US2878636A - Control system and method - Google Patents

Description

March 24, 1959 J. w. HICKS, JR., ET AL 2,878,635

CONTROL SYSTEM AND METHOD Filed Aug. ll, 1955 R. J, wm om mum l WHR Y IMU mm "L TL f Nw iw um WN m L lal WW W PJY B /w w lk w/ h x11/wm wm i m mw uio/w om wv mm Nm *www g h @w m 0mm W @N m H Q llJll. om nl@ l Il. A Q K WN Nv @N Nw n@ ATTORNEY United States Patent t) CONTROL SYSTEM AND METHOD John Wilbur Hicks, Jr., Southbridge, Mass., and Philip N. Smith, Clemson, S.C., assignors to Deering'Milliken Research Corporation, Pendleton, S.C., a corporation of Delaware Application August 11, 1955, Serial No. 527,683

9 Claims. (Cl. 57-38.3)

The present invention relates to control systems and more particularly to control systems of the type wherein a sequence of control signals controls one or a plurality of elements. The invention comprises a novel system of this type wherein the control signals are of intermittent occurrence of constant or of random duration, or

response to occurrence of a phenomenon, the duration of which control condition is completely independent of the duration of the phenomenon.

It is a further object of the invention to provide a novel control system which sets and terminates .a control condition or signal having a selectively predetermined maximum duration in response to occurrence of a phenomenon, the control condition being independent of the duration of the phenomenon.

Still a further object is to provide a unique control system which sets and terminates a control condition or signal in response to occurrence of a phenomenon, wherein the maximum duration of the control condition or signal may be selectively predetermined independently of the duration of the phenomenon, and wherein the duration of control condition below the maximum is dependent on the duration of the phenomenon.

Another object is to provide an improvement in apparatus for forming novelty yarn, particularly yarn having slubs, wherein slubs of selectively predetermined length are formed in response to certain phenomena, and wherein the length of the slubs is independent of the duration of the phenomena.

A further object is to provide an improvement for yarn slub forming apparatus of the type in which a slub is formed in response to occurrence of a phenomenon, such that the slubs may be made to have either a maximum selectively predetermined length or a lesser length determined by whether the duration of the phenomenon is equal to or greater than a certain selectively predetermined period or is less than such predetermined period.

Still a further object is to provide a control apparatus for production of novelty yarn wherein novel yarn formations of intermittent Occurrence in accordance with occurrence of intermittent phenomena may be made to conform in length selectively either to a selected value independent of the duration of the phenomena or alternatively to a selectively predetermined maximum length independent of the duration of the phenomena or a less length proportionate to the duration of the initiating phenomena, depending on whether the duration of the phenomena is equal to or greater than a selectively predetermined period or is less than such period.

A still further object is to provide an improved method of forming novelty yarn in which yarn variations are formed having the variation length proportional to the duration of an occurring phenomena when the phenomena duration does not exceed a selected time period, and of a selected maximum length corresponding to the se lected time period when the duration of the phenomena exceeds the selected time period.

Still other objects and many attendant advantages will become apparent from the following detailed description of one preferred embodiment of the invention, taken in conjunction with the accompanying drawing, wherein the figure is a diagrammatic illustration of one preferred embodiment of the invention as applied to novelty yarn forming apparatus.

In the figure, a source of random or other intermittent phenomena is diagrammatically indicated at 12, and a device for detecting variations in the source 12 and converting such variations into a corresponding sequence of positive electrical pulses is indicated at 14. Source 12 may be one, or a plurality of, counter tubes actuated upon penetration by cosmic rays or by radiation from radioactive material, as disclosed in U. S. Patent No. 2,612,743 to F. P. Strother, or a phonograph pickup or other suitable transducer which may be used with a record of desired phenomena or other source of suitable phenomena, such as disclosed in Anderson Patent No. 2,595,220, or alternatively may be any other source of suitable and desired phenomena. Device 14, when source 12 is of the above described types, may be a simple amplifier or a coincident circuit, as in the Strother patent, or other suitable phenomena responsive pulse forming device, depending upon the phenomena source 12 and the desired output of pulses from device 14. So far as the present invention is concerned, source 12 may be considered as a conventional cosmic ray actuated counter, such as a Geiger-Mller counter tube, or as a suitable transducer together with a recording of signals corresponding to cosmic ray or other intermittent phenomena, and device 14 may be considered as an am plilier and as a means for emitting a positive pulse upon each discharge of the counter, or pickup of each new signal by the transducer, of source 12. The positive pulses emitted by device 14 initiate control signals by means of the circuit now to be described.

