US2035358A - Telemetric system and mechanism for use therewith - Google Patents

Description

Mal-ch24, 1936. P. YATES 2,035,358

TELEMETRIC vSYSTEM AND MECHANISM FOR USE THEREWITH .Filed May 12, 1952 5 Sheets-Sheet l INVENTOR 55a Papal Ydteis Mmh 24,1936. YATES 2,035,358

TELEMETRIC SYSTEM AND MECHANISM FOR USE THEREWITH Filed May 12, 1932 5 Sheets-Sheet 2 INVENTOR P ul Yates 5530 0? B a Y 43 m'ro nwws March-24,1936. Q P. YATES 7 2,035,358

TELEMETRIC SYSTEM AND MECHANISM FOR USE THEREWITH Filed May 12,- 1932 5 Sheets-Sheet '5 MOTOR CONTROL JACK INVENTOR Ikzul m s Q ATI'ORNE Marchz l, 1936. YATES 2,035,358

TELEMETRIC SYSTEM AND MECHANISM FOR USE THEREWITH INVENTOR ml YZzJ/es 24,1936- P. YATES 2 2,035,358

TELEMETRIC SYSTEM AND MECHANISM FOR USE THEREWITH Filed May 12, 1932 5 Sheets-Sheet 5 v r 14 l 147 W V '3 VHIIV PLATE CURRENT nAlAAA GRID VOLTAGE INVENTOR Paul m5 Patented Mar. 24, 1936 UNITED STATES PATENT oFFicE TELEMETRIO SYSTEM AND MECHANISM FOR USE THEREWITH Pennsylvania Application May 12, 1932, Serial No. 610,883

11 Claims.

This invention relates to the method of and apparatus for reading indications of meters or other devices at a distance.

One of the objects of the invention is the provision of a method of and apparatus for reading meters at a distance by using telephone circuits in conjunction with local transmitting equipment and suitable receiving equipment at a distant location.

Another object is the provision of a system of control whereby signals indicating the readings of meters and the like can be transmitted over standard telephone circuits, whether manually or automatically operated, without either affecting the operation of the automatic telephone equipment, or giving undesired signals to the telephone operator in the exchange, or otherwise interfering with normal operation of the telephone system.

Another object is the provision of a system and apparatus for indicating the reading of numerous meters at a distance from the meters through one set of transmitting equipment.

Another object is the provision of means for reading meters at a distance which is simple in operation, relatively rapid, and relatively inexpensive when compared with previously proposed systems.

Another object is the provision of means for reading meters at a distance which does not interfere with the operation of the meter mechanism or require modification of standard meter mechanisms.

Other objects will be apparent to those skilled in the art to which this invention ap-pertains.

In the accompanying drawings,

Figure 1 shows a general plan of the elements of a system for reading three meters in accordance with this invention and transmitting to the telephone circuit the corresponding impulses;

Fig. 2 is a vertical front view, with parts broken away, of a selective reading mechanism designed to be attached to a standard watt-hour meter;

Fig. 3 is a side elevational View, with parts broken away and in section, of the structure shown in Fig. 2;

Fig. 4 is an enlarged front view of the contact or jumper mechanism attached to each indicating shaft in place of the indicating hand ordinarily used;

Fig. 5 is an enlarged section of a contact or reading dial taken along the line 55 of Fig. 6, showing a contact dial in operative relationship with the selector mechanism shown in Fig. 4;

Fig. 6 is an enlarged back view taken from the meter side of the reading mechanism showing the meter side of the contact dial;

Fig. 7 is a plan view of an electrical contact spider forming part of the face of the dial shown in Fig. 6, before bonding of the anchor lugs into 5 their final positions;

Fig. 8 is a side view of the contact spider shown in Fig. '7;

Fig. 9 is a plan view of the mechanism of the transmitter;

Fig. 9a is an enlarged section of a portion of a contact segment of the transmitter shown in Fig. 9 taken on the line indicated at Sat-9a in Fig. 9;

Fig. 10 is a side elevation of the transmitting 15 mechanism showing the means for operating the control jacks used in the transmitter;

Fig. 11 is a plan view of the control jack mechanism; g

Fig. 12 is a vertical section through the mag- 20 netic brake used with the driving motor of the transmitter taken on the line indicated at l2l2 of Fig. 9;

Fig. 13 shows the control jack for energizing the circuit for the driving motor of the trans- 25 mitter and the cam mechanism that controls its operation;

Fig. 14 is a wiring diagram of the apparatus shown in the preceding figures;

Fig. 15 shows a portion of a modified form of transmitter illustrating an additional camshaft and jack system, whereby a number of groups of three meters each can be read successively by the same transmitter;

Fig. 16 is a wiring diagram of the meter selecting circuits used in connection with the transmitter shown in Fig. 15;

Fig. 17 is a wiring diagram showing the elements of the transmitter and showing a receiving equipment suitable for receiving the signals sent out by the transmitting equipment;

Fig. 18 is a graph showing the method of operation of the vacuum tube used in Fig. 17 as part of the receiving equipment;

Fig. 19 is a diagrammatic showing of a circuit and oscillator, for inducing any desired audible frequency into the signal circuit;

Fig. 20 is a fragmentary view of a part of the oscillator shown in section and illustrating a mechanism for producing the audible oscillations.

