US2040918A - Telemetering device - Google Patents

Description

` w lllllllllllllllllll Z6 50 Z7- 541-' I I",

May 19, 1936. C, W, BRlSTOL 2,040,918-

TELEMETERING DEVICE Filed Sept. 14, 1954 .2 Sheets-Sheet l IIIIIHIUB @Hill May 19, 1936. l c. w. BRls'roL 2,040,918 TELEMTERING DEVICE Filed Sept. 14, 1954 2 Sheets-Sheet 2 INVENTOR CARL ro/v W 3R/WOLA BY r ATTORNEY Patented May 1.9, 1936 muren STATES PATENT OFFICE TELEMETERING DEVICE Application September 14, 1934, Serial No. 743,967

6 Claims.

The invention relates to telemetering systems; and more particularly to receiving devices for use therein and adapted, for example, to a system of the nature set forth'in U. S. Patent #1,822,683 (reissued January 2, 1934, as #19,039). In systems of this type, signals of a time duration corresponding to a quantity of variable magnitude-and controlled jointly by a substantially constant speed motor means constantly operable and a quantity responsive means-are transmitted, as recurrent electrical impulses of equal magnitudes but varying durations, over a suitable connecting circuit to a receiver device comprising substantially constantspeed motor means and means actuated thereby for the duration of said signals.

The present invention has for an object the provision of a receiving device, for use in a telemetering system of the aforesaid type, which shall be free from the objectionable feature of mechanical backlash which has heretofore characterized receiving mechanisms utilized in such systems.

A further object of the invention resides in the provision of receiving apparatus embodying simple solenoidal magnets` of standard construction whereby there is eliminated the use of intricately designed electromagnetic structures which require provision for both axial and rotary movement.

Another object of the invention resides in the provision of a receiving device in which the parts subject to intermittent motion shall be of relatively small mass to reduce inertia effects to a minimum.

A further object of the invention resides in the provision of means whereby there is given a positive indication of the presence of trouble in the transmission means between the receiving and J transmitting instruments or of trouble at the latmeans, motor means continuously operable at substantially constant speed, and means controlled jointly by the responsive and motor means to produce the signals of a time duration corresponding to the quantity affecting the quantityresponsive means. One of the said gear members, furthermore, is adapted to operate continuously and another to be stopped by said braking elementin accordance with the transmitted irnpulses, whereby the position of said planetary member and associated mechanism may be governed.

The nature of the invention, however, will best be understood when, described in connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary front elevation of the Figs. 6 and '7 are respectively a front elevation, I

with parts broken away, and a side elevation, of a transmitting device suitable for use with the novel receiving device.

Fig. 8 illustrates, more or less diagrammatically, the arrangement of the various members in a telemetering system.

Referring to the drawings, more particularly Figs. l to 3 thereof, I0 and II designate suitable frame plates for the mounting of the various parts of the novel receiving device, the former plate constituting the base and the latter the front plate. A dial plate I2 is also pnovided, being located in front of the plate I I; and the said plates are secured together and spaced apart by suitable posts I3 and a post I4, the former being disposed near the extremities of said plates and the latter centrally located and provided with a cylindrical portion adapted to serve as a bearing.

Between the plates Ill and II are mounted for rotation two similar epicyclic trains or differential gearings I5 and I6 carried on spindles Il and I8, respectively, and having the following operative relationship. The train I5 comprises two bevel gears 2D and 2l both running freely on the spindle Il, and both having meshing engagement with one or more beveled piniohs 22 carried on a shaft member 23 located perpendicularly to the spindle I'I, the shaft being mounted rotatably thereon through a hub 24. Thus, if the spindie I1 be held stationary and either of the gears 20 or 2| rotated, the other of the gears will tend to rotate in the opposite direction with the same angular velocity. Moreover, if either of the gears 2l or 2| be held stationary and the other gear rotated, the pinions 22 will roll upon the stationary gear as planet wheels and will impart to the shaft 23 an angular velocity which is half of that with which the gear is rotated.

Attached to beveled gear 20 is a spur gear 25 and to the gear 2| `a braking wheel 26 adapted for positive engagement with an oscillatable brake element 21, either by friction vor by a more positive means and whereby the said braking wheel 26 and gear 2| may be brought to a positive standstill.

The train I 6 is a duplicate in all respects to the train I5, having the two beveled gears 28 and 29 running freely upon the spindle I6; and having also in common mesh one or more beveled pinions 33, carried upon a shaft 3| attached by a hub 32 to the spindle I6 for rotation thereon. Thus, under conditions as hereinbefore set forth, the

said pinions 33 may be caused to function asl planet wheels.

