US1598595A - Recording meter - Google Patents

Description

Sept. 7 ,-1926. 1,598,595

D. J. ANGUS RECORDING METER Filed March 19. 1926 2 Sheets-Sheet 2 T 1x1 two/e. DOnald. I. Hflgus,

1 fromm'. 4

,Pennini Sept. 7, 1926.

UNITED STATES PATENT OFFICE.

DONALD JnxEs Anous,- oE INnmNAroLrs, misma.

"RECORDING METER.

Application ami umn 19, i926. serial' No. 95,526.

' In the ordinary .operation of graphic meters, anentirely adequate'record may be ol)- tamed on a slow-moving chart; for the vaf -riations from second to second, or even from minute to minute, are ordinarily of com-l paratively slight im ort.

In emergencies, however, especially, in vthe larger electric supply systems in which many stations-and generators are intercom# nected, what happens from'second to second, oreven in fractions of seconds, becomes extremely important; and the things which happenin the Very beginning of the emer-- gency, and especially during the raction of the first second, are often of the greatest importance. .The detail of sucht 'happenings which occur within a ,few seconds is completelyr lostin the record on the ordinary slow-moving chart; and it is information regarding such detail, and especially regarding the detail of the happen.-

ings -in the first fraction of the first second,

thatis frequentl most desired.

In my prior atent No. 1,545,078,

'ed July 7, 1925, I have described aA graphic meter 1n which the chart'ordinarily operates i at a desired slow speed; but in which upon theoccurrence of an emergency the chart starts at once to operate at-a predetermined higher speed, to give in minute detail the' v ord 7s not secured. This is because, with the unmodified apparatus that patent shows, the chart must haye moved a certain distance .at the high speed before the emergency ceases in order to permit the high-speed drive to continue for the desired predeter- .mined period. f

It is the object of my present invention to provide a' meter which in general operates in the manner of theA meter set forth in my aforesaid prior patent; but which u on a shift of the chart-drive from low spee to firstv small granthigh speed upon the occurrence of` an emergency acts independently of any'prerequislte high-speed movement to prevent "such chart-drive from returning to low speeduntil after the chart has had `a predetermined movement at high speed, even though 'the emergency isiof too short duration to maintain such shift in chart-drive effective kfor the desired predetermined turn with the unmodified .apparatus shown in my aforesald prlorpatent. .That is, it is my object to cfiect the change from low speed to high speed, not only minimum'time so that the' chart will be moving at the high speed very early in the first second of the emergency, but without possibility of interruptingy the high-speed drive and destroying the'highspeed record. until the desired predeterminedmovement at high-speed has been ac complished. The accompanying drawings illustrate my invention: Fig. 1` is a semi-diagrannnatic view of a meter chart with both the normal or low-speed driving` mechanism andv an emergency or high-speed driving mechanism l arranged in accordance with a preferred enibodiment of my inv/ention and applied to an electrical distribution; Fig. 2 is a fragmexr" tary detailwof the stop mechanism of the high-speed drive of Fig. 1, showing 'such` high-speed `drive in stopped position; Fig. 3 is a fragmentary View similar to Fig. 2, but showing the high-speed drive at the moment ,of releaseat the start of .the high.- .speed operation; Fig. 4 is a section on the line lf-4 of Fig; 3; Fig. 5 is a fragmentary view of a modified form of high-speed drive,

with some of theparts broken away in order better to show thosefbhind; Fig. 6 is a fragmentary and diagrammatic viewmf another form of control for the high-speed drive, with the parts in the position they have during the low-speedoperation of the chart, or

-with the high-speed drive ineffective; Fig.

7 .is a viewv similar to Fig. 6, but with the parts in the position they occupy just as the high-speed operation is about to stop; and Fig. 8 is afragmentary section, .substantially on the line 8--8 of Fig,`v` 6. l

The chart 10 may be the chart of Aany graphic meter; and usually .has longitudi' nal lines 11 indicating values of the quantity the meter-mei 1s1 u es,. and transverse lines 12, usually arcs,'1,nd1cat1ng tlme.