The positive potential output lead 16, which may for example be the output lead from a cathode follower rectifier-filter pulse forming circuit, of device 14 is con nected to the control element, in the example, grid 18, of a rst electron control device, such as triode tube 20. In the plate circuit of tube 20 there is connected the coil of a relay 22 or other suitable electroresponsive control device, one side of which is connected to a suitable source of positive potential, indicated at B+. Relay 22 which may be of any conventional or suitable construction, is of the double pole, double throw type having a pair of contact arms 24 and 27 and associated contacts 25, 26 and 28, 29, respectively.

When no pulse is emanating from device 14, tube 20 is normally in a quiescent condition such that the quiescent current ow is insutlicient to pull in relay 22. In this normal deenergized state of relay 22, its contact arm 24 makes contact with contact 26, thereby connecting a voltage divider network, including resistors 30, 31 and 32, to B+. These resistors are of suitable value such that the voltage thus appearing across grid bias resistor 32 more than suiciently positively biases the control element, such as grid 34, of a second electron control device, such as electron tube 40, to cause the tube to conduct sufficiently to energize or pull in a second electro-responsive contact device, which in the illustrative embodiment is a relay 42.?'3Relay 42 is of the double pole single throw type, having a pair of normally open contact arms 44, 48, and associated contacts 46, 50.

Also, during the time that relay 22 is in a deenergized state, the contact arm 24 being closed with contact 26 connects a variable capacity element, such as a variable condenser 36, and shunt resistor 38 to B+ through resistor 30. Thus, during the quiescent state of tube 2t) the variable condenser 36 is charged to substantially the same positive potential as that existing at the junction of resistors 30 'and 31.

During energization of relay 42, its movable contact arms 44 and 48 are in contact with contacts 46 and Si), respectively; however, during deenergization of relay 22 no circuit is completed through these contacts of relay 44. f

Upon the transmittal of a positive pulse of sufficient amplitude from device 14 through lead 16 to the grid 18 of tube 20, the tube is rendered conductive to such a degree as to pull in relay 22. This opens contact arms 24 and 27 of the relay armature from their associated contacts 26 and 28 respectively, and causes relay contact arm 24 to make with'contact 25 and relay contact arm 27 to make with contact 29.

Making of contact between contact arm 24 and contact completes a holding circuit for tube 28 and relay 22, which runs from B+ through contact arm 24, con*- tact 25, lead 60, contact 58, contactA arm 48, vlead 62, resistor 64, jumper 66, to the grid 18 connection, and resistor 68 to ground. `Resistor 64 is of such value in relation to resistor 68 (which may suitably serve an additional function as the cathode resistor of a cathode follower rectifier andlter circuit in the preceding stage of the device 14), as to povide a bias voltage on the grid 18 which will maintain the tube 20 conductive sufciently to maintain energization or hold-in of relay 22 so long as the holding circuit from B+ through lead 62 is unbroken.

The breaking of contact between contact arm 24 and V'contact 26 disconnects the circuits for the control grid 34 and the condenser 36 from B+, and thereupon positively charged condenser 36 begins to discharge through resistors 31, 32 and 38. lAt the beginning of this discharge period the charge on condenser 36 is suicient to maintain the tube 4l) conductive with a sucient current ilow to maintain relay 42 energized. At the end of a predetermined time, determined substantially by the RC circuit including condenser 36 and resistors 31, 32 and 38, the condenser 36 will have discharged to a point i where the voltage appearing across resistor 32 provides a grid bias such that the ow of current through tube 4G insufficient to hold the relay 42 in (i. e. to maintain 1t in energized position), and it Will then fall out to deenergized position, at which time contact arms 44 and 48 will break contact with contacts 46 and '50 respectively. It will readily be apparent that the time period of energization of relays 22 and 42 together may be selectively varied as desired by selectively varying condenser 36 and thus effectively changing the above mentioned RCcircuit time constant.

