US 1920153 A
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Description (OCR text may contain errors)
July 25, 1%3. A. A. CLOKEY CALL BOX REGISTER CIRCUIT Filed July 17, 1930 INVENTOR ALLISON A. CLOKEY ATTORNEY come. ever, is toprovidesimpler arrangements tomg descriptlon:
Patented July 25,1933
* UNITED STATES,
PATENT err-rin f:
ALLISON A. .OLOKEY, or RUTHERFORD, NEW JERSEY, A ssIGnons'ro m'rnnnnrroivnn COMJVIUNICATIONS LABORATORIES, INC., .NEW YORK v Application filed. 1.111; 17,
This invention relates to calllbox register circuits, such as messenger call systems, fire. alarm systems and watch'mens signalling systems. It has particular reference to the line relay and other means whereby the code register may be; caused to function, even under abnormal conditions of the circuit.
Systems which include" a number of code signalling stations in series'on one circuit. are frequently subject to line trouble such as an open circuit, a ground, or'a combina-, tion of the two. Means are known in the art whereby such line troubles can be over- The object of this invention, howrender the'register operative under abnor mal as well as normal conditions, and particularly to employ only one' relay 'in the line circuit rather than twoas heretofore.
In carrying out this invention it is preferableto use call boxes equipped with code} impulsing wheels and to provide a contact device in association with the impulsing wheels such that in makinga call not only is the line momentarily grounded but also opened for each pulse of the signal; This signalling means in combination with the novel arrangement'of the receiving relay and its associated switching mechanism re ders the circuit'operative from a call box located on either side of an accidentally grounded point or break in the line, or a combination of the two. 1 i I In the drawing accompanying the follow .Fig. 1 shows diagrammatically the call box' circuit and the arrangements at the register station.
Fig. 2 shows a typical detail of the code wheels within a call box.
Fig. 3 shows anarrangement ofthe line relay and its connections alternative to the portion of Fi 1 comprehended in the broken line one osur'e; c
vIn Fig. 1 four loop circuits, A, B, G and D illustrate respectively each of fourline conditions which may possibly occur on any one circuit. The call boxes, 4," 5, 6 and 7 are placed at any desired points along. the line. The two ends of the loop-"T and R,
OF. NEW .YORK,.'N.' Y., A CORPORATION OF .cALL' Box REGISTER cmcnir 1930, Serial No. 468,606.
should be regarded as' terminating at the register station where they are connected respectively with ther'eceiving relay circuit as at T and R. v v c Loop .A shows a normally closed circuit over which signals maybe transmittedjfrom any call box by 'openingthe circuit for each code impulse; Loop B shows a break or opencircuit condition as at Loop C shows an abnormal ground as at F. Loop D sh'owsat Gr an Y ground. a c c The receiving apparatus comprises a line relay 8, akey, switch having three positions designated 1, 2 and 3' respectively, abo e signal. register 9 and sources of potential 10 and 11, the voltages of which may beisuitably cut down'for.practicalpurposes by the use of the resistances 12 and'13; Inthe' call box, Fig.2, the. code wheel 14: isrecessed as at 16 to provide a series of open pulses when the wheel rotates in a clock-wise direction asindicated. This particular code wheel has notches arranged to send the signal c2 3+1. Associated with it is the code wheel'15 on whichare teeth 17 arranged in the same code combin ation'jas [the notches 16 on wheel'-11.""The contact spring 18' bearing against code wheel. 14
normally completes the circuitthrough the box in the directionR-T of the loop.-] The contact spring 19 bearing against the'teeth 17 of code wheel 15 momentarily puts ground on the loop immediately prior to opening it for thefsignalling pulses. I
The operation lows: 1
open circuit andat H a of the system is as fol} The normally closed circuit condition 7 will first; be assumed as represented'by loop A; The proper position of the key switch for this condition is with its contact-spring operating lever 1n posltion 1 as shown. Prior to sending a signal, current flows from battery 11 throughiresistance 13, con-f tacts 20 and 21, loop A in the direction lay 8 and contacts 24-and 25 130 ground."
ever, close any circuit through the regiswill send out a series of open pulses corresponding to the code number characteristic of that particular box. These open pulses cause relay 8 to release, thus closing the register circuit for each open pulse and" tape Whichwfll be understood tobe issued by the register 9.