The recratchet wheel 27 fixed on said shaft.

ord is made by moving the chart beneath a pen 13, which makes a graph on the chart.Y

The chart 10 is shown as suitably driven by a roller 14 on a shaft 15; which roller has radially projecting pins 16 for meshing lwith holes 17 along the edges of the chart. After passing the roller 14, the chart is wound up on a wind-up roller 19. The details of how the chart is driven from the shaft 15, how the wind-up roll 19 is operated, and how the pen 13 is operated under the control of the conditions to which the meter is responsive, may beV anything desired, depending upon the type of meter used and the thing which the meter is to record. As shown, the meter is assumed to be an electric meter, associated inany`suitable Way with a supply circuit 18; but it is not necessary to my invention that the meter be an electric meter, or that it be associated with any particular Way with the supply-circuit 18 if it is an electric meter.

' The shaft 15, which is the driving shaft for the chart 10, has two driving mechanisms. One of these is the normal driving mechanism, for operating the chart 10 'at low Speed; and may consists of a conventional clock-work mechanism, indicated by a gear 20, driving a gearV 21 loose on the shaft 15 but associated with such shaft by a suitable clutch which will permit the shaft 15 and roller 14 to move forward at high speed without corresponding high-speed movement of the gear 21. Such clutch ymay take any suitable form; but instead of the pawl-and-ratchet overrunning clutch shown in my aforesaid prior patent," although that or any other suitable form of overrunning clutch may be used, the form I now prefer is a simple friction clutch 22 of which the friction issuticiently greater not to let the clutch slip when the drive of the shaft 15 is from thegear 21 at low speed but sufficiently small to let the clutch slip when the highspeed drive is in operation. The nature of the normal driving mechanism is immaterial, and the clock-work mechanism is mentioned and indicated `only because it is a simple and ordinary driving mechanism for meter charts.

The other driving mechanism for the chart-moving shaft 15 is the emergency driving mechanism, for driving the shaft 15 at high speed. For this, in the preferred form in'which I have illustrated my invention in Fig. 1, the shaft 15 has loose thereon a gear 25; which, like the gear 21, is connectible to the shaft 15' by a suitable overrunning clutch, here shown, as a pawl 26 carried by said gear 25 and engagingha T e gear 25 meshes with a pinion 28, which is fixed to a Worm-wheel 29 to rotate therewith. The pinion 28 and worm-Wheel 29 arecarried by a frame 30 pivotedon the Shaft 15, so that such frame and the parts carried thereby may be moved about 'the shaft 15 asa pivot'without disturbing the meshing of the gear 25 with the pinion 28. The gear 25, pinion ,28, and worin-wheel 29 are normally stationary. The worm-wheel 29 is one member of a normally open clutch, the other member of which is a constantly rotating worm 31. The worm 31 is desirably operated at substantially constant speed, continuously, so that it is always ready to start into action in moving the chart 10, without the necessity for any period of acceleration. While various mechanisms may be used for obtaining this continuous constant operation of the clutch-member or worm 31, I desirably obtain it by a continuously running motor 32, the shaft 33 of which carries the worm 31. Desirably the motor 32 for operating the worm 31 is supplied from a source of current separate from the main supply circuit 18, as from a special generator 34; so that such motor 32 will not be affected by what happens to the main supply-circuit 18.

The two clutch-members 29 and 31, as already stated, are normally out of mesh with each other; so that while the clutch-member 31 is continuously rotated at constant speed, the clutch-member 29 is normally stationary.

These two clutch-members 29 and 31 are moved into mesh upon the occurrencei of an emergency; as by an electro=magnet 35 acting on the frame 30 to tilt it and the parts it carries in a counter-clockwise direction to' lift the worm-wheel or clutch member 29 into engagement with the worm or clutchmember 31. The frame 30 is normally 'spring-pressed in a clock-wise direction, as' by a spring 36, to de-mesh the two clutchmembers 29 and 31; but when the electromagnet 35 is energized, it moves the frame 30 against the spring 36 to produce meshing of the two clutch-members. Upon such meshing of the two clutch-members 29 and 31, the worm-wheel 29, pinion 28, and the gear 25 are'at once startedinto operation; and the movement of the gear 25 is faster than that of the gear 21, so that the overrunning clutch` 26-27 takes hold and drives the lshaft 15 at the desired higher speed, as permitted by the clutch 22 of the normal driving mechanism. y.

