US3659409A

US3659409A - Electric circuit means for textile strand ends down detecting apparatus

Info

Publication number: US3659409A
Application number: US77101A
Authority: US
Inventors: David W Saunders
Original assignee: Parks Cramer Co
Current assignee: Parks Cramer Co
Priority date: 1969-10-14
Filing date: 1970-10-01
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02
Also published as: CH518230A; DE2050498B2; DE2065850B2; JPS5611769B1; DE2065862B2; DE2065862A1; ES384922A1; JPS5539651B1; DE2050498C3; DE2065850A1; CA920682A; DE2050498A1; GB1323430A; DE2065862C3; DE2065850C3; JPS5535485B1

Abstract

Improved electric circuitry for use in an apparatus which travels a detector along textile strand processing machines such as spinning frames for determining the absence of ends of yarn from locations therealong at which such ends normally are present and for thereby locating ends down on the textile strand processing machines. The electrical circuitry disclosed herein incorporates detectors generally pulse electrical signals, pulse shaping circuits receiving pulse signals from the detectors and shaping the characteristics thereof, and logic circuits receiving shaped pulse signals and generating an output pulse on a determination that an end is absent from a location at which the same normally is present.

Description

United States Patent Saunders [4 1 May 2,1972

[541 ELECTRIC CIRCUIT MEANS FOR TEXTILE STRAND ENDS DOWN DETECTING APPARATUS [72] Inventor: David W. Saunders, Fitchburg, Mass. [73] Assignee: Rarks-Cramer Company, Charlotte, N.C. [22] Filed: Oct. 1, 1970 [2]] Appl. No.: 77,101

Related US. Application Data [63] Continuation-impart of Ser. No. 866,265, Oct. 14,

1969, abandoned.

[52] US. Cl. ..57/34 R, 57/56, 57/81 [51] Int. Cl. ..D0lh l3/26,D01h 13/16,D0lh 13/32 [58] Field of Search ..57/34 R, 56, 52-54,

[56] References Cited UNITED STATES PATENTS 3,099,829 7/1963 Namonyi-Katz ..57/81 X Primary Examiner-Donald E. Watkins Attorney-Parrott, Bell, Seltzer, Park & Gibson 57] ABSTRACT lmproved electric circuitry for use in an apparatus which travels a detector along textile strand processing machines such as spinning frames for determining the absence of ends of yarn from locations therealong at which such ends normally are present and for thereby locating ends down on the textile strand processing machines. The electrical circuitry disclosed herein incorporates detectors generally pulse electrical signals, pulse shaping circuits receiving pulse signals from the detectors and shaping the characteristics thereof, and logic circuits receiving shaped pulse signals and generating an output pulse on a determination that an end is absent from a location at which the same normally is present.

18 Claims, 9 Drawing figures 1 May 2, 1972 United States Patent Saunders SHEET 10F 5 PATENTEDMAY 2 I972 INVENTOR:

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DISTANCE: (louvre-217 (QZ INVENTOR: DAVlD SAuNDExas MMJL1%M{ A NEYS ELECTRIC CIRCUIT MEANS FOR TEXTILE STRAND ENDS DOWN DETECTING APPARATUS This application is a continuation-in-part of copending application Ser. No. 866,265 filed Oct. 14, 1969, and now abandoned and entitled identically to this application.

It has heretofore been proposed that the efliciency of operation in certain textile strand producing operations be improved by providing apparatus for detecting and reporting the ends down condition of textile yarn or thread forming apparatus such as spinning and twisting machines. In accordance with such proposals, apparatus is provided within a textile mill room, such as a spinning room, for moving detector means along the textile apparatus in a predetermined manner and for registering the response thereof.

It is an object of the present invention to facilitate improved determination of the absence of ends of yarn from locations at which ends of yarn normally are present along textile strand processing apparatus such as spinning frames.

It is another object of this invention to provide improved electrical circuit means for ends down locating and reporting systems which is more accurate and provides greater flexibility and adaptability to various conditions, resulting in more positive and reliable operation under varying practical textile mill conditions.

It is another object of this invention to provide improved electrical circuit means for an ends down detecting and reporting system which is compatible with peripheral circuit equipment such as computers which may be available to and used in conjunction with the detector means. More particularly, the electrical circuit means of the present invention functions by the generation and processing of pulse electrical signals and includes logic circuit means for between the absence and presence of ends of yarn on the traversed textile machine.

