US2710951A - Code detecting apparatus - Google Patents

Description

June 14, 1955 c. E. STAPLES 2,710,951

CODE DETECTING APPARATUS Filed Aug. 17 1951 a E i 1.1 T i i NH RI? 7 LL L.--

a M a i a MR br i i .1 3' I 2 II L 0 Hi I Controlled a Circuit LB N INVENTOR. Crawford if Staples BY ULRHW.

HIS ATTORNEY United States Patent CODE DETECTING APPARATUS Qrawford E. taples, Pittsburgh, Pa., assignor to Westinghouse Air Ilrake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August 17, 1951, Serial No. 242,311

1 Claim. (Cl. 340-447) My invention relates to code detecting apparatus for use in connection with coded signaling systems, and more particularly relates to an arrangement for providing code detection apparatus which will detect the recurrent operation of any one or any combination of a plurality of recurrently operating contacts.

In coded signaling systems, it is sometimes required to detect the code following operation of any one or any combination of a plurality of recurrently operating contacts, which may or may not be operating in synchronism.

It has previously been proposd to provide a separate code detecting arrangement including a code detecting relay to check the recurrent operation of each of the code following contacts, and to govern the control circuits over contacts of the associated code detecting relays in series or in multiple. Such arrangements require the use of a separate code detecting relay for each of the code following contacts, the operation of which it is desired to check.

It is an object of my invention to provide code detecting apparatus for checking the recurrent operation of a plurality of contacts which apparatus requires the use of only one code detecting relay, which relay is energized when any one or any combination of the code following contacts are recurrently operated, whether or not the contacts operate in synchronism.

Another object of my invention is to provide a simplified code detecting apparatus for detecting the operation of a plurality of recurrently operating contacts, which apparatus does not normally require the expenditure of energy.

A further object of my invention is to provide code detecting apparatus of an improved type, in which a common code detecting relay is supplied with energy from energy storage devices the charging of which is governed by a plurality of recurrently operating contacts.

Still a further object of my invention is to provide code detecting apparatus in which an individual storage capacitor is associated with each of a plurality of recurrently operating contacts, and is arranged to be charged when the associated contact is in one of its two positions, and to be discharged through the winding of a common code detecting relay when the contact is in the other of its two positions.

Other objects of my invention and features of novelty thereof will be apparent from the following description taken in connection with the accompanying drawing.

In practicing my invention, I provide a code detecting relay of the slow release type, which is constructed and arranged so that its contacts will remain picked up during intervals in which no energy is supplied to its winding, provided these intervals do not exceed a predetermined length. Additionally, I provide a suitable capacitor associated with each of the recurrently operated contacts the operation of which it is desired to detect. Each of these capacitors is charged from a source of low voltage direct current energy when the contact of the asso ciated relay is in one of its two positions. When the con- 2,710,951 Patented June 14, 1955 tact is operated to its other position, the energy which is stored in the capacitor is supplied to the winding of the common code detecting relay, to thereby energize the relay.

I shall describe one form of code detecting apparatus embodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view of a circuit arrangement for detecting the operation of one or the other or both of two code following relays, adapted to be recurrently energized by a line circuit which is supplied with coded energy of one polarity at times, the opposite polarity at other times, and impulses of alternate polarity at still other times.

Referring to the drawing, there is shown a pair of code following relays NR and RR, which may be of the polar bias type, that is, of a type in which the contacts are picked up when and only when energy flows through the winding of the relay in a direction indicated by the arrow on the symbol for the relay coil. A suitable pair of capacitors NQ and RQ are associated with the relays NR and RR, respectively. A code detecting relay NRPR of the slow release type is provided and is controlled by the recurrent operation of the contacts of relays NR and RR, in a manner to be subsequently described. The slow releasing characteristic of relay NRPR is symbolically indicated by the downwardly pointing Vertical arrow through the contact of the relay.

