US2689342A

US2689342A - Pressure operated switching device

Info

Publication number: US2689342A
Application number: US183690A
Authority: US
Inventors: Paul R Goudy
Original assignee: Kollsman Instrument Corp
Current assignee: Kollsman Instrument Corp
Priority date: 1950-09-08
Filing date: 1950-09-08
Publication date: 1954-09-14
Anticipated expiration: 1971-09-14

Description

Sept. 14, 1954 P. R. GOUDY PRESSURE OPERATED SWITCHING DEVICE Filed Sept. 8, 1950 I. 5 m T m H V m. 0 E a m I 5 1 a e Z 4 7 7 M M 1 j. 2 M w, p g. .2 6 l 5 2 u M i a} y W rl mlk Patented Sept. 14, 1954 PRESSURE OPERATED SWITCHING DEVICE Paul R. Goudy, Milwaukee, Wis., assignor, by mesne assignments, to Kollsman Instrument Corporation, Elmhurst, N. Y., a corporation of New York Application September 8, 1950, Serial No. 183,690

4 Claims.

This invention relates to a radiosonde modulator system, and more particularly to a pressure actuated switching means for selectively con necting various circuits elements into the modulation circuit of a radiosonde transmitter, and to a means whereby a plurality of pressure responsive devices having individual pressure response ranges may be utilized through their most sensitive range.

The object of the present invention is to provide a modulator for a radiosonde transmitter in which pressure actuated switching means are utilized to select the channels for a transmitter modulator circuit.

Another object of the present invention in accordance with the previous object is the provision of the means whereby, the accuracy of the radiosonde modulator device may be extended over a greater pressure range.

A more specific object of the present invention is the provision of a pair of pressure sensitive devices designed so as to motivate a pair of brushes across a pair of commutators whereby the movement of the brushes will connect a plurality of sensitive elements individually with a transmitter input circuit, and an arrangement whereby one pressure sensitive device will operate through a first pressure range while the second will operate through another pressure range which is a continuation of the first and will thereby provide not only a means for accurately presenting a response of the sensitive elements, but will also provide means for accurately determining pressure through a wide range of pressures.

Figure 1. is a schematic representation of the pressure switched channel selecting means of the radiosonde modulator.

Figures 2, 3 and 4 are schematic showings of the circuits of channels A, B and C respectively of Figure 1.

Figure 5 is a schematic showing of the circuit with a brush on the insulating segment of the commutators of Figure 1.

In the schematic representation of Figure 1, two commutators are shown at I and 2, both commutators having channels A, B and C. Arms 3 and 5 carrying

brushes

4 and 6 are pivotally mounted so as to be movable across commutators l and 2 respectively to contact repeating conducting segments of channels A, B and C on the commutators. Commutator 2' has, in addition to channels A, B and C, a conducting tab D through which arm 5 and brush 6 are connected to arm 3 carrying brush 4. (Pivoted arm 5 with brush B connects commutator 2 to a common return, here shown as ground, and to the transmitter input as shown in Figure 1 at 2|, 22 and 23.) Aneroid capsules 1 and 8 are operatively connected through links 9 and I i to the arms 3 and 5 respectively to effect movement of the arms. Aneroid capsules 1 and 8 have diilerent pressure ranges such that one, for instance 8, will become operative when the other has passed through its most sensitive range.

The coinmutators i and 2 may be constructed of polystyrene, or some similar material, which has been etched and then coated with a conducting material, such as silver, to produce the construction of the channels as shown in Figure l. The channels may have any order of repetition, but as shown in Figure 1, the order of repetition is channel A, four channels B with that order repeating twice and then followed by a channel 0. This order of repetition is continued across the entire commutator.

Through the channels A, B and C of commutators i and 2, and the channel of the insulating segments of the commutators, a variable resistor 22 and a fixed resistor i3, a humidity sensitive element 54, a temperature responsive element 55, and a relay it are variously connected. Relay it has contacts at El and :8 and a movable con tact carrying armature l9. These responsive element circuits are connected so that when the active brush t or 6 is on a conducting segment of one of channels A, B, C or on an insulating segment of the commutator, the circuit through the commutator will be as is shown in Figures 2 through 5.

In Figure 2 is shown the circuit when the active conducting brush is on a segment of channel A. Here, the circuit is completed from terminal 2! through variable resistor i2 and fixed resistor i3 and then through the conducting segment and brush to ground.

