US2518174A - Automatic alarm system - Google Patents

Description

Aug. 8, 1950 Filed Jan. 7, 1948 A. s. H. PICKING ET AL 2,518,174

AUTOMATIC ALARM SYSTEM 2 Sheets-Sheet 1 IN VEN TUE-5 P .5.14. PICK/N6 AMD H. eoawsv 1950 A. s. H. PICKING ET AL 2,518,174

AUTOMATIC ALARM SYSTEM Filed Jan. 7, 1948 2 Sheets-Sheet 2 INVENTUES 4.5.14 PICK/N6 AND /-/.2oa-5Y Patented Aug. 8, 1950 AUTOMATIC ALARM SYSTEM 1 Alfred'Samuel Horace Picking, London, England, and Ian Harold Rooney,v Melbourne, Victoria,

- Australia Application January '7, 1948, Serial No.1,030 In Great Britain March 15, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires March 15, 1965 r initial alarm signal and the object of the invention is to .provide apparatus for putting through a telephone cailjon receipt of an alarm signal so as to call the police, fire-brigade or other authority or assistanceas maybe required.

In its broadest aspect the invention consistsvin an automatic alarm system for use in conjunction with a dialling telephone set for the purpose of dialling a predetermined telephonenumber and sending a warning signal, wherein an initiating alarm signal is arranged to cause a rotating .switch device to be set in operation, said rotating switch device essentially comprising a plurality of rotating discs and a contact member progressively translated so as consecutively to co-operate I with the peripheries of said discs, such peripheries being chosen to have conducting and non-conducting parts whereby each disc may make electrical connection with'said translatable contact over a pre-determined angular travel of the disc 7 ,to allow intermittent completion through the switch device of a circuit that includes an electro- ,magnetic means which, when energised, causes a member to engage a finger hole in a telephone set dial, and which itself rotates synchronously with theswitch device so as to be capable of carrying out predetermined dialling operations, said switch device being such that when thepre-determined dialling operation is completeda sound producer is then brought into operation thereby,

to provide an audible signalfor transmission by the telephone transmitter ofthe telephone set.

v Fig. 1 is a sectional .layout of an'apparatus in accordance with the invention, the drawing being diagrammatic,

Fig. 2 is an electrical circuitdiagram, I r Fig. 3 is a view of a normal telephone dial,

v I Fig. 4 is a sectionaldetail, and

' Fig.5 shows in side and'end elevation adetail .ofa modification, the drawing being mainly. diagrammatic.

The apparatus shownin Fig. 1: essentially consists of abed plate I, supporting brackets 2 and 3. The latter have bearings 4 and 5 for the support .of ashait 6 to permit the same to be turned about its axis.' An electric motor I is-also mounted on the bed I, andthrough a reduction gear 8 drives ;a-gear-wheel 9' fastfupon the shaft li. Walls .ll) l l. aresecured tothe-Joed'i and form partof an enclosing casing there. being also an upp,er

7 Claims. (Cl. 179-5) ratchet wheel 39, and anadditional pawl lid-like wall I2. The end wall Ill has a circular aperture I3 normally masked by a disc I4 secured as by a bolt [5 to one extremity of the shaft 6. A solenoid winding I6 is secured to the disc l4 and has a movable core I! provided with a finger I8. The core I! rides upon a stub-shaft I9 which is secured as, by screw-threading in an arm 20 formed integral with a boss 2! fixed upon the shaft 6. A helical spring v22 atone end presses upon a rim formed upon the exterior of the core I! and at the other end reacts upon the casing of the solenoidwinding l6, so that the core I is normally pressed towards an outer position with respect to the solenoid winding in the manner shown in Fig. '1 of the drawings. In the outer position of the core I] it will be noticed that the finger 18 projects through the disc l4 and through the circular aperture l3. In a manner which will be explained hereafter, the finger I8 is intended to co-operate with the dial 23 of atelephones'et generally indicated at 24. The set 24 is ot er mal kind and has-a rest 25 which normally'supports the receiver-microphoneof theinstrument. The rest .25 is associated with the normal; switch element 26, and the end'panel lli'isformedwith an aperture 21 which allows the telephone set,2'4 to be held in the position indicated in Fig. relation to the apparatus of the invention. ji