Referring particularly to Fig. 1 of the drawings, an electric meter I, a gas meter 2, and a water meter 3 are shown connected to a transmittter 4 that is arranged to transmit suitable electrical impulses to a conventional telephone system indicated generally by the telephone box 5. A control box 6 serves to control the operation of the system and its connection to the telephone lines. Suitable multiple cables II, I2, and I3 respectively, connect the three meters to the transmitter 4. The transmitter is connected to the control box 6 and the telephone box 5 by suitable multiple cables Ill and IUa. Although three meters are shown in this drawing, later reference to Figs. 15 and 16 of the drawings will show .an application of the principles of the invention to the reading of any reasonable number of meters from one transmitter. The meters, for example, in a large office or apartment building may be read by simple duplication of the apparatus hereinafter disclosed. This apparatus is located at the residence of the subscriber. A wiring diagram for the equipment at the power station for receiving the impulses transmitted by the apparatus shown in Fig. 1 is shown in Fig. 17 and Fig. 18.

Figs. 2 to 8 show a meter reading attachment arranged for mounting on a standard watt-hour electric meter. This consists of a supporting case I adapted to be substituted for the glass cover conventionally used on these meters. The case 1 has a cylindrical housing 8 which serves to support a meter selecting solenoid 9. Secured to the bottom of the casing I is a frame I4 which has spaced vertically projecting lugs I5 which pivotally support a bell crank lever arm I8 by means of adjustable pivot screws I6. The frame I4 also has a vertical yoke I! that carries an adjustable stop screw 2| and a horizontal yoke 23 that serves as an anchor for one end of a tension spring 24. The remaining end of the tension spring 24 is attached to the bell crank lever I8 to hold the pivoted bell crank lever I8 away from the meter face, as shown in dotted outline 20, when the meter selecting solenoid 9 is not energized.

One arm of the bell crank lever I8 carries an armature I9 at the extremity of one arm that cooperates with the meter selecting solenoid 9 to draw the meter reading mechanism carried by the other arm of the bell crank lever I8 into operative relation with the meter face when the solenoid 9 is energized as indicated in full line in the drawings. The upper end of the lever I8 is forked and carries a vertical contact carrying plate 22 made of an insulating material such as bakelite. In this particular structure the contact carrying plate is segmental in shape and of sufficient size to cover all of the indicating dials of the meter. The plate 22 carries four contact dials 25, shown in more detail in Figs. 5, 6, 7, and. 8, whose centers are oppositethe centers of the four indicating spindles of the meter. Each of the contact dials 25 consists of ten separately insulated contact elements 25 on the inner or meter side of the plate 22 and corresponding in position to the numerals of the dial opposite which they are placed. Each contact element 26 has a projecting lug 3| that extends through the plate 22 to form a connection terminal 32 and an anchor lug 3 I a that serves to anchor the contact element in place on the plate 22. Suitable wires from the multiple cable I I are brought up along the lever arm I8 as shown particularly in Figs. 2, 3, and 5, and separately distributed to their respective connecting terminals 32 on the dial contact carrying plate 22 in the manner shown in Fig. 14.

Overlying the adjacent edges of the contact elements 26 and insulated from them by an insulating spider 39 of corresponding shape, is a. contact spider 21 consisting of a ring portion 28 and radial projections .29. Each of the projections 29 has a knife edge on the inner or meter side terminating in a base element that covers the interval between adjacent contact elements 26. The insulating spider 30 directly underlies the contact spider 21 and is disposed between the spider 21 and the edges of the contact elements 26. The contact spider 21 has a set of three lugs 33a. projecting through the plate 22 for anchoring the spider in place. Each contact spider 21 also has a terminal member 33 extending through the plate 22 for electrically connecting the spider to a suitable bus that is also carried in the multiple cable II. One of the lugs 33a may be used for electrically connecting the spider if such is desired.

The conventional indicating hands of the meter I are removed and an indicating contact member or jumper 38, shown particularly in Figs. 4 and 5, is substituted. The jumper 38 consists of two electrically connected contact members 34 and 35 that are of diiferent radial length and are flexibly mounted on an insulator 34a that is carried by the dial spindle. The flexible mounting and the electrical connection for the contact members 34 and 35 are provided by the coil springs 36 and 31 that carry the contact members and form the arms of the jumper 38. The contact member 34 extends a sufficient radial distance from the indicating spindle of the meter to contact with one of the contact elements 26. The contact element 34 is wedge shaped or pointed at its outer end so that it will be guided into contact with the associated contact element 26 by the tapered face of the corresponding radial arm 29 of the spider 21. The contact member 35 extends a sufiicient radial distance from the meter spindle to contact with the ring 28 of the contact spider 21. When the lever I8 is in the position 20 neither of the contact members 34 or 35 is in engagement with the contact dial 25, but when the magnet 9 is energized, the bell crank assumes the position shown in solid line, and electrical contact is then made between one of the contact elements 26 and the contact spider 2'! of each dial 25. The knife edges of the radial projections 29 insure that each of the contact members 34 of the jumpers 38 will contact decisively with one or another of the contact elements 26 and not bridge two adjacent contact elements 26. In this way, when the magnet 9 is energized, a connection corresponding to the position of the jumper 38 is made between the contact spider 2i and the corresponding contact element 26 for each dial. How this connection is used to signal the position will be later shown.

