US2787044A - Control device for strand handling machine - Google Patents

Description

April 2, 1957 P. N. SMITH CONTROL DEVICE FOR STRAND HANDLING MACHINE Filed April 22, 1953 INVENTOR.

PHILYIP N, SMITH ATTORNEY United States Patent 2,787,044 CONTROL DEVICE FOR STRAND HANDLING MACHINE Philip N. Smith, Clemson, S. C., assignor to Deering Milliken Research Corporation, Pendleton, S. C., a

corporation of Delaware Application April 22, 1953, Serial No. 350,375 Claims. (Cl. 28-51) This invention relates to a new and improved control device for a strand handling machine and more particularly to an arrangement for stopping the machine when relaxation or loss of tension in a strand occurs, and for giving a selective indication of the fault location.

The stop motion device constituting my invention, while generally applicable to all strand handling or processing machines as used in the preparation of cord, thread or yarn or in wire fabrication, is particularly adapted for use with a textile warper and will, therefore, be de scribed with reference thereto.

One form of stop motion heretofore in use with conventional warping machines has utilized a drop Wire switch associated with each strand as drawn from the creel to directly control electromagnetic relays for opening the power circuit to the electric drive of the machine on the occurrence of a break or loss of tension in the strand.

Material improvements have been effected by using these 3 drop wire switches to control a normally energized electronic tube, which in turn provides the control for deenergizing a relay used in controlling the electric drive. Electronic controls permit the use of high voltage across the drop wire switches, thereby insuring reliability of operation even under adverse conditions, such as, the presence of dirt or lint on the switch contacts. The use of high voltage across the drop wire switches does not constitute an operational hazard in that the current in the electronic tube grid circuits to which the switches are connected may be held to a safe limit by the use of suitable resistors.

It is also desirable in control systems of the type here under consideration to provide a suitable signal on the occurrence of a fault in any of the strands being drawn from a conventional two-sided Warping creel, so as to indicate the particular side of the creel on which the fault occurred. Heretofore this has been accomplished by the use of signal lamps respectively energized through the operation of relays controlled by electronic tubes.

The foregoing arrangement requires the use of normally energized electronic tubes, a multiplicity of relays and signal lamps, all of which are complicated in structure and costly to construct and maintain.

It is, therefore, a principal object of my invention to provide a control system for a strand advancing machine which is simple in construction, low in first cost, and inexpensive to maintain.

A further and more specific object of my invention is to provide a simplified stop motion and fault indicating system for strand handling machines that possesses greater reliability and longer normal life than devices heretofore employed for a similar purpose.

Other objects and advantages will become apparent as the description of the invention proceeds.

In general, I accomplish the foregoing objects by the use of cold cathode gas discharge tubes having their anode circuits connected in parallel to a normally de-energized electromagnetic relay co-acting with a second relay for the control of power to the electric motor drive of the machine. Any number of drop wire switches may be associated with the starter anode of a given tube. How- Patented Apr. 2, 1957 ever, in the case of a stop motion for a textile warping machine, only two tubes are required, that is, one for each side of the supply creel. Thus, the drop wire switches associated with the strands being drawn from one side of the creel are joined in parallel and serially connected through a current limiting resistor and high voltage source of potential to the starter anode of one tube. The drop wire switches associated with the strands drawn from the other side of the creel are similarly connected to the starter anode of the other tube. The first strand to lose its tension causes its associated drop wire to close to impress a high voltage on the starter anode of its associated tube thereby rendering the tube conducting, which condition is utilized to actuate a suitable relay control circuit for stopping the electric drive of the machine. The cold cathode tubes are of a type that glow with considerable brilliance when energized, thereby giving a visual indication of the side of the creel on which the fault occurred.

A simple lockout arrangement is provided so that the tube energized in response to the first strand to slacken will be the only tube that is made conductive, thereby preserving the indicating function of the system. Lockout of the second tube is accomplished in that conduction of the first tube reduces the voltage available to provide anode conduction of the second tube so that the latter will not be fired.

A more specific description of the invention may be had with reference to the accompanying drawing in which the single figure shows in schematic form a textile warping machine embodying the control device of my invention.

