US2159437A - Dental flask - Google Patents

Description

W. D. KIRBY DENTAL FLASK May 23, 1939.

' Filed Aug. 12, 1937 ATTORNEYS Patented May 23, 1939 UNITED STATES PATENT oFFICE 2 Claims.

I My invention relates to the manufacture of dentures and includes among its objects and advantages the provision of an improved dental flask particularly adapted for duplication work.

In the accompanying drawing:

Fig. l is an elevational View of my flask;

Fig. 2 is a view along the line 2--2 of Fig. l with a portion broken away for the sake of clearness;

Fig. 3 is a fragmentary view taken from the position indicated by line 3-3 of Fig. 2;

Fig. 4 is a sectional View along the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary view taken from the position indicated by line 5-5 of Fig. 2; and

Fig. 6 is a fragmentary view taken from the position indicated by line 6-5 of Fig. 5.

In the embodiment selected to illustrate my invention, the flask comprises a bottom section In, a middle section I2, a top section I4, and a cover I5 provided with an opening I'I. Middle section I2 is made up of two parts I6 and I8, with the part I8 provided with two spaced flanges 20 between which the lug 22 carried by the part I6 is loosely positioned. Parts 23 and 22 are provided with aligned openings for the reception of a pin 24 which hingedly connects the parts I6 and I8. Fig. 2 illustrates the parts I6 and I8 in their latched relation.

Part I8 carries a finger 26 which lies between lugs 28 on the part I6 and extends a short distance beyond the lugs, as illustrated in Figs. 2 and 3. Finger 25 includes an inwardly extending lug 30 spaced a short distance from the lugs 28. Parts I6 and I8 may be firmly latched in the position of Fig. 2 by driving a tapered pin 32 between the lugs 28 on the part I6 and the lug 30 carried by the finger 26.

Section I0 carries two spaced lugs 34 on opposite sides to have guiding relation with pins 36 formed integrally with the section I2. These pins extend above and below the top and bottom edges, respectively, of the section I2, and the upper ends of the pins have guiding relation with lugs 38 carried by the section I2 on opposite sides in alignment with the lugs 34. The upper ends of the pins 36 include inwardly projecting lugs 40, which lugs are spaced short distances from the lugs 38. Top section I4 may be clamped firmly to the middle section I2 by driving tapered pins 42 between the lugs 40 on the pins 36 and the lugs 38 on the top section I4. Pins 32 and 42 may be serrated along one edge, as at 44, for holding purposes, but good results have been secured with smooth pins.

In Fig. 4, I illustrate the denture generally at 46 while lines 48 and 50 indicate generally lines of separation of the plaster encasing the denture. Means are provided for fracturing the plaster in the middle section I2 on the median line of the denture 46, as indicated'by dotted lines 52 in Fig. 2. To this end the parts I6 and I8 are provided with inwardly extending ribs or wings 54 and 56, respectively. In operation, sections I0, I2 and I4 are easily separated while the parts I6 and I8 of section I2 may be separated about the axis of the pin 24. The denture is located in the middle section and is completely surrounded by plaster when the three sections of the flask are assembled. However, when the upper and lower sections of the flask are removed, both faces of the denture are laid bare. Thus the denture will be surrounded by a band only of plaster, which band lies between the denture and the wall of the middle section. The separation of the plaster in the upper and lower sections from the band remaining in the middle section is predetermined in the usual manner.

Because of the wings 54 and 58, the plaster in section I2 will be divided on a median line with respect to the denture 46 While the wings are of such construction as to eifectively hold the plaster within the two parts. With the parts It and I8 separated, the denture 46 is easily removed from the investment. In separating the parts I6 and I8 with the plaster therein, a pointed tool may be driven between the wings 54 and 56 adjacent the finger 26 for fracturing the plaster. Tapered pins 32 and 42 perform a good clamping function with respect to the middle and top sections l2 and I4, and are easily placed in position and removed.

The keys 32 and 42 draw the contacting edges of the sections I2 and I4 into such pressure relat ion as to establish a complete seal, thus preventing the escape of excess rubber incident to heating and pressing in the press. In establishing an effective seal about the abutting edges of the sections I2 and I4, I prevent a generally darker base rubber from penetrating natural colored rubber employed on the labial part of the denture.

Without further elaboration, the foregoing will so fully explain my invention that other may, by applying current knowledge, readily adapt the same for use under various conditions of service.

I claim:

1. A dental flask comprising three separable sections, means for holding the sections in assembled relation, one of said sections comprising two parts hingedly connected together, each of said parts having inwardly projecting wings arranged in abutting relation with the wings on the other part in the closed position of the parts, said wings being of such construction and arrangement as to rupture the plaster in. the said one section when said parts are pivoted outwardly about their axis.

2. A dental flask comprising a top section, a

bottom section and a middle section between the top and bottom sections, said middle section comprising two parts hingedly connected together,

. the parts of said middle section being provided with plaster rupturing means for dividing the plaster between a denture located therein and the middle section when said parts are separated about the axis of their pivotal connection.

WILLIAM D. KIRBY.

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