It is obvious that the supporting case I and the arrangement of the dials 25 on the plate 22 may readily be adapted to fit the casing and dials of the gas meter 2, the water meter 3, or any other meter or dial instrument whose readings are to be transmitted over the proposed equipment.

The'selecting and transmitting mechanism 4 is shown in detail and on a larger scale in Figs. 9 to 13, illustrating its use for the reading of a set of three meters. Referring to these figures, 39 is a synchronous motor of a self-starting type, similar, for example, to motors used extensively in electric clock movements. On its shaft is a pinion 40 that drives a gear 4| carried on a vertical shaft 42. The shaft 42 is journalled in the frame 43 and projects through the top of the frame. The upper end of the shaft 42 carries an arm 44 having at its extremity a rotary wiping contact finger 45. Secured to the upper member aosaerse of the frame 43- is an insulating dial 46. Metallic; contact segments 5l to 60' respectively, having one to ten circuit-making contact projections. 41 thereon, are arranged in order about. the'periphe cry of the insulating dial 46' in the order of their number counterclockwise. These con-tact. segments collectively occupy about five-sixths of the circumference of the dial 46.

Upon the rotation of shaft 42 the contact finger 45 that is carried thereby successively makes, contact with the-segments 5| to 60. in the order of their number. The contact segment 5| has. a single contact making projection 41 extending above its surface. This projection, which may be in the form of a tongue struck up from the body of the segment as shown in Fig. 9a extends: high enough so that the contact. finger 45?, upon rotationof the shaft 42, will contact with the pro.- jecti'on A? when it passes over, but will not contact. with the remainder of the segment. The segment 52 has two such projections 41, and accordingly, when the contact finger 45 passes over it two contacts will be made. The contactv segment 53 has three such projections, and so on, increasing in steps of one. until the contact segment 60 is reached, which has ten such projections 41. The driving member 48- of a Geneva motion mechanism is also carried by the shaft 42, the driven member 48 serving to periodically actuate a cam shaft 50.. The driven member 49. has four stations arranged at 90 intervals about it, and the driven cam shaft 50, which, is made of a non-conducting material, has four contact.- controlling cams 6I1 disposed at 90 intervals about the cam shaft 50 and offset. longitudinallyalong the shaft 50. The cams 6! are each so. positioned on the shaft 50 with respect. to. thedriven member 49 that, for each of the. four stations of the driven member 49, one of the cams. 6| actuates one of the jacks 62 to 65, whose fingers preferably are arranged in a vertical line parallel to the shaft 56. and at a short distance from it. The cams 6| respectively actuate in succession the jacks 62, 63, 64, and 65. in the order in which they are numbered as the driven member 49 occupies its four successive stations. The series of jacks 62 to 65 provides successive circuit connections between the dial indicators for each particular meter. I

The driving member 66 of a similar Geneva motion is mounted on the shaft 50, the driven member 61 of which actuates a camshaft 6-8.. For each complete rotation of cam shaft 50, the cam shaft 68 is advanced one station. The camshaft 58 has three stations in the device here illustrated, in order to successively connect meters l, 2, and 3 in circuit with the transmitter 4., This Geneva movement for driving the shaft 68 has. three stations at intervals of 120. On the shaft 68 are four cams, the upper cam 69, shown more clearly in Fig. 13, being continuous except for a narrow interrupted portion of its; circumference. Three lower cams 16; are also disposed at 120 intervals about the circumference of the shaft 68, at different positions along its axis. The cam 69 operates a motor energizing jack; H. Thisjack H is immediately closed upon energization of the system and does not open again until the mechanism has passed through its complete cycle of operation. The cams 10 successively operate meter selecting jacks l2, l3 and 1'4 as the driven member 61 occupies. its three stations. The cam. 69 maintains the motor energizing jack H in circuit-completing contact position, except at the moment when the driven member 6'! is changing from the station at which a circuit is completed through jack 14 to that causing the completion of a. circuit through jack 12. The camshaft 68, and: its. associated jacks, thereby shift the connections of the transmitter mechanism from meter to. meter successively, and control the op eration of the motor.

