US331829A - Spirometer - Google Patents

Description

(No Model,)

W. A. SHEPARD.

SPIROMETER.

No. 331,829. Patented Dec. 8, 1885.

Ni'rnn Snares Pia-TENT @rrrcn \VILLIAM A. SHEPARD, OF ELGIN, ILLINOIS.

SPIROMETER.

gPECIFICATION forming part of Letters Patent No. 331,829, dated December 8, 1885.

Application filed February 24, 1885. selial No. 156,814. (No model.)

To all whom it may concern..-

Be it known that I,WILLI.-in A. Snnraan,

of Elgin, in the county of Kane and State of,

Illinois, have invented certain new and useful Improvements in Spirometers; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to that class of spirometers which comprise, generally,a station ar Y receptacle or vessel adapted to contain a quantity of water or other liquid, and a mov able open-bottomed vessel or receiver into which the air ex pellcd from the lungs is forced, said receiver being located within the stationary vessel with its side walls immersed in the liquid, which thereby forms a water-seal to prevent the escape of air from the interior of the receiver, a suitable index being usually provided for showing by the upward movement of the receiver the quantity of air entering the latter.

Spirometers of the character above mentioned, as heretofore commonly constructed, have consisted of an opentopped stationary vessel having abottomiaud vertical side walls and a bottomless vessel or receiver of app roX'imately the same size and shape as the first vessel, the stationary vessel being, when the device is used, nearly filled with water, so that when the receiver is at the lower limit of its movement a relatively small air-space will be left between the top surface of the water and the topof the receiver. In devices constructed in this manner means have usually been provided for conveying the air into the receiver, consisting of a tube extending from the bottom of the vessel upwardly through the liquid therein and opening within the receiver above the said liquid.

A spirometer constructed as above set forth has been found to be objectionable for several reasons, the principal ones being that when the vessel is filled with liquid to form a seal the apparatus is too heavy to be conveniently portable, and that the upper end of the inlettube being located below the level of the top wall of the receiver when the latter is at the lower limit of its movemenhand consequently only a short distance above the top level of theliquid in the outer vessel, the said liquid,in case the apparatus is moved or jarred, is liable to splash over and enter the open end of the said tube. The use of a large body of fluid is also object'oiable on account of the cost of the latter when a noncongealable liquid-such as oil or glycerine-is employed, as is sometimes desirable.

In the device herein shown as embodying my invention the stationary part or vessel of the spiroineter is provided with parallel inher and outer side walls, which form anarrow space closed at its bot-tom and open at its top, for containing the liquid which forms the seal, and between which the side walls of the receiver are located whenithe parts are in posi (ion for operation. By this construction only the small quantity of liquid which is contained in the narrow space between the inner and outer walls of the stationary vessel is necessary to form the seal, and the apparatus will therefore be of little weight when in condition for use, and may therefore be readily moved or transported from place to place.

As another feature of improvement in devices of the character described, also, the inlet-tube, which is attached to the stationary vessel and extends upwardly into the space within the movable receiver above the liquid in said stationary vessel, is extended vertically above the top of the receiver, and the latter isprovided with an upwardly-extending closed tube surrounding the upper end of the said inlet-tube, whereby liability of the said liquid entering the tube by the tipping of the apparatus or otherwise will be entirely prevented, as will hereinafter more fully appear.

The invention may be more fully understood by reference to the accompanying drawings, in which Figure l is a perspective view of a spirometer constructed in accordance with my invention,with a portion of the casing broken away to more clearly show the internal portions of the apparatus. Fig. 2 is a vertical central section of the same.

In the drawings, A represents the exterior vessel or casing of the spiroineter, (herein shown as of cylindric shape,) and B is a vertically-movable open-bottomed vessel or receiver, also of cylindric shape, and located within the vessel A. The said vessel A is preferably made somewhat higher than the receiver B, and is provided at its lower portion with an inner wall, 0, parallel with the outer or side wall of the said vessel A,and con nected about its lower edge with the bottom A of the vessel A, so as to form a narrow annular space, closed atits bottom, for containing the water or other liquid to form the seal or air-tight joint between the stationary vessel and the side walls of the movable receiver. The receiver B will in this construction also be of cylindric shape, and its side walls will preferably be of the proper diameter to enter midway of the space between the inner surface of the vessel A and the inner wall, 0.