The electro-magnet 35 may be energized in response to any desired conditions. I shall not attempt to enumerate the various conditions to which it may respond. In-the illustration shown, it is suppliedv romaa suitable source of current 40, and is controlled by an overload relay` 41 and a no-voltage relay 42 suitably associated with the main 'supply-circuit 18 to respond to current and voltage conditions therein. With these relays, the electro-ma et 35' is ener ized to `cause the high-Spee operation of t e chart 20 three by way of illustration.

35 snap mechanism at t e end oflsuch 45 of lthe notch`48 and sto substantially radial of t e disk, in order,- to get a positive stopping at a definite posi'-v 55' ridin y upon the occurrence of an overload on the circuit 18 or upon failure of the voltage of such circuit.

In addition to means for causing the highl speed driving mechanism to drive the chart during the continuance of an einer ency, I provide means for continuing sucIi hlghspeed driving of the chart after the expirationv of the kemergency until the total 10 time of high-speed driving is sufficient to produce a high-speed movement of thechart through a predetermined distance, desirably equal to an integral numbemof minutes, hours, or days of slow movement; and for l5 doing this even though the emergency itself continues for suchl a small fraction of a second that the shift to the high-speedidrive has hardly been completed. This may be done in anumber ofvways, of which Ishow In,` each lof these, the arrangementis such that if the emergency lasts long enough .to shift .to the high-speed driveand that requires only a very small fraction of a second--it acts independently of any highspeed movement of the chart to' prevent the immediate stopping of the high-speed o ration.' In all these illustrated forms o my invention, there is a quick-,acting sna mechanism operated upon the shift to hig -s eed drive' for preventing a shift back to owspeed drive u'ntil there has been a predeter-l mined movement of the chart at the high speed;vand a resettin of such quick-acting termined movement.

In the arrangement shown in Figs. 1', 2, and 3, the frame 30 carries agear 45 which meshes with the inion 29, and which is 40 therefore tilted w en the frameA is tilted.

On the shaft 46 of the gear 45 there is fixed a disk 47., which has a peripheral notch 48 which co-operates with a fixed stop 49.

The cooperating stopping faces 50fand 51 49`v| are desirably tion. These faces are 1n engagement when the stop 49 isin/the notch 48 and the frame 5 30 'is lowered, at which time the clutch members 29 Iand 31 are demeshed'; but 4when `the frame is`raisedto produce meshing of suchV clutch members, it isheld raised with such clutch members meshed by reason of .the of the unnotched remainder of the perip e of the disk-47 on the stop 49.

In or er to prevent the disk 47, 'when it 'has once been raised, from dropping immediately back 'to lowered position before o it has been moved far enough to produce disalin'ement of the stopping faces 50 and 51, if by any chance the emergency'which is terminated that quickly, I provide a disk .55 which is loose on the shaft 46 and .65 has alimited spring-pressed movement thereon with respect tothe disk 47. The disk lies behind the disk 47, as shown' in Figs. 1, 2, and 3; and both disks co-operate with the stop 49. The disk 55 lis convenienly substantially like the disk 47, in size an To get the the two dlsks, a pin 57 from the disk 55 projects through an arc-shaped slot v58 inthe disk 47; and a'tension sprin 59 acts between such pin 57 and a pin 6() xed on the disk 47, so that such spring 59 tends to draw the disk 55 in a clockwise direction (Figs. 1,- 2, and 3,) with relation to the disk 47, and to move the two notches 48 and 56 out of registry, as is indicated in Fig.-3. With the two notches thus out of registry, the s to 49 is prevented from entering the notch 48,v ecause an `unnotched portion of the disk 55 lies oversuch notch 48 and rides 'on the end of the stop when .the disk 55 is moved in a counterclockwise direction, from the position shown in Fig. 3 to the position shown in Figs. 1

and 2, and the spring 59 is thereforeit 1n a counter-clockwise direction with respect to the disk 55-or rather to hold the` ripheral shape; so that it has la notchv 56 w ich is like the notch 48. limited spring-pressed movement between` disk 55 still while the disk 47 advances in l `the'clutch 22. During this normal slowspeed operation, the frame 30 is in its lowered position, shown in Fig. 1, because the stop 49 is\in both notches 48 and 56; which notches'are in registry because the disk 55 has been moved against the spring 56 to produce such registry. Therefore, the worm-wheel 29 is out of mesh 'with the constantlyrotating worm 31, the gears 25, 28, and 45zare all at rest, and the' overrunning clutch 264-27 merely rmits the shaft 15 to turn under the drivlng force of the lowthe device a` whole is cutspeed clock-work mechanism. The motor 32 land. the worm or clutch-member 31, however, are in continuous operation at the desired speed, in readiness to .producel the highspeed operation immediately when the emergency arises; so that upon the occurrence of the emergency no time will be lost :for

