Патент USA US2301995код для вставки
Nov. 17, 1942. Q_ M_ BACKER 2,301,995 RAILWAY sïGNALING APPARATUS Filed Aug. l, 1939 ` 6’ 7) 10/ /ll ) l DA 4 M5 la' - 25~ R4 C? Y f @www I R6 i 12a! 19 Cog‘po! Cipeaz'ä. Fig. 2. ' lV ENTOR Caf» BY ' H15 Bacher. ArroRNEY 2,301,995 Patented Nov. 17, 1942 UNITED STATES PATENT OFFICE 2,301,995 RAILWAY SIGNALING APPARATUS Carl M. Backer, Pittston, Pa., assigner to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application August 1, 1939, Serial No. 287,731A ¿l Claims. (Cl. 175-32-0) My invention relates tofrailway signaling appa~ ratus, and particularly to signaling apparatus-for signal systems using coded current. Railway code signal systems using time spaced impulses of direct current have been proposed, the codes being either of the polarity code type or of the frequency code type. For example, in a polarity code system-one code may consist of uni formly recurrent impulses of current of positive polarity, a second code may consist of uniformly recurrent impulses of current of negative polaru ity and such impulses of current alternately of positive and negative polarity may be used for a third code. In a frequency code type, the im pulses of current may be all of the same polarity but of different rates, such as a rate of 180, 120 or 75 impulses per minute. Of course, a combi nation of different polarities and rates may be used if desired. Also, in such code systems it has been proposed to make the individual im pulses of current of short duration, that is, the duration during which current flows is short as compared withrthe duration between successive in response to code impulses of current which are short in durationA as compared with the dura tion between successive impulses. A further fea ture of my invention is the provision of code re sponsive apparatus of the type here involved which automatically obtains substantially equall “on” and “oit” periods of operation over a rela tively wide range of different code frequencies or rates. Again, a feature of my invention is the provision of code responsive apparatus of the type here contemplated? which is economical in construction» and’ operation. Other objects and advantages of my» invention will> appear as the specification progresses. I shall describe two forms of apparatus em bodying my invention, and shall then point out the novel features thereof` in claims. In the accompanying drawing, Fig. 1 is a dia grammatic view of one form of apparat-us em 20 bodying my invention when used with the train carried apparatus of a cab signal system. Fig. 2 is a diagrammatic view of a modiñcation of the apparatus of Fig. 1 which also embodies my in vention. impulses when no current ilows. Current im In each of the two views like reference charac pulses of short duration are desirable because 25 they can be made of relatively high peak voltage as an aid to reliable operation of the signal sys tem without an excessive energy output from the current source- which ordinarily is a battery. In ters designate similar parts. Referring to Fig. 1, the reference characters la and Ib designate the track rails of a railway and to which rails code impulses of current are ap such systems, a code following relay responsive to such impulses of current is normally biased to one position to which it is moved by its biasing plied according to different- traifc conditions/'of element when no code current flows and is ener code impulses of current to the rails la and lb and such apparatus is not shown for the sake of simplicity. A form of such code transmitting apparatus that may be used is disclosed and claimed in an application for'United States Let gized and operated to a second position while a the railway. lViy invention is not concerned with either the means or the manner of applying the' code current impulse perisists. Thus, the code following relay is operated to its second position for only a brief period in response to each indi ters PatentY Serial No. 222,883 filed August 3, 1938, vidual impulse of current and is operated to its by W. P; Place for Signal systems and now Pat iirst position for a relatively long period between the successive impulses of current. In other 40 ent No. 2,197,414. It is suiiicient for the present application to words, the code following relay is operated at point out that the track rails la and Ib are sup unequal “on” and “ofi” periods, the “on” periods plied with impulses of direct current ofV diiîerent when current flows being relatively short and the polarity patterns'to reflect different trafiic con “01T” periods when no current flows being rela ditions or are supplied with impulses of direct tively long. The decoding apparatus of such sys current of ditïerent code rates or frequencies to tems is selectively governed by the code follow reiiect different traffìc'conditions. In as'far- as ing relay according to the difîerent codes and a the'instant case is concerned the signiñcant fea more satisfactory operation of such decoding ture of such impulses of current is the fact that apparatus is effected when the code following re lay is operated at substantially equal “on” and 50 the individual impulses are of short duration as compared with the durationbetween successive “oir” periods. Accordingly, a feature of my inventionvis the provision of novel and improved means where With a code following relay or device is operated impulses of the same code. Also'that the dura tion between successive impulses of current may be different for different codes. To'illustrate with substantially. equalA “on” and “oiiï’ periods 55." such-circumstances, it-may beLpointed'A out that 2 2,301,995 when a code rate of 180 impulses per minute or 3 impulses per second is used, each code cycle is of substantially .33 second duration with current tacts I4 and I5 because of the short