In the drawing the reference numeral 10 diagrammatically illustrates a warped creel having frame members 12 and 14, each carrying a plurality of cones of yarn 16. The strands of yarn are drawn from the cones Each strand of yarn drawn from a cone 16 is threaded 1 through an eye 30 associated with one of a plurality of drop wire switches, in this instance designated as S1, S2, S3, and S4. The drop wire switches are arranged in two groups, one of which is associated with the yarn strands drawn from the creel frame 12 and the other associated with yarn strands withdrawn from creel frame 14. As illustrated, switches S1 nad S2 are associated with the frame side 12 whereas switches S3 and S4 are asscociated with strands drawn from frame side 14. All drop wire switches associated with frame side 12 are movably supported from a terminal bar 32, while all remaining drop wire switches associated with creel side 14 are movably mounted upon a terminal bar 34. All drop wire switches are normally maintained in the open circuit position by tension in the strands of yarn being drawn from the creel 10. However, when the tension in the strands slackens or a strand breaks, its associated drop wire switch is adapted to make contact with a contact bar 36 common to all switches.

Terminal bar 32 is connected by a conductor 38 to the starter anode 40 of a gaseous discharge tube 42 having a cold cathode 44 and an anode 46. Terminal bar 34 is similarly connected in that a conductor 48 connects it with a starter anode 50 of a gaseous discharge tube 52 having a cold cathode 54 and an anode 56. The contact bar 36 which is common to all drop wire switches is connected by a conductor 58 through a high ohmic value current limiting resistor 60 which is connected to the positive terminal of a suitable source of direct current potential shown for the purpose of illustration as batteries 62 and 64. The negative terminal of battery 64 is connected through a switch 66 to the cold cathodes 44 and 54 of tubes 42 and 52, respectively. The anodes 46 and 56 of tubes 42 and 52 are connected in parallel and serially through coil 68 of electromagnetic relay 70 to the positive terminal of battery 64. Relay 70 includes contacts generally indicated at 72, which contacts are normally closed when the relay is de-energized. The relay contacts 72 are serially connected with coil 28 of relay 26 in order to control the energization thereof. A manually operable push-button switch 74 is also serially connected with the relay contact 72 and the coil 28 so as to provide manual means for de-energizing the relay 26. Since the contacts of relay 26 which control the motor 22 also control energization of the coil 28 of relay 26, a by-pass circuit is needed to initially energize the coil 28. Such by-pass circuit is provided through the pushbutton start switch 76 which is adapted to be manually operated for initially energizing the coil 28. It will be noted from the circuit connections that once coil 28 is energized switch 76 may be released.

As shown schematically in the drawing, switches 66 and 76 may have a common actuating button 77 and conventional operating means normally biasing switch contacts 66 to the closed circuit position and switch contacts 76 t the open circuit position. It will thus be readily apparent that when button 77 is depressed, switch 66 will be opened and switch 76 will be closed and releasing the button will enable the switches to be returned to their normal positions.

The improved control circuit of my invention operates as follows: Assuming that yarn from the cones 16 has been threaded through the eyes 30 and the ends placed in position on the beam 20, the beam can be rotated by starting motor 22 as" by closing push-button switch 76. Once relay 26 is closed, the holding circuit therefore is complete through the holding ceil 28, relay contacts 72 and the push-button stop switch 74'. If, during the warping operation, a strand drawn from the frame 12 of the creel should slacken or break, its associated drop wire switch will make contact with contact bar 36. The closing of the associated drop wire switch impresses the available positive potential of batteries 62 and 64 on the starter anode 40 of tube 42 thereby rendering the tube conducting. The rendering of tube 42 conducting energizes relay coil 68 to open the contacts 72 thereby breaking the circuit to holding coil 28 of relay 26. The opening of relay 26 disconnects motor 22 from its source of power thereby stopping the warping machine.

When the warp beam stops, all strands being withdrawn from the creel'10, have a tendency to lose their tension, thereby causing an indiscriminate tendency to close a large number of drop wire switches. The subsequent closing of drop wire switches associated with strands from frame 14 of the creel, however, will not cause the gas discharge tube 52 to be fired. The impedance of relay coil 68 is so selected that the voltage drop thereacross will lower the available voltage at the starting anode 50 of tube 52 to an extent that the tube cannot fire. It will thus be seen that the first drop wire switch to close will be the one which determines the ignition of either of the gaseous discharge tubes. Tubes 42 and 52 are the type which produce considerable brillance during their conductivity. A conducting tube can therefore serve as a visual indicator of the particular location of a fault in the strand. Locating the fault with respect to either side of the warping machine is of particular importance since normally the operator observes the operation of the warping machine from a position adjacent the warper beam. Thus, when a fault occurs the glow of either of tubes 42 or 52 immediately gives the operator an indication on which side of the warping machine the fault occurred. Such an indication permits the operator to go directly to the location of the fault thereby avoiding a circuitous route about the machine which may become 4. necessary in the event the proper fault location is not indicated.