There is attached, also, to the beveled gear 28 a spur gear 33 which meshes with the similar spur gear 25 of the other train. As in the case of said other train, a brake wheel 34 is carried by the opposite gear 23 of train I6; `and this wheel is adapted to be engaged by the brake element 21 alternatively to the brake wheel 26,

A constant speed motor 35 is carried by the base plate I|| and may be of the well known A. C. synchronous clock type. -Through a pinion 36 meshing with the gear 33, and driven by the said motor, continuous rotation in opposite directions is communicated to the said gears 25 and 33, and through these to the respective associated trains |5 and I6.

The shaft 23 of train I5 is extended at one end beyond the periphery of the beveled gears 20 and 2|, forming a stop 31 adapted to engage an adjustable screw member 36 threaded through one of the posts I3 and locked thereto by a thumb nut 39. A spiral spring 40, having its inner end ailixed to the spindle I1 and its outer end to a post 4| on the rear surface of plate serves to urge the spindle in a counter-clockwise sense and to hold the stop 31 in engagement with the end of screw 36. Spindle I1 is extended through the plate II and carries a crank member or dog 42 whose position at all times will correspond to that of said shaft 23.

Similarly, the shaft 3| of the gear train |6 is extended to form a stop 43 adapted to engage a screw member 44 threaded through and adjustably locked to another of the posts I3 by a nut 45. The spiral spring 46 between the spindle I8 and an abutment or post 41 on theplate I I, serves to urge the said spindle I3 in a clockwise sense and to hold stop 43 in engagement with the end of a screw 44. A crank or dog 46 is xed to an extension of the spindle I6 so that its `position at all times will correspond to that of the shaft member 3|.

A lever arm 5U, journalled upon a cylindrical portion of post Il, carries the brake element 21 as well as an armature 5I of ferromagnetic ma terialwithin the field of an electromagnet 52, which tends to actuate the lever arm in opposition to a spring 53 attached thereto, so that under iniiuence of the magnet the brake will be applied to the wheel 34, and under that of the spring it'will be applied to the wheel 26.-

A43, respectively, so that rotation may thereby be imparted to the said pinions. Centrally disposed at the rear of the dial plate I2, and fixed to a `spindle 58 which extends through to the. front of the dial plate I2, is a gear member 59 meshing with both the pinions 54 and 55. Carried by the forward extension of the spindle 53V is a pointer 50, which, by its position relatively to a graduated scale 6I on the dial plate I2, serves to provide an indication of the angular position of Vthe gear member 59. 1

The `operation of the apparatus as thus far described is as follows: The motor 35 is caused to operatecontinuously so as to impart to the gear 33 rotation in a counter-clockwise sense and to the 'gear 25 rotation in a clockwise sense. Assuming for the momentA that the brake element 21 be inoperative, it will be seen that, the shaft members 23 and 3| being restrained against their stops by the springs 43 and 45, the pinions 22 and 3U will rotate about their respective axes; and the brake wheels will revolve freely, wheel 26 in a counter-clockwise sense and wheel 34 in a clockwise sense. Under actual conditions, however, wheels 26 and 34 will never both be simultaneously. free, one or other being engaged by the braking element 21., according to whether or not the magnet 52 is energized.

Assuming that the magnet is energized, the

braking element 21', under iniluence of the magnet, will engage the brake wheel 34, definitely stopping its rotation. Under this condition the bevel gear 29 will remain at rest, and upon its surface, actuated by the bevel gear 26, will roll the pinions 30, causing the shaft 3| and the parts carried thereby .to rotate in a counter-clockwise sense with an angular velocity half that of the gears 26 and 33, winding up the spring 46. This will cause the dog 46 to approach the arm 51, and. after engaging the same, will cause the pinion 55 to rotate, driving the gear member 59, whereby the pointer will tend to advance across the scale 6I in a clockwise sense.

Assuming, now," that the magnet 52 be de-ener gized, the armature 5| will at once be released, allowing the brake member 21 under the inuence of spring 53 to disengage the wheel 34 and immediately to engage the braking surface of the wheel 25. 'Ihe brake wheel 34 being no longer restrained by the brake member 21, the shaft 3| with the parts carried thereby, under the influ encev of the spring 46, will have been returned to the position where the stop 43 engages the screw 44. the dog 48 leaving the arm 51 in its position of maximum excursion.