The register circuit may" be tracedjfron'rl battery through resistance 12, contact springs 28 and 27 ofthe"key-svviteh,-backcontact and armature33 of, relay 8 and thence to the register, 9 Whichis grounded. YIf the line is" accidentally. opened; as shown at E on loop"B a' continuous mark will thenibe recorded. by the. register 9 7 owing to the release'io relay '8. To over- V circuit is grounded.
position 3. 25v
come this" condition thet operator at the register. station places the switch key in The operation of the enema B win that fbefas follows:- No current fiowstffroni; bat
tery 11 ,eXceptWhen sending a signal and when the teeth 1710f the code Wheel '15 are traversed 5 by the grounded contact 19.
The circuit then established for each signal ling pulse-may be traced iroin battery ll through springs 26and 24 of the key switch to the connecting "point 31 between the two windings of.relay..8, through onefof said windings or the other according to thewlo cation of the. break E withrespectl to the box; from which the call is beingfniadei thence. the current 'ffiows either through loop terminalR tocallboX 5 or through ter}: minal T to one of the boxes :4, thecalling Belay 8,'thelfefbre, pulls up iits 33' for each. signalling. pulse. The register 9 now.re sponds .to the closure of the a'rina ture; 33 and front contact .34 of relay 8,: sincethekey-switch contacts 28 and 29 are closed together. v V p F or "the condition of ground as indicated at F on loop C,- the coils of reh yf8 have to be. differentially connected as shown and these windings have equal resistance and anequal number of turns.v
' To meet this .lcondition the key-snitch is placed, in position?) and, current flows from" battery. 11. through resistance 13, contacts 26 and 24,. through both Windings'oir relay 8,111 opposition (causingthef relay to bet ile-energized) .and thence through both legs of the loop circuit C to ground F; In pass? ing to leg It; current flowsfrom relay coil 3l,32, through key-switch contacts 22 and Assuming noW that (me or at seem a on loop 0 makes a call, then'thecode signal box in any case b'eingtheflpoint Where the will be transmitted in the form of open impulses on the leg T of the loop C. This willtle-enei'gize coil 30-31 of relay 8, while I p v V other side of the ground? should call, then recording the code number on the register the signals would be received" over the leg R of loop C and relayS Would operate from the continuance of current flow in. coil "30- 3l ,*-;While coi1"31-32 dehnergized at each slgnalhng pulse.
"The fourth condition Which is provided rel-1st breaklG and aground 'H, as shown in. loop DQ', This fault iscorreetedby placing the key switch n posit on 2,. whercat the operatioiifof the circuit is as follows Before zrcall is" made, current will now:
through stations 4 of this loop to ground.
Tlhe open circuit at 'fGf fde en'ergizes the opposing winding 31 32 andhence the armature. 33 1S, normally pulled'up. Slnce con-.
tacts 28and 29fia're open for position 2 of the key-switch; no current can pass to: the 9 while therelay 8 1'61113111561101 register glzed.
otfthefstations'l on loop D; heopen iin pulses .will de energize coil 31 30, of relay 8, causing its armature 33 to makew th its back contactflfi,- thereby operating the reg ister 9. Iffa callis initiated from boX. 7 which is on theR-side of the break G, then the ground impulses resulting from the rotation of code; wheel 15 will cause cur-rent to energize coi-l 31.32 in opposition to thepre v ously energizedfeoil 81 30. Each impulse gwill, therefore; cause the relay to release,
operating the register-. 9 whenns armature makes-With the backcontact.
arrangement of the line relay and key switch will be explained,v n1 tlllS-lllbQtlh ment of the invention itis not necessary for the relay winding to be tapped at the middle, but instead, two equal rcsistOrsSS and 89 are provided and the r connections through the key-switch are such that they; niay be bridged across betweenthe-terminals of the relay winding,.while the inidpointbetween the two resistorsisj connected to the battery 11- through the resistance 13.
' Relay 41 operates in the following manner Assume n w that a call is made from one ';Refer;1'i1 1g now to Fig.3,an alternative under the four conditions indicated by the 2 loop circuitsA, B, O and D re speetivelyz Thenormally closed circuit represented by loop isproyided Whenthekey switch is i set iniposition 1. Current flows from battery ll throughresistances 13 and 39, loop terminals Rif -R, thence through the call boxes 4 to loop terminals T whichfare and 29 as in Fig. 1,-and'it-.will be recalled that these springs supply current from battery 10 eitherto thefront contact 34 or to the back contact 35, according as it is required that the register shall record signals when the line relay energizes or de-energizes.