As shown in Figs. 9, 10, and 12, a solenoid 15 is mounted alongside the motor 39 with its axis parallel to the axis. of the motor. The solenoid 7.5. has an armature 16 which is attached to the supporting frame outwardly of the solenoid by a pivot T1, extends inwardly across an end of the solenoid and has a pointed extremity 78 at its inner end which is engageable between adjacent segments 19 of the rotor 80 of the motor 39 to hold the rotor 80 against turning movements. As shown in Fig. 10 the armature 1B, which is formed of resilient sheet metal, is supported on its pivot at a slight inclination to the axis of the solenoid so that itspointed extremity l8 bears with spring pressure against the inner face of the rotor 80 and will spring into place between the segments 19.. The; armature 16 holds the rotor 89 against turning movements and serves to lock the mechanism during the periods when it is not in use. Upon energization of the solenoid 15 the armature 1.6 is sprung inwardly from the position shown in dotted lines. in Fig. 12 to the position shown in full lines, withdrawing the pointed extremity 18 from engagement with the rotor 80 and leaving the rotor free to turn.

Fig. 14 shows the wiring diagram for the apparatus shown in Fig. 1 with connections established for the reading of meters l, 2, and 3. The system i shown in the process of reading the first dial of meter I. Three main circuits are involved. The first main circuit 8| preferably carries alternating (lo-cycle 110-volt current, althou h, it may carry any other current for which the substantially constant speed motor 39 may be adapted. The circuit 81 serves to energize the motor 39, admission of current to the motor being controlled by the motor control jack 'H and a relay that is operated by the low tension current in the second main circuit 82. The second main circuit 82 is preferably energized from the secondary of a suitable transformer 8.3: in order to provide a relatively low Voltage for operating the control equipment. O e. branch of the second main circuit 32 energizes the. line relay that connects the telemetric equipment to the telephone line, the motor control relay 85 that connects the motor 33 to its main circuit 81-, and the motor brake solenoid 15 that then permits operation of the motor armature. The windings for the relays S6 and 65 and the motor brake solenoid 15 are connected in series relation in one branch of the second main circuit 82. The meter selecting solenoids 85, 81, and 88, each of which corresponds to the solenoid 9 shown in Fig. 1 and Fig. 2, are connected respectively in the second branch of the second main circuit 82 by operation of the meter selecting jacks l2, l3, and 14.

The line relay 80, the motor control relay 85, and the motor brake solenoid 75 are initially energized by depression of the push button 89 that is preferably mounted. on the subscribers phone. After initial energization of this circuit branch and initial movement of the motor armature 39, the control jack 7! is closed by the cam 69 and this connects the terminals of the push button 89 until the equipment has operated through its entire sequence when the jack II is again opened.

The third main circuit 84 is connected to the telephone lines by means of a suitable relay 90, which substitutes the signalling or meterreading equipment for the local subscribers telephone equipment. This circuit includes a. resistance element I46 that is connected between the telephone lines, and a circuit for bridging, all or a part of, the resistance element including one of the dial selecting jacks 62, 63, 64 or 65 that are operated in sequence by the associated cams, one of the meter dial connectors 25, and the distributor arm with its associated contact segments. This general circuit is shown separately in Fig. 17.

There are provided ten trunk or bus wires 9II00, only 94 being shown in its entirety. These trunks respectively are connected to the segments 5| to on the dial of the transmitter 4, 9| being connected with BI, 92 with 52, and so on until I00 is connected with 60. Referring tothe bus wire 94, which is fully shown, this bus is connected with the similarly numbered contact elements 26 in each of the contact dials 25 for each dial of each meter in the system. This particular bus wire 94 is connected to each contact element 25 opposite to the numeral 4 in the case of each dial. Similarly, the bus wire 9| is connected to contact elements 25 opposite to number I in the case of each dial, and so on for each digit in each dial, the numeral 0 being represented by the contact element 26 that is connected with the bus wire I00.

There are also provided bus wires IOI, I02, I03, and I04 that are connected to the common return wire I05 through the jacks 62, 63, 64, and 55. Bus wire IOI is connected to the contact spider 21 of the first or unit digit dial Ia, 2a and 3a of each meter. Similarly, I02 is connected to lb, 21) and 3b, representing the tens digit of each meter, Similarly, I03 is connected to Ic, 2c, and 3c, representing the hundreds digit, and I04 to Id, 201, and 3d, representing the thousands digit of each meter. The common return Wire I05 that is connected to one side of each of the jacks 62, 83, 64 and extends to one side of the telephone circuit 84 and to one end of the bridging resistance I46. Wire I05 extends from the contact point I48 on the bridging resistance I45 to the contact arm 45 of the transmitter 4. The operation of the equipment for the reading of a series of three meters from the power station will now be described.