The breaking of contact between contact arm 48 and contact 50 breaks the holding circuit'v for tube 20 and relay 22. Thus, immediately after fall out of relay 42, relay 22 will fall out (i. e. will become deenergized) and the condenser 36 charging circuit and grid 34 bias circuit to B+ will again be established through contact arm 24 and Contact 26 of relay 22. Thus, the apparatus is returned to its original normal ready position and state wherein relay 22 is deenergized and relay 42 is lenergized` The control signal or condition which is' controlled as to initiationv and termination by the above describedcircuitryand apparatus is a signal or condition initiated and maintained-only when contact arms 27 and 44' arein contact with contacts 26 and 46 respectively, thus completing a circuit from one lead 70 to a suitable source of power (not shown) through contact arm 44, contact 46, lead 72, contact 29, contact arm 27, lead 76, instrument 89 (which in the illustrative example is an electroresponsive clutch) and the return power lead 74. It will be apparent from the foregoing that this signal is initiated upon the transmittal of a pulse to the grid 18 of tube 20 and the consequent closing of contact arm 27 with contact 29 through energization of relay 22. Since the control signal or condition requires making of both contact arm 27 with Contact 29 and contact arm 44 with contact 46, the fall out of relay 42 will result in the immediate termination of the control signal or condition through the consequent breaking of contact arm 44 and contact 46. The time duration of the control signal, as brought out above, will for any selected tube 48, relay 42 and B+ voltage, be determined by the time constant of the RC circuit controlling bias on grid 34 and this is dependent on the selected value of variable condenser 36. Thus, to increase or decrease the time duration of the control signal or condition it is only necessary to increase or decrease the capacity of Variable condenser 38.

The randomly or otherwise intermittently occurring control signals of selectively constant duration obtained by the described circuit may have a wide variety of applications and may be used whenever it is desired to control an element after intermittent intervals of predicted or unpredicted duration.

Preferably, the signals are used to insert slubs into yarn and for this purpose relays 22 and 42 control the actuating circuit of a device which, when energized, decreases the draft of a yarn drafting and spinning mechanism, as for example, by increasing the rate -of rotation of the feed or back rolls of the mechanism. In the illustrated embodiment, such a control device is diagrammatically indicated as a magnetic, solenoid operated, or other electroresponsive clutch 80. As indicated supra, the energizing circuit of the clutch includes a pair of power leads 70, 74 connected to any suitable source of energy (not shown), relay arm 44, relay contact 46, relay contact 29, relay arm 27, and lead 76. The clutch is thus energized during each controll signal or condition. When energized, it couples a shaft 82 to a drive shaft 84 and such coupling through suitable over-riding clutches, or the like, indicated diagrammatically at 86, increases the rate of rotation of the driven feed roll 88 of a yarn drafting and spinning mechanism. The parts of the yarn drafting and spinning mechanism, other than the roll 88, have not been illustrated in the drawing inasmuch as such mechanisms are well known in the art and the details thereof form no part of the present invention. It will be understood that during the intervals between control signals, the roll 88 is driven as usual from the main drive shaft 90 of the mechanism at a constant rate of rotation.

During control signals, that is during energization of relays 22 and 42 and magnetic clutch 80, the feed rolls are driven at an increased rate from shaft 84 through shaft 82 and the over-riding clutch 86. The increased rate of rotation of the feed rolls decreases the draft of the mechanism and increases the diameter of the yarn, and hence intermittently spaced slubs -of a length determined by the period of duration of the control signals will be inserted in the yarn.

