US2079344A - Thermometer for melting point apparatus - Google Patents

Description

W. O. GEYER THERMOMETER FOR MELTING POINT APPARATUS May 4, 1937.

Filed Aug. 31', 1935 I NVENTOR zllzam 0 6'9 g; Y

46 ATTORNEY \\1 J DLLLLLLLII J:

Patented May 4, 1937 UNITED STATES PATENT FFICE THERMOMETER FOR MELTING POINT APPARATUS Claims.

This invention relates to chemical apparatus and more particularly to apparatus for the determination of the melting points of materials. One of the objects of the present invention is to provide apparatus wherein a plurality of melting point determinations may be made at the same time. v Another object is to provide means to support and sustain a plurality of samples for melting point determinations in such apparatus.

Still another object of this invention is to provide an improved means and apparatus for mak ing melting point determinations.

Other objects and advantages will be apparent as the invention is more fully disclosed.

In accordance with the above objects I have devised a melting point apparatus which is provided with means to support and sustain a plurality of samples within the apparatus in such position relative to a thermometer that melting point determinations may be made on the plurality of samples at one and the same time.

Before further disclosing the present invention reference should be made to the accompanying drawing wherein Fig. 1 illustrates one type of melting point apparatus including the improvement of the present invention;

Fig. 2 illustrates a second type melting point apparatus including a modification of the present invention;

Fig. 3 is an enlarged View of the thermometer and material supporting means of the present invention;

Fig. 4 is an enlarged view of a modification of the same;

Fig. 5 is a view along plane 55 of Fig. 3;

Fig. 6 is a View along plane 6-6 of Fig. 3;

Fig. 7 is a view along plane 1-! of Fig. 4.;

Fig. 8 is an enlarged section of a modification of the present invention.

Referring to Figs. 1 and 3, the melting point apparatus indicated comprises a flask I having an elongated neck 2 sealed from the atmosphere to the outer periphery of re-entrant tube 3, the

bottom of tube 3 extending to the approximate center of flask I. Stoppered opening means 4 and 5 are provided in neck 2 to permit the introduction of suitable fluid 6, such as water, oil, waxes or sulfuric acid, in flask l.

Re-entrant tube 3 is provided with a stopper 1 (preferably of cork) through which extends thermometer 8, the bulb end 9 of said thermometer being located adjacent the bottom of re-entrant tube 3. Means are provided to sustain and support at least one and preferably a plurality of samples of material H to be subjected to melting point determinations, about the bulb end 9 of thermometer 8 in determined spaced relationship 0 to the said end 9.

It is usual in making melting point determinations to dispose the material IT in tube l 0 of relatively small internal diameter and to dispose the same in the bottom of re-entrant tube 3 with the bulb end 9 of thermometer 8 located adjacent the material.

There are obvious difficulties of inserting and removing the tube ID from tube 3. To overcome this it has been customary to temporarily secure the tube Ill to thermometer 8 as by tying the same thereto with string, wire or rubber band. These expediencies while overcoming the mechanical difiiculty of inserting and removing the tube Ill have introduced errors in melting point determinations such that check results on successive portions of the same material are difficult to obtain. Moreover, in some instances the temporary securing material often becomes charred or otherwise destroyed during heating and tube l0 falls off and this often interferes with the determination.

I overcome this difficulty by providing the bulb end 9 of thermometer 8 with means H and I2 (Fig. 3) to support and sustain a plurality of tubes l0 about the outer periphery of the said bulb end in determined spaced relationship to the said end. The heat radiated by fluid 6 through the walls of tube 3 upon the material in tube l0 strikes each tube l9 uniformly. As bulb end 9 is disposed at approximately the axial center of flask I it also is uniformly heated from all sides. Accordingly each of the tubes Ii] when filled with the same material will melt simultaneously and the thermometer reading will be in a definite fixed ratio to the true melting temperature depending upon the spacing of the tubes ID from the outer peripheral surface of the thermometer. By making this spacing as small as economically practical the recorded temperature may be brought in relatively close agreement with the true temperature of melting and any difference therebetween will remain a constant factor which may be calibrated and allowed for.

This uniformity in spacing of tube H] from the bulb end 9 of the thermometer 8 heretofore has not been accorded proper consideration in melting point apparatus. I obtain this as indicated in Figs. 3, 5, and 6 by providing the peripheral surface of thermometer 8 at a suitable distance remote from the bulb end, with a plurality of annular extensions ll having a center opening slightly larger than the external diameter of tube 10. Bulb end 9 of thermometer 8 is provided with a plurality of extensions l2 having recesses l3. The axial centers of annular extensions H and recesses 13 of extensions l2 are aligned in the same plane parallel to the longitudinal axis of thermometer 8 and as close to the surface of thermometer 8 as is economically practical.

material in the bottom of tube In.

Preferably annular extensions H and recessed extensions l2 are comprised of glass of the same composition as employed in thermometer 8 to avoid unequal expansion and contraction and resultant stresses and strains, and are fused or.

otherwise made integral With the peripheral surface of thermometer 8.