The power company, which we Will assume has contracted with the gas and water companies to read meters for them, calls the customer on the telephone. When the telephone is answered by the subscriber, the subscriber is informed that the meters are to be read and is instructed to push the button 89. This energizes the relay 90 which completes the circuits, through wires I05 and I05 across the telephone line, together with the motor control relay and the motor brake solenoid I5. At the time the button 89 is pressed, the jacks are all in open circuit position, but operation of the motor 39 causes immediate closing of the motor control jack II. The subscriber can then hang up the receiver, since the telephone line circuit remains closed through the variable resistance I46 shunted across the leads I05 and I06 which replace the subscribers telephone. The jack II bridges the contacts of push button 89 and thereby maintains the relays 85 and and the solenoid I5 energized. The dial selecting jack 62 and the meter selecting jack I2 are also closed by the initial operation of the motor. The meter selecting solenoid 86 is energized from jack I2 and the contact dials Ia, Ib, and I0 are thereby pressed forcibly against the jumper 38 of each dial of meter I. In the meantime the radius contact arm of the transmitter that carries the contact finger 45 begins to revolve about the dial of the transmitter 4. When the meter selecting solenoid 86 is energized as shown in Fig. 14, current from the telephone line 84 can pass to the dials Ia, Ib, I c, or Id of the meter I as the dial selecting jacks 62, 63, E4, and 65 are successively closed but current cannot pass through the other meters since the other meter selecting solenoids 81 and 88 are unenergized. With the solenoid 86 energized and the jack B2 closed a circuit through the dial Ia may be established. The telephone circuit is normally closed through the resistance element I43 but this resistance element is bridged when the contact finger 45 engages the segment 54 of the transmitter 4. When, therefore, the contact finger 45 reaches the energized segment 54 of the dial 49 of the transmitter 4, current flows from the telephone system through the wire I06, the contact finger 45, the bus wire 94, the jumper 38 of contact dial Ia to the bus wire IOI, the jack 62, and to the telephone circuit through the wire I05. The bridging resistance I45 is accordingly Wholly or partially short-circuited, depending on the adjustment of the contact point I48, as the contact 45 passes over the four raised portions 41 of this particular segment corresponding to numeral 4 of the dial. This causes four variations in the telephone current, which are received at the other end of the telephone connection and which can be used either to get an audible reading of the dial Ia in the meter I, or can be used to actuate any desired form of printing or recording apparatus.

After one revolution of the shaft 42, carrying the contact arm 45, the Geneva motion 48 and 49 operates to turn the shaft 50 ninety degrees, thereby releasing the jack 62 and contacting the jack 63. This brings dial Ib into circuit and, as shown here, the jumper 38 is at the position 2. The current, accordingly, can flow only through the bus wire 92, and as the contact finger 45 passes over the segment 52 the resistance I46 is twice short-circuited and two impulses are received at the power companys ofiice. Jack 53 is now released, 54 is held in contact, and dial I0 is similarly read, and in the same manner, dial Id. The shaft 50 has now made one complete revolution and the Geneva motion 66 and 61 now turns the shaft 68 one hundred and twenty degrees. This releases the solenoid 85, and energizes the solenoid 81. Contact can now only be made through the dials 2a, 2b, 2c, and 2d. Precisely the same procedure is gone through in reading the four dials of meter 2. The jacks 62, 63, 64, and 65 are successively closed during successive revolutions of the contact finger 45 and in this way these four dials are read in precisely the same way as the dials of the first meter. When this has taken place, operation of the second Geneva motion causes a further rotation of the camshaft 68, thereby causing the jack I3 to open and the jack I4 to close, and so releasing solenoid 81 and energizing solenoid B8. The dials 3a, 3b, 3c, and 3d are similarly read as before. At the conclusion of reading of dial 3d, if it were not for cam 09 and jack II, the camshaft 68 would again turn 120 and the whole process would be repeated. The notch in cam 69 is, however, so

placed as to release jack II when this 120 turn is only partially completed. At this moment, the contact finger 45 is in the vacant are between the segments 5| and 60 on dial 46 of the transmitter 4. The release of this jack'c'auses relay to open and solenoid I5 to cease to be energized. This cuts off current from the motor 39, and the armature 16 carrying the projection I8 flies up and arrests operation of the rotor 80 of the motor 39. At this moment the jacks I2, I3, and I4 and 62, 63, 64, and 55 are all open. Consequently, the plates 22 have all fallen away from the meter mechanisms proper, and the latter are free to function normally. Opening of jack II also opens the relay 9!], which opens the telephone circuit and gives a signal to the central operator to break the connection, or causes the release of the locking relay of the automatic telephone exchange.

It has been noted above that modification of the transmitter shown in Figs. 1 to 14 can be easily made to read more than three meters. I can, for example, use more than three stations in the driven member 61 of the Geneva motion. I usually prefer, however, to add another camshaft driven by a Geneva motion from camshaft 68, this Geneva motion having any appropriate number of stations. For each station of this motion three meters can be read if there are three stations on camshaft 68 or more if there are more.