A further object of the present invention is the improvement of an apparatus of the general type described above wherein the detector means is combined with a pneumatic cleaner for travel on a track along a plurality of yarn forming locations, and wherein enhanced compatibility with the traveling pneumatic cleaner is achieved.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is an end elevation view, partially in section, of a traveling pneumatic cleaner and spinning frame incorporating ends down detecting apparatus in accordance with the present invention;

FIG. 2 is a perspective view, from one side and above, of certain portions of the structure illustrated in FIG. 1, showing an application of a first embodiment of the electrical circuit means of the present invention;

FIG. 3 is a perspective view generally similar to FIG. 2 of certain portions of the structure illustrated in FIG. 1, showing an application of a second embodiment of the electrical circuit means of the present invention;

FIG. 4 is a block diagram of alternative embodiments for the electrical circuit means of the present invention;

FIG. 5 is a schematic circuit diagram of the first embodiment of electrical circuit means for the apparatus illustrated in FIGS. 1 and 2;

FIG. 6 is a schematic circuit diagram of the second embodiment of electrical circuit means for the apparatus illustrated in FIG. 3;

FIG. 7 is a schematic circuit diagram of a third embodiment of electrical circuit means for use with apparatus such as is generally illustrated in FIGS. 1 and 2;

FIG. 8 is a schematic circuit diagram of a fourth embodiment of electrical circuit means for use with apparatus such as is generally illustrated in FIGS. 1 and 3; and

FIG. 9 is a schematic circuit diagram of a fifth embodiment of electrical circuit means for use with apparatus such as is generally illustrated in FIGS. 1 and 2.

Referring now more particularly to the drawings, there is generally illustrated apparatus which travels detector means along textile strand processing machines such as spinning frames for detecting and reporting the ends down conditions. As will be noted from FIGS. 1 and 2, the present invention is particularly concerned with apparatus in which the travel of detector means results from the combination of electrical circuit means with a traveling pneumatic cleaner generally indicated at 10 mounted on a track generally indicated at ll for movement above and along a plurality of spindles on at least one textile strand processing machine such as a spinning frame generally indicated at 12. For a more extensive discussion of the advantages and benefits which flow from such a combination, attention is directed to United States Pat. No. 3,523,413 issued Aug. 1 1, 1970 entitled Apparatus and Method for Detecting and Repo'ning Ends Down on Textile Machines and owned in common with this application. As the broad relationship of the traveling pneumatic cleaner in FIG. 1 to the textile strand processing machine may be fully understood from the disclosure in the aforementioned patent and reference therein made toother and further pertinent patent disclosures, the present application shall not repeat at length such discussion and disclosure, but is directed to the particular improved electrical circuit means for such ends down locating and reporting apparatus.

A textile strand processing machine such as the spinning frame 12 conventionally has locations spaced therealong at which ends of yarn normally are present during operation of the machine. In the spinning frame 12, such locations are related to the locations of spindlm l4 spaced along the length of the machine, in that each end of yarn passes fi'om front delivery rolls of drafting systems 15 through a stationary guide such as a pigtail 16, then to a rotating guide such as a traveler 18 moving about a spinning ring, and onto a package or bobbin being fon'ned at each spindle location. Thus at each spindle location a portion of the path of movement followed by an end of yarn presents the yarn moving generally along a line (namely between the front delivery rolls and the pigtail 16) while another portion presents the yarn moving in a rotating balloon (namely between the pigtail l6 and the traveler 18). As will be pointed out hereinafter, advantage is taken of these characteristics of yarn movement in order to insure proper response in determining the absence of ends of yarn from locations between the drafting rolls l5 and spindles 14 at which such ends normally are present.

In accordance with the present invention, a determination of the absence of ends of yarn from a textile strand processing machine such as a spinning frame is accomplished by electrical circuit means generally comprising detector means generating a pulse electrical signal in response to the presence of ends of yarn, signal conditioning means comprising pulse shaping circuit means electrically connected to the detector means for receiving and shaping pulse signals therefrom, logic circuit means receiving shaped pulse from the pulse shaping circuit means and responsive to normal traversal of a textile machine for distinguishing between absence and presence of ends of yarn and for generating an output pulse signal upon an end of yarn being absent and an output electrical device responsive to an output pulse from the logic circuit means for registering an ends down condition thus sensed and determined. As to each of these elements which are in the electrical circuit means of the present invention, certain alternatives are available and will be described more fully hereinafter.