As herein shown and preferably constructed, the space within the inner wall, 0, of the vessel will be covered or inclosed by a top or cover, 0, attached to the upper margins of the wall 0, so as to form a closed chamber or air-space, G, which takes the place of the body of water present in spirometers of this class, as heretofore usually constructed. wall 0 will usually be made of approximately the same height as the receiver, so that when the latter is at the lowerlimit of its movement its top will come in contact, or nearly so,with the top 0 of the chamber 0 so that nearly all of the air within the receiver will at such time be expelled therefrom.

In the particular form of the device herein shown air is admitted to the interior of the receiver through a pipe or tube, D, located at the base of the vessel A, and communicating with the chamber C", and an upright tube, D, attached at its lower end to the top 0 of the chamber 0 and extending upwardly through an aperturein the top of the receiver B to a point considerably above the said top of the receiver B, said receiver being provided with a closed tube, B, surrounding the tube D in its part which extends above the top of the receiver, so as to preventthe escape of air from the receiver at the aperture formed therein for the passage of the said tube D. B is somewhat larger in diameter than the tube D, so that the said tube B may move freely over the stationary tube D in the vertical movement of the receiver, and. a free space will be formed between the tubes for the free upward and downward passage of air from the receiver to the top of the tube D. The said tube D will be arranged to terminate at its upper end at a point which, when the receiver is at its lowest limit of its movement, will leave a space between the open upper end of the said tube D and the closed end of the outer tube, B, so that the passage from the receiver to the tube D will be at all times open.

By the construction above, set forth it will be observed that the air from the lower inlettube, D, passes through the chamber 0 before reaching the receiver. This construction of the parts is not, however, essential, and the tube D may be extended upwardly through The- The tubethe chamber G and united with the tube D; or, in other words, the tubesD and D may be made continuous, as indicated in dotted lines at D Fig. 2, with the same result, so far as the operation of the other parts of the device is concerned. A sufficient quantity of water or other liquid, indicated at E in the drawings, Will usually be placed in the space between the outer wall of the vessel and the wall 0, to fill said space nearly to the level of the top of the said wall, so that the receiver may be raised until its bottom is nearly to the top of the wall before escape of the air therefrom will occur, whereby the entire area of the receiver may be utilized. The object of extending the tube D above the top of the receiver is to prevent the possibility of any liquid entering the air-inlet passage, which may, by the accidental tipping or tilting of the apparatus in moving it or otherwise, flow over the top 0' of the chamber.

As herein shown, a suitable flexible tube, D provided at its outer end with a mouthpiece, D is attached to the outer end of the fixed inlet-tube D.

As preferably constructed, the vessel A is made somewhat more than twice as high as the receiver B, and is provided at its top with a removable cover, A", having in it a central aperture, through which the upper end ofthe tube Bextends, and by which the said tube and the upper end of the receiver are guided in their vertical movement. A suitably divided or graduated scale or index for showing, by the height of the receiver above its normal or lowest position, the quantity of air therein is preferably placed upon the side of the tube B, the index being read against the edge of the said cover. Any suitable guide for the upper end of the tube may, however, obviously be used in place of the cover shown, and when the latter is used it will be desirably provided with an aperture, A, to permit the free exit of air from the vessel which is displaced by the receiver during the upward movement of the latter.

In the use of a guide for the tube B other than the cover A", the side walls of the vessel A may be made to extend only slightly above the level of the liquid therein, the top portion of the vessel shown obviously serving only as a support for the cover A, and to inclose and,protect from dust the parts of the apparatus within. it.