duration or' the code impulses of rail current. The code following relay MRI controls a de flowing (impulse of current) for, say, .05 second coding relay DR, the circuit for decoding relay and no current ilowing for the remaining portion Ul DR including one terminal of a battery I8, front of the cycle or about .28 second. Again, if a cede contact IS-I'l of relay MRI, winding of relay rate of '75 impulses per minute or 11/5 impulses per second is used, each code cycle is of .80 sec~ ond duration with current flowing for, say, .05 DR and the opposite terminal of battery I8. De coding relay DR is slow releasing in character and when periodically energized it remains picked second the same as before and no current iiowing 10 up from one energizing impulse to the next. for substantially .'75 second. Again, the impulses De coding relay DR controls at its front contact I9 of current may be of either positive or negative a signal circuit as desired. polarity, the duration of the impulses and the rate of occurrence being the same for the dii ferent polarities. It will be understood, of course, decoding relay DR receiving an energizing impulse that I do not wish to limit my invention to the code rates and duration of impulses cited above, and that other rates and durations may be used. The reference characters 4 and 5 designate two It is clear that with _of current only during the “on” period of code »» following relay MRI, it may not be eliectively energized because of the short period the relay MRI is picked up. That is to say, it is desirable that front contacts I3-I‘I of code following relay MRI be retained closed for an interval long train carried coils or inductors mounted on a train in the usual manner in inductive relation enough for the energization of decoding relay DR ship with rails Ia and Ib, respectively. rI‘he two inductors 4 and 5 are connected together in such manner that the electromotive forces induced therein in response to a code impulse of current ilowing in the rails are additive, and the two coils To increase the “on” period of code following relay MRI so that the “on” period is substantially are connected across the input terminals of a de tector-amplifier DA by means of wires 5 and 1. The detector-ampliñer DA may be of any one of several well~known types and it is shown con- . ventionally only for the sake of simplicity since its speciñc structure forms no part of my inven to build up to an eiîective value. equal to the "oiT” period and a more satisfactory control of decoding relay DR is effected, I provide equalizing apparatus which retains the code iol lowing relay MRI picked up for an interval after the impulse of current applied to the pick up winding 8 ceases. This equalizing apparatus comprises condensers CI and C2, a charging re sistor RI, a discharging resistor R2, a by-pass resistor R3, holding winding 9 of relay MRI tion. The detector-amplifier DA may be that shown in the aforementioned Place application and circuit connections with battery I8. The equalizing apparatus can best be explained Serial No. 222,883 where electron tubes of the by describing its operation. During the “oli” controlled ionization type are used with the tubes period of relay lVIRI and its :back contact I2~-I4 normally non-conducting and rendered momen tarily conductive in response to each of the individual impulses of current flowing in the track rails. A train carried code following relay MRI of closed, the condenser CI is charged from battery the direct current neutral type is provided with two windings, the iirst winding being a pick-up winding 8 and the second windingr being a holding winding 9. The pick-up winding 8 of relay MRI is included in the output or anode circuit of de of battery I8. Also, condenser C2 is charged by tector-ampliner DA by means of wires I0 and II. It follows that when no electromotive force is being applied from inductors 4 and 5 across 23 and 2| and to the negative terminal of bat tery I8. The quantity of charge created on con densers CI and C2 depends, Within limits, on the time back contact I2-I4 of relay MRI is closed. With the polarity of battery I8 as indicated by the input terminals of the detector-ampliñer DA, no current flows in the output circuit thereof and pick-up winding 8 of relay MRI is deenergized so that the contact lingers I2 and I3 of that relay fall by gravity into engagement with back con tacts I4 and I5, respectively. At least there is no attractive force applied to contact fingers I2 and I3 by magnetic ñux created by winding 8. I8 by a circuit that can be traced from the posi tive terminal of battery I8 over resistor RI, back contact I2-I4 of relay MRI, wire 2l), con denser CI, wire 2| and to the negative terminal a circuit which includes the positive terminal of battery I8, resistor RI, back contact I2-I4 of relay MRI, Wire 20, condenser C2, resistor R3, wire 22, holding winding 9 of relay MRI, wires the plus and minus signs, the right-hand plate of condenser CI and the lower plate of con denser C2 as viewed in Fig. 1 are positive and the left-hand plate of condenser CI and the top plate of condenser C2 are negative. When the pick-up winding 8 of relay MRI is energized in response to a code impulse of rail current and relay MRI is picked up opening back When an electromotive force is applied from in ductors 4 and 5 to the input terminals of detec tor~ampliñer DA in response to an impulse of cur 60 Contact I2-I4 and closing front contact I2-I5, the condensers CI and C2 are disconnected from rent ñowing in the track rails, an impulse of battery I8 and are connected with the holding current momentarily iiows in winding 8 of relay winding 9 of relay MRI for discharge there MRI and that relay is energized to attract con through, condenser C2 being also connected with tact fingers I2 and I3 into engagement