In accordance with the present invention, the detector means provided preferably are photosensitive means which have a predetermined field of view and which generate pulse electrical signals in response to variations in illumination in that field of view such as are indicative of the presence of an end of yarn. Such photosensitive means is mounted for traversal of the field of view along a plurality of locations, such as spindles, at which ends of yarn normally are present, and the fields of view indicated by phantom line cones generally indicated at 20 in FIGS. 1 3 represent such fields of view of photosensitive means. While the photosensitive means is enclosed, for protection and convenience in handling, within an appropriate protective housing 21 (FIG. 1), neither the protective housing 21 nor a detailed representation of the photoelectric means has been included in FIGS. 2 and 3, in order that the relative positioning of the field of view to elements of the spinning frame 12 may be more clearly seen. The photosensitive means is mounted for travel with the traveling pneumatic cleaner 10, generally as described more fully in the aforementioned U.S. Pat. No. 3,523,413.

In FIGS. 1 2 phantom line cones 20 representing the field of view of photosensitive means are shown to be directed toward those portions of the textile strand processing machine at which ends of yarn normally are moving in lines between the delivery rolls l5 and the pigtail 16. FIG. 3 illustrates the direction of such phantom line cones 20 directed toward a portion of the textile machine at which ends of yarn are normally ballooned between the pigtails l6 and travelers on the rings 18. it is contemplated by the present invention that the electrical circuit means herein disclosed for detennining the absence of ends of yarn from locationsalong a spinning frame or the like may function in detecting ends of yarn at least in either of these general areas at which ends of yarns normally are present. in both instances, it is to be noted that travel of the phantom line cones illustrated in FIGS. 1 3 longitudinally of traversed textile apparatus will result in scanning of all locations therealong at which ends of yarn are normally present.

In accordance with circuitry preferred for certain applications of the present invention, the photosensitive means incorporated in the electrical circuit means is a photomultiplier device. As is generally well known, a photomultiplier device is a vacuum tube structure in which secondary emission of electrons is used to amplify the effect of light on an emissive surface in the device. When a photomultiplier device is arranged as photosensitive means having the field of view 20in FIGS. 1 3, electron flow through the device is determined essentially by the relative brightness of objects in the field of view 20 or across which the field of view moves. Thus, ends of yarn present in the field of view 20 give rise to variations in electron flow in the photomultiplier device by virtue of the relative brightness of such ends of yarn against the background of the textile strand processing machine elements. This is true both in that portion of the machine at which ends of yarn move along generally fixed lines from the delivery rolls to the pigtall 16 as well as in that portion where the ends of yarn follow ballooned paths between the pigtail l6 and a traveler, although the response of the photomultiplier is in the latter instance subject to shifts in level as disclosed more fully hereinafter.

The response obtained from a photomultiplier device or other photosensitive means may be enhanced by insuring that a significant distinction in brightness exists. As discussed more fully in the aforementioned copending application, this is preferably accomplished by the addition of a light source which illuminates the field of view of the photosensitive means and which moves therewith along a traversed textile machine. Such a field of illumination is indicated generally in FIGS. 1 3 by the phantom line cone 24.

It is to be recognized that other photosensitive means are known which have the capability of functioning as required in the present invention, that detector means may sense phenomena other than reflected illumination, and that the present invention contemplates the use of such other detector means. By way of example and without limitation, known photosensitive means of possible use in the electrical circuit means herein described include such electrical current modifying devices as photoresistors or phototransistors as well as photosensitive means which give rise to electrical voltages on application of light thereto such as photo cells. Such photosensitive means are known to respond to a wide range of wavelengths of radiant energy, including wave lengths which are outside the range visible to human eyesight. in any instance, the present invention contemplates that the photosensitive means generate a pulse electrical signal in response to movement of the field of view thereof across a location on a traversed textile apparatus at which an end of yarn is present. Typically, the relatively rapid movement of a relatively bright object such as an end of yarn into and through the field of view of a photosensitive means gives rise to a relatively steep rising and falling variation in the electrical characteristic of a photosensitive means. Such a relatively steep rising and falling variation, very roughly approximating a square wave front, is referred to herein as a pulse electrical signal generated by the photosensitive means.

