US2527023A - Electric impulse counter - Google Patents

Description

Oct. 24, 1950 E MlLLEN 2,527,023

ELECTRIC IMPULSE COUNTER Original Filed May 11, 1944 3 Sheets-Sheet l INVENTOR. 0WIN R. mILLtI/V.

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65AM v a T TOQNE 71S Oct. 24, 1950 Original Filed May 11, 1944 E. R. MlLLEN ELECTRIC IMPULSE COUNTER IT/VESSES BY 7 mm ow r v @LMM has a 7' TOR/Vi Y5.

3 Sheets-Sheet 2 INVENTOR. 0 WIN 2. mILLEN Oct. 24, 1950 E. R. MILL EN 2,527,023

ELECTRIC IMPULSE COUNTER Original Filed May 11, 1944 3 Sheets-Sheet 3 Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE ELECTRIC IMPULSE COUNTER Edwin R. Millen, McCandless Township, Allegheny County, Pa., assignor to Fisher Scientific Company, Pittsburgh, Pa., a

7 Pennsylvania.

corporation of I Original application May 11,1944, Serial. No.

535,156. Divided and this application June 26, 1946, Serial No. 679,531

vices essentially comprise a relay or solenoid actuated by the pulsating current to be measured and an escapement or other mechanism operatively connected to the counter arm. Such de vices present serious deficiencies which, at least to a large extent, the present invention overcomes. Among'these is the fact that in a high speed mechanical escapement, a large number of light parts are required to translate the linear motion of the relay to the rotary motion of the counter arm with the result that the small surfaces of these partswear rapidly and soon cause inaccuracies in the counting. Also, the large number of mechanical parts may result in a lagging of the counting indication behind the energy impulses and this lag produces inaccuracies, particularly when counting high speed inputs, or when taking a random count of impulses which might vary instantaneously from a pulse rate of 3 claims. (Cl. 235 92) one per second to one of fifty per second. Further, the lightness of the material required for high speed operation limits the travel of the counter arm to small magnitudes, thereby limiting the load that the counting devices can carry. and necessitating the use of small counter scales which are diflicult to read. Another disadvantage also related to the mechanical escapement is that certain signals, due to their Wave shape voccasionally fail to activate the relay of the device. 3

Accordingly, it is an object of this invention to provide an impulse counting device that is of simple and rugged construction, effects immediate translation of each input impulse into properly indexed rotary motion, responds promptly and accurately to widely varying impulse rates,

affords adequate power to permit wear resisting construction and the operation of easily read scale means, and avoids or reduces the aforementioned disadvantages.

Other objects will appear hereinafter.

In accordance with this inventioma counting device for measuring pulsating energy is provided which comprises a motor having at least two electrically opposed pole pieces or electromag netsdisposed in theisameplane and a specially formedfrotondescribed more in detail hereinafter, mountedin the plane of the pole pieces. Preferably, geometrically opposed pairs ofpole pieces areprovidedthe'pairs of which are energized and de-energized successively by an electronicswitch orftriggerfcircuit, suchas a form of the familiar Eccles-Jordan ,trigger circuit, which connects opposed pairs of the pole pieces successively to the source of, energy.

The rotor provided by the invention has an even number of uniformly. spaced and diametrically opposed armfs' each of which is provided at its endwith'a shoulder which projects laterally in the directionflof rotation of the rotor and which progressively decreases in cross sectional area in that direction, Pulse counting mechanism is operated by the rotor for recording the counts represented by the individual movements of the rotor,v e. g., a finger that moves over a calibrated dial or a calibrated dial that is moved energization permits the arms to move to the energized poles and be locked there. The next impulse reverses'this action by energizing the next succeeding pair of pole pieces and de-energizing the previously energized pair. The shaping of the arms results inpa rotation in one direction only, i. e., in the direction toward which the progressively decreasing shoulder projects. Thus, the rotor and the counter means actuated by it are rotatably indexed by each succeeding impulse in one direction, and an accurate count of impulses is conveniently achieved.

Referring now to the drawings, Fig. 1 is a perspective, exploded front view of one form of motor provided by the invention, with associated operating mechanism, certain portions being cut away to show underlying parts; Fig. 2 is a section taken along the vertical diameter of an assembled electric switch; and Fig. 4 is a front elevationof one permissible alternate form of the rotor.