As a specific embodiment of the present invention the outside diameter of thermometer 8 above the bulb end 9 approximates 7 millimeters. The outside diameter of tube It approximates 2 millimeters. The length of tube I ll approximates millimeters;

I dispose annular extensions ll about the peripheral surface of thermometer 8 at a distance about 5.4 millimeters from the tip end of bulb 9 with the axial center about 6 millimeters away from the surface. With two annular extensions II on opposite sides of thermometer 8 the over all diameter of the thermometer approximates 18 millimeters.

Extensions [2 are built out similarly from the bottom of bulb 9, thus bringing the longitudinal center of tube l K! disposed in any aligned extensions and [2 to Within 3 millimeters of the bulb end 9 of the thermometer 8. This is just about as close as the tube lil may be disposed to bulb end 9 and still maintain its longitudinal axis parallel to the longitudinal axis of the thermometer 8. The depth of the recesses in extension l2 may vary widely Without departure from the present invention. In determining melting points of materials in this type of apparatus it is customary to observe the melting point of the It is essential therefore to maintain the tip end of tube Ill in such position that the first indication of melting of the material in the end may be observed. As indicated in Figs. 1 and 3 this may be accomplished by providing very shallow recesses in extension !2. Alternatively as indicated in Fig. 8 a deeper recess may be employed when the tube M is provided with an extension 15 adapted to be received in the deeper recess leaving the material level above the recess, if desired.

In the modification illustrated in Figs. 2, i, and '7, the material supporting and sustaining means is altered to provide a flat disc l2 in place of the plurality of extensions l2 and two sets of annular extensions ll and I! are provided to insure the retention of tubes I B in parallel spaced relationship with the thermometer 8.

The modif ed flask l indicated in Fig. 2 is not a part of the present invention except when used in combination with the thermometer 8 and tube [0 Supporting and sustaining means H and I2 (I I and 12) as heretofore described. In such modified flask l the thermometer 8 is immersed directly in fluid 6 with the open ends of tubes [0 extending above the level of fiuid 6. Burner I4 is utilized to heat fluid 5 in channel E5 of flask I.

While I have herein above disclosed that a plurality of tube l0 supporting means H and i2 are desirable, it is apparent that I may provide one or more of such means up to as many as may be disposed about the peripheral surface of thermometer 8. Other modifications and adaptations of the present invention and of the supporting and sustaining means H and I2 (H and i2) will be apparent to one skilled in the art but all such are contemplated as may fall within the scope of the following claims.

What I claim is:-

1. A thermometer for melting point apparatus, the bulb end of said thermometer being provided with means to sustain and support a portion of the material to be tested in determined spaced relationship to said bulb end, said means comprising an annular extension and a recessed extension attached to the surface of said thermometer, the annular extension being disposed at spaced distance from said end and the recessed extension being attached to said end, the axial center of the annular opening of one being aligned with the axial center of the recess of the other in a plane parallel to the longitudinal axis of said thermometer, and a tubular member for retaining the sample to be tested adapted to be received in said annular opening and to rest in said recess with the material in the bottom of said tubular member in full view.

2. A thermometer for melting point apparatus, the bulb end of said thermometer being provided with means to support and sustain at least one tubular member in axial parallel spaced relationship with said end, said means comprising a plurality of annular extensions disposed about the periphery of said thermometer a distance from said bulb end, the annular openings of said extensions at least approximating the outside diameter of said tubular member, and means integral with the said bulbend to receive and retain the bottom of said tubular member when disposed within said annular extension.

3. A thermometer for melting point apparatus, the bulb end of said thermometer being provided with means to support and sustain at least one tubular member in axial parallel spaced relationship with said end, said means comprising a plurality of annular extensions disposed about the periphery of said thermometer a distance from said bulb end, the annular openings of said extensions at least approximating the outside diameter of said tubular member, and a plurality of recessed extensions integral with the bottom of said bulb end aligned with said! annular extensions with the recess in a position adapted to receive the bottom of said tubular member when disposed within said annular extension and to retain said tubular member in determined spaced relation to said bulb end.

i. A thermometer for melting point apparatus, the bulb end of said thermometer being provided with means to support and sustain at least one tubular member in axial parallel spaced relationship with said end, said means comprising a plurality of annular extensions disposed about the periphery of said thermometer a distance from said bulb end, the annular openings of said extensions at least approximating the outside diameter of said tubular member, and a disc extension integral with the bottomo-f said bulb end with a flat surface in position to receive the bottom of said tubular member when disposed within said annular extension, thereby retaining the said tube in spaced relation to said bulb end.

5. A thermometer for melting point apparatus, the bulb end of said thermometer being provided with two sets of annular extensions in spaced alignment about the periphery of the said thermometer a spaced distance from the bulb end of the thermometer and a fiat disc extension integral with the said bulb end the diameter of said disc extension being at least equal to the overall diameter of said thermometer and said annular extensions.

WILLIAM O. GEYER.

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