a period of acceleration of the motor 32 and the normally'runnin -parts 'associated therewith. lThese norma y running parts,

clockwise movement of the including the motor 32, have a relatively high moment of inertia as compared with the gears 25, 28, and 45, the disks 47 and 55, the shaft 15, the chart 10, and the various parts lmoving with the shaft 15 and chart 10.

When the emergency arises, such as an overload to produce the closing of the relay 41 or a failure of voltage to produce a closing of the relay 42, the electro-magnet 35 is immediately energized. This electro-magnet at once lifts the frame 30, to shift the 4clutch-member 29 into engagement with the moving clutch-member 31. At the same time, the lifting of the frame separates the notches 48and 56 from the stop 49. Immediately upon such separation, the spring 59 snaps the disk 55 in a clockwise direction with respect to the disk 47, or to the position indicated in Fig. 3, and thus in effect closes the notch 48 against the immediate reentry of the stop 49 thereinto, even though the emergency ceases practically at once. This closing of the notch 48 is independent of any rotation of the disk 47. The engagement of the two clutch members 29 and 31, however, at once starts the gear rinto motion, and the overrunning clutch 26-27 at once begins to drive the shaft 15 and chart 10 at high speed, while the now-slipping clutch 22 merely serves to permit the overrunning of .the shaft 15. In other words, the high-speed drive takes thedriving of the chart 10 away from the low-speed drive. By reason of having the motor`32 andthe clutch-member 31 in continuous rotation, it becomes possible to start the highspeed drive of the cha-rt much more promptly after the rise of the emergency than is otherwise possible.

The emergency usually lasts only a few seconds, and sometimes only a small fraction of a cycle. When the emergency ceases, the electro-magnet 35 releases the frame 30; but this ordinarily does not at once de-mesh the parts 29 and 31 because the peripheries of `the disks 47 and 55 ride on the end of the stop 49 and prevent. the frame 30 from dropv ping suficiently to produce such demeshing. Thus the high-speed drive ordinarily continues for a while. However, when in such high-speedoperation the notch 56 in the disk next comes to the stop 49, the side of such ntch catches on such stop, as it is permitted to do beca-use of thecut-away part of the disk 47, and thus the forward or disk 55 is stopped. The forward movement of the disk 47 continues, however, the spring 59 stretching `to permit it, until the notch 48 has come into registry with the notch 56. As the two notches then come into registry, to bring the stopping-faees50 and 51 in line and thus to open the notch 48, the frame 30 drops farther to de-mesh the clutch-members 29 and 31 and thus to stop the highspeed drive. Thereupon the low-speed drive resumes its driving ofthe chart.

Thus the high-speed movement of the chart continues for a predetermined dis- `tance, or some multiple thereof. This may be any desired distance. Desirably, the gearing 25, 28, and 45 is so proportioned that the disk 47 makes one complete rotation for a travel distance of the chart equal to one days normal travel. This is a very dcsirable proportioning, as it permits the highspeed movement of the chart to continue for 'a distance equal to some integral number of days of normal chart-travel, so that at thc end of the emergency the pen 13 will be at the same hour and minute on the chart that it occupied at the time the emergency started, though one or more days later on the chart. lith that arrangement, at the end 'of the emergency the meter will resume its normal low-speed recording operation at a chart-indication corresponding to the actual time of day, and the normal record may be obtained from the chart at the proper' hour and minute indications by merely skipping that part of the chart which has made the highspeed record of the emergency. The time required -for the emergency or high-speed travel is negligible on the chart at the lowspeed travel..

The ratio low-speed movement, of the chart may be made anything desired, by suitably proportioning the gearing and suitably choosingr between the high-speed and the the speed of the motor 32. lVhile Aother relations may be used, asset forth in my aforesaid prior patent, the one I prefer is with the high-speed motion 360() times as fast as the low-speed mot-ion: so that the chart will travel the same distance in a sccond at the high speed as it does in an hour at the low speed. With this arrangement, the hour-lines 12 on the chart become indications of seconds during the emergency.