In Fig. 15 I show a portion of the transmitter 4, provided with a third camshaft having four stations, being able in this way to read twelve meters in groups of three, the portion of the wiring diagram having reference to meter selection being given in Fig. 16. The method of doing this will be clear from reference to Fig. 14. Here it will be noted that a bus wire I01 supplies current to all three of the meter selecting solenoids 86, 81 and 88. In Fig. 16 a wire I08, corresponding to wire I 01 in Fig. 14 but leading to four jacks ms, III], III, and H2, controls admission of current to the four group bus wires I I3, I I4, I I5, and H6.

meters, for example, the bus wire I I3 connects one side of solenoids 86a, 81a, and 88a; bus wire 4' connects 86b, 81b, and 882); bus wire I I5 connects 86c, 81c, and 380; and bus wire IIB connects 86d, 81d, and 88d. The other side of the circuits to these solenoids is supplied through the lead II1 that extends to the jacks 12a, 13a, and 14a, corresponding in function to the jacks I2, I3, and I4 in Fig. 14. The jack 12a, however, instead of controlling current admission to a single solenoid, controls admission to a bus wire II8 which supplies the other side of the four solenoids 88a, 88b, 88c, and 88d. The wire 13a similarly supplies, through the bus wire I I9, the solenoids 81a, 87b, 81c, and 81d, and similarly, 140,, through the bus wire I29, supplies the solenoids 86a, 86b, 86c, and 86d.

Referring now to the sequence of operation of these jacks, Fig. 15 shows the driving mechanism of the various camshafts controlling them. As before, the shaft 42 has the driving member 48 of a Geneva motion driving the fourstation driven member 49 on shaft 50. This shaft, as before, controls the jacks 62, 63, 64, and 65 in the telephone circuit which is not shown in Fig. 16. As before, the shaft 50 has mounted on it the driving member 66 of the second Geneva motion, the driven member 61 being mounted on the shaft 68a. This shaft is precisely similar to shaft Each of these bus wires energizes one side of the solenoids controlling a group of three 68, except that it does not include the motor controlling cam 69. Shaft 68 mounts the driving member I4I of the third Geneva motion, the driven member I42 of which has four stations and is mounted on the camshaft I43. This shaft I43 actuates the four jacks I09, III), III, and I I2 in precisely the same way that the jacks 62, 63, 64, and 65 are controlled by the shaft 56. On it is mounted the cam 69a controlling the jack II which controls the motor 39 in precisely the same Way as heretofore described.

This embodiment of my invention is handled precisely as is the case in the first embodiment. Each corresponding station on the indicating dials 25 for every dial and every meter is mani folded to one of ten bus wires, as is the case with the three meters shown in Fig. 14, to four wires connected to the four jacks 62, 63, 64, and 65. In operation the telephone connection is put through from the central station as before, and the twelve meters are read in sequence in precisely the same way as before, one group: being first read, then the second, then the third, then the fourth, in the manner outlined in connection with Figs. 1 to 14.

It is clear that the above described transmittercauses a variation in the steady talking current in the telephone system which may be kept within a range such that this variation does not affect any of the central station equipment, whether manually or automatically operated by properly proportioning the resistances of the meter and telephone circuits.

As shown, this consists in periodically shortcircuiting a resistance connected across the telephone line which is substituted for the telephone transmitter in the subscribers set. Either the whole of such resistance or a part of it may be so short-circuited to produce these impulses. It

is possible, of course, without departing from the:

spirit of the invention, to operate the transmitting equipment in the reverse sense. That is, the contact finger 45 can maintain a contact which is periodically broken, and in this way a resist-- ance can be added to the line, such resistance being placed in parallel with 'the contact made and broken by the contact finger 45, to thus transmit an indicating impulse over the line. For most purposes, however, I prefer the arrangement shown. I

In Fig. 17 is shown the wiring diagram of the elements of the transmitter and'telephone circuit connections, together with a wiring diagram for a receiving equipment in the power companys ofiice. The remainder of the wiring diagram has been omitted for the sake of simplicity. The telephone lines leading to the subscribers equipment are brought to the relay which, in its unenergized state, affords connection to the subscribers telephone equipment. In its energized condition the connection to the telephone set is broken and connection is made to the leads I05 and I06 shown in Fig. 14. Bridging these leads is the resistance I46 a part or all of which may be short-circuited by the transmitting equipment- This equipment is shown here only in its essentials as the jack 62, contact dial 25 and transmitter 4. Through dotted lines representing the central exchange station-and connecting telephone lines, telephone lines I2I and I22'leading from the subscribers telephone I23, or transmitter 4,. are connected with telephone lines I24 and H5 leading to the telephone equipment of the power companys ofiice. Both the subscribers and the power companys telephone equipment are assumed to be of the usual type, consisting of a transmitter I26 which is connected to the line through impedance I28 that is coupled to an impedance I29, a condenser I30, and the transmitter I26 through the contact operated by the hook I2! which also serves to energize an ear piece I3 I. From the extremities of the impedance I29 of the power station telephone, leads I32 and I33 pass to the equipment for receiving the transmitted signals. This may be of various characters. I have preferred to show it as consisting of a thyratron or grid glow tube I38, receiving its plate supply through the secondary of the transformer I34, the plate circuit including a sole noid I35 and a filter condenser I36. The grid of the tube I38 is negatively biased by a battery I31 which is of such a value that current in the plate circuit is ordinarily prevented. When, however, a change in current occurs in the impedance I28, there is an induced potential in the coupled impedance I29, which potential is either addedto or subtracted from the potential developed by thebattery I31, accordingly as current increases or decreases. Consequently, for each signal there is one instant at which time this superimposed potential causes the total minus potential on the grid of the tube I38 to be less than the critical value. Under these conditions, flow of current becomes free in the tube I38 and the solenoid I35 isenergized, thereby attracting the armature I39. The motion of this armature may be either read visually or by ear or preferably may operate any standard printing device such as a printing wheel I40 in ways that are well known in the art.