Inasmuch as, the liquid forming the seal is liable to be thrown. or forced up between the vessel A and the receiver in case the latter is depressed faster than the air can escape therefrom through the pipes D and D, the side walls of the said vessel will preferably in all cases be arranged to extend sufficient] y above the level of the liquid to prevent its overflow under such circumstances.

Although the vessel A is herein shown as of cylindric form, yet it is obvious that, as far as the principles of the invention are concerned, the said casing may be rectangular or of other suitable shape, the receiver B and the inner wall, 0, in all cases being of the same shape as the outer vessel, so as to form a relatively narrow space for liquid to form the seal, and to thereby render necessary the use of a small quantity only of the latter.

The vessel A is, as herein shown, provided with a base formed by afiange or rim, A, within which the stationary part 1) of the inlettube is supported.

The construction in which the inlet-tubes D and D communicate with the chamber G will usually be preferred, for the reason that by this construction a desirable elastic body of air or air-cushion is interposed between the month-piece and exit end of the inlet-tube.

The tube D may obviously be made of less length than shown, and, as far as the features of the device relating to the water-seal are concerned, said tube need extend onlya short distance above the top of the chamber 0 The construction shown is preferred, however, as by its use any liability of the entrance of the fluid to the inlet-tube is entirely obviated.

Aside from the advantages in point of lightness and convenience obtained by the use of a narrow annular space for the water seal, which have been hereinbefore pointed out, the construction of the parts in which a relatively-narrow space only is present between the vessel A and the inner wall, 0, atfords a means of holding and guiding the receiver in its upright position without the necessity for the employment of separate guides for this purose.

p It is obvious that the principles of the invention may be carried out in devices of other form than herein shown, and I do not desire, therefore, to limit my invention to the exact construction herein set forth, but to cover all devices embodying the general principles of construction embodied in the apparatus herein illustrated and described.

I claim as my invention- 1. A spirometer comprising a stationary vessel, A, having an inner wall, G, forming with the wall of the vesselA aspace for contain ing liquid to form a seal, the space within said wall 0 being covered by a top, 0, and a vertically-movable open-bottomed receiver, B, located within the said vessel A, substantially as and for the purpose set forth.

2. In a spirometer, the combination, with l a stationary vessel, A, containing liquid to form a seal, and a vertically-movable openbottomed receiver located within said vessel A, of an inlettube for the receiver attached to the bottom partof the stationary vessel and extending upwardly within the latter to a point above the top of the receiver, said receiver being provided with an upwardly-extending closed tube, B, surrounding the upper end of the ,inlettube, substantially as and for the purpose set forth.

3. A spirometer comprising a stationary vessel provided with an inner wall, 0, forming, with the wall of the vessel, a narrow space for containing liquid to form a seal, a vertically-movable open-bottomed receiver, B, located within the vessel A, and provided with an upwardly-projecting tube, B, closed atits top, and having upon it a suitable index or scale, and an inlettube extending upwardly from the bottom of the stationary vessel within the receiver and the tube B, and terminating Within the latter, substantially as and for the purpose set forth.

at. In a spirometer, the combination, with a stationary vessel, A, having an inner wall, 0, forming, with the wall of the vessel A, a space for containing liquid to form a seal, the space within said wall G being covered bya top, 0, of a vertically-movable open-bottomed receiver, B, provided with an upwardly-projectiug tube, B, closed at its top, and an air-inlet tube extending upwardly from the top G into the tube B, substantially as described.

5. In a spirometer, the combination, with the vessel A, provided with 'an inner wall, 0, in its lower portion and with an apertured removable top, A", of a vertically-movable receiver, B, provided with an upwardly-ex tending tube, B, having upon it a suitable index or scale, said tube being closed at its top and engaged with the aperture of the top A and an air-inlet tube extending from the base of the vessel A upwardly through the receiver and tube B, and terminating within the latter, substantially as described.

In testimony that I claim the foregoing as my invention I aiiix my signature in presence of two witnesses.

WILLIAh A. SHEPARD. Witnesses:

WILLIAM GRoT-E, JAS. R. LANE.

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