with re a closed discharging circuit to be shortly de spective front contacts I6 and I'I. Consequently, scribed. The discharge current from condenser the pick-up winding 8 of relay MRI is momen CI tends to ilow from its positive plate over wire tarily energized in response to each code impulse 28, front contact I2-IG of relay MRI, resistor of the rail current and relay MRI is picked up R2, wire 22, holding winding 9 and wire 23 to and released once for each code impulse of cur- ,_ the negative plate of condenser CI. The dis rent, the “on” period of relay MRI during which charge current from condenser C2 tends to flow Contact lingers I2 and I3 engage the respective from its positive plate over wire 20, iront contact front contacts i6 and Il being short as compared I2~-I6 of relay MLRI, resistor R2, resistor R3 and with the “ofi” period during which contact iin to the negative plate of condenser C2. The dis gers I2 and I 3 engage the respective back con 75 charge current from condenser C2 creates a volt~ 3 2,301,995 age drop across resistor R2 which is of the same polarity as the voltage drop across resistor R2 as detector-amplifier DA in response to a code im pulse of current flowing in the track rails, an created by the discharge current from condenser CI. Hence, the discharge from condenser C2 in impulse of current momentarily flows in the winding 24 of relay LR and that relay is picked creases the total IR drop across resistor R2 and such increase in the IR drop has the same effect as an increase in its ohmic resistance as far as , up opening back contact 25-21 and closing front the discharge current of condenser Cl is con cerned. ri‘his action delays the discharge of con denser Ci. Condenser C2 is shortly discharged relay MR are connected in parallel across the now charged condenser C3. To be explicit, condenser so that the IR drop across resistor R2 lessons and condenser Ci then discharges more quickly. The connection of winding 9 is such that the dis charge current flowing therein creates a mag~ netiofflux that aids the flux created by the cur rent impulse iiowing in pick-up winding 8. Con sequently, the flux created by winding Si tends to retain the relay MR! picked up. The parts are so proportioned and adjusted that relay MRI is retained picked up by means of ñux created through holding winding t for a period after the current impulse ceases t0 now in the pick-up winding 8 and relay MR! is operated with sub~ stantially equal “on” and “oiî” periods. It the code rate is that of 75 impulses per minute, the f time back contact iii-_i4 of relay MRi is closed is relatively long and the charges created on con densers Ci and C2 are correspondingly large so that relay MRi is retained picked up by the dis~ charge current through holding winding il for a correspondingly long period and substantially equal “on” and “oir” periods of operation of re lay MRE obtains. Again, if the code rate is that of 180 impulses per minute, the time baci; con tact !‘¿-‘4 is closed is correspondingly short and the charges built up on condensers Ci and C2 are correspondingly small so that the discharge cur contact 28-2ß~ With front contact 26 23 of relay LR closed, condenser C4 and winding 2g of , C3 discharges through condenser C4, resistor R1, front contact 26--28 of relay LR and resistor R4; and also through winding 29 of relay MR, resis tors R5 and R1, front contact 2?-23 and re sistor R4. Since the current impulse operating `relay LR is short, that relay immediately re leases to reconnect condenser C3 with battery IB. The charge built up on condenser Cit now `dis charges through winding 29 of relay MR and resistor R5. Relay MR is thus picked up and retained energized for an interval after the im pulse of current from the detector~ampliñer DA ceases to flow in winding 24 of relay LR and re lay LR releases. Condenser Cê soon discharges and relay MR is then released ready for the next code impulse. The extent to which condenser C3 is charged depends, within limits, on the time baci; Contact Zâ-«Z'i of relay LR is closed and hence the charge built up on condenser C4 in re sponse to the discharge from condenser C3 is pro portional, within limits, to the rate at which re lay LR is operated, with the result that the time relay MR is retained energized in response to the discharge from condenser C4 due to the charg ing thereof by the discharge of condenser C3 is greater for the slower code rate than for the higher Code rate. In other words, the relay MR is retained picked up for a longer period at the lower code rate than at the higher code rate. IV~ have found that with proper proportioning of the parts the relay MR is operated with substan tially equal “on” and “oii” periods at both the 75 and 180 code rates. Furthermore, I have found that two code following relays when used as shown in Fig. 2 give substantially equal “on” and “oit” periods and critical adjustment in re cies. sistances and capacitors are not necessary. Also, In Fig. 2, the train carried inductors 4 and 5 contact adjustments of the relays are not criti are mounted in inductive relation with track rails ia and Ib, and are connected with the input ter~ cal. minals of detector-amplifier DA the same as in It is to be pointed out that resistors R6 and Rl Fig. l. In Fig. 2, the code following relay means 50 are provided to prevent sparldng at the contacts consists of a first code following relay LR whose of relay LR. Hence, it is clear that resistances operating winding ‘24 is interposed in the output R6 and Rl may be omitted if desired, 'I‘hat is circuit of detector-amplifier DA, and a second to say, the resistors R‘4, R6 and R1 of Fig. 2 may code following relay MR which is controlled by be combined into one resistance R4. the first relay LR through equalizincr apparatus Although I have herein shown and