The bracket 3 is extended at its upperpart to form an anchorage 28 forone end of a rod 29 the other end of which is secured in the end plate ll of the casing. A carriage 30 slides upon the rod 29 and possesses an inclined abutment 3 I adapted to engage with the end of a lever 32lpivoted as "at 33. The lever 32' is formedwith a cranked end 34 which is adapted to engage the switch element 26 of the telephone set 24. A spring 35 tends to hold the carriage 3!! always in the position shown in Fig. 1 and resists the movement of the carriage in its travel towards the left. The carriag-e'30 is formed With a series of indentations or gaps 36 forming a rack which "co-operates with thejteeth of a gear wheel 31. The latter is carried upona shaft 38 on which there is also fixed a ratchet wheel 39. A pawl 40 engages the ratchet teeth upon the wheel 39 and is pivotally carriednpo'n a rod 4| spring loaded to engage with a steep snail .cam, 43 (see Fig. .4) mounted rigidly upon the shaft 6. A torsion spring 44 ensures that the pawl 40, remains in engagement with the teeth of the checks any undesired rotation of the ratchet wheel as.

The carriage 30 supports a w-wiping .contacti,. i6 adapted to cooperate-withgthe peripheriesf of winding 16.

.55 there is a switch 51.

discs 57. It will be observed that there are seven of the discs 4? and they are all mounted against one another upon the shaft 6. The shaft is conveniently formed with a square section so as to locate the discs 4'! in a fixed angular relation to one another and to the shaft. The discs are all formed of an electrically conducting material, but peripherally each possesses a portionwhich is non-conducting. In the illustration of Fig. 4, a typical disc 4'! is seen, and it will be observed that a portion 48 of the periphery thereof is formed from a non-conducting material, such portion 48 extending over an arc of approximately 90 degrees. There is also mounted upon the shaft 3 a slip-ring 49 insulated from its surroundings, but engaged by a brush Eli which establishes electrical connection with the ring 49 when the latter is rotating with the shaft 6. The shaft 3 is hollow and one end of the solenoid winding :6 is con .nected by an insulated conductor which runs 53 rides upon one of the discs so as to provide an electrical connection with all three of them.

-It will now be. useful to consider the electrical circuit diagram of Fig. 2 and from this diagram it. will be observed that there is a source of electro-motive force 54 at one side connected with the contact 46. The other side of the source isconnected with the brush .50 which co-operates with the slip-ring 49 that is permanently connected with one end of the solenoid winding It. The other end of the solenoid winding connects with all the discs 41. In Figure 2 the contact 4B,.is shown as co operating with the first disc 4? and when the contact. 46 embraces a conducting ortion of the periphery of the disc 41, then a circuit will be completed through the solenoid With a circuit completed between the winding l6 and the source of electro-motive force, 54, the core I! will be. drawn into the solenoid winding [3.

- The electric motor I is connected by means of leads 55. and 56 with the source 54 and in the lead When the switch 51 is closed it will be obvious that the motor I will :be

supplied with power and will operate. The discs device of some known kind, which willmechani cally, or through the agency of electric relays, serve to close the switch 51. When the switch 57. is initially closed, the apparatus of the invention is in the position shown in Fig. 1 and the contact .46 does not engage the periphery of any of the discs 41 o 52. The closing of the switch 51 therefore initially completes a circuit only through, the motor I and the latter begins to drive the shaft 6 through the intermediary of the indicated in Fig. 4.