As heretofore indicated, the slubs inserted in the yarn by the illustrative system will all be of the same length, and this length may be changed by adjustment of the time constant of the RC timing circuit, particularly by varying the condenser 36. The illustrated system may be readily modified, as desired, for production of yarn with slubs of selectively different lengths therein. For this purpose, means may be provided for continuously or intermittently varying condenser 36, as desired, in any suitable manner, such as by continuous or inter-v mittent rotation of theplates of the condenser, as shown `for example in U.S. Patent No. 2,638,731 to Norman E. Klein.

As described above, the ilustrated system provides a control signal which is completely independent as to duration thereof with respect to the intermittent phenomena or pulses to which the system is responsive. The system is further particularly advantageous in that through the removal of jumper 66 the control signal may be made to vary both as to the time duration determined by the RC timing circuit including condenser 36, and also the duration of the pulse from device lll, should such pulse be of a shorter time duration than the timing period set by the selectively controllable RC circuit.

It will be apparent that when jumper 66 is removed, the holding circuit through lead 62 to the control grid 18 of tube 20 will be rendered ineffective, and thus tube 20 will continue to conduct at a relay energizing level only so long as a positive control pulse is transmitted through lead 16 from the device 14. if the pulse transmitted through lead 16 is of longer duration than the timing period of the RC control circuit for tube 40, then the RC timing circuit will control or determine the length of the duration ofthe control signal of the system. Thus, if a control pulse of one second duration is applied to the control grid of tube 20, with the condenser 36 of the RC circuit set for a time controlling period of 1/2 second, the tube 40 will be cut off or otherwise insufficiently conductive to hold in relay 42 at the end of 1/2 second after origination of the control signal, and thus the control signal will `be terminated at this time through the breaking of contact between relay arm d4 and contact 46. On the other hand, with an output pulse from device 14 of 1/2 second and a setting of the RC circuit for a control period of one second, although the tube d@ will continue to conduct sufliciently to hold in relay 52 for one second, the tube 20 will return to its quiescent condition at the end of 1/2 second due to termination of the pulse from device 14, and will thus cause termination of the control signal at the end of 1/2 second through the opening of relay 22 and consequent breaking of contact between relay 24, 27 and relay contact 29. Thus, it will be seen that a maximum period or duration of the control signal may lbe set with this modification of the system, and the control signais will thus be of this maximum duration or less depending upon Ywhether the input pulse on control grid l is of longer or shorter duration than the time setting of the RC circuit including variable condenser 36.

The control system of the invention has now been described with particular reference to its appli-cation to the production of yarn having slubs therein at random intervals or otherwise intermittent intervals and of fixed or of random lengths as desired. In the particular embodiment of the invention illustrated, a control system has been indicated as controlling the insertion of slubs of yarn by increasing the rate of rotation of the feed rolls of the yarn spinning and drafting mechanism to reduce the duration thereof. It will be understood that the draft could lhe reduced with the increased rate of feed roll rotation, for example, by change in ratch length or by decrease in rate of rotation of the draft rolls, or by change of rotation of the feed of the roving and the ratch in the case of conical feed rolls, and that slubs could be injected into yarn with the change of draft, for example, by the addition of loose fibers to the roving. Also, slubs could lbe injected into continuous filament yarn during its fusion or spinning thereof, or during stretch breaking and drafting thereof.

The control system of the invention could be advantageously employed for purposes other than the injection of slubs into yarn. For example, novel printing effects on fabrics, or on Wall coverings or other surfaces, could be obtained in accordance with the invention by control of a printing element in response to the control signals, or the control signals could `be used to provide intermittent movement of a target in a shooting gallery. Other applications of the invention to fields wherein random or otherwise intermittent variations of a characteristic of an article or an erratic or otherwise intermittent sequence of events may be desired, will occur tc those skilled in the art.

Obviously, modifications both in the described method of the invention and in the specific means illustrated and described herein will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the invention, and we therefore do not intend the invention to be limited except as defined by the scope of the appended claims.