In the arrangement shown in Fig. 5, I have shown a modified high-speed drive. Here there is no meshing and dcmeshing of gears, but merely a clutching action.

The motor 32 drives the worm 31 as before, but this worm is here in constant mesh with the worm-wheel 29. This worm-wheel 29 is here shown as being directly' but loosely mounted on the shaft l15. which drives the chart 10. 0n this shaft 15 there is also loosely mounted a member 65,' which is intermediate in the power-train between the worm-wheel 29 and the shaft 15. Between the member 65 and the shaft 15 there is a suitable over-running clutch, such as the pawl-and-ratchet clutch 2(3#27 already described. (As is indicated by the crosshatching :of the carrying pins thereof, the pawl 26 and its yoperating spring are carried by the member 65 in front of them in the drawing, although that member is broken away over such pawl and spring; and are not carried bythe worm-wheel 29 which lies behind them in` the drawing.) Between the memberv 65and the worm-wheel 29 there is a friction clutch, which is ordinarily ineffective .but is made effective when an emergency7 rises and remains effective for a predetermined time extending beyond the' termination of the' emergency.

This friction clutch may take various forms. I have illustrated it as an arm 66 which is pivotally mounted on the member 65 on a pivot axis 67 displaced from the axis of theshaft 15. This arm 6 6 extends from its pivot axis 67 across the axis of the shaft 15, and carries a pin 68 which `co-operates with an annular rib 69 projecting from the face of the worm-wheel 29. The arm 66 s.-suitably slotted or notched around the shaft 15, so that such shaft will not interfere with the movementof the arm about its axis 67. Because of the eccentricity of the axis67 with respect; to the shaft-axis, the pin 68 is free from the rib 69 when the arm'66 lies diametrically of the worm-wheel 29; but the arm 66 is lspring-pressed in a.

. clockwise direction about vits pivot pin 67 with respect to the member `65, by a tension spring 70,A so that such spring tends to move the arm 66 out of such diametrical line and thus to force the pin 68 against the inner face of thev annular rib 69 to lock the member 65 to theworm-wheel 29. The

Iouter end of the arm 66 co-operates with a ivoted stop-arm 71, which is s ring-pressed A into the path of such outer en by a spring of the ment ofthe arm 66 justv 72, but may be drawn'lout of such path by the magnet already described.

When the magnet 35 is not energized, the sto -arm-71 engages the arm 66,'and holds su arm in its diametrical position `with respect to the worm-wheel 29, with the spx 70 stretched, so that thel pin 68 is rom the rib 69 and in. consequence the'v worm-wheel 29 rotates freely without moving the member 65. Under those conditions, the motor 32 and worm-wheel 29 run idly, without affecting the shaft 15, which shaft at that time is bein driven by the low-speed drive. These are t e normal operating condtions. n f

Uppn `the occurrence of, an` emergency whic energizes the magnet 35, -the stop arm 71 is drawnoutof the path of the arm 66. At once the'sp'ring 70 swings the arm 66 about its pivot 67, to produce engagement in 68` with the rib 69. Once the arm 66 as been released from the stop arm 71, it cannot be stoppingly re-engaged thereby until the arm 66 hasdmade at least one revolution. The spr' -produced moveescribed thus in effect clutches the memberl to the wormwheel 21, through the pin 68 and lrib 69, anld 05 the continued movement of the worm-wheel 29 thus causes the same .movement of the member 65, which in turn acts through the overrunning clutch 26--27 to drive lthe shaft 15 and chart 10 at high speed and thus take the chart-drive aWay from the low-speed driving mechanism. i

When theemergency terminates, the stop arm 71 is released by the electro-magnet 35 and returns lto its4 normal position in the.

- path ofthe arm 66.- Thel next time the arm 66 comes around, whetherv that is'at the end of. the first revolution or of some subsequent revolution in the high-speed; drive,

such arm 66 strikes the stop arm 71, and is` stopped thereby. The worm-wheel 29, however, continues to rotate, and in consequence the arm 66 is swung backward about its pivot 67 to stretch the spring 70 and release the pin 68 from the rib 69, thus stopping the high-speed drive untill the' occurrence' of the next emergency.