By way of example of phenomena other than reflected illumination which may be detected by suitable means and thereby provide pulse electrical signals indicative of the presence of an end of yarn, it is known that yarn being formed may create an electrostatic charge and that certain components at each spindle location become heated by formation of ends of yarn. The presence of an electrostatic charge may be detected by apparatus such as disclosed in copending Ser. No. 41,136 filed May 25, 1970, entitled Electrostatic Charge Sensitive Ends Down Detecting Apparatus and Method" and owned in common with the present application. Detection of components which are heated by formation of yarn at a spindle location may be accomplished as disclosed in US. Pat. No. 3,523,414 issued Aug. 11, 1970 and entitled Temperature Responsive Ends Down Detecting and Reporting Apparatus and Method.

in accordance with the present invention, a pulse signal generated by the photosensitive means or other detector means is received by a signal conditioning means comprising a pulse shaping circuit means electrically connected to the photosensitive means. The function of the signal conditioning means is, in part, to shape the characteristics of received pulse signals to a predetermined, shaped characteristic. As briefly mentioned above, the pulse electrical signal generated by a photosensitive means, while recognizable as such, does not have such smoothly shaped characteristics as are desirable for compatibility with logic circuit means of the type discussed more fully. hereinafter. When used in conjunction with the configuration illustrated in FIG. 3, the signal conditioning means further incorporates elements for insuring response of the electrical circuit means to movement of the field of view of the photosensitive means across a location at which a balloon or vibrating length of yarn is present.

Pulses shaped by the pulse shaping circuit means are delivered to a logic circuit means which is responsive to normal traversal of the detector means for distinguishing between the absence and presence of ends of yarn on a traversed textile apparatus and for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same normally is present. As pointed out more fully hereinafter, logic circuit means as contemplated by the present invention may take several forms in detaiLbut it is a general characteristic of the logic circuit means that a cadenced determination is made thereby in coordination with traversal of the photosensitive means field of view along the length of traversed textile apparatus. That is, the cadenced determination may be time based where the speed of movement of the field of view 20 of the photosensitive means along a traversed textile machine is known or may be positioned based where such movement is otherwise accurately. indicated.

Upon determination by the logic circuit means that an end of yarn is absent from a location at which the same normally is present, generation of an output pulse electrical signal by the logic circuit means is used to control energization of an appropriate output device for reporting such condition. Referring specifically to the system and structure disclosed in aforementioned U.S. Pat. No. 3,523,4l3, one appropriate form of output device may include a solenoid, in which a pin is extended in response to accumulation of a predetermined count in a counter and to trip a switch on movement over the switch location. Yet another alternative output device is radiant energy emitting means to be energized under predetermined circumstances and for transmitting information to a stationary receiver station as described for example in application Ser. No. 866,266 filed Oct. 14, 1969, now US. Pat. No. 3,595,005 and entitled Information Transmitting Means for Textile Strand Ends Down Detecting Apparatus."

Referring more particularly to the alternative embodiments available for the electrical circuit means of the present invention, attention is directed to FIG. 4. A number of alternative arrangements for the electrical circuit means of the present invention are there set forth in block diagram form, with various elements to be selected being identified by legends in the blocks and with contemplated systems of interconnection being indicated by connection of the various block representations. The photosensitive means 30 as described above is illustrated by the uppermost block. Signal conditioning circuit means are generally indicated in the block diagram circuit at 31 and comprise an amplifier 32, a tank circuit 33, an integrator circuit 34, and a dififerentiator circuit 35. Logic circuit means are generally indicated at 36 and comprise a resettable oscillator 37 and a gate device 38 operatively connected with either a second photosensitive means 39 or an oscillator 40. The final element of the block circuit diagram is an output device 41.

Considering FIGS. 1, 2 and 5 together, the electrical circuit means of the present invention is shown in a first embodiment and applied to the combination with a traveling pneumatic cleaner mounted on a track for movement above and along textile strand processing apparatus of electrical circuit means in which a cadence signal generating means produces a pulse electrical signal coordinated to the position of the photosensitive means field of view and which signal is fed to a distinguishing means comprising a gate device. The gate device will pass an output signal upon a pair of pulse signals being simultaneously fed thereto but blocks passage of any signal upon only one of the pair of signals being separately fed thereto. In this particular application of the electrical circuit means of the present invention, cadencing is positively done and is coordinated to the physical position of the traveling pneumatic cleaner relative to the spindles of a traversed textile machine. Another embodiment with similar position based cadencing will be disclosed hereinafter.

