Electric heating – Inductive heating – Specific heating application
Reexamination Certificate
2002-09-27
2004-10-19
Leung, Philip H. (Department: 3742)
Electric heating
Inductive heating
Specific heating application
C219S665000, C219S667000, C219S668000, C219S674000, C422S022000
Reexamination Certificate
active
06806447
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a spatula heating apparatus used for wax molding and adjustment for precision casting in the fields of dental prosthesis and metalwork with precision casting.
2. Description of the Related Art
A dental wax spatula is a tool for wax molding that is used to form and adjust casting models for dental crowns, denture bases or the like, using wax, in the process of simultaneously forming dental crowns and denture bases from dental alloys through precision casting such as lost-wax process. The wax spatula is frequently used for forming a wax model utilized for centrifugal casting of metalwork as well.
As shown in
FIG. 13
, a conventional spatula is formed with a metallic spatulate portion
102
which may take various shapes such as paddle-like, knife-like, lancer-like, or needle-like one at a distal portion of a grip stick
101
. When using the conventional spatula, the spatulate portion
102
used to be repeatedly brought close to flame
105
of a touch burner
104
connected to an end of a gas pipe
103
, with the grip stick
101
being held by a hand so that it may be heated by the touch burner
104
of a gas burner type, thereby using it for wax molding.
On the other hand, due to too evil stench emitted from wax at the time of heating by the aforementioned gas burner, an electro-thermal spatula heating apparatus is recently proposed as disclosed in, for example, Japanese un-examined patent publication No. 10-108872 or 2001-314421. As shown in
FIG. 14
, such spatula apparatus comprises, a spatula body
113
including a built-in electro-thermal body (not shown in the drawing) in a distal portion of a grip
112
with a spatulate portion
111
fixed thereto, a temperature regulator
115
connected to the spatula body
113
through a cord
114
, and a foot switch
116
. When the softening and melting temperatures of wax used are set in advance by operating respective adjusting dials
117
,
118
of the temperature regulator
115
and then a power switch is turned on, the spatulate portion
111
is brought into a state where it is usable at a level of the wax melting temperature, while the temperature of the spatulate portion
111
is thereafter switched to either the wax melting temperature or the wax softening temperature every time the foot switch
116
is stepped on.
However, the electro-thermal spatula heating apparatus shown in
FIG. 14
has the following problems. That is, users have had difficulties in performing wax molding work due to the hindrance by the cord
114
which is connected as a power wire to the grip
112
. Further, the spatula body
113
has to be exclusively used for the very apparatus as the electro-thermal body is built in the spatula body
113
, so that users' favorite spatulas which have been used together with a gas burner cannot be used even in an apparatus to which several different types of the spatulate portions
111
are appended. Furthermore, as the spatulate portion
111
of a different shape is usually required for each of different wax molding works, troublesome replacement works for fixing a particular different type of the spatulate portion
111
relative to the temperature regulator
115
must be carried out ad hoc. Moreover, there is a problem that a spatula body equipped with a large-sized spatulate portion
111
for wax embanking works cannot be employed as the large-sized spatula needs too large an amount of heating to be fully heated, and a temperature sensor built in the grip
112
is unable to detect accurate temperature.
SUMMARY OF THE INVENTION
To eliminate the above-mentioned problems, it is, therefore, an object of the present invention to provide a spatula heating apparatus with excellent usability, by overcoming the drawbacks of the conventional gas burner type and electro-thermal type heating apparatus.
According to a spatula heating apparatus of the present invention, a spatula is heated through electromagnetic induction by feeding current to a heating coil. Hence, no exhaust gas nor exhaust heat is generated unlike the conventional gas burner type apparatus, thus reducing the loss of consumption energy to an extremely small value. Further, users can work safely due to the absence of open flames, while they suffer from less emission of an evil stench due to no smoke being generated from wax.
Further, a power wire such as a cord or the like need not be connected to a spatula itself, so that there is no such a nuisance accompanied with wax molding works as that in the electro-thermal type apparatuses. Furthermore, as such a small loss of consumption energy enables the easier heating of even large-sized spatulas, conventional spatulas inclusive of large-sized ones for wax embanking works can be used as they are without modifying them.
According to the spatula heating apparatus of the present invention, users can determine properly whether the heating of the spatula is ongoing or not through an information device such as a buzzer or the like.
Also, according to the spatula heating apparatus of the present invention, users can determine properly an electric power fed to the spatula through a display device.
REFERENCES:
patent: 3898410 (1975-08-01), Peters, Jr.
patent: 4206336 (1980-06-01), Cunningham
patent: 4492840 (1985-01-01), Lex
patent: 4725948 (1988-02-01), Mierzwinski
patent: 6670590 (2003-12-01), Pacholok et al.
patent: 2002/0023909 (2002-02-01), Usui
patent: 4-215286 (1992-08-01), None
patent: 10-108872 (1998-04-01), None
patent: WO 95/24931 (1995-09-01), None
Hommura Osamu
Kato Yoshio
Kawaguchi Hiroaki
Watanabe Yoshinori
Leung Philip H.
Senterfitt Akerman
Toshiba Home Technology Corporation
LandOfFree
Spatula induction heating apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spatula induction heating apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spatula induction heating apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3271604