We claim:

l. The method of producing a novelty yarn which comprises utilizing intermittent phenomena of varia-ble duration to obtain a plurality of intermittent control signals initiated by said intermittent phenomena, terminating said control signals upon termination of said phenomena when the initiating phenomenon does not exceed in duration a selected predetermined time period, and terminating said control signals upon expiration of said selected predetermined time period when the duration of the initiating phenomenon exceeds said selected predetermined time, and varying the yarn formation from normal during the control signals.

2. A control system comprising a first normally deenergized relay having a pair of normally open contacts, a second normally energized relay having an energizing circuit and a pair of normally closed contacts, said pairs of relay contacts being in series connection and comprising a control circuit, means responsive to a control phenomenon for energizing said first relay to thereby close said normally open contacts, a holding circuit for and operatively connected to said first relay and responsive to occurrence o control phenomenon to hold said first relay in energized position, saii holding circuit including a pair of normally closed contacts of said second relay, and time controlling means operatively connected to said second relay energizing circuit and responsive to occurrence of said control phenomenon to initiate timing of a control period and at the end of said control period to deenergize said second relay and thereby break said control circuit and said holding circuit.

3. A control system as defined in claim 2 wherein means are provided for selectively rendering said holding circuit inoperative.

4. A time controlling device comprising first normally open and second normally closed series connected switches, a first normally deenergized relay operatively connected to said first switch and responsive to a first condition to close said first switch to set a first controlled condition, and `a second normally energized relay operatively connected to said second switch, and means operatively responsive to occurrence of said first condition to initiate a predetermined selectively controllable time interval, said second relay being operatively responsive to termination of said time interval to open said second switch and thereby terminate said controlled condition.

5. A time controlling device comprising first normally open and second normally closed series connected switches, a first normally deenergized relay operatively connected to said first switch and operatively responsive to a first condition to close said first switch to set a first controlled condition, a second normally energized relay operatively connected to said second switch, and means operatively responsive to occurrence of said first condition to initiate a predetermined selectively controllable time interval, said second relay being operatively responsive to termination of said time interval to open said second switch and thereby terminate said controlled condition, and a normally open holding circuit including a normally open switch operative to close in response to said first condition and operative upon closing to hold said first mentioned switch closed until termination of said time interval.

6. A control system according to claim 2 wherein means are provided for selectively rendering said holding circuit operative, said last named means comprising a removable electrical jumper conduit.

7. Apparatus for producing a novelty yarn, comprising means for varying the yarn formation from normal in response to a control system, said means including an electrical responsive element, said apparatus further comprising a control system comprising a rst normally deenergized relay having a pair of normally open contacts, a second normally energized relay having an energizing circuit and a pair of normally closed contacts, said pairs of relay contacts being in series connection and comprising a control circuit, means responsive to a control phenomenon for energizing said rst relay to thereby close said normally open contacts, a holding circuit for and operatively connected to said first relay and respOnsive to occurrence of said control phenomenon to hold said rst relay in energized position, said holding circuit including a pair of normally closed contacts of said second relay, and time controlling means operatively connected to said second relay energizing circuit and responsive to occurrence of said control phenomenon to initiate timing of a control period and at the end of said control period to deenergize said second relay and thereby break said control circuit and said holding circuit, said electroresponsive element being in series connection with said pairs of series connected relay contacts, whereby said yarn varying apparatus including said electroresponsive element is under control of said control system.

S. A control system according to claim 2 wherein said means for energizing said rst relay includes an electron control valve, said holding circuit further including a pair of normally open contacts of said rst relay whereby said holding circuit is effective only when both of said relays are energized.

9. Apparatus according to claim 2, further including a controlled load in series connection with said rst two mentioned pairs of series connected contacts.V

References Cited in the ile of this patent UNITED STATES PATENTS Re. 23,790 Strother Feb. 23, 1954 1,516,646 Roseby Nov. 25, 1924 2,339,750 Bartholy Ian. 25, 1944 2,622,282 Hare Dec. 23, 1952 2,731,559 Marshall et al Ian. 17, 1956

Images