Referring to the block circuit diagram of FIG. 4, the circuit now to be described would result from connection of the photosensitive means 30 and amplifier 32 to the gate device 38, with the gate device receiving cadence signals from the second photosensitive means 39. Circuit elements in FIG. 5 serving the functions of the block diagrammed elements in FIG. 4 carry the reference characters applied in FIG. 4.

In FIG. 5, the photosensitive means 30 is schematically indicated as a photomultiplier device. Through a coupling capacitor C1 and a set point potentiometer P1, pulse electrical signals generated by the photosensitive means 30 are fed to an amplifier 32. Amplified signals passing from the amplifier 32 are directed through suitable coupling means to a pair of coupled transistors TAl and TAZ. The transistors TAl and TA2 are arranged to function as a circuit for shifting the level of signals and squaring the signal to a uniform characteristic for application to one of two semiconductor elements arranged as a flip-flop or bistable multivibrator generally indicated at 42. A pulse signal originating with the first photosensitive means 30 and passing through the circuit elements just described is directed to the bistable multivibrator 42 through a coupling diode D1, to insure proper polarity of the applied signal. Inclusion of the coupling capacitor C1 between the photosensitive means 30 and the amplifier 32 insures that response of the pulse shaping circuit means, through which the pulse signal generated by the photosensitive means 30 is passed to the bistable multivibrator 42 is indicative of a rapid change in the level of illumination applied to the photomultiplier device, such as occurs upon movement of the field of view thereof across a reflective object such as an end of yarn, rather than being characteristic of a more gradual variation in the electron flow through the photomultiplier device such as may be indicative of a gradual change in the general illumination of the field of view thereof.

As will be noted from FIG. 2, the track 11 on which the traveling cleaner i0 is mounted for movement above and along the traversed textile machine 12 has secured thereto spaced apart indicia means in the form of reflective elements 45. Preferably, the reflective elements 45 are strips of a retroreflective tape. Each strip of retro-reflective tape is positioned on the track 11 (or any other desired location) in predetermined positional relation to a corresponding one of the spindles 14 of the spinning frame 12. An auxiliary photosensitive means housing 46 (FIGS. 1 and 2) is mounted from a portion of the undercarriage of the traveling cleaner 10 and encloses the second photosensitive means 39 which functions as a second detector and as a portion of the logic circuit means 36.

The second photosensitive means 39 is illustrated as a photoresistor PR1 (FIG. 5) enclosed within the housing 46, together with a suitable electrical lamp source 48 and a reflective element such as a halfsilvered mirror 49. By the physical arrangement of the light source 48, the reflective element 49 and the photoresistor PRl functioning as the second photosensitive means 39, light emitted from the lamp 48 is directed onto the track 11 during traversal thereof by the traveling pneumatic cleaner 10. Upon passage of the auxiliary housing 46 by a location at which a retro-reflective strip 45 is present, light emitted from the lamp 48 is reflected to the photoresistor PR1 to vary the resistance thereof. Upon such variation in the resistance value of the second photosensitive means, a pulse electrical signal is generated which is directed to a plurality of interconnected transistors TA3, TA4, TAS, TA6 for conditioning to a desired pulse signal characteristic. Thus, by means of the second photosensitive means 39 and associated circuitry, a pulse electrical signal is produced at each location where an end of yarn should normally be present, and at which the first photosensitive means generates a signal indicative of the presence of an end of yarn.

From the circuitry of FIG. 5, it is to be noted that a cadence pulse electrical signal resulting from reflection of light to the photoresistor PR1 from a retro-reflective strip 45 is applied through two lines of circuitry. First, through the transistors TA5 and TA6, a signal is applied through an inverter 50 to one side of the bistable multivibrator 42. At the same time, a signal is coupled to an output shaping transistor TA7, to be applied through an inverter 51 to the gate device 38 which also has applied thereto a signal indicative of the conductive state of onehalf of the bistable multivibrator 42. By means of a delay circuit including semiconductor elements identified by the reference characters 52 and 53, a pulse passed through TA7 is also applied to the same side of the bistable multivibrator 42 as the pulse signals passing from the first photosensitive means 30 through the amplifier 32 and the signal shaping transistors TA] and TA2.