Upon the correction of the fault condition, the warping machine is again put into operation by depressing start button 77 thereby closing the switch 7 6. Switch 66 will be opened simultaneously with the closing of switch 76 to de-energize the conducting tube 42. As soon as the machine goes into operation, again restoring the tension on all strands, starting but-ton 77 is released allowing switch 66 to be closed placing the control circuit in readiness .0 indicate or detect a future fault.

In the event that a fault or a slackening of strands associated with the frame 14 of creel 10 occurs, an associated drop wire switch will energize starting anode 50 of tube 52. Tube 52 will then become energized to energize coil 68 to open relay contacts 72 in the same manner previously described in connection with the operation of tube 42. It will thus be seen that the tubes 42 and 52 provide a selective means for bringing about the stopping of the warping machine upon the occurrence of a fault or the slackening of any strand from either side of the creel. I have selected gaseous discharge tubes preferably filled with neon gas since such tubes produce a glow that is clearly visible to the operator, thereby giving him an indication as to the location of the fault.

I have discovered that a gaseous discharge tube known commercially as an RCA Type 1-C21 is desirable and possesses the characteristics required to give satisfactory operation. Also, by way of example, satisfactory operation is obtained with batteries 62 and 64 that are capable of delivering volts. 1 have also determined that the combined voltage of batteries 62 and 64 is sufficient when impressed across the drop wire switches to impress a positive pulse on the starter anodes of the tubes when the drop wire switches are closed in spite of the fact that the contacts may be coated with dirt or lint customarily found in the particular environment in which the warper is operated. By the use of a current limiting resistor 60 having a resistance of the order of five megohms, current fiow in the starter anode circuits to the tubes 42 or 52 is maintained within safe limits.

Further, by way of example, the impedance of coil 68 is so chosen that during the conduction of one tube the voltage drop across the coil will be of the order of 77 volts. The available anode voltage in such instance is just high enough to prevent anode extinction but is below the minimum starter voltage required to fire a second tube.

While I have shown a specific control system for a textile warping machine, it is to be understood that the same is for the purpose of illustration and that changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. In a textile warping machine, an electric motor for driving said machine to advance a plurality of warp ends, an electromagnetic relay for controlling said motor, a second electromagnetic relay for energizing said first relay, a drop wire switch for each warp end arranged in two groups, each of said switches being normally held in the open position by tension in its associated warp end and adapted to be closed on loss of tension, a pair of gaseous discharge tubes having their anode starter circuits respectively connected to one side of the switches in said groups, the other side of said switches of both groups being connected in common to a current limiting resistor, the other side of said resistor being connected in series with a source of anode potential to the cathodes of said tubes, the first of said switches to close in response to a loss in tension of a warp end causing a high voltage pulse to be impressed on the starter anode of its associated tube to render the same conducting and energize said second relay, said second relay on being energized causing said first relay to be de-energized to stop said motor.

2. The combination of claim 1 wherein the voltage drop across the coil of the second relay during conduction of one of said tubes is sufiicient to reduce the available anode potential below the firing potential of the other tube.

3. The combination according to claim 1 wherein the gaseous discharge tubes glow when in a conducting state to provide a visual signal of a fault condition in the associated group of warp ends.

4. Control apparatus for a device having means for moving material in a path, comprising a pair of movable senslng contacts engageable with said material at spaced apart points, said points being spaced apart transversely to said path, a bus contact engageable by each of said movable contacts, a pair of gaseous discharge tubes each having an anode, cathode, and control electrode, a translating device connected in common with the anode and cathode of each of said tubes, a source of direct E. M. F. operatively connected in series with the anode and cathode of each of said tubes and with said translating device for rendering the anode of each of the tubes positive with respect to the cathode "and for supplying the current required to operate the translating device, each of said contacts being connected to a corresponding one of said control electrodes, said bus contact being operatively connected to the positive side of said source of E. M. F. at a. potential point corresponding substantially to that connected to the anodes for individually applying positive potential to an individual one of said control grids upon movement of a corresponding one of said movable contacts into contact with said bus contact.

