US1174536A - Apparatus for indicating changes in atmospheric pressure. - Google Patents

Description

M. ALBRECHT.

APPARATUS FOR INDICATING CHANGES IN ATMOSPHERIC PRESSURE. APPLICATION FILED MAY 27, 1914.

1,174,536. Patented Mar. 7, 1916.

'/IIIII/IIIIIII/IIIIIII' E I E I 2 z I A Wfhawm I I file/1%? i wi h MARTIN ALBRECHT, OF FRANKFORT-ON-TI-IE-MAIN, GERMANY.

APPARATUS FOR INDICATING CHANGES IN ATMOSPHERIC PRESSURE.

Specification of Letters Patent.

Patented Mar. '7, 1916.

Application filed May 27, 1914. Serial No. 841,339.

To all whom it may concern:

Be it known that I, MARTIN ALBREGHT,8I1

gineer, a citizen of the German Empire, re-

siding at Frankfort-on-the-Main, Hesse- Nassau, Prussia, Germany, have invented certain new and useful Improvements in Apparatus for Indicating Changes in Atmospheric Pressure; and I hereby declare that the following is a full, clear, and'exact description thereof, reference being had to the accompanying drawings, which form part of this specification.

The present invention relates to apparatus for indicating changes in the gaseous condition of the atmosphere, for example, for indicating the presence of fire-damp or choke-damp in mines.

It relates in particular to such systems in which a chamber covered with a porous plate is furnished with a pressure measuring device in the shape of a U-tube which is partly filled with liquid and can be made very useful. These apparatus in themselves known are of only limited use and means are described below which renders this system considerably more widely applicable. The one disadvantage of these apparatus consists in the fact that the pressure effect produced by the diffusion chamber is only comparatively small, so that in mines or other applications it cannot be sufficiently well recognized.

According to the invention, the two limbs of the system of tubes connected to the diffusion chamber are provided with a siphon tube, so that it is only necessary for the liquid to rise up to the top of the siphon tube in order for the rest of the liquid to run out. Consequently, the siphon tube acts as a multiplier for the measurement. The introduction of the siphon has yet a further ad vantage in the present case, viz. that the liquid no longer runs back when the increase or decrease in pressure subsides and accordingly can be retained on either side, and that a temporary alteration in the gaseous state of the atmosphere is known to be present. The latter retaining action can also be brought about by the aid of other means, that is, by mounting back pressure valves in the tube which in fact allow the liquid to pass through but prevent it returning.

Another point of the known apparatus consists in the feature that an indication once produced is maintained for several moments. Owing to the great danger due to 4 general.

the presence of fire-damp, for example, in

mines, this is very undesirable. If, for example, in consequence of a surge of gasleak-,

ing out of-the bed of coal, which can be removed by the ordinary ventilation, the apparatus 1S operated and indicates such a change n the gaseous state of the atmosphere, it 1s not known whether this change is quite However, an alarm in the whole mine would be very inconvenient if it were unnecessary. Now according to the invention the diffusion chamber is provided with a passage accessible from the outside, so that it is possible by momentarily opening and closing this passage to remove the increase or decrease in pressure existing in the diffusion chamber. If it is established many times in succession, that such a change in the gaseous state of the atmosphere has taken place, it must be taken that the same exists in the whole space and that danger is really approaching. Since some air with the contaminating gases passes into the diffusion chamber through the opening in the outlet passage device the indication would be prejudiced by this, if the outlet were kept open for an unnecessary long time. I

This disadvantage however can easily be avoided by employing a displacing apparatus instead of the outlet device, that is to say forexample, by using a fixed piston which does away with an existing increase in pressure when drawn out and equalizes a decrease in pressure when it is pushed in.

An example of construction according to the present invention is illustrated in the accompanying drawings in which:

Figure 1 shows a communicating system of tubes which is furnished with a siphon tube and Fig. 2 shows a diffusion chamber which is provided with an outlet devio operable from the outside.

In the drawing the porous plate 1 covers the diffusion space 2 from the outside. One limb of the communicating system of tubes 3 is inconnection with the diffusion chamher 2 and the otherlimb is in connection with the atmosphere through the pipe 4. If an increase or decrease in pressure is produced in the diffusion chamber 2 by reason of the porous plate 1 then the liquid in the system of tubes 3 is displaced. According to the invention, a siphon tube 5 is sealed into the system of tubes 3. If, forexample, owing to a decrease in pressure in the diffusion chamber 2 the liquid is pushed up into the right hand limb to such a distance that it passes over the top of the siphon tube 5, then by the law of siphons, so much liquid is passed into the other limb until the liquid level in the other tube has reached the end of the siphon tube 5. Thus by this means the indicating device is made consit erably more sensitive.

In Fig. 2 the diffusion chamber 2 is provided With a valve 6 which can be operated from outside bv means of a press button 7. Consequently, if an increase or decrease or" pressure is set up in the system of tubes 3 this indication can be removed and started afresh if the diffusion chamber isplaced in communication With the external air for a moment by opening the valve 6.

Having now particularly described and ascertained the nature of my said invention and in What manner the same is to be performed, I declare that What I claim is 1. An apparatus for indicating changes in the gaseous condition of the atmosphere having a diffusion chamber, a U-shaped barometric pressure measuring apparatus in communication With said chamber, and means connecting the two legs of the barometric apparatus to prevent excessive displacement of the liquid therein, together With means for restoring normal pressure to the diffusion chamber.

2. An apparatus of the character described, having a diffusion chamber, a U- shaped barometric pressure measuring apparatus in communication with said chamber, and an inverted U-shaped tube c0nnecting the two legs of the barometric apparatus to prevent excessive displacement of the liquid therein.

3. An apparatus for indicating changes in the gaseous condition of the atmosphere having a diflusion chamber, a U-shaped barometric pressure measuring apparatus in communication With said chamber, and

means connecting the two legs of the barometric apparatus to prevent excessive displacement of the liquid therein, substantially as described.

4. An apparatus for indicating changes in the gaseous condition of the atmosphere having a diffusion chamber, a U-shaped barometric pressure measuring apparatus in communication with said chamber, and a siphon tube connecting the two legs of the barometric apparatus to prevent excessive displacement'o'f the liquid therein substantially as described.

In testimony that I claim the foregoing as mv own, I aflix my signature in presence of two Witnesses.

MARTIN ALBRECHT.

Witnesses: I

FRIEDRICH CARL WENTZEL, MAX HERMANN Horrnnn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). 0.

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