The gate device 38 included in the circuitry of FIG. 5 is of the type referred to as a NAND" gate. Such a gate device has a characteristic of passing an output pulse signal only when a pair of signals are applied thereto and blocking or inhibiting such a signal in the absence of simultaneous application of the pair of signals. That is, should the gate device 38 simultaneously receive signals from the inverter 51 and the bistable multivibrator 82, an output pulse signal is passed through the gate device. Should a signal be absent from either the inverter 51 or the bistable multivibrator 42, then the other signal applied to the gate device 38 is blocked from passage through the gate 38 to a suitable output device.

In operation, movement of the second photosensitive means 39 included in the logic circuit means past a location at which a retro-reflective strip 45 is positioned results in two rapid transitions in the resistance value of the photosensitive means 39, the first occurring at the leading edge of the finite width of the retro-reflective strip 45 and the second occurring at the trailing edge thereof. A pulse resulting from the leading edge transition passes through the signal conditioning transistors 'IA3, TA4, TAS, and TA6 and the inverter 50 to be applied to the bistable multivibrator 42. This pulse sets the bistable multivibrator 42 in condition to apply a signal to the gate device 38. Thereafter, as the field of view of the first photosensitive means 30 passes a location at which an end of yarn normally is present, the presence of such an end of yarn gives rise to a pulse signal passing through the amplifier 32 and signal conditioning transistors TAl and TA2 to be applied to the other ele-' ment of the bistable multivibrator 42, changing the state of the bistable multivibrator and removing the signal otherwise present at the gate device 38. Then, the trailing edge signal originating from the second photosensitive means 39 and passing through the signal conditioning transistors TA3, TA4,

'TA7 to the inverter 51 is directed to the gate device 38 but will not result in an output pulse from the gate device because a pair of signals are not being simultaneously fed thereto.

Should an end of yarn not be present at the spindle location traversed by the first photosensitive means 30, the bistable multivibrator 42 continues in such state that a signal is directed to the gate device 38 therefrom. Thus, on application of a signal through the inverter 51 (resulting from the trailing edge of the reflective strip 45) two signals are simultaneously present at the gate device resulting in an output pulse being delivered from the gate device 38 to a suitable output device.

As disclosed in aforementioned US. Pat. No. 3,423,413 with particular reference to FIG. 11 thereof, a suitable output device or reporting means may be a counter connected to a signaling solenoid through a binary-digital convertor switch and a latch means of appropriate type. Alternatively, where it is considered desirable to respond to detection of a single end down, the output device connected to the gate 38 may be latching relay or other element responsive to a signal pulse by energizing a further circuit. From these briefly stated alternatives, it is apparent that the present invention contemplates any suitable form of output device which may be adapted to the circuitry of FIG. by a skilled electrical or electronic technician, such as a radio transmitter, computer, etc., whereby the determination of ends down may be reported as each location is traversed or accumulated and reported at intervals.

Referring now to the embodiment illustrated in FIG. 3, it is to be noted that the signal conditioning circuit means used in conjunction therewith must respond to passage of the field of view 20 of the photosensitive means along a location at which ends of yarn are present in balloons. Further, the embodiment illustrated in FIG. 3 does not incorporate a photosensitive means for generating a position coordinated cadence pulse as is done in the embodiment of FIGS. 1 and 2. Instead, electrical circuit means in accordance with the present invention and operative in the embodiment illustrated, in FIG. 3 takes the form schematically represented in FIG. 6.

Referring additionally to the block diagram of FIG. 4, electric circuit means useful in connection with the embodiment of FIG. 3 include an arrangement incorporating the photosensitive means 30, the amplifier 32, a frequency responsive circuit which is a selected one of the tank circuit 33 or the integrator circuit 34, and a logic circuit which is a selected one of the resettable oscillator 37 or the gate device 38 being supplied with a cadence pulse from the oscillator 40.

If desired a differentiator circuit may be inserted between the tank circuit and the resettable oscillator or gate device, respectively, or between the integrator circuit and the resettable oscillator or gate device respectively. The schematic diagram of FIG. 6 discloses an arrangement in which an integrator circuit corresponding to the circuit 34 of FIG. 4 is used in conjunction with an optional diflerentiator circuit corresponding to the circuit 35 of FIG. 4 and a resettable oscillator corresponding to the circuit 37 of FIG. 4.