In Fig. 18 I have shown the characteristics of tube I38 such as is used in the receiving equipment. In this figure plate current is plotted against grid voltage. It will be seen that, with a certain negative biasing of the grid no current flows, but that if the negative bias is less than a certain figure the plate current is not controlled by the grid voltage. Therefore, if the grid voltage is originally placed, say, at the value a, no current flows in the plate circuit except when the superimposed potential I) in its positive swing brings the total potential, say, to the amount less than the critical potential (1, when a momentary current flows.

In place of the tube I38 I may use a sensitive relay of a semi-sustaining character, or may use an ordinary amplifying system, the solenoid I35 being in this case preferably a balanced relay operating only on certain predetermined current values, or I may rely upon the signal given in the power station telephone receiver with further modification.

It will thus be seen that I have devised a method whereby, from a central station, a large number of meters may be read at a distant point, either by ear or by the use of recording equipment, the ordinary telephone equipment being used to transmit signals which are themselves of such a character that they do not interefere with the operation of the telephone system, whether that be automatic or manually operated. It will further be seen that I have devised a method of doing this, using one transmitting mechanism for the reading of a number of meters. It will further be seen that I have devised a system which is capable of using the standard meters used for measuring the consumption of electricity, gas, water or other metered commodities, it being necessary toadd only a simple attachment to each meter.

It will further be seen that the mechanism which I have devised is simple, accurate and rugged, does not interfere with the operation of the meter mechanisms proper, and that this apparatus is not easily susceptible to malicious interference, and is convenient for the subscriber of the services which are metered by the system.

Numerous mechanisms have heretofore been proposed for answering telephones in the absence of subscribers and such selectively controlled mechanism could be used for like purpose in connection with special installations warranting the expense of such additional equipment. Such conditions would be present in the case of isolated power substations having meters indicating the condition of the machinery or other matters which it is desired be read from a central station.

In Fig. 19 and Fig 20 is illustrated a system wherein a current variation of any desired frequency is induced in the telephone line circuit through any suitable impulse-producing device, such as the oscillator winding I50 that is mounted on a core member II of magnetic material. The permeability of the magnetic circuit through the iron core is changed at a fixed frequency by means of the rotating disk I52 that is driven by the motor 39 or other suitable motor. In this device a tooth I53 of magnetic material passes through the gap in the magnetic core at predetermined intervals to thereby induce an alternating current of definite frequency that is superposed on the direct current flowing through the telephone lines. If the frequency of this alternating current component is made about one thousand cycles per second, an audible whistle tone will be produced when the contact 45 passes over an energized segment of the transmitter. This will render it much easier to record the successive meter readings when audibly taken. In this apparatus the winding of an oscillator I50 and a damping induction winding I54 is connected across the telephone line by the relay 98 in order to complete the telephone circuit and maintain the telephone relays, etc., connected for talking condition. The inductive impedance I54 serves to damp out the oscillating signal current variation inductively produced by the impulse-producing device, except when the inductive impedance is short-oircuited by the contact arm 45 of the distributor. This mechanism operates the same as the system previously described except that it produces a more audible signal tone each time the contact arm 45 short circuits the inductive damping winding I54,

Furthermore, it is to be understood that the particular form of apparatus shown and described, and the particular procedure set forth, are presented for purposes of explanation and illustration and that various modifications of said apparatus and procedure can be made without departing from my invention as defined in the appended claims.

What I claim is:

1. The combination with a telephone system, of a telemetric system comprising, a resistance element, manually controlled means for connecting said resistance element across the lines of said telephone system, automatic means for maintaining said resistance element connected across the lines of said telephone system, signal means for automatically short-circuiting said resistance element a selected number of times for indicating the signal to be transmitted, and means for interrupting the connections of said resistance element in the telephone system and for re-establishing normal telephone circuit connections after a predetermined number of signals have been transmitted.

2. The combination with a telephone system, of a telemetric device comprising, switching means for connecting a signal-sending circuit to the lines of said telephone system, means for interrupting said signal-sending circuit and reestablishing normal telephone connections after a predetermined number of signals have been transmitted, means in said signal circuit for superposing an audible frequency alternating current on the telephone lines, means in said sending circuit for materially damping the superposed alternating current, signal-sending means, and means controlled by said signal-sending means for rendering said damping means inoperative to thereby transmit signals of a pitch corresponding to the frequency of said superposed alternating current.

