US2377182A - Barometer - Google Patents

Description

May 29, 1945. A A, RASPET Y y 2,377,182

l BAROMETER Filed sept. 4, 1944 NVENTOR. 9060.577- /769/57- -Patented May 29, 1945 Eo: STATES PATENT OFFICE.`

Kenyonlnstrument Co., Inc.,A Hunting-toni Sta-v tion, Long Island, N. Y., afcorporationr of" New York Applicatoirseptember 6 Claims.

This inventioareiates to ammeter's ana'simi; lar instruments. operated by Variations of atmospheric pressure and has for its' objectH to provide la. novel' and improved instrumentv of' this type.

Anotherobject ofthe invention is to provide a recording altimeter or barograph' whichis highly sensitive `and accurate yet small and light'enough to be carried'by a model airplaneV orglider with out materially increasing its weight.`

Another object' of' the invention isto provide an instrument of the above type having'novel and improved details ofr construction and" features of operation; Various other objects and advantageswill be apparent as the nature of theiinvention is more fully disclosed'.

Although the novel leatureswhioh4 are characteristic of this invention are set forth more in detail'in the claims" appended hereto; the nature and' scope oftheinventionv may be better 4, 1944', serial No; 552,615' (Cima-38e);

Ail() understoodby referring t0 thefollowingdescription,.taken in connection with theraccompanying drawingfo'rming a' parvthereof, in which a specificembodiment has' been setforthfor purposes ofA illustration;

In the'idrawing:U

Fig. Il"` is" a" vertical4 sectionall View, taken on lineIi-I" ofFig; 2; showing anin'strument embodyingtheV invention;

Fig. 2 is horizontal sectional? view taken* on the line 2^-2of Fig: 1;

Fig: 3i is 'a' transverse lsectional f View; takenon line`3L-3'LofvFijg". 1, illustrating the mounting of the re'cordingl'stylum and Fig.l 4l isa' perspective View of therec'ord and a. transparents'cale forreading same.- In the` following' description `certainA speci'c terms are used* for convenience inref'erring to the' various details" of the invention; These terms; however; are tobe interpreted as broadly as 'the state of the' art will'permit.

The instrumentU shownin the `drawing includes a base I"having tabs ZOrsecurin'g' same to'a support, a curved end`iwall'3', anda light transparent hoodforcover Il which ts over the base and has'notches Stinits'lower' edge-engaging pins B'on the; en'dfwall to secure the hood in place.v

A* motor,` preferably `aV conventional stem-winding watch nfiovemeni;A 1; ismountedon' lugs 8 securedvto r:tlie'baserlwith the stem 9 of the w-atch pointing forward so as to be engaged and turned by a suitable key which may be inserted through an opening I0 in the front end of the hood 4.

The arbor I2, which normally carries the hour or minute hand in a conventional watch, has a Lil) flange I3formingj a seatfora thin disc or chart I`^4which has a central hole" I5 for centering same upon the' arbor. The arbor I2"is threaded for engagement with" a knurled nut IS `which clamps the dise I'4.t`o the flange I3? Accordingly, whenl the "wat'cli 'I has once' been wound", the ensuing'unwinding'movement causes the'` disc I 4to rotate inH a' clockwisedirection' as viewed in Fig; 2; the time" required to eiectA a complete revolution of the disc being either twelve` hours "or A-one hour; depending 'upon which arbor" of the Watchjisjemployed, although itl will be understood thatthis timemay be varied'if desire'd v In' the embodiment illustrated, the upper sur: face of the disc I4 is polished, andibef'ore the instrument is used this surfacev is completely coated with lampblack', ehalkorany othersuitable fugitive material of' distinctive colorwh'ich is easilyrubb'edj'off'j ortetchedby'a pointedV object such' as". thel frictional stylus hereinafter' described. y

The exhausted boxor bellowsI'I, of the type commonly employeddn self-registering barometers; is riveted or otherwise secured tothe end wall 3" of the: instrument; A pair of posts I8, likewise' secured tothe end Wall 3 of the instrument; project' forward Lbeyond the 'bellows I1 and carry a skeleton" frame I9 which is thusVv sus'- pended between the bellows and the motor T. The bellows. I'I and'thepostsA I8` are preferably coinposedof the same material, or'o'f materials having the same coefficient of "expansion, so' that expansionV orw contraction of the bellows" due to temp'eraturechan'ges will be accompaniedl by a corresponding change inthe position of the skeleton'fr'ame I9 carried by posts'l 8.

A flat metal band or Wire 20is drawn taut between the' upper and'loweredges of the skeleton frame I9 and has its endsweldedlor otherwise secured to said frame as shown'inV Figs. 1 and 3.

Theband'ZIVhasa central tubular portion 2 I; in-

` tegral therewith orsecured to the band inany tubular portion 2l of band 20 as previously de-` scribed, is drawn taut toward the bellows I'I with suicient tension to twist the band axially out of its normal flat plane, and the end of wire 22 is then locked securely in the projection 23 of bellows I'I byi pin 24 under this tension which maintains the band 20 in its twisted condition.