described embodying my invention. The eoualizing appa only two forms of apparatus embodying my in ratus of Fig. 2 comprises condensers C3 and C4; vention, is it understood that various changes and rent retains relay MRi picked up after the cur~ rent impulse flowing in pick-up winding 8 ceases is correspondingly short and substantiaily equal “on” and “ofi” periods of relay MRI obtains. Consequently, nearly equal “on” and “oiî” op~ eration periods of relay MR! are eiifected over a relatively wide range of different code frequen resistors R4, R5, Rb“ and Rl; and connections with battery Iß, The code following relay MR modifications may be made therein within the terposed in a signal control circuit the same as claim is: l. In combination, a relay having a iirst and a second winding and biased to a ñrst position and operable to a second position when current momentarily iiows in said ñrst winding, a ñrst scope of the appended claims without departing of Fig. 2 in turn controls at its front Contact 25 60 from the spirit and scope of my invention. decoding relay DR whose front contact I8 is in Having thus described my invention, what I in Fig. 1. When no electromotive force is supplied from inductors 4 and 5 to the input terminals of de toeter-amplifier DA of Fig. 2, no current ñovvs in the output circuit thereof and relay LR is de~ energized closing its back contact 26 21. With relay LR thus released, condenser C3 is charged and a second condenser, a source of direct cur rent, a resistor, means including a Contact of the relay closed at said first position to connect said from battery I8 over a simple circuit which in 70 condensers with said source to charge the con cludes positive terminal of battery IS, resistor densers in parallel, means including said resistor R6, back contact '2E-_21 of relay LR, resistor R4, and a contact of the relay closed at said second condenser C3 and negative terminal of battery i8. When an electromotive force is applied from inductors 4 and E across the input terminals of position to connect said first condenser with said second winding for energizing said relay after current ceases to now in the first winding, and 4 2,301,995 said second condenser connected across said re sistor over said last mentioned relay contact to prolong the discharge of the first condenser second Winding to retain the Contact at its seo ond position due to the discharge of the first condenser once said contact has been operated through said second Winding. to said second position due to energization of said 2. In combination, a relay having a first and a second Winding and biased to a first position and first Winding, and said second condenser con operable to a second position when current mo mentarily flows in said ?rst Winding, a first and a second condenser, a source of direct current, a ond position oi said contact to control the rate at Which said ñrst condenser is discharged through nected across said second resistor over said sec the second Winding, ` first and a second resistor, means including said 10 4. In combination, a two winding relay biased first resistor and a ñrst position contact of said to a first position and operable to a second posi relay to connect said source with said condensers to charge said condensers in parallel, means in tion when either one or both of its windings are energized, means connected to one of said Wind cluding said second resistor and a second position ings to momentarily energize said one Winding to contact of said relay to connect said ñrst cori 15 operate the relay, a ñrst and a second condenser, donser with said second Winding to energize the a first, a second and a third resistor, a source of relay, and said second condenser connected across direct current, a ñrst circuit including a biased said second resistor over the last mentioned relay position contact of said relay and said first re Contact to increase the voltage drop across that sistor to connect said direct current source to said resistor by the discharge from said second con first condenser to charge the ñrst condenser, said denser to prolong the energization of said relay 20 second condenser in series with said third re by the discharge from said first condenser, sistor and the other one of said windings con 3. In combination, a relay having a first and nected in parallel with said ñrst condenser to a second winding and a circuit controlling con charge the second condenser by said ñrst circuit, tact biased to a ñrst position and operable to a a second circuit including an operated position second position when either or both of said -»vin/i 25 contact of the relay and said second resistor to ings are energized, a ñrst and a second condenser, connect said first condenser to said other Wind a source ol direct current, a ñi'st and a second resistor; a first circuit including said first resistor and said ñrst position of said contact to connect ing to energize said other Winding by the dis charge of the ñrst condenser to retain the relay at its operated position, and said second con said source or” direct current across said ñrst con denser in series with said third resistor connected denser to charge the first condenser, said second across said second resistor over said operated po condenser in series with said second Winding con sition contact of the relay to increase the voltage nected across said ñrst condenser to charge said drop across the second resistor due to the dis second condenser in parallel with said ñrst con 35 charge of the second condenser to prolong the denser by said ñrst circuit, a second circuit in energization of said other winding by the dis cluding said second resistor and said second posi charge of the ñrst condenser. tion of said contact to connect said first con denser to said second Winding to energize the CARL M. BACKER.