In signalling as onloop A,.-with switch-key lay 4 1 releases. 1 I
,To meet the cond'tions that may exist either on loop B ,}o'1 loop. :C, thekeyswitch is placed in position 3. If the circuit is accidentally opened as YatE then the potential at the two terminals of the relay winding is normally equalized by the equal resistances 38 and 39, and no current will flow until a signal is initiated at one of the call boxes, say box 5. Thereat the grounding of the loop on the side ofthe terminal R,
in position 1,'--the register operateswhen rewhen the code wheel teeth 17 are traversed of loop B to call box 5 where the code signal respond equally well to a call originated at one of the stations 4 on loop B, but current will flow through coil 40 in the opposite 'di rection to that caused by call from box 5.
is originated. Current will also be bypassed through resistance 39, butnevertheless the drop of potential through coil 40 will besuflicient to operaterelay 41in response to the signals. The relay .41 will If the circuit is accidentally grounded as at F. on loop C, current will normally flow about equally. through the two legs R and T of the loop C. Hence the drop of potential throughrelay winding 40 will be negligible until a call is made. When a-call originatesat one of the boxes 4, the, opening of the circuit by means of thecode wheel 14 at that box willremove ground from leg T of loop C- and hence the potential drop in resistance 38 will be diminished and a cur:
rent flow through coil 40 will be setup, ex-
tending through leg R to the groundedpoint.
balanced potential across .its winding 40 when each signal ceases.
It is obvious that a signal originating 'at one of the call boxes 6 on loop C would like- J wise actuate relay 41 except that the drop of potential through its winding 40 "would be in the opposite direction to that just described. The fourth condition of an: open, G, and
ground, H, as represented by loop D is taken care :of by placing the key-switch in position 2. Current normally flows from battery ill-through resistances 136116.39, contacts 46 and-44, relay winding 40, and terminals T-T to the grounded point H, thus energizing the-relay. Current is also by-passed through resistance 38. but this .has no effect until a call is originated, say at one of the boxes 4. The opening of the circuit on the T side of loop D causes the potential to be equalized across the winding 40 so that the relay 41 is deenergized in response to the breaking ofthe circuit for each signal from thecalling box '4.
Thepotentialacross the winding 40 is also equalized but with current flowing when signals are transmitted from call box-7. In this case the code Wheel 15 at call box 7 putsground 'on the B" side of loop D, so
that current flows equally through, resistance 39 tothe groundedcontact '19 and through resistance 38 to the accidental ground H. V
The relay 41 at this time de-energizes in response to each signal.
The operation of the register 9 in each of the four cases described in reference to Fig. 3 will be understood from the description applying to Fig. 1. 1 i
It will likewise be understood from an examination of the drawing and the accompanying description that whenever the switch key is positioned to take care of one condition of the loop circuit, as abreak condition, and another condition of the loop then occurs, as a combination break and groundrcondition, the register 9 is arranged to mark continuously in response to the changed condition until the key has been properly positioned.
What is claimed is: I I
1. Ina signalling-system, the combination of a loop interconnecting a plurality of calling devices each provided with means for grounding and then opening a point on said loop, a relay and a register controlled to the release of said relay, said switching,
means; being operable when an accidental break occurs in said loop to connect each leg Thus the relay .will be energized in reof said loop through equal resistances to. a
grounded source of" potential, to condition said, register to respond to the operation of. said relay, and to connectsaid relay 1n shunt across said loop whereby sald relay is operated upon each grounding of the leg on one ans 1 f the. operation of any calling-device therein,- and .condltloning said register to :respond to the release of s'aidarelay, said switching means being operable *when an accidental grounding of both legs of said loop occurs to connect each leg thronghequalresistances to agrounded source of potential', tocondi tion said register to respond'to theso'peration,
of said relay, and to connect-said relay in shunt across saidrloop whereby said relay is operated .upon each opening of the leg ,on one side of said'ground by the operation of any calling device included insaid leg.
c In a signalling systennthe combination of a loop interconnectinga plurality of call- L ing :deviceseach provided'with means for grounding and then opening a point on said loop, a relay and a 'rcgistercontrolled there by, and switching means normally connecting said relay :and'saidloop in a closed series circuit, whereby said'relay is de-energizableuponeach opening of said loop by the operation of any. calling device therein,
( and conditioning said register to respond to the release of said relay, said switching means being operable when'a break'in said loop'occurs and the leg on one side of the break is grounded to connect each leg of said loop through equal resistances to a grounded source :of potential, to condition said register to respondto the de-energization of said relay, and to connect said relayin shunt across said loop whereby said relay is de-energizedfupon each it grounding of the ungrounded le'g by the; operation of-any calling device therein and is also Lie-energized upon each opening of thergrounded' leg by the operation ofany calling device in said i) i [ALLISON A. oLoKEY.