In the preferred embodiment shown by the g drawings,gamstandard l supports a housing 2,

18 will be rotated by the rotor H. rotation is, in turn, produced by energy impulses feeding through a trigger circuit 3|, Fig. 3, to

A rotor H is mounted on a shaft 12 and it is provided with six arms l4 extendingradia-lly from the shaft and spaced at 60 intervals thereabout. The rotor is mounted with the arms l4; disposed in the plane of the stator pole pieces and extending substantially to their faces. The ends of the arms are specially formed, in a manner to be described, so as to rotate only in a" Rotor shaft [2 has its rear clockwise fashion. end rotatably mounted in a bearing formed in 4 will fire initially, when the battery or anode supply voltage is first applied, this being due to minute variations in the tubes such as element spacing, gas pressure, heater temperature, activity, etc. It also should be noted that the particular circuit shown includes means such as a common cathode resistor for automatically adjusting hold-off bias and evening out variations in battery supply voltage, as well as a pair of condensers which cause a gradual dissipation of coil energy and produce smoother rotor rotation. These elements will be readily understood by those acquainted with these circuits. However, since it also will be evident to such persons that rte-arrangements of this particular circuit can produce the same effect, it should be understood the housing (Fig. 2) and the other end is rigidly I attached to a shaft l8 carrying a pinion H. An

indicator disc, or drum, is is geared to the motor shaft through a gear train consisting of pinion I1, gear (9, pinion 28, and gear 2|, Fig. 1. Gear 2| is keyed on a stub shaft 22 which extends through drum i8 and is locked thereto by a nut 23 so that the drum will rotate with it. Pinion is mounted on a shaft 24, and both shafts, 22 and 24 are rotatably mounted in a disc 26 which functions as a bearing for these shafts.

From the above, it is apparent that the drum The rotors successively energize and de-energize the pairs of pole pieces of the motor. The switching effect of the trigger circuit is achieved through the use of thyratron tubes 32 and 33, such as R. C. A. 2050 or 2051. Tube 32 is electrically connected to the pair of magnets 4 and 5, and tube 33 is connected in the same manner to the pair 6 and I. A battery 36 supplies the power for the circuit and the motor, or, if desired, an A. C. power supply with conventional rectifier and filter arrangement may be substituted.

When it is desired to make a count of the energy impulses in any electric circuit, terminals 31 and 38 of the trigger circuit are connected to the output of the circuit to be tested. When the first impulse is received from that circuit, tube 32 is rendered conductive and the current flows to energize pole pieces 4 and 5 and the rotor arms disposed at 150-330 (Fig. 1) are magnetically attracted to the faces of these pole pieces. The next impulse, regardless of wave shape, renders tube 32 non-conductive and tube 33 conductive so that pole pieces 4 and 5 are deenergized and release their'hold on the rotor arms, while pieces 5 and I are energized and magnetically attract to their faces the rotor arms then disposed at 60-240 (Fig. 1). Each successive impulse energizes and de-energizes .the pairs of pole pieces in the manner just described to rotatably index the rotor, as well as drum 18. The periphery of drum I8 is calibrated so that each impulse will advance it one mark. An index finger 39 is mounted as shown and indicates the total impulses.

The switching action of the trigger circuit is due to the fact that the tubes are so connected together that the firing of one establishes a negative grid bias in the other which prevents the other from firing. With such a condition pertaining a subsequent positive input pulse slightly larger in amplitude than the established bias will then fire the second tubeand extinguish the tube formerly conducting. Also, only one tube that the invention is not limited to this particular circuit.

It is preferable for some purposes to provide means for automatically shutting off the power supply of the motor after 'agpredetermined number of counts. This can be done in various ways as by mounting cam members at appropriate points on the face of drum l8 to operate switches in the power circuit, or in other ways/that will appear to those skilled in the art.

It is important to this invention that rotor arms is be formed in such a way that they rotate in one direction only. Accordingly, each arm is provided with a shoulder portion 4! that pro-- gressively decreases in cross sectional area in the direction of the, rotation, most suitably to a relatively sharp nose as shown. In this way the mag netic reluctance of the rotor decreases in the desired direction of rotation and increasesin the other direction. The result is that, as seen from Fig. 1, when two aligned arms are aligned with a pair of magnets, the next adjacent pair of aligned arms in the direction of rotation lie with their noses closely adjacent to the pair of magnets which will be energized next. Thus, when thyratron tube 32 fires, the rotor is caused to move in a clockwise direction, there being little tendency for it to rotate counter-clockwise. It is noted that the magnetsnot only pull the arms to them, but also lock these arms magnetically in position after each impulse. This locking action is normally sufficient to prevent; mechanical chattering or vibration. However, for high speed action, a ratchet or no-back mechanism (not shown) may be added to help mechanical damping.