In Figure 3 is shown the circuit when the active conducting brush is on a conducting segment of channel B, the brush and conducting segment completing a circuit from terminal 23 through the coil of relay ES to ground. This effects closing of contact It and completes the circuit from terminal 2! through variable resistor I 2 and fixed resistor 13 and the humidity sensitive element M to ground.

In Figure 4 is shown schematically the circuit when the active conducting brush is on a conducting segment of channel C. Here the circuit is completed from terminal 2i through variable resistor I2 and the conducting segment and brush to ground.

In Figure is shown schematically the circuit when the active conducting brush rests upon an insulating segment of either commutator I or 2. Here a circuit is completed from terminal 25 throughflariable resistor L2, fired resistor l3, the temperature sessiye elementltfaiid contact l8 to ground.

The operation of the radiosonde modulator system specifically illustrated in Figure 1 is as follows:

The package enclosing the modulator system and its radiosonde transmitter isldesigned'to be either dropped from a high altitude, with a small parachute controlling its rate of descent or is lifted from a low altitude through the aid of a gas filled balloon. In thedscription of the operation herein, the balloon lifted type radiosonde will be used although it will be readily apparent that the operation of, a descending radiosonde will befsimilarl withonly a change in the aneroieland commutator first actuated.

As the. radios ride. rises 'intoregions of lower pressure, aneoid capsule 'l-will beginto expand and through 11m; 9, andarm 3 will cause brush 4 to, move acrosscojmmutator' I so as to connect into the radiosonde transmitter input circuit, the various elements connected through channels A, B and C. Channel Apr'esents thecircuit of Figure 2 and is a reference circuit. Channel B presents the circuit of Figure 3, wherein the relay H5 is energized, causing its contact carrying armature to move so as to eng ge Contact I"! and present the humidityrespon'sive element I4 into the radiosonde transmitter, input. Channel C presents the circuit of Figures into the radiosonde tr nsmitter input and is. another reference circuit. In Figure 5 is shownthe circuit arrangement when either brush 4 or 6', depending upon which is presently controlling the modulation, is on an insulating segment. 'In this circuit, relay i5 is net energized and the contact carrying armature it is in the position shown in Figure 1 and the temperature responsive element I5 is presented into he input circuit of the radiosonde transmitter.

As the pressure continues to decrease, and aneroid capsule I continues to expand, the brush i is moved further across commutator i to contaet the repeating channels A, B and C. When the atmos heric pressure has decreased to the int at v ch the low pressure aneroid capsule 5 begins to xpand, brush 5 through link i! and arm 5 will be moved across commutator 2; brush '3 will first be moved to leave conducting tab D to disconnect arm 3"from the circuit. When this occurs, the high pressure section of the radiosonde modulator is no longer controlling the circuit and all channel selection will be done by the low pressure section of the device as brush 6 is moved ss commutator 2. The channels provided by co; mutator 2 are the same as those provided by commutator I, being electrically common there-- with, and the transmitter is modulated again in accordance with high and low reference circuits and the humidity and temperature sensitive elements. The selection of the resistances in varianleresistor I2, fixed resistor 13 and the impedances l t and 15 are such thatthe radiosonde transmitter output will be'm'o'dulated in accordance with the changes in not only pressure as the conta ct'arnis are 'movedto present'the resistances and impedances into the circuit but also temperature and humidity as there aerological factors change. The use of a low pressure aneroid greatly increases the accuracy of the radiosonde modulator by providing a pressure responsive device which gives greater movement at the very low pressures encountered in high altitudes. In this manner, pressure responsive devices having individual sensitive ranges maybe used to provide an improvedoverall accuracy in the radiosonde modulator.

From the foregoing explanation, it will be apparent that the atmospheric pressure at which the temperature andhumidity will be as is indicated on a chart produced by a suitable receiver is determined, at the beginning of each of the traces. The reference circuits will produce on the receivers chart a trace by which the calibration of the receiver may be checked or adjusted and the spacing of the two reference traces on the. chart will provide an aid in the determination oi the contact number engaged by the brush by 'ng a means for counting the consecutive tr ngrou A, such, as fives or tens depending upon the construction of the commutator in use. Theinitiation pressure for each commutator segment will beprevi'ously determined by test calio be. understood that applicant is not restrictinei himself to onlyjtwo commutators and tlieirassociated" pressure responsive devices as sh wn, as desired number of repeating units y be employedto develop the desired accuracy iii var ous sectionsof the atmosphere, nor is he restricting himself with the choice of sensitive elementsas shown inthe figures of the drawings, for it will be obvious that any sensitive element be employed withthedisclosure and any order of sensitive 'elementsmay beselected Without changing the spirit of applicants invention, and,"while certain pref erre dembodiments of the invention have been specifically disclosed, it is understo'odthat the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its'broadest possible interpretation withinthe term'sYof the following ciaims. What is claimed is:

l; A pressure operated switching device comprising a pairof commutators, brush 0 contact arrns'movable across said conim a 'pairof aneroid' capsules operative to move sad brush carrying contact arms across said co1nmu tators,"said commutatorsan'd aneroid capsules being designed so 'thateachhas an individual response range while the device has a continuous pressure response characteristic, and means whereby one of said aneroid capsulesand cont'act arms electricallydisconnects the other of said pair of aneroid capsules and contact LllliS When said one aneroid capsule has entered its pressure responsive range, said one contct arm being continuously connected to ground, utilisation circuits, relay means connected to said coininutators andoperable at positions of saidcontact armson' said commutators for successively connecting said utilization circuits to said comi'nutators.

2. A pressure operated switching device comprising a plurality of commutators providing repeating circuit selecting conductor segments, temperature, humidity and reference circuits con nected to individualrepeating segments of cfommutatorfs repeating segments, a brush carrying contact arm movable across each of said commutators providing means for selectively connecting said temperature, humidity and reference circuits into the modulator circuit of a radiosonde transmitter, one of said contact arms being continuously connected to ground, pressure responsive means operative upon said brush carrying contact arms to move said arms across said commutators, said pressure responsive means being individually operative in separate pressure ranges yet collectively operative over a continuous range of pressure, said commutators providing means for successively connecting each alone in the selection circuit as their associated pressure responsive means enter their separate pressure ranges.

3. A pressure operated switching device comprising a first and a second commutator having a plurality of channels therethrough, a plurality of sensitive elements responsive to changes in atmospheric conditions connected to said plurality of channels, a first and a second brush carrying contact arms movable across said first and second commutators respectively, said second commutator having a separate channel thereon at its upper end through which the brush carrying contact arm of said first commutator is connected to the brush carrying contact arm of said second commutator, a first and a second pressure responsive device operative individually on said first and second brush carrying contact arms so as to move said brushes across said commutators, the range of said second pressure responsive device being a continuation of the range of said first pressure responsive device into a range of lower pressure, said second pressure responsive device operating to disconnect said first pressure responsive device from circuit control by moving the brush carrying contact arm associated with said second commutator out of contact with said separate channel whereby said brush carrying contact arm associated with said first commutator is disconnected from said switching device, the said contact arm of said second pressure responsive device being continuously connected to ground, utilization circuits, relay means connected to said commutators and operable at positions of said contact arms on said commutators for successively connecting said utilization circuits to said commutators.

4. A pressure operated switching device comprising a first and a second commutator having a plurality of channels therethrough a plurality of sensitive elements responsive to changes in atmospheric conditions connected to said plurality of channels, a first and a. second brush carrying contact arms movable across said first and second commutators respectively, said second commutator having a separate channel thereon at its upper end through which the brush carrying contact arm of said first commutator is connected to the brush carrying contact arm of said second commutator, a first and a second pressure responsive device operative individually on said first and second brush carrying contact arms so as to move said brushes across said commutators, the range of said second pressure responsive device being a continuation of the range of said first pressure responsive device into a range of lower pressure, said second pressure responsive device operating to disconnect said first pressure responsive device from circuit control by moving the brush carrying contact arm associated with said second commutator out of contact with said separatechannel whereby said brush carrying contact arm associated with said first commutator is disconnected from said switching device, the contact arm of said second pressure responsive device being continuously connected to ground, utilization circuits, relay means connected to said commutators and operable at positions of said contact arms on said commutators for successively connecting said utilization circuits to said commutators, said first and second brush, upon moving across said first and second channel, sequentially connecting and disconnecting said plurality of sensitive elements, one of said sensitive elements being energized when said first or second brush touches a conducting portion of said first or second channel and a second of said sensitive elements being energized when said first or second brush does not make contact with a conducting portion of said first or second channel.

References Cited in the file of this patent UNITED STATES PATENTS Name Date De Giers Aug. 13, 1946 OTHER REFERENCES Number