reduction gear box 8 and the gear wheel 9. As the shaft 6 revolves, the cam 43 thereon causes the member 4! to be vertically reciprocated. In each revolution" of the shaft b, the member 4| makes one vertical reciprocation and this causes the pawl 40 to rotate the ratchet wheel 39 sharply through one tooth pitch. This corresponds to an angular displacement of the gear-wheel 31 through one tooth pitch and hence the carriage 30 is translated to'the left (as seen in Fig. 1) by an equivalent amount. The showing of the gear wheel 31, as also the ratchet 39 in Fig. 1, is diagrammatic only in the sense that the number of teeth thereon will have to be determined b the desired operation of the apparatus as described hereafter. There is a gap in the teeth upon the wheel 31, which gap is opposite the series of teeth in thecarriage 30 formed by the indentations 36, so that during the initial revolution of the shaft 6 the gear wheel 31 may not necessarily engage the rack formed in the carriage. As soon as the wheel 31 does. engage the rack it begins to translate the carriage to the left so that the abutment 3] moves away from the end of the lever 32 with which it is in contact. To ensure that this contact is normally maintained, a spring is provided. Under the action of this spring the lever 32 swings about its pivot 33 and thereby allows the cranked end 34 to lift so that the switch element 26 of the telephone set is raised. This brings the telephone set. to the position normal for dialing to obtain a desired number. As the shaft 6 continues to rotate the contact 46 is brought into engagement with the peripheryof the first disc 41. It remains in contact therewith during a complete (or almost complete) revolution of the disc 41 and it is, for the purposes of illustration, assumed that this disc 4'! is that Thus over the arc 43 the contact 45 will not be in effective electrical connection with the disc 41, but will be so connected over the remainder of the periphery of the disc. In Fig. 3 a normal telephone dial is illustrated, and it will be supposed that such dial hasa centre 0. If it is desired to dial the number 8 then it will be appreciated that the dial must be turned through the angle BOA, where Bindicates the normal position of the finger hole in the dial corresponding to the digit 8; whilst A. indicates the limit position to which one of the dial holes may be turned during a dialling operation. It is of course the major arc BOA which comes into question. The disc 47 shown in Fig. 4 is so arranged that when the finger I8 is opposite the dial hole corresponding to the digit "'8, the contact 45 begins to cooperate with the conducting portion of the disc 41. Such co-operation will at once energise the solenoid winding I6 whereupon the finger 13 will be thrust forward into the dcsired dial hole. The solenoid and finger will then continue torotate with the finger in the selected dial hole until the position corresponding to that indicated at A. in Fig. 3 is reached, whereupon the contact 46 will once more encounter the insulated portion 48 of the disc 41 whereupon discs-ass peripherydesig ed to select by means of "the. Solenoid finger l8 a further dialjhole on th dial 23 in the samemanner as describedin nection with the first disc .41. In the illustratedfexample itih'a's been supposed that seven discs" 41 will be. necessary to securea complete dialling of the telephone, and thearrangement maybe" suchthat the first three discs'selectthe characteristic three letters of anexchange whilst the next four discs select theicharacteristic numbeiswhich' are: associated with the subscriber that it is desired to call with the aid of the telephone set 24. After the contact 46 has co-operated with all .the discs 41 the carriage 30 is further translated tothe left to .bring the contact into co-operation with the first of the discs 52. At this time thedialling is'complete and the subscriber who has been called would have answered ashes-11a. Thecontinued revolution of the discs 52 will cause the contact 46 to make consecutive engagement therewith and the sound producer 58 may, be impulsed by temporary completion of thecircuit therethrough corresponding to the co- 'operation; with the three discs52. Thus the sound producer 58 might for' eirample take the former an electric bell. orbuzzer which willprodupe in Morse a signal depending upon. the arrangement of the discs 52. In Fig. there is shown an alternative arrangement of these discs in which they are replaced by three discs 10, II and 12 made each of a difierent diameter and co-operating with wiping contacts 13, 14 and 15 which are in permanent co-operation with the discs. All the contacts 13, 14 and 15 are joined to a single conducting strip 16 and it is intended that in the final travel of the wiping contact 46' the latter should be continuously in engagement with the stationary strip 16. There are conducting inserts 11 upon the peripheries of the discs 10, H and 12 which will account for transmission of a given code signal from the sound producer 58.

Other forms of warning device may be employed and are within the scope of the invention. Thus for example the discs 52 or the. discs 10, H and .12 may be wholly replaced b a conducting cylinder which will remain in continuous co-operation with the contact 46, and the sound producer 58 may then be in the form of a phonograph which will produce a pre-determined audible message so long as it is energised.

When the carriage 30 has .been translated to the position where the contact 46 has co-operated with the last disc 52 (or other equivalent arrangement) the gear-wheel 31 is once more in the position shown in Fig. 1 where the blank in its teeth is opposite the rack formed in the carriage 30. As a result the carriage 30 is free to resume its inoperative position under the action of the spring 35 and the whole apparatus is re-set. Thereafter if the switch 51 still remains in the closed position the cycle described will once more be followed and the dialling operation will commence afresh. This ensures that if the first warning signal is not answered by the subscriber to whom it is to be addressed, then the subscriber will be called afresh.