The pinions 54 and 55 both being in permanent mesh with the gear 59, the arms 56 and 51 will at all times bear a deilnite position relationship to each other and to the pointer 60. Thus, the position in which the arm 56 will lle at the instant the dog 42 begins its excursion will depend upon the position in which the arm 51 was left by the dog 45 at the time the brake-wheel 34 was released, The relative position of the elements of the mechanism as shown in Figs. 1, 2 and 3 is that in which the dog 46 is about to engage the arm 51.

Upon the braking element 21 engaging the brake wheel 26, the differential train I5 will be caused to function in a manner identical with that described for the train I6, so that the dog instant of disengagement between the dog 48 and the arm 51. If the engagement of the braking element 21 with the Wheel 26 is of suicient duration, the dog`42 will reach the arm 56 and will cause it to rotate the pinion 54, whereby the pointer 60 will be caused to travel across the scale 6I in a counter-clockwise sense.

At the same time, through the action of pinion 55, the arm 51 will be forced toward the dog 48 as it lies in the position to which it was reset when the brake-wheel 34 was released. Thus it willbe seen that the pointer 60 will tend to lie in a position relative to the scale where it was left by the latest of the impulses coming alter-- nately from the trains I5 and I6, andthat if the excursion of either of these exceeds the magnitude of its previous excursion the pointer will be advanced to a new position on the scale.

It will thus be apparent that if the magnet 52 be energized for a time interval sufficiently long for the pointer 68 to make a complete transit of the scale 6I, then momentarily de-energized,

and then re-energized for a similar interval, the pointer will take up a position at the upper limit of the scale. Similarly, if the magnet be left de-energized for a time corresponding to the complete transit of the pointer and then momentarily energized, the pointer will take up a position at the lower limit of the scale.

It will further be apparent that if there be established a recurrent series of electrical impulses, in which equal cycles are made to correspond in duration with thetime of transit of the pointer, the latter, under the alternating inuence of the trains I5 and I6, will tend to take up on the scale a position in which its excursion from the lower limit of the scale (i. e. its total deflection) will bear to the total length of the scale a ratio equal to that existing be' tween the length of the interval in each cycle during which the magnet 52 is energized and the time of the complete cycle.

It will be observed that as no definite stops are provided for the arms 56 and 51, the position of the pointer will at any time be determined by the latest of the impulses from one or other of the dogs 42 and 48, and that the normal working angle of deflection of the pointer will be governed by the angle through which either of these dogs will rotate during the normal time interval of a cycle.

If the parts be so proportioned and adjusted that the normalangle or travel of the pointer corresponds exactly to the normal time interval as hereinabove set forth, and the pointer be free to overtravel the scale if so impelled, it will be apparent that, so long as the transmitting apparatus and circuit function in a normal manner, the pointer will remain within the limits of the scale, and that an excursion of the pointer above or below these limits will represent a period of energization or de-energization prolonged beyond the normal time interval of the transmitter, which in turn will provide an indication of faulty circuit conditions in the connecting line or of malfunctioning of the transmitting device.

While the epicyclic trains embodied in the mechanism as above set forth take the form of bevel gear differentials, it will be apparent to those skilled in such mechanisms that identical performance could be obtained by embodying in the design trains taking other mechanical forms.

For example, an epicyclic reverted gear such as that shown in Fig. 4 (sometimes known as a "Crypto gear) could be substituted for the type used in the trains I5 and I6 of Figs. 1, 2 and 3, with equivalent results. Here spur gear 65 carried upon a shaft 66 is to be directly connected to the elements of the mechanical system driven from the motor. An annular gear 61 running freely upon the shaft 66 has its outer surface adapted to serve as a brake wheel. In the space between the outer periphery of the gear 65 and the inner surface of the gear 61 runs a planetary gear 68, carried upon an arm 69, which is free toswing about the shaft 66 vas a center of rotation. The arm 69 corresponds to the dog 42 indicated in Figs. 2 and 3.

The general modification of the associated mechanism necessary to incorporate this gear train in the place of those shown whereby equivalent results will be obtained will be apparent to those versed in the art, and requires no further elucidation here. It will alsov be apparent that the functions of the gears 65 and 61 can be interchanged, so that 61 may be the driven gear and 65 attached to the brake-wheel.

