rigid steel wire for retaining the shape of the hose and resin-coated electrically conductive wire for current conduction are helically wound on the hose along the circumference of the hose, and a hose wall is fitted and stuck onto the outer circumferential surfaces thereof. On the other hand, there is generally known a synthetic resin hose which is configured so that a wall of the hose is formed of two layers, that is, inner and outer layers, and either one of or both of rigid steel wire and coated electrically conductive wire are helically put between the two layers.
As described above, each of the conventional general synthetic resin hoses with electrically conductive wires is configured so that rigid steel wire and electrically conductive wire are helically disposed over the whole length of the hose to thereby utilize the strength of the rigid steel wire to retain the shape of the hose body.
Accordingly, this kind of conventional synthetic resin hose with electrically conductive wire has a problem that the weight of the synthetic resin hose as a whole is heavy, and large fatigue is caused when the hose is pulled in use, because rigid steel wire for retaining the shape of the hose and electrically conductive wire are helically disposed over the whole length of the hose.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to solve the problem in the conventional synthetic resin hose with electrically conductive wire, and to provide a synthetic resin hose with electrically conductive wire, which is configured so that the shape of the hose is retained by use of the shape retention of the hose wall per se without use of any rigid steel wire as a reinforcing wire material and the wiring structure of electrically conductive wire is provided as such a special wiring structure as the electrically conductive wire has substantially the smallest length and is supported to the tube wall securely without use of any adhesive agent or the like, to thereby attain great reduction of the weight of the hose as a whole and form a structure in which fatigue is little even in the case where the hose is pulled in use for a long time.
The synthetic resin hose according to the present invention in order to achieve the foregoing object includes a tube wall formed corrugatedly in a direction of its axis, and an electrically conductive wire or a coated electrically conductive wire disposed over the whole length of the tube wall, in which the electrically conductive wire or coated electrically conductive wire is disposed substantially straight along the direction of the axis of the tube wall and configured so that the whole length of the electrically conductive wire or coated electrically conductive wire in the inner circumferential surface side thereof is covered with the tube wall and the outer circumferential side thereof is enclosedly covered with peak portions of the tube wall.
Further, the method for producing a hose having such a structure as described above comprises the steps of: using a hose molding mold assembly constituted by a pair of semicylindrical molds each having a large number of intrusion grooves formed along the axial direction in the cylindrical surface of each of the semicylindrical molds substantially at regular intervals and supplying electrically conductive wire or a coated electrically conductive wire into the hose molding mold assembly substantially linearly along a direction of the axis of the mold assembly; extruding a molten resin tubularly to supply the molten resin into the mold assembly after the supply of the electrically conductive wire or coated electrically conductive wire; supplying high-pressured air into the inside of the thus extruded molten resin tube to thereby expand the molten resin tube along the corrugated surface of the mold assembly from the inner circumferential surface side of the electrically conductive wire or coated electrically conductive wire to bring the molten resin tube into contact with the corrugated surface of the mold assembly and, at the same time, making a part of the tube go around to the outer circumferential surface side of the electrically conductive wire or coated electrically conductive wire along the intrusion grooves of the mold assembly to thereby enclose the outer circumferential side of the electrically conductive wire or coated electrically conductive wire in the part of the tube; cooling the molded resin tube to retain the shape of the tube T; and opening the mold assembly so that a hose body integrated with the electrically conductive wire or coated electrically conductive wire is taken out from the mold assembly. Incidentally, not only means (blow molding means) for supplying high-pressure air into the tube but also means (vacuum molding means) for sucking air around the outside of the tube from the outside can be used additionally as the expansion molding means for the molten resin tube.
In the aforementioned synthetic resin hose or in the aforementioned hose producing method, the coated electrically conductive wire may be in which electrically conductive wire is helically wound on a fiber yarn excellent in flexibility as an axial yarn and the outer circumference of the wire is covered with an electrically insulating material, or may be a wire in which fiber strings excellent is flexibility and electrically conductive wires are mixed and twisted in the form of a twisted yarn and the outer circumference of the twisted yarn is covered with an electrically insulating material. Consequently, it is possible to obtain a synthetic resin hose containing electrically conductive wire which is hardly broken even in the case where bending or contraction and expansion of the hose is repeated, by use of such an electrically conductive cable.
Further, in the case where the electrically conductive wire or coated electrically conductive cable is used, for example, as an electrostatic induction line or an earth line in an antistatic hose, the hose may be practiced as: a hose containing only one line wired; a hose containing one-round-trip lines (two lines) wired as a signal line or a drive power transmission line or containing two-round-trip lines (four lines) or one-round-trip lines and one earth line (three lines in total) collectively wired in parallel in one place as a signal line as well as a drive power transmission line; or a hose containing those lines wired substantially in two opposite places separately. Further, the synthetic resin material forming the hose wall is not limited specifically but polyolefin resin represented by polyethylene, polypropylene, etc. is preferred in terms of good self-restoration against contractive deformation due to external force.
Further, in the producing method, the structure of the mold assembly may be formed not only into a structure in which the mold assembly is constituted by semicylindrical molds each having a large number of intrusion grooves formed in the cylindrical surface thereof substantially at regular intervals along the axial direction but also into a structure in which the hose molding mold assembly contains a linear groove formed substantially straight along the axial direction so as to be shallower than the intrusion grooves and independent of the intrusion grooves so that the electrically conductive wire or coated electrically conductive wire may be supplied into the mold assembly along the linear groove of the mold assembly. The linear groove may be designed so that only one electrically conductive wire or coated electrically conductive wire can be disposed therein. Otherwise, the linear groove may be designed to have such a width that not only one but also two, three or f
McGuireWoods LLP
Silbaugh Jan H.
Staicovici Stefan
Totaku Industries, Inc.
LandOfFree
Synthetic resin hose and method for producing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synthetic resin hose and method for producing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synthetic resin hose and method for producing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2471686