It must once more be emphasised that the illustration of Fig. 1 is wholly diagrammatic in the sense that the gear wheel 31 must clearly have more teeth than indicated thereon. For convenience in drawing and clarity of reproduction, the teeth upon the gear-wheel 31 have been shown as enlarged beyond the size which they would normally appear. In like manner the degree of travel apparently permitted in Fig. l to the car- 8, ri a;gj'e"3ll wouldlclearly be i'risufiicient, since the abutment would contact the casing before the traveljof thecarr'iage is complete. It may also be remarked that seven discs" 41 have been shown in Fig 1 as also injFig. 4, butthe number of discs employed inpractice will clearly depend uponthe number of individual dialling movements that must be inadein order to obtain a'desired subscriber with the telephone set. The employment of anfelectric motor 1 represents a desirabl feature, but a clockwork mechanism could of course be substituted therefor. In this 'case'the switch 51 would be replaced by an equivalent mechanical arrangement capable of releasing thelclockwork for operation when an alarm signal isto be trans;- mitted. .Alt'ernatively, instead of clockwork, grayity driven mechanism could be employed.

, '.Ihe,.audible soundeprodu'cer may advantagefously be arranged to transmitindicati'ons ofthe place and/ornature of the alarm messagewhich is-tohe sent tothe subscriber. I

1. An automatic alarm system foruse in conjunction withv a dialling telephone set for the purpose of dialling a predetermined telephone number and. sendinga warning signal,,,compris'- ing a member arranged to perform axialmovements, a support for said member such SuDDOrt being disposed for rotation about an axis set'substantially in continuation of the axis of rotation of the telephone dial, electro-magnetic means disposed to effect, on energisation, axial movement of said member in order that the member should engage a finger hole of the telephone dial, means for rotationally driving said support, a device for initiating a simple alarm signal, such device serving to bring into operation said means for rotationally driving said support when the device initiates an alarm signal, a rotating switch driven from said means for rotationally driving said support and having a plurality of co-axial rotating discs, a contact member associated with said discs and disposed for translational movements thereby to consecutively co-operate with the peripheries of said discs, electrically conducting and non-conducting parts disposed about the peripheries of said discs, a pair of electrical supply terminals, electrical connections as between a number of said conducting parts and said contact member, this number corresponding to the number of integers in the predetermined telephone number, said electrical connections including in series the electro-magnetic means and said terminals, an electrical sound producing device disposed in the vicinity of the microphone of the associated telephone to produce audible sounds for transmission by said telephone, and further electrical connections as between at least one of the remaining said conducting parts and said contact member, this remaining conducting part being one which is disposed for co-operation with said contact member after co-operation between the latter and said member of conducting parts has taken place, said further electrical connections including in series said terminals and said sound producing device.

2. A system according to claim 1, and further comprising a translationally displaceable carriage for said contact member, a support for the carriage and means operable from the movement of the rotating switch to cause the translation of said carriage.

3. A system as claimed in claim 2 and further comprising reciprocating mechanism driven in common with the rotating switch to produce eeo pr-oca ons durin the rotati n of. hetltotating switch device, a pawl disposed to exper nce said reciprocations, ratchet mechanism for cooperation with said pawlto produce a rotational movement, a. toothed Wheel connected to follow said rotational movement, and a rack, bar attac-hed to said carriage and disposed for cQ-operation with said toothed wheel to produce thetranslational movement of the carriage.

l, A system according to claim 1, and further compr si a co trol member for con ac n he switch element of the standard telephone set, and. means for releasing said control member to close: said switch element, said means, being brought. into. operation y the initial r tatin movement of, the rotat n sw tch. device.

5. A system according to claim 4, inwhich said control member takes the form of a lever pivoted as between its ends and disposed with one end for engagement with the switcl element 01 '1- A sy cma oordih l' o c1ain1,. n which see eraladditional discs are providedin the rotating switch, su h ys em furth r QmR Ii'SingT 533 6 wiping contacts one in respect of each additional disco, a strip. effectively e oc r c lly'c nec ine al s d. wip n contacts, th st p b d spos for encountering by said contact member after co-operation between said contact member and said number of conducting parts hastaken Place; and additional electrical connections as between the additiona1 discs and said contact member,

said additional electrical connections including,

in series the electrical supply terminals, and said sonnclprod cing device. ALFRED SAMUEL HORACE PICKING. AN H OLD RO NE REFERENCES CITED The following references are of. record inthe file of this patent: l

UNITED STATES PATENTS

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