Referring in particular to the elements schematically shown in FIG. 6, photosensitive means 30 takes the form of a photomultiplier device coupled through a capacitor Cl and a set point potentiometer P4 to an amplifier 32 in similarity to -a corresponding portion of the circuit discussed above with reference to FIG. 5. Pulse signals passing through the amplifier 32 are passed to signal conditioning transistors TR] and TR2. In distinction from the arrangement discussed above with reference to FIG. 5, the movement of the field of view 20 of the photosensitive means 30 is along a portion of a textile machine at which the yarn is present in balloons, as shown in FIG. 3, and results in generation of a pulse train having a frequency characteristic of the rotational speed of the yarn balloon. That is, as the end of yarn rotates with the traveler moving about the ring of a ring-spinning frame, relative brightness in the field of view of the photosensitive means 30 is modulated at a speed reflecting the rotational speed of the end of yarn in the balloon. Thus, during the time that the field of view traverses a particular spindle location, a train of pulses of predetermined frequency are generated by the photosensitive .means 30 and pass through the amplifier 32 and the transistors 'I'Rl and TR2. In order to distinguish the presence of such a train of signals, the pulse shaping circuit means included in the circuitry of FIG. 6 comprises a frequency responsive circuit (integrator circuit) electrically connected to the amplifier 32 for receiving shaped pulse signals therefrom and for passing substantially unimpeded a pulse signal indicative of variations in illumination in the field of view 20 of the photosensitive means 30 occurring at a predetermined frequency coordinated to the rotational speed of the ballooned ends of yarn.

As suggested by the block diagram of FIG. 4, such a frequency responsive circuit may comprise a tuned tank circuit of inductance and capacitance elements selected to attenuate pulse signals having repetitive frequencies other than the predetermined frequency or may comprise an integrator circuit of resistance and capacitance elements selected to attenuate pulse signals having repetitive t'requencies below the predetermined frequency. In the form illustrated in FIG. 6, an integrator circuit 34 is provided, formed by a capacitor C2 and a resistor R1. Such an integrator circuit builds a staircase charge on the capacitor C2 during application thereto of pulse signals at a predetermined frequency, giving a voltage rise coordinated to the particular predetermined frequency chosen. The integrator circuit is used in conjunction with a breakdown device 55 such as a Diac, which normally is nonconductive while voltages applied thereto remain below a particular predetermined level. Upon the voltage applied to the breakdown device exceeding the predetermined level, as will occur when a pulse train at a predetermined frequency is applied to the integrator circuit 34, the breakdown device 55 becomes conductive and passes a pulse signal onward to further circuit elements.

The distinction between the choice of a tank circuit 33 and an integrator circuit 34 lies, in part, in the effect of those circuits on pulse trains applied thereto. As contemplated by the present invention, a tank circuit 33 causes an effective shortto-ground for trains of pulses having repetitive frequencies other than that indicative of the presence of a yarn balloon or vibrating yarn in the field of view 20 of the photoelectric means 30 and if a tank circuit 33 is substituted for the integrator circuit 34 (FIG. 6) the breakdown device 55 is omitted.

A pulse signal passing from the frequency responsive circuit included in the signal conditioning circuit means of FIG. 6 passes to an amplifier 56 and is then delivered to a single shot monostable multivibrator generally indicated at 58, through a coupling capacitor C3 and coupling diode D2. On application of a pulse signal to the single shot monostable multivibrator 58, a single output pulse of standardized characteristics is delivered therefrom to the differentiator circuit 35, composed of a capacitor C4 and a resistor R2. Taken together, the functions of the multivibrator 58 and diflerentiator circuit 35 are to complete shaping of a signal passed through the frequency responsive circuit means to a standardized pulse characteristic. A signal having the desired standardized pulse characteristic is then applied to coupled transistors TRS and TR6 and results in application of a pulse signal of desired characteristics to a resettable oscillator generally indicated by the reference character 37, which functions in the circuit of FIG. 6 as the logic circuit means.