3. In combination with a telephone system, a meter reading system adapted to read a plurality of meters, each having a plurality of indicating spindles, comprising a transmitter for transmitting a plurality of distinctive signals to a distance, selector means operated by said transmitter for selecting each meter for reading in predetermined order, selector means operated by the spindles of each of the dials of said meters for selectively indicating the angular position of the spindles, dial selector means operated by said transmitter to successively connect the selector means operated by the spindles with said common transmitter, means for impressing said successively produced signals on the transmission lines of the telephone system, means for manually starting said transmitter and for automatically connecting said transmitting system with said telephone communication system, and means for automatically interrupting such connection after the reading of all of said meters.

4. A transmitter for transmitting the readings of meters to a distance comprising, a motor, means operated by said motor for mechanically producing a plurality of different electrical signals, selector means operated by the meter indicating spindle for selecting one of such signals for transmission to a distance, and selector means operated by said transmitter whereby each dial oi the meter being read is successively and selectively caused to control the selection of the signal to be transmitted.

5. In combination with a telephone system, a meter reading system adapted to read a plurality of meters, comprising a transmitter for transmitting a plurality of signals to a distance, selector means operated by said transmitter to select the meters to be read in predetermined order, signal selector means operated by the spindles of each of the dials of said meters, dial selector means operated by said transmitter whereby each of the dials of a meter are successively selected in predetermined order to control the operation of the signal-sending means, said dial selector means operating successively for each dial of each meter and then repeating for every succeeding meter, and means for impressing said successively selected signals on the transmission lines of the telephone system whereby the readings of said meters may be determined by the character of signal received by a telephone receiver of conventional character.

6. The combination with a telephone system, of telemetric mechanism for reading dial equipped meters" comprising, a common contact member for each dial, an insulated contact member for each, numerical position of each dial of each meter to be read, means carried by each dial for connecting said common contact member with one of the contact members for the numerical positions of the dial, distributor mechanism having a segment for each numerical position of one of the meter dials, each of said distributorsegments having electrically connected Contact elements of a number corresponding to the numerical position of each meter dial segment and electrically connected with the correspondingly positioned insulated member of each dial, a contact arm for sweeping said distributor segments, means for successively connecting the common contact memberof the meter dials in predetermined order with the corresponding contact segments of said distributor, and means for continuously operating said contact arm to sweep over all said distributor segments for each dial in predetermined order until all the dials of the meter are thus read.

'7. In a meter reading mechanism, the combination With a meter dial having a spindle, of a plate, a series of insulated contact elements mounted on said plate for each numerical position of said dial and overlying said dial, a second contact element insulated from the first series of contact elements and also overlying said dial, a contact jumper carried by said spindle and designed to contact with said second contact member, said contact jumper also having an arm designed to selectively contact with the overlying insulated contact elements, means for moving said plate toward and away from said contact dial, and electrical connections from each of said insulated contact elements and from said common contact member for establishing selective connections depending upon the angular position of said spindle.

8. Meter reading mechanism for use in connection with a meter dial having an indicating spindle thereon comprising, a jumper'mounted on and insulated from said spindle, a plate, a series of individually insulated contact elements mounted on said plate and overlying the numerical positions of said dial, a second annular contact element overlying said dial, said jumper having one end adapted to make electrical contact with said annular contact member and the other end adapted to make contact with said individually insulated contact elements, means for moving said plate toward and away from the dial to bring said jumper into selective electrical contact with the contact elements carried by said plate, and electrical connections from each of said contact elements.

9. A meter reading contact element for use in a telemetric system comprising, a plate of insulating material having apertures therethrough, contact elements arranged in circular order with adjacent spaced edges and having leg portions extending through certain of the apertures in said plate for providing electrical connections for said elements, and for clamping said elements in sharp edge on the outer face thereof and a relatively broad base where they overlie said insulating member certain of the radial arms of said contact member being bent at right angles to the plane of said member and extended through certain of the apertures in said plate for clamping said contact member in place and providing electrical terminal connection for said member, and jumper means arranged to selectively contact with said circularly arranged contact elements and with said annular contact member, and means for separating said plate and said jumper.

10. Distributor mechanism for use in a telemetric system, comprising a series of separately insulated contact segments each having electrically connected contact elements that corre spend in number to the numerical readings to be indicated by said distributor, a contact arm for sweeping said segments in predetermined order, means for operating said contact arm at substantially uniform speed, dial reading means including control circuits for energizing said segments and means for successively connecting control circuits to the segments in accordance with the number of rotations of said arm to successively read a succession of indicating dials.

'11. A distributor mechanism comprising, an insulating dial, a series of separately insulated contact segments having from one to ten electrically connected circuit-making contact elements thereon arranged around a segment of the periphery of said insulating dial in the order of the number of circuit-making contact elements on the segments, a contact arm, means for causing said contact arm to sweep said segments successively, and means for selectively energizin'g one of said contact segments for each rotation or said arm.

PAUL YATES.

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