A further alternative, whose application will also be apparent to those skilled in the art, is shown .in Fig. 5. Two similar spur gears 10 and 1I are mounted coaxially on a common shaft 12,

one at least being free to rotate thereon. Two spur pinions 13 and 14 are supported on an arm 15, also rotatable about the shaft 12. The pinion 13 meshes with the gear 10 and the pinion 14 with the gear 1I, and the pinions mesh with each other. 'I'hus it will be seen that there has been provided a differential gearing whose per.- formance will in every respect be a duplicate of the train i5 or I6 in Fig.. 1.

It will further be apparent that in any of the several types of epicyclic train which have been described, the driving forces as they affect the meshing of the gears will never be subject to reversal, so that under all operating conditions backlash between the gears will be taken up,

whereby errors due to lost motion will be eliminated from the mechanism.

So far as the transmitting device for operation of the receiving means aforesaid is concerned, any

suitable device may be utilized which will provide r l tions perforated to form guides for a bar 83 free 'to slide vertically therein. The Bourdon spring 82 is fixed at one end to the supporting member 8| and has attached to its free end a shaft 84 which passes centrally through the spring and projects to the forward part of the supporting member 8| and bears upon its forward end an indicating pointer 85.

Fluid pressure which it may be desired to measure, is conveyed to the interior of the Bourdon spring by a pipe 86, whereby the angular position of the free end of the spring and shaft 84 and the pointer 85 may be made representative of, and substantially proportional to, the pressure under measurement. By means well known to those skilled in the art of measurement, the

pressure in the pipe ll may be made representative of any one of a variety of magnitudes, such as temperature, head of water, etc.

Attached to the forward part of the supporting member Il is a dial plate l1, having engraved thereon a graduated scale to which is juxtaposed the indicating extremity of the pointer $5, so that the position of the pointer as indicated on the scale I1 becomes a measure of the pressure within the Bourdon spring l2 or of the magnitude represented thereby. Carried upon the shaft Il immediately behind the bar ll is a metal sector 8l having a contour conformed to a polar curve about the center line of the shaft u, whereby the radius of the sector in a selected xcd direction will vary in accordance with the angular posi- .tion of the sector. Thus if the contour of the sure in the Bourdon tube, as indicated by the` pointer Il on the scale I1.

Rotatably mounted upon a'hub I9, concentric with the shaft ll is a gear member Sl carrying a cam member Il, on the upper surface ci which rests a small roller l2 pivoted on a stud or bracket 93 which is fixed to the sliding bar 8l, whereby as the cam member 9| is caused to rotate, the bar Il will be smoothly reciprocated up and down. The stud 93 passes over the sector B8 at a point vertically above the center line of the shaft 84, and bears an insulated contact piece 94 adapted to engage the contour of the' sector and thus to form an electrical contact with the body of the instrument. Carried on the support of the instrument are two terminals 95 and 88, one electricaliy connected to the frame and the other connected through a flexible lead to the contact piece M.

A constant speed motor $1, which may be oi the A. C. synchronous clock motor type, is mounted upon the frame of the instrument; and

through a pinion il, meshing with the gear 90, the motor serves to rotate the cam member Bi at a constant velocity. Thus, as the motor is caused to operate.- the bar 8l will move up and down periodically. and as the contact piece 94 engages the sector 8l, the weight oi the bar will be taken thereby, and the cam will continue to rotate freely until it re-engages the roller 92 and lifts the bar.

1f the contour of the cam member Slvhas an Archimedian spiral conformation both on its ris ing and falling portions, the velocity of the bar 83 will be uniform in both directions diu'ing the portion of its cycle while it is in motion.

Thus, it will be seen that if the terminals 95 and 98 be connected to complete an electrical circuit.' there will pass in that circuit a series of cyclical impulses; and the duration of Athe interval of current flow'will bear to that of the complete cycle a ratio proportional to the magnitude of the measured iiuid pressure or condition rep` resented thereby.

In order that the complete cycles be' donned, the relative dimensions of the sector 88 and the cam 9| are so proportioned that with the pointer l! and the associated sector 8l at the upper limit of the scale, there will still take place a momentary interruption of the circuit as the cam member Si passes its highest point; while, with the sector in a position corresponding' to the lower limit of the scale, a momentary contact will be made as the cam member passes its lowest point.