The resettable oscillator 37 comprises a unijunction transistor 60 and is free running in that the unijunction transistor normally generates an output pulse electrical signal at a predetermined time interval, established by appropriate selection of resistance and capacitance values included in the oscillator 37 and coordinated to the linear velocity of the photosensitive means 30 field of view 20 relative to a traversed textile machine. As pointed out more fully hereinafter, the predetermined time interval is slightly greater than the interval at which the photosensitive means field of view normally traverses the spindle location at which ends of yarn are normally present. Timing of the predetermined interval is initiated by a change in the conductive state of a coupling transistor TR7 included in the resettable oscillator 37, with such a change in conductive state discharging a timingcapacitor C incorporated in the oscillator 37, in a manner generally known to electronic technicians skilled in the design and application of unijunction timing circuits. It is to be noted that the conductive state of the coupling transistor TR7 is dependent upon delivery thereto of a shaped pulse signal through the transistors TRS and TR6, so that cadenced resetting of the oscillator 37 by shaped pulse signals indicative of an end of yarn being present at a traversed spindle location inhibits generation of an output pulse signal by the oscillator In operation of the circuit of FIG. 6, movement of the field of view of the photosensitive means along a portion of a traversed textile machine at which ends of yarn normally are ballooned between stationary and rotating guides, as shown in FIG. 3, results in periodic application to the frequency responsive circuit means of trains of pulses at a frequency coordinated to the rotational speed of the yarn balloons. Upon application of a train of pulses having the desired frequency characteristic, a pulse signal is passed through the additional signal conditioning circuit means provided and is delivered to the resetting transistor TR7. Cadenced resetting of the oscillator 37 inhibits completion of timing of the predetermined interval which would lead to an output pulse being generated by the resettable oscillator. Upon an end of yarn being absent from a location at which an end normally is present, the oscillator 37 is not inhibited, timing of the predetermined interval is completed, and a change in conductive state of the unijunction transistor 60 results in generation of an output pulse from the resettable oscillator. Such an output pulse is applied to an appropriate output device such as discussed above, to carry out the detennination of the absence of an end of yarn from the traversed textile strand processing machine.

The description of the circuits schematically illustrated in FIGS. 5 and 6 has encompassed certain major variations in choice available among the block diagram arrangements suggested in FIG. 4. While it is believed apparent that a skilled electronic technician working from the block diagram of FIG. 4 and the illustrative schematic diagrams of FIGS. 5 and 6 may carry forward other variations on the electrical circuit means of the present invention, it is considered appropriate to point out certain other possibilities including a third embodiment which represents a particularly direct application of the present invention.

Referring to FIG. 7, it is to be noted therein that an arrangement is proposed in which photosensitive means 30 may be mounted for traversal of the field of view 20 thereof along a portion of a traversed textile machine in which ends of yarn normally move along fixed paths, somewhat in similarity to the arrangement of FIG. 2. However, reliance is not placed upon a second photosensitive means and gate device for position based cadencing, but a resettable oscillator of the type discussed above with reference to FIGS. 6 and 3 is used and cadence is determined by intervals of time corresponding to the yarn end spacing. In the circuit arrangement of FIG. 7, a pulse signal generated by the first photosensitive means 30 viewing a yarn moving in a line in its normal position'is fed to the amplifier 32 through a coupling capacitor C1. The amplifier 32 and associated passive circuitry conditions the pulse and passes the same to the resettable oscillator 37 which functions in the manner described with respect to FIG. 6 for the second embodiment. Thus in the absence of a yarn from a location where it normally should be, an output pulse is generated.

While the disclosure hereinabove of an embodiment which operates in conjunction with indicia means provided by reflective elements 45 has pointed out circuitry which employs separate photosensitive means functioning as first and second detectors, it is contemplated that a single photosensitive means such as the photosensitive means 30 may operate in conjunction with circuitry which accomplishes cadencing by distinguishing between two signals passing from the single photosensitive means 30. Such circuitry is disclosed, as a fourth embodiment of thepresent invention, in FIG. 8 and wherein the photosensitive means 30 is electrically connected both to a circuit which recognizes a rotating balloon of yarn and to level shift recognization circuit means which distinguishes between difiering levels of response. More particularly, it will be noted fi'om FIG. 3'of the drawings that the field of view 20 of the photosensitive means 30 passes adjacent not only the rotating balloons of yarn but also passes adjacent the body of yarn wound about bobbins on the spindles 14. As a result, the electrical characteristics of the photosensitive means 30 change in two