The condensers NQ and RQ are supplied with energy from a source of low voltage direct current, such as the battery LB shown, having its positive terminal designated by the reference character B and its negative terminal designated by the reference character N.

Also associated with the contacts of relays NR and RR are two resistors R1 and R2, the function of which will be later described. The relays NR and RR are adapted to be energized by coded energy supplied over a circuit including the wires 5 and 7. The apparatus shown at the right-hand end of the sheet is arranged to supply energy in the form of impulses having one polarity at times, having the opposite polarity at other times, and having an alternate polarity still at other times. This apparatus includes a control switch SW which governs the operation of the relays PCR, MCR and PMCR, which determine the polarity of the energy supplied to the Wires 5 and 7 from a control battery CB, and a coding device CT, which coding device is constructed and arranged so that its contacts are recurrently operated at a predetermined rate, for example, times per minute, when the winding of the coding device is connected across the terminals of the source of direct current energy, as shown in the drawing.

It is believed that the description of applicants invention will be best understood by describing the operation of the apparatus under different conditions of energization of the relays NR and RR.

The apparatus is shown in the drawing in the condition which it assumes when the circuit comprising the wires 5 and 7 is deenergized. At this time the switch SW is in its first or lowermost position, and the control relays PCR, MCR and PMCR are deenergized. Accordingly, no energy is supplied to the circuit including the wires 5 and 7, and the relays NR and RR are both released. At this time, energy is supplied from the low voltage source to the condensers NQ and RQ, by circuits including the back contacts a of relays NR and RR, having the resistors R1 and R2 interposed in series in the circuit, in order to limit the initial surge of current when the condensers are being charged. It will be seen that at this time the condensers NQ and RQ are charged to a voltage equal to that of the direct current source. At this time, no energy is supplied to the winding of the code detecting relay NRPR, and accordingly, the contact a of this relay will be released, to thereby interrupt the one circuit and close the other circuit controlled over this contact.

It will now be assumed that the switch SW is moved to its second position, to thereby energize the relay PCR by a circuit which is obvious from the drawing. When relay PCR picks up its contacts, a circuit is established for supplying coded energy to the relays NR and RR which circuit may be traced from the positive terminal of the control battery CB, over the recurrently operated contact a of the coding device CT, front contact a of relay PCR, wire 5, the windings of relays NR and RR from left to right, wire 7, and front contact b of relay PCR to the negative terminal of the battery CB. Accordingly, impulses of energy will be supplied to the winding of relays NR and RR at this time. Since the flow of energy through the winding of relay NR is in the direction to cause the contacts of the relay to operate, the contact a of relay NR will be recurrently picked up and released in response to the pulses of energy supplied to the relay. Since the flow of energy through the winding of relay RR is in the opposite direction to that required to operate the relay, the contact a of relay RR will remain released at this time. Each time that the contact a of relay NR picks up, it establishes a circuit for supplying energy from the associated condenser NQ to the winding of the code detecting relay NRPR. Each time the contact a of relay NR releases, the condenser NQ is recharged through the circuit including resistor R1, with the result that the recurrent operation of contact a of relay NR causes the supply of recurrent impulses of energy to the Winding of the code detecting relay NRPR. Accordingly, the con tact a of relay NRPR will be picked up at this time, to

thereby open or close the circuits controlled over the con- 1'- tacts. As previously explained, the relay NRPR is sufficiently slow in releasing that its contact a will remain picked up during the short intervals between the supply of impulses of energy to the winding of the relay.

It will be seen therefore, that at this time, with the line circuit energized with energy of a polarity such as to cause the operation of relay NR alone, the code detecting relay NRPR will be picked up in response to the operation of relay NR.

