Conversion of a Bunsen burner into a furnace

Conversion of a Bunsen burner into a furnace

A . H . Tamarin, D .D .S ., Chicago

A Bunsen burner may be converted into a furnace by a simple, inexpensive device easily constructed by a dentist. It consists of: 1. A 26 gauge sheet metal cylinder 12 inches in length and 2 inches in diameter (Fig. 1, left). 2. A 26 gauge sheet metal cylinder 12 inches in length and 4 inches in diameter (Fig. 1, righ t). 3. Eight 3 /1 6 inch stove bolts V / 4. inches long (Fig. 2, A ) . 4. Eight 3 /1 6 inch nuts (Fig. 2, B ) . 5. Eight brass sleeves % inches long by 3 /1 5 inches in diameter (Fig. 2, C ) . 6. A small bracket to fit over the Bunsen burner spider (Fig. 3 ) . 7. A small handle (Fig. 4 ) . T h e inner cylinder is elevated 2 inches above the outer cylinder and held in posi­ tion by the eight stove bolts and the eight small sleeves. T h e proper relation between the two cylinders can be obtained easily by the following method: 1. A straight line is bisected on a piece of paper. 2. T h e point of intersection is used as a center, and two circles are inscribed, one 2 inches in diameter and one 4 inches in diameter (Fig. 5 ) . Each cylinder is placed on its corre­ sponding circle, and four vertical lines are marked on the outer surface of each with a pencil. T h e lines coincide with and are perpendicular to the lines which divide the circles on the drawing. W ith a ruler, the locations of the holes for the stove bolts are marked. T h e holes in the inner cylinder are located 2 inches lower than the corresponding holes in the outer cylinder. T h e eight stove bolts are passed through the holes in the outer cylinder, they are encased in the eight

short 5 /1 6 inch sleeves, and then they are inserted in the holes in the inner cylinder. Each bolt is locked in place with a nut. T h e bracket (Fig. 3) can be con­ structed from the web of an old lamp­ shade so that the small center ring will be directly over the Bunsen flame. The ends of the bracket wires should be clamped over the rim of the burner spider. Th e double cylinders are placed on the bracket so that the lower rim of the inner cylinder rests on the bracket permitting the lower rim of the outer cylinder to project 2 inches below the burner to form an apron. A handle is assembled (Fig. 4) and at­ tached to the outer cylinder midway be­ tween its upper and lower rims. The appliance in position on the Bunsen burner is shown in Figure 6. A P P L IC A T IO N

T h e ring containing the inverted wax pattern is placed slowly in the flame and the wax eliminated. Then the ring is placed immediately over the flame and the furnace positioned on the Bunsen burner spider. T h e flame is turned up to its greatest intensity. Within ten minutes the ring assumes the appearance of a glowing mass and the sprue channels ap­ pear as glowing points at which time the pattern is ready for casting. C O N C L U S IO N

This device is simple, efficient, reliable, inexpensive and easy to construct. It con­ centrates and intensifies the heat from the burner flame, thereby saving the busy dentist many hours of valuable time. 25 East Washington Street

T A M A R IN . . . V O L U M E 66, J A N U A R Y 1963 • 135/121

Fig. I • cylin d e r

L e ft:

Small

cylinde r.

R ight:

Large

R 2 • A : Stove b o lt. B: N u t. C : Brass spacer sleeve

Fig. 4 •

H andle

Fig. 3 • Bracket

Fig. 5 • C ircum ferences o f cylinders

Fig. 6 • Finished mechanism in position