However, this stopping of the high-speed drive cannot occur after tlre occurrence of an emergency until the shaft L3 has made at, least-one revolution under the high-speed drive, no matter howfshort the emergency is,

ust so longas the emergency is of sufficient en th to swing the stop-arm 71 out of the pat of the arm 66; for immediately thereupon the spring 77 snaps the arm 66 for?y ward, and such armA cannot be reset in clutchreleasing positiony until the shaft made at least one revolution.

15 has A In the arrangement shown in 6,

and 8, the clutch in the hi h-speed drive is held in clutching position e cetro-magneti cally,` instead of mechanically as` `in the j otherl arrangements.' In lthis arrangement,

the' earingls' the samel as is shown in 1, with the gea'rs 25, 28, 29, and 45 cai'fried s ring-pressed by a spring 36 tofde-mes t e worm-wheel 29 from the constantly run- -i ning worm 31 but may be lifted by an elec- A tro-magnet 35 tofproduce meshing of the" worm-wheel 29 with the worm 21 td make the high-'speed drive f effective. Because all the same as is shown in de- The electro-magnet 35 in the arrangement shown in Fi A. 6 and 7, however, not only serve to hol i up the frame 30 .during the continuance `of the emergency, but in addition holds such frame up after the termina-- tion of the emergency until the movement of the chart at high speed has continued for a predetermined time.

To this end, I provide three spring- contactl members 75, 76, and 77, which togetherconstitute a switch which is in shunt to the switches controlled by the overload'relay'lll and. the underload relay 42, so that the electro-magnet 35 will remain energized as 105 by the tiltable frame 30, which is normali long as the switch 7 5- 7 6-7 7 isclosed. The wires leading to the last-named switch lead to the contacts 75 and 7,7, so that for the closing of the switch it is necessary that all three of the contacts be in Contact with each other, and the switch will be open if the middle contact 76 is out of engagement with either of the two outer contacts 75 and 77. The free ends 78 and 79 of the two contacts 75 and 7 6 are bent towards a disk 80, which is lixed to the gear L15 to rotate therewith. Tliedisk 80 carries a pin 81 which may cooperate witli the bent end 79 of the switch arm 76 when the frame' 30 is raised, and with the bent end 78 of the switch arm 75 when the frame 30 is lowered; but clears the bent end-79 when the frame 30 is lowered, and clears the bent end, 78 when the frame is raised. That is, the two bent ends 78 and 79 are oii'set from each other, as is perha s best shown in Fig. 8, 'so that the pin A81will miss one-of them if it strikes the other.

In normal operation, the parts are as shown in Fig. 6, with the frame 30 lowered and the chart being driven at low speed. At this time, the pin 81` lies against the bent end 78 of the spring-contact member 75, and holds that contact member out of engagement with the contact member 76; so that there `is no circuit through the switch 75f76-77 even though the spring-contact member `7 6 is againstl the spring-contact vmember 77.

When an emergency occurs, such`J as a overload or a lfailure of voltage, the rela- ys 41 or 42 closes the circuit of the electromag# net 35. That magnet at once lifts the lframe 30, to put the high-speed drive into operation by meshing the worm-wheel 29 with the worm 31. This lifting ofthe frame 30 disengages the pin 81 from the bent end 78 of the spring-contact member 75, and such spring-contact member 75 at once springs l into engagement wit-h the intermediate s )ring-contact member 7 6, as is indicated in otted-lines in Fig. 6. This completes the circuit through the Switch 7 5-76-77 to maintain the circuit of the electro-magnet 35 even though the circuit through the relay 41 or 42 is immediately broken.

Uponv the meshing of the worm-wheel 29 with the worm 431, the high-speed drive starts into operation, to drive the chart -at A the desired high speed as already explained. When the disk 80 has about completed one revolution, the pin 81 carried thereby strikes the bent end 79 ofthe intermediate springcontact member 76. This swings' both con-l tact members and 76 towards the left, to separate the intermediate contact member 76 from the right-hand contact member 77, as vis clear from Fig. 7. Fig. 7 showsthis condition at .the very momentA it occurs, -before the frame 30 has dropped, although the electro-magnet 35 -is de-energized by this opening of the switch 75-76-77 unless one of the'relays 41 or 42 remains closed. If such relay remains closed, the pin 81 continues in its clockwise movement, and merely snaps past the spring-member 76, to permit the latter to return into contact with the member 77. However, if at thetime the spring-contact member 76 is moved to the left (Fig. 7 the relays 41 and 42vare both open, the electro-magnet 35 is deenergized, so that it permits the frame 30 to drop to demesli the worm-wheel 29 from the worm 31 and thus stop the high-speed drive. As the frame 30 thus drops, the pin 81 drops below the bent end 79 of the intermediate springcontact member 76, and lets such intermedite spring-contact member swing over towards the right into engagement with the spring-contact member 77, to the position shown in Fig. 6. However, while the pin 81 drops out of the path of the vbent end 79 of the intermediate contact member 76, it dro s into the path of the bent end 78 of the le hand spring-contact member 75 -and so prevents such left-hand spring-contact member 75 from s ringing over toward the right, and thus disengages it from the intermediate Contact member- 7 6. This leaves the parts in the position shown in Fig. 6, in which they were during the normal low-speed operation; and the parts remain in this position until the next emergency occurs.

