US244105A

US244105A - Feedeeick bahmann

Info

Publication number: US244105A
Authority: US
Publication date: 1881-07-12
Anticipated expiration: 1898-07-12

Description

(Model.)

F- BAHMANN FEVER THERMOMETER INVEISTTOBQ ATTORNEY TN ESSES M UNITED STATES PATENT OFFICE.

FREDERICK BAHMANN, OF BROOKLYN, NEW YORK.

FEVER-THERMOM ETER.

SPEGIFICATION forming part of Letters Patent No. 244,105, dated July 12, 1881.

Application filed April 14, 1881. (Model.)

To all 'whom it may concern Beit known that I, FREDERICK BAHMANN, of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Fever-Thermometers, of which the following is a specilication.

The self-registerin g fever-thermometers heretofore in use were either made simply of a graduated tube above the mercury-bulb, in which the indexing-column is separated by a small air-space, or by drawing out the end of the mercury-bulb into a thin tube and bending the same above the bulb into a flat S or loop shaped portion, which latter serves to retain the indexing-column of mercury and to prevent the return of the same into the bulb. The thin drawn-out glass tube is protected by an exterior tube soldered tothe mercury-bulb. Vithin the protecting-tube is arranged, back of the mercury-column, a scale of opaque glass, which is securely connected to the exterior protecting-tube at the upper end. The objection to these well-known forms of thermometers was, that in the former case the indexing-column of mercury was liable to return into the blub, so as to defeat the very object of the thermometer, while the second thermometer was too complicated, requiring too many pieces.

The object of my'invention is to furnish a fever-thermometer in which the advantages of both thermometers heretofore described are combined-to wit, simplicity of construction and a reliable self-registering of the indexing mercury-column without any liability of its re turning into the mercury-bulb 5 and the invention consists of a fever-thermometer having a graduated upper tube, with a fine center-hole extending through the entire length of the same and sealed at the top, said tube being drawn out at the lower end and bent into a lia-t S or loop shape, and connected to a second protecting-tube, which contains in its lower part the mercury-bulb, and which is connectedto the main tube above the finely-drawnout loop-shaped portion.

In the accompanying drawings, Figure 1 represents a front view, and Fig. 2 an enlarged vertical central section, of the lower portion of my improved fever-therxnonneter.`

Similar letters of reference indicate corresponding parts.

A in the drawings represents the upper or main part of my improved fever-thermometer, which consists of a graduated glass tube having a thin central perforation, within which moves the indexing-column of mercury. The upper end of the main tube Ais sealed, While the lower end is drawn out into a iine tube, B, and jointed to the mercury-blub C of a second glass tube, O. Before the drawn-out lower part of tbe main tube A is jointed to the Inereury-bulb of the tube O it is bent into the shape ofa Eat S or a flat loop, a, as shown in the drawings, which has the well-known efect of preventing the return of the indexing-column of mercury into the bulb of the lower protecting-tube, C. The upper part of the protectingtube O is sealed onto the lower part of the main tube A above the point Where the same is drawn out, so as to inclose the looped or S- shaped portion and prevent its breakage. The lower protecting-tube, C, and the bulb C form, with the main tube A, a thermometer ot' uniform diameter throughout, which is fully protected, not liable to breakage, and which preserves in an accurate and reliable manner the temperature indicated by the highest position of the indexing-column, owing to the fact that the same cannot return into the bulb, but is always reliably kept above the same.

Having thus described my invention, I claim as new and desireto secure by Letters Batent- A self-registering fever-thermometer constructed of a graduated main tube closed at the top and provided at the lower part with a drawn-out and bent or looped portion, and of a protecting-tube sealed to the main tube above the drawn-out portion, and provided with a mercury-bulb at the lower part, which latter is sealed to the lower end of the drawn-out portion of the main tube, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as Iny invention I have signed my name, in presence of two witnesses, this 9th day of April, 1881.

FREDERICK BAHMANN,

Witnesses PAUL GOEPEL, CARI. KAEr.