US1660869A - Wax eliminator - Google Patents

Description

Feb. 28, 1928. 1,660,869 I L. V. FEIKE ET AL WAX ELIMINATOR Filed Feb.5. 1926 Patented Feb. 28, 1928.

UNITED STATES 1 1,660,869 PATENT OFFICE.

LAWRENCE V. IEEIKE AND JAMES R. PAYTON, OF DES MOINES, IOWA- VAX ELIMINATOR.

Application filed February The object of this invention is to provide a convenient electrically heated device in which a dentists mold may be placed and heat applied for the purpose of melting and eliminating the wax pattern and also for thoroughly drying the plastic material of the mold to prepare it for making a cast.

A further object of this invention is to provide improved means for eliminating a fusible pattern from a small mold such. as used by dentists, means being provided for determining and regulating the degree of heat to be applied.

A further'object of this invention is to provide an improved electrical heating device or stove especially adapted for use by dentists in making ready for the cast the molds which are used for producing inlays, crowns and the like, and also convenient for use in sterilizing instruments.

Still a further object is to provide an improved construction for an electrical heating device of the character described.

With these and other objects in view, our invention consists in the construction, arrangement and combination of elements hereinafter set forth, pointed out in the claim and illustrated by the accompanying drawing, in which Figure 1 is a plan View, partly in section, of our improved device.

Figure 2 is a side elevation of the same, also partially in section.

Figure 3 is a detail elevation on the line 3-3 of Figural, showing a mold in posi tion for use in and treatment by the device.

Figure 1 is an elevation, partly in section, illustrating an accessory which may be used with the device for the purpose of sterilizing instruments and the like.

Figure 5 is a. diagram of the electrical connections employed in the heater.

In the construction of the device as shown the numeral 10 designates a base which may be of any suitable insulating material. On the base 10 is mounted and secured a housing which is preferably cylindrical, and is composed of an inner wall 11 having an integral bottom 12 which rests on the base 10. Concentric with the inner wall 11 is an outer wall 13 formed at its lower margin with an outturned flange 14 resting on and secured to the base. The walls 11 and 13 are spaced apart to form an air space between them, and at its upper margin the outer wall 13 is formed with an inturned flange 3, 1926. Serial No. 85,560.

15 which extends across the top of the air space and inwardly of the top margin of the inner wall 11, leaving a circular opening at the top of the housing which is closable by a cover 16 resting on said flange 15. A lining 17 of sheet asbestos or similar heatinsulating material preferably is mounted in the air space between the walls and in contact with the outer wall 13, and said lining also is extended inwardly at its top beneath the flange 15. A packing 18 of corrugated sheet asbestos or the like may be mounted in and partially fill the air space between the walls if desired.

Conductor wires 19 and 20 leal t the iase l0 and are adapted to be placed in circuit in a common manner through an ordinary lamp socket or wall opening connected with a source of electrical energy. In circuit with the lead wires 19 and 20 are resistance wires 21 which preferably are arranged circumterentially within the housing and substantially from bottom to top thereof, and supported as insulating beads 2:2 carried by the inner wall 11, to supply heat to the nousing when the current is on. Preferably the resistance wires 21 are arranged. in series as indicated in Figure f and spaced contact points and 24; are provided adapted for selective engagen'ient by a controlling switch 25 mounted on the base. The point 23 is isolated and not in circuit and ordinarily, when a low heat is desired, the switch is placed on it for convenience and the current flows through all the resistance elements; but when a higher heat is desired the switch is placed on the point 246 so that a portion of the resistance is cut out of the circuit. At times, also, it is desirable to have means for automatically cutting O'T the current when certain temperatures have been reached, and for this purpose a thermostat of common form, designated at 26, is provided, mounted in a recess 27 in the base. A contact point 28 is in circuit with the thermostat and is engageablo by the switch 25 at times, and the degree of heat at which the thermostat will operate may be adjusted and determined by an adjusting screw 29 on the base. A thermometer of common form may be mounted on the housing to enable the operator to determine at any time the degree of heat.

This device is especially designed for use in eliminating the wax or other fusible patterns from a mold in the process of produca ing inlays, crowns 'or other small castings. For making such castings it has been custon'iary to use a mold of suitable plastic material such as is designated by the numeral El in Figure 3. After the impression has been taken a wax or similar fusible pattern P3? is constructed, which in'ibedded in the plastic ot the mold Ill, which may be supported by a metallic ban 33. The mold 31 is formed with a conical mouth B l and a duct 35 leads from said mouth to the location 01" the pattern 32. In using our improved device, the mold containing the pattern is placed in inverted position within the housing. as shown in Figure 3, the cover 16 is placed in position and the current turned on. The heat thus generated acts to melt and drive off the wax or other material of the pattern 32, the melted s bstance passing tl'irough the duct and through holes 36 formed in the bottom 12 oi the housing and also through a hole or holes 3? inthe base 10, which preferably is slightly elevated "from the bench or table by knobs or the like 38 on its under surface; The heat also acts to thoroughly and raoidly dry out the plastic oi the mold to leave it in proper condition for receiving tlie'cast. When this is done the mold is removed and the cast made by pouring molten metal into the mouth 34-, it passing to the mold cavity by means of the duct 35, in the ordinary manner. it is to be understood that the construction of the mold and its method of use have nothingto do with our present invention, but the illustration and description thereof are inserted here simply to make clear the method and purpose ol? our electrical eliminating device.

This device provides a very convenient and ellicient means for accomplishing this purpose, as will readily be understood by those skilled in the art.

This electrical heating device may alsobc used for another purpose, that of sterilizing instruments and other small objects. For

this purpose We have provided an accessory shown in Figure 4, comprising a sterilizing can 39 provided with a removable cover 40. This can preferably is of greater depth than the housing and is adapted to be placed therein so that its contents may be subjected to any desired degree oli heat for sterilizing them. A small bucket l-l, having perforations 42 in its wall, may be mounted loosely in the sterilizing can 39 to contain very small objects to be sterilized, and it is provided with a bail handle 43 or other suitable means for handling it.

The cover 16 ot the housing may be provided with ventilating ports l i, through which a circulation of air is permitted because ot the elevation of the base by the knobs 38, and the presence or the hole 37 in the base and the holes 36 in the bottom of the housing.

It is to be understood that various changes and modifications are possible in the arrange ment and construction of the various parts of thedevice, without departing from our invention as defined within the scope of the appended claim.

We claim as our invention A device for eliminating fusible patterns from dental molds and the like, comprising a base and a housing mounted thereon, said housing including an inner -all having a bottom resting on said base, an outer wall spaced from the inner wall to form an air snace therebetween, said outer wall being formed at its top with an inwardly extending flange projecting across and closing the air space and extending inwardly of the top margin of the inner wall and its inner margin forming an opening for access to the housing, and a removable cover adapted to be mounted on said flange to close said access opening.

LAWRENCE v. rnntnj JAMES R. PAYTUN.

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