Stock material or miscellaneous articles – Composite – Of inorganic material
Reexamination Certificate
2001-12-26
2003-07-29
Jones, Deborah (Department: 1775)
Stock material or miscellaneous articles
Composite
Of inorganic material
C428S697000, C428S699000, C428S701000, C428S702000, C428S469000, C106S031050, C106S692000, C106S823000
Reexamination Certificate
active
06599647
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an insulator such as a suspension type insulator, a long-rod insulator, a station post insulator (SP insulator), a line post insulator (LP insulator), a hollow insulator, or a solid-core insulator.
2. Description of the Background Art
As one form of insulators, there are insulators having hardware joined to at least one side of the insulator body via a cement kneaded product cured body. In the category of the insulators of this form, there are suspension type insulators, long-rod insulators, station post insulators (SP insulators), line post insulators (LP insulators), hollow insulators, solid-core insulators, and others. Typically, the insulator body is formed of an inorganic insulating material such as porcelain or glass. Japanese Examined Patent Application (Kokoku) No. 05-42387/1993 discloses a suspension type insulator which is a typical example of the insulators of this form.
The suspension type insulator includes a porcelain body, a metal cap joined to one side of the porcelain body via a cement mortar cured body, and a metal pin joined to the other side of said porcelain body via a cement mortar cured body. Generally, a Portland cement mortar is used in the cured body of the suspension type insulator. The Portland cement mortar is a cement kneaded product obtained by kneading a Portland cement, a water reducing agent, an aggregate, and water, and this is cured to form the cement mortar cured body. The cement mortar cured body in this state firmly joins the metal cap and the metal pin onto the porcelain body.
Further, in other insulators or hollow insulators of this form, a base hardware and a metal flange are adopted as hardware in place of the metal cap and the metal pin; however, in the case of assemblage by joining the base hardware and the metal flange onto one side or onto both sides of the insulator body or the hollow insulator body, a cement mortar cured body of Portland cement is used for joining the base hardware and the metal flange.
In the meantime, in the insulators of this form, high mechanical strength (tensile strength and others) and high electrical strength (dielectric breakdown strength and others) are required in view of the uses thereof, and also it is required that the high mechanical strength and the high electrical strength are maintained for a long period of time. For this reason, the cement mortar cured body requires a high mechanical strength of its own both initially and over a long period of time. In order to meet these requirements, it is optimal to use a cement that can form a cured body having a high strength as the cement constituting the cement mortar cured body.
For this reason, as a cement for forming the cement mortar cured body of an insulator of this type and form, it is desirable to adopt an alumina cement that can exhibit a high strength, as compared with a Portland cement, in place of the Portland cement that is currently used. Further, as compared with the Portland cement, the alumina cement has a small degree of shrinkage as a cement mortar cured body with small variation in the mechanical strength, thereby being advantageous in terms of strength, and also requires a short curing time for curing the cement mortar, thereby being advantageous in this respect as well.
However, since the alumina cement mortar shows dilatant flow properties, a difficulty is involved in the assemblage work for assembling the insulator by injecting the alumina cement mortar into a gap between the insulator body such as a porcelain body and a hardware such as a metal cap or a metal pin. Particularly, in the case of adopting means for allowing porcelain sands to adhere to the joining site of the insulator body, there arises a problem such that the assemblage work is made more difficult.
Therefore, an object of the present invention is to enable the adoption of alumina cement as a cement constituting the cement mortar cured body of an insulator of this type and form, so as to provide an insulator having a high mechanical strength and a high electrical strength and being capable of maintaining the high mechanical strength and the high electrical strength for a long period of time, and further to shorten the curing time in forming the cement mortar cured body to thereby reduce the cost of producing the insulator.
SUMMARY OF THE INVENTION
The present invention relates to insulators, particularly to suspension type insulators, long-rod insulators, station post insulators (SP insulators), line post insulators (LP insulators), hollow insulators, solid-core insulators, and others as objects of application.
Therefore, in the present invention, these insulators and hollow insulators are generally referred to as insulators; the dielectric bodies constituting these insulators and hollow insulators are generally referred to as insulator bodies; and the metal caps, metal pins, base hardware, and metal flanges constituting these insulators and hollow insulators are generally referred to as hardware.
Now, the first insulator according to the present invention is an insulator comprising an insulator body and a hardware joined to at least one side of the insulator body via a cement kneaded product cured body, characterized in that the cement kneaded product cured body is a cured body formed by curing a cement paste that is obtained by kneading an alumina cement having a specific surface area of at least 3500 cm
2
/g and having an amorphous phase of at least 10 nm thickness on an outer peripheral surface of particles, a water reducing agent, and water, said cement paste being cured in a wet state and at a temperature of 40° C. or higher.
The second insulator according to the present invention is an insulator comprising an insulator body and a hardware joined to at least one side of the insulator body via a cement kneaded product cured body, characterized in that the cement kneaded product cured body is a cured body formed by curing a cement mortar that is obtained by kneading an alumina cement having a specific surface area of at least 3500 cm
2
/g and having an amorphous phase of at least 10 nm thickness on an outer peripheral surface of particles, a water reducing agent, an aggregate, and water, the cement mortar being cured in a wet state and at a temperature of 40° C. or higher.
The first insulator and the second insulator according to the present invention belong to the first category which is one and the same category having the same principal construction with each other. In both of these insulators, the specific surface area of said alumina cement can be set within a range from 3500 cm
2
/g to 5000 cm
2
/g, and the thickness of the amorphous phase that the particles of said alumina cement has can be set within a range from 10 nm to 10
3
nm. The thickness of the amorphous phase can be adjusted by a length of time for leaving the ground alumina cement to stand. Here, the length of time for leaving the alumina cement to stand represents the period of time in which the ground alumina cement is left to stand before being kneaded with water.
The third insulator according to the present invention is an insulator comprising an insulator body and a hardware joined to at least one side of the insulator body via a cement kneaded product cured body, characterized in that the cement kneaded product cured body is a cured body formed by curing a cement paste that is obtained by kneading an alumina cement having a specific surface area of at least 3500 cm
2
/g, a polymer-steric-hindrance type water reducing agent, and water, the cement paste being cured in a wet state and at a temperature of 40° C. or higher.
The fourth insulator according to the present invention is an insulator comprising an insulator body and a hardware joined to at least one side of the insulator body via a cement kneaded product cured body, characterized in that the cement kneaded product cured body is a cured body formed by curing a cement mortar that is obtained by kneading an alumina cement having a specific surface
Imai Osamu
Oguri Noriyasu
Suzuki Hironori
Burr & Brown
Jones Deborah
KoppiKar Vivek
NGK Insulators Ltd.
LandOfFree
Joined insulator body does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Joined insulator body, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Joined insulator body will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3078938