I claim as my invention 1. In a graphic meter, the combination of a chart, a marking device for the chart, a low-speed driving mechanism for normally driving the chart, a high-speed driving mechanism for driving the chart at a higher speed, said high-speed driving mechanism being normally inelfective to drive the chart, and means controlled b the occurrence of an emergency for making said high-speed driving mechanism effective to drive the chart and for maintaining the high-speed drive effective immediately thereupon and continuously thereafter for a predetermined time independently ofthe cessation of the einer frency meanwhile.

2. lrI`he combination set forth in claim 1, with the addition that said high-speed driving mechanism includes a continuously moving driving device. i

3. In a graphic meter, the combination of a chart, a marking device for the chart, a low-speed driving mechanism 'for normally driving the chart, a high-speed driving mechanism for drivingthe chart at a higher speed, said high-speed driving mechanism containing a continuously moving driving device and a normally open clutch between said continuously moving driving device and said'chart, and means includin a snapaction device for closing said clutc on the occurrence of an emergency and maintain? ing such clutch closed immediately thereuptinuance of the emergency.

4. In a ,graphic meter, the combination of a chart, a 'markingdevice for the chart, a low-speed driving mechanism for'normally driving the chart, a high-speed driving mechanism for driving the chart at a higher speed, said high-speed driving mechanism containing a continuously moving driving device and a normally open clutch between said continuously moving driving device and said chart, and means for closing said clutch on the occurrence of an emergenc and maintaining such clutch closed imme iately thereupon and continuously thereafter for a predetermined time regardless of the discontinuance of the emergenc 5. In a graphic meter, t e combination of a chart, a marking device for the chart, a lowspeed driving mechanism for normally driving the chart, a. hiUh-speed driving mechanism fordriving the chart at a higher speed, said high-speed driving mechanism including a continuously moving' driving device and a normally open clutch betweeny said continuously moving drivin device and said chart, means for closing sai clutch on the occurrence of an emergency, and a snap-action device for preventing the opening of said Vclutch following' its closing until a predetermined movement athigh speed has been Given the chart.

6. In a graphic meter, the combination of a chart, a marking device for `the chart, a low-speed driving mechanism for normally driving the chart, a high-speed driving mechanism for driving the chart at a higher speed, said high-speed driving mechanism being normally ineffective to drive the chart, and means controlled'by the occurrence'of an emergency for making said high-.speed driving mechanism effective to drive the chart, said means including a device acting independently of any prerequisite highspeed movement for maintaining the highspeed drive even though the emergency ceases.

7. The combination set forth in claim 6. with the addition of means whereby said maintaining device is automatically rendered ineffective after a time following the p cessation ofthe emergency.

8; In a graphic meter, the combination of a chart, a marking device for the chart, a low-speed' driving mechanism for normally driving the chart, a high-speed driving mechanism for driving the chart at a higher` speed, said high-speed driving mechanism being normally ineffective to drive the chart, and means controlled by the occurrence of an emergency for making said high-speed driving mechanism effective to drive the chart, said means including a spring-pressed member which is released by the shift to the high-speed drive and acts upon such release to maintain such high-speed drive, and said means also including a member for resetting such springpressed device and stopping such highspeed drive at a time subsequent to the cessation ofthe emergency. y

In witness whereof, I Ihave hereunto set my hand at Indianapolis, Indiana, this 17th day of March, A. D. one thousand nine hundred andl twenty-six. i

DONALD JAMES ANGUS.`

Images