Other forms of rotors are possible provided they are so shaped as to have increased reluctance in one direction of rotation and decreased reluctance in the other. Such an alternate form is shown in Fig. 4 and has the shoulders 55 which are decreasingly tapered in a counter-clockwise direction to produce rotation in that direction. This rotor completesone 360 revolution with every 20 input pulses while that shown in Fig. 1 makes a complete revolution with 12 input pulses. Another form of rotor (not shown) which could be used, would have successive lengths of its periphery crimped in a saw-tooth fashion so as to provide the rotor with decreased magnetic reluctance in the desired direction of rotation.

Although this invention has been described with reference to geometrically opposed pairs of pole pieces, it should not be limited thereto. As will be readily apparent to those skilled in this one of the pole pieces during two successive en ergy impulses becomes first electrically opposed to one of its adjacent pole pieces and next electrically opposed to the other adjacent one so as to rotatably index the rotor in the manner previously described. Subsequent impulses then cause other pole pieces to form electrically opposed pairs with their adjacent poles to carry on the revolution of the rotor.

The various uses to which this invention can be put will be apparent to those in the else-- tronic art. It is particularly useful for random counting or counting the impulses in high frequency currents, and by reason of the fact that it provides a high ratio of conversion of electrical energy into mechanical torque, the motors can be made not only to operate power switches but also as powerful as need be for the purposes to Which these impulse actuated devices are put. Further, the circuit shown is sensitive todirections or polarity of the input pulses so that, if an alternating current voltage is applied to the A input, the counter will indicate one count for each cycle. By known methods, it is possible to make the switch sensitive to impulses of either positive or negative at will.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the a'ppended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. Apparatus for counting pulses of electrical energy of varying wave shapes and durations comprising opposed pairs of pole pieces disposed in the same plane, a rotor mounted within the plane of said pole pieces and having successive lengths of its periphery shaped to provide decreasing magnetic reluctance in the desired direction of rotation, counting means operatively connected to said rotor, ,a source of electrical power for energizing said pole pieces, a circuit operatively connecting said pole pieces with said source and adapted to successively energize and deenergize the pairs of opposed poles, said circuit including an electronic switch electrically connected to the source of said electrical pulses,

said switch including at least a pair of thyratron tubes operatively connected together to alternately transfer in response to said impulses said power to successively energize and deenergize the pairs of pole pieces.

2. Apparatus for counting pulses of electrical energy of varying wave shapes and durations comprising opposed pairs of pole pieces disposed in the same plane, a rotor mounted within the plane of said pole pieces, said rotor having an even number of uniformly spaced arms each provided at its end with a shoulder projecting laterally in the desired direction of rotor rotation and progressively decreasing in cross sectional area in that direction, counting means operatively connected to said rotor, a source of electrical power for energizing said pole pieces, a circuit operatively connecting said pole pieces with said source and adapted to successively en-- ergize and deenergize the pairs of opposed poles, said circuit including an electronic switch e1ectrically connected to the source of said electrical pulses, said switch including at least a pair of thyratron tubes operatively connected together to alternately transfer in response to said impulses said power to successively energize and deenergize the pairs of pole pieces.

3. Apparatus for counting pulses of electrical energy of varying wave shapes and durations comprising two pairs of opposed pole pieces disposed at right angles in the same plane, a rotor mounted within the plane of said pole pieces, said rotor having an even number of uniformly spaced arms each provided at its end with a shoulder projecting laterally in the desired direction of rotor rotation and progressively decreasing in cross sectional area in that direction, counting means operatively connected to said rotor, a source of electrical power for energizing said pole pieces, a circuit operatively connecting said pole pieces with said source and adapted to successively energize and deenergize the pairs of opposed poles, said circuit including an electronic switch electrically connected to the source of said electrical pulses, said switch including at least a pair of thyratron tubes operatively connected together to alternately transfer in response to said impulses said power to successively energize and deenergize the pairs of pole pieces.

EDWIN R. MILLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 362,322 Sheehy May 3, 1887 491,970 Meston Feb. 14, 1893 1,258,497 Straub Mar. 5, 1918 1,371,096 Howe and Warner Mar. 8, 1921 1,638,973 Walker Aug. 16, 1927 1,933,086 Battegay Oct. 31, 1933 2,156,969 Bryce May 2, 1939 2,249,029 Mullerheim July 15, 1941 2,428,882 Kolff Oct. 14, 1947 FOREIGN PATENTS Number Country Date 401,987 Great Britain Nov. 23, 1933 522,557 Great Britain June 20, 1940

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