5. Control apparatus for a device having means for moving material in a path, comprising a pair of groups of movable sensing contacts engageable with said material at spaced apart points, said points being spaced apart transversely to said path, a bus contact engageable by each of said movable contacts, a pair of gaseous discharge tubes each having an anode, cathode, and control electrode, a translating device connected in common with the anode and cathode of each of said tubes, a source of direct E. M. F. operatively connected in series with the anode and cathode of each of said tubes and with said translating device for rendering the anode of each of the tubes positive with respect to the cathode and for supplying the current required to operate the translating devlce, each of said groups of contacts being connected to a corresponding one of said control electrodes, said bus contact being operatively connected to the positive side of said source of E. M. F. at a potential point corresponding substantially to that connected to the anodes for individually applying positive potential to an individual one of said control grids upon movement of a corresponding one of said movable contacts into contact with said bus contact.

6. Control apparatus for a device having means for moving material in a path, comprising a pair of movable sensing contacts engageable with said material at spacedapart points, said points being spaced apart transversely to said path, a bus contact engageable by each of said movable contacts, a pair of gaseous discharge tubes each having an anode, cathode, and control electrode, a translating device connected in common with the anode and cathode of each of said tubes, said tubes having their anode-cathode connections in mutually parallel relation, a source of direct E. M. F. operatively connected in series with the anode and cathode of each of said tubes and with said translating device for rendering the anode of each of the tubes positive with respect to the cathode and for supplying the current required to operate the translating device, each of said contacts being connected to a corresponding one of said control electrodes, said bus contact being operatively connected to a source of positive E. M. F. for individually applying positive potential above the normal necessary control bias potential for firing to an individual one of said control electrodes upon movement of a corresponding one of said mov l c n into contact with said bus contact, the load impedance of said anode-cathode circuits being so proportioned relative to the available anode potential and the minimum necessary anode firing potential for the individual tubes that the voltage drop across the load impedance upon firing of one of said tubes lowers the common anode potential below the minimum necessary anode initial firing potential of said tubes.

7. A stop motion for sensing transverse movement of linearly moving material comprising first and second transversely disposed material sensing movable contact fingers, a common bus contact means for said fingers, current translating means, a current limiting impedance and auxiliary source of direct E. M. F. operatively connected between said bus contact means and said translating means, the positive side of said source being connected electrically toward said bus contact means, first and second gaseous discharge tubes each having an anode, cathode, and control electrode, a main source of E. M. F., said translating means and said main source of E. M. F. being each connected in series relation with the anode and cathode of each of said tubes, the anodes and cathodes of said tubes being in mutual parallel relation, the negative side of said main source of E. M. F. being connected electrically toward said cathode, said main source and said auxiliary source of E. M. F. being connected in series relation, said first and second contacts being operatively connected respectively to the control electrodes of said first and second tubes.

8. A stop motion for sensing transverse movement of linearly moving material comprising first and second transversely disposed groups of material sensing movable contact fingers, a common bus contact for said fingers, curerent translating means, a current limiting impedance and auxiliary source of direct E. M. F. operatively connected between said bus contact and said translating means, the positive side of said source being connected electrically toward said bus contact, first and second gaseous discharge tubes each having an anode, cathode, and control electrode, a main source of E. M. F., said translating means and said main source of E. M. F. being each connected in series relation with the anode and cathode of each of said tubes, the anodes and cathodes of said tubes being in mutual parallel relation, the negative side of said main source of E. M. F. being connected electrically toward said cathode, said main source and said auxiliary source of E. M. F. being connected in series relation, said first and second groups of contacts being operatively connected respectively to the control electrodes of said first and second tubes.

9. A stop motion according to claim 7 wherein said translating means is an electroresponsive relay having a contact arm and a contact, a drive motor for linearly moving said material, an energizing circuit including a holding circuit for said motor, said contact and contact arm being operatively connected in said holding circuit.

10. A stop motion according to claim 9 wherein said holding circuit further having an initiating circuit for said motor energizing and holding circuit, a switch having a first normally closed movable contact in the common anode-cathode circuit of said tubes and a second normally open movable contact in said initiating circuit, said first and second movable switch contacts being in ganged relation, whereby actuation of said switch substantially concurrently de-energizes said tubes and energizes said initiating, motor energizing, and holding circuits.

References Cited in the file of this patent UNITED STATES PATENTS 2,032,514 Swart Mar. 3, 1936 2,390,799 Linsenmeyer et al. Dec. 11, 1945 2,436,023 Sepavich et al. Feb. 17, 1948 2,473,916 Snyder June 21, 1949 2,569,442 Anderson Oct. 2, 1951 2,569,475 Klein Oct. 2, 1951

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