In the embodiment illustrated, the tension whichr bellows I'I exerts upon wire 22 at normal atmospheric pressure is such that rthe flat intermediate portion of the band 20 carrying stylus arm 21 is twisted at right angles to the flat ends of the band which are anchored in skeleton frame I9, as shown in Figs. 1 and\ 3. This twisting of band 2i) gives it a torque which produces rotation or torsion of said band when the tension of wire 22 is eased by the expansion of bellows I'I.

It will thus be seen that when the bellows II is contracted, due to an increase of atmospheric pressure, the wire 22 will be drawn tighter, or toward the left as viewed in Fig. 1, thereby iurther twisting the band 20 and correspondingly shifting the stylus arm 21. And when the bellows Il expands, due to a decrease of atmospheric pressure, the tension on wire 22 will be slackened and the torque of band 20 will produce a corresponding untwisting of said band and a consequent shifting of the stylus arm 21 in a direction opposite to that previously mentioned.

When the altimeter is used, for example, in a model airplane or glider, the record disc I4, coated in the manner previously described, is secured in place beneath the stylus 28, and the motor 'i is wound up as already explained. As the altimeter functions during the iiight the deflections of the stylus will be traced or etched upon the record disc I4, forming a track 29 thereon as illustrated diagrammatically in Fig. 4.

At the conclusion of the flight the disc Illy is removed from the instrument and the record interpreted by means of a transparent disc 30, containing a suitable scale y3l, which is superimposed upon the disc I4 in the proper position to provide a reading in terms of altitude or atmospheric pressure, or angle of glide, as desired.

It will be understood, however, that the scale may be marked directly on the disc I4, for example on an uncoated margin of said disc, if desired.

The instrument described above is extremely light and compact, yet highly sensitive, and at the same time more rugged and durable than many larger altimeters and ,barographs Although a specific embodiment of the invention has been shown for purposes of illustration it will be evidentl that the invention is capable of various modifications and adaptations without departing from the scope and spirit of the appended claims.`

What is claimed is:

1. An instrument of the type described, comprising a bellows responsive to changes in atmospheric pressure, a taut ilexible band having a cylindrical central portion perpendicular to the axis of said bellows, a wire wrapped around the cylindrical portion of said band and secured to said bellows under a tension twisting said band in an axial direction, a stylus carried by said band, and a movable chart cooperating with said stylus.

2. An instrument of the type described, comprising a bellows responsive to changes in atmospheric pressure, a frame adjacent said bellows, a taut flexible band having a cylindrical central portion and flat end portions secured to said frame in a plane perpendicular to the axis of said bellows, a wire wrapped around the tubular portion of said band and secured to said bellows under a tension twisting said band axially and causing same to twist and untwist with the contraction and expansion of said bellows, a stylus carried by said band, and a movable chart cooperating with said stylus.

3. An instrument of the type described, comprising a support, an expansible bellows responsive to changes in atmospheric pressure having one end mounted on said support and a movable end extending outwardly therefrom, 'a xed frame adjacent said movable end, supporting members for said frame attached to said support, a taut ilexible band having a cylindrical central portion and flat end portions secured to said frame in a plane perpendicular to the axis ci said bellows, a wire wrapped around the tubular portion of said band and secured to said movvable end of said bellows under a tension twisting said band axially and causing same to twist and untwist with the contraction and expansion of said bellows, and an indicator carried by said tubular portion.

4. An instrument of the type described, cornprising a bellows responsive to changes in atmospheric pressure, a frame adjacent said bellows, a taut flexible band having a cylindrical central portion and flat end portions secured to said frame in a plane perpendicular to the axis of said bellows, a wire wrapped around the tubular portion of said band and secured to said bellows under a tension twisting said band axially and causing same to twist and untwist with the contraction and expansion of said bellows, and an indicator carried by said tubular portion.

5. An instrument or" the type described, comprising a bellows responsive to changes in atmospheric pressure, a taut flexible band having a cylindrical central portion perpendicular to the axis of said bellows, a wire wrapped around the cylindrical portion of said band and secured to said bellows under a tension twisting said band longitudinally, a stylus carried by said band, and a rotatable disc cooperating with said stylus and having a coating of fugitive material adapted to be etched by frictional contact with said stylus.

6. An instrument of the type described, comprising a bellows responsive to changes in atmospheric pressure, a frame adjacent said bellows, a taut flexible band having a cylindrical central portion and ilat end portions secured to said frame in a plane perpendicular to the axis of said bellows, a wire wrapped around the tubular portion of said band and secured to said bellows under a tension twisting said band longitudinally and causing same to twist and untwist with the contraction and expansion of said bellows, a stylus carried by said band, and a rotatable record disc cooperating with said stylus land having a coating of fugitive material adapted to be etched by frictional contact with said stylus.

AUGUST RASPET.

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