It Will now be assumed that the switch SW is moved to its third position, to thereby deenergize relay PCR and energize relay MCR by an obvious circuit. When the contacts of relay MCR pick up, a circuit is established for supplying energy of opposite polarity to the circuit including the line wires 5 and 7, which circuit may be traced from the positive terminal of battery CB, over from contact a of the coding device CT, front contact b of relay MCR, back contact b of relay PCR, wire 7, the windings of relays RR and NR from right to left, wire 5, back contact a of relay PCR, and front contact a of relay MCR, to the negative terminal of the control battery CB. Accordingly, it will be seen that the supply of coded impulses to the windings of relays NR and RR at this time are such as to cause the operation of the contact a of relay RR, while the contact a of relay NR will remain released. With the contact a of relay RR in recurrent operation, the condenser RQ is recurrently charged with energy from the low voltage source through the resistor R2 each time that contact a of relay RR releases. Each time that contact a of relay RR picks up, the energy stored in the condenser RQ is supplied through the Winding of relay NRPR. Accordingly, it will be seen that the code detecting relay NRPR is recurrently supplied with impulses of energy at this time as the result of recurrent operation of contact a of relay RR, with the result that contact a of the code detecting relay will be picked up to open or close the circuit governed thereby. It is apparent therefore that the code detecting relay NRPR will be energized by the operation of the relay RR While the relay NR remains inoperative.

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It will now be assumed that the switch SW is moved to its fourth or uppermost position, so that relays PCR and MCR are deenergized and relay PMCR is energized by an obvious circuit. At this time, the line circuit is supplied with impulses of energy of alternately opposite polarity as a result of the operation of the polechanging contacts b and c of coding device CT. When the contacts of the coding device CT are picked up, the positive terminal of battery CE is connected to wire 5 over front contact b of coding device CT, front contact a of relay PMCR, and back contactsaof relays PCR and MCR, and the negative terminal of battery CB is connected to Wire 7 over front contact 0 of coding device CT, front contact b of relay PMCR, and back contacts b of relays PCR and MCR. When the contacts of the coding device CT are released, the connections to the battery CB are reversed. Accordingly, the relays NR and RR are recurrently energized by pulses of energy of alternately opposite polarity. The alternate polarity of the code impulses will cause the relays NR and RR to alternately pick up and release, so that the condensers NQ and RQ are alternately connected to the source of energy to receive a charge therefrom. During the time that the contacts a of the relays NR and RR are picked up, the energy stored in their respectively associated capacitors is discharged through the winding of the code detecting relay NRPR, so that relay NRPR is picked up under these conditions also.

It will be apparent from the foregoing that the code detecting arrangement embodying my invention is capable of detecting the code following operation of a plurality of recurrently operated contacts, and it will be readily understood that the contacts need not operate in synchronism, since the energization of the relay NRPR is dependent only upon the charge and discharge of the individual capacitors associated with the contacts, and not upon the operating time relationship of the contacts. It will also be understood by those skilled in the art that the contacts need not be those of code following relays, but may be any type of recurrently operated contacts, the operation of which it is desired to detect.

Although I have herein shown and described only one form of code detecting apparatus embodying my invention, it is to be understood that various changes and modifications may be made therein within the scope of the appended claim without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

In combination, a first and a second code following relay, each having a contact adapted to be recurrently operated between a first and a second position in response to impulses of energy supplied to the relay, coding means for supplying impulses of energy to said first and second relays alternately, whereby the contacts of said relays are recurrently and alternately picked up and released, a first and a second capacitor associated with said first and said second relays, a source of direct current energy, means for charging said capacitors from said source including the contact of the associated code following relay closed in its first position, a slow release codedetecting relay, means for discharging the energy stored in each of said capacitors through a winding of said codedetecting relay including the contact of the associated code following relay closed in its second position, and

a circuit governed by said detecting relay.

References Cited in the file of this patent UNITED STATES PATENTS 2,442,427 Mullerheim June 1, 1948 2,462,655 McHenry Feb. 22, 1949 2,472,526 Frazee June 7, 1949 2,504,996 MacDonald Apr. 25, 1950

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