The particular manner of interconnecting the receiving unit of the system with its associated transmitting unit is shown in Fig. 8. As indicatedthe constant speed motors 91 and 35, of the transmitting and receiving umts respectively, are supplied with electric current from suitable sources |00 and Iiii, not necessarily in synchronism with each other, but the speeds of the moA tors and the ratios of associated gear trains being so selected that the time which would be required for the pointer 6I to make a complete 10 transit of the scale BI in the receiving unit, with thebraking element 11 maintained in one position, is substantially equal to the time of one l complete revolution of the cam member Si in the transmitting unit. l5

The interconnecting or transmission line may consist of a two-wire circuit Il! including the electromagnet 51 of the receiving unit, the terminals 95 and 86 of the transmitting unit and a suitable source of current, as a battery lill, all connected in series, so that when the circuit is closed between the terminals 95 and 98 by engagement of the contact member SI with the sector 88, the magnet 52 will be energized with current from the battery |83. 25

Operation Y interval in each cycle ci operation during which the magnet 52 is energized. It will, therefore, be apparent that with an electrical interconnecting circuit made up as hereinbeiore set forth the pointer or indicator Eil on the receiving unit will tend to take up a position on the scale il which will be representative of, and proportional to, the magnitude of the condition measured by the transmitting unit.

It will be further apparent that, while the device has been shown as embodying an electrical circuit for carrying controlled impulses of electric current as almeans of transmission of the magnitudes of a measured quantity I do not wish to be restricted thereto as the transmission may be otherwise accomplished; and it will be also understood by those versed in the art that the receiver mechanism herein may readily be adapted for purposes other than recording without departing from the spirit of the invention.

I claim:

' 1. In a telemetering system: a receiving device subject to transmitted electrical impulses and 6U comprising an epicyclic gear train including a normally rotating portion and a normally stationary portion, a second cpicyclic gear train including a normally rotating portion and a normally stationary portion, means to impart con- 6.3 tinuous rotation to both trains, means to stop the normally rotating portion of the first-named train during transmission oi an electrical impulse and permit concurrently therewith rotation of the normally rotating portion ci the second-named Tr] train, and vice versa, and means associated with the respective normally stationary portions of both trains for engagement therewith and subject to deflection thereby in opposite senses.

`2. An electrical impulse-responsive device To f adapted to reproduce proportionately the effects ofv electrical impulses oi.' determined duration, said device comprising two epicyclic gear trains, each including a spindle member and a driving member, a planetary member,'an impelling mem' ber, and a free-running member, all carried by said spindle member for rotation thereon, an indicatingelement, means whereby said indicating element may bepositioned alternatively by the respective impelling members of the said trains,

,means to rotate continuously the driving members of said trains, and means associated with the free-running members and subject to a received electrical impulse to .stop rotation of one or thel members of said trains, and electromagnetically operated braking means, subject to`a received electrical impulse to stop rotation of one or the other of said free-running members.

4. An electrical impulse-responsive device .adapted to reproduce proportionately the effects of .electrical impulses of determined duration, said device comprising two epicyclic gear trains, each including a. spindle member and a driving member, a planetary member, an impelling member, and a free-running member, all carried by said spindle member for rotation thereon, an indicating element, means whereby said indicating element may be positioned alternatively by the respective impelli'ng members of the said trains, means to rotate continuously the driving members of lsaid trains, means associated with the free-runningmembers and subject to a received electrical impulse to stop rotation oi.' one or the f yother of said free-running members, and means to restore an impelling element to a predeter- `mined position when rotation oi the associated free-running member is no longer stopped.

5. An electrical impulse-responsive device adapted to reproduce proportionately the effects of electrical impulses of .determined duration, said device vcomprising twoepicyclic gear trains, each including a spindle member and a driving member, a planetary member, an impelling member; and a free-running member, all carried by said spindle member for rotation thereon, an

indicating element, 4means whereby said indicat-l ing elementv 'may be positioned alternatively by the respective `impelling members of the said trains, means to rotate continuously the driving' members of said trains, means associated with the free-running members and subject to a received electrical impulse to .stop rotation ofone or the other of said free-running members, means to restore an impelling element to a predeter-y mined position when rotation o'f the associated free-running member is no longer stopped, and

means to adjust the angularpositions of the re-l spective impelling elements lwhen the latter are in a state of repose.

6. An electrical impulse responsive device adapted to reproduce proportionately the eilects of electrical impulses of determined duration, said device comprising two epicyclic gear trains, means s mechanically interconnecting the gear trains, a driving means common to said gear trains with the drive gears of each continuously rotated therefrom in opposite directions at substantially constant speed, mechanically interconnected indicator actuating mechanisms, followup means for alternately driving invopposite div rections the respective indicator actuating means from the corresponding gear trains, and braking means under the control of telemetered impulses to engage one or the other of the gear trains to effect operation of its follow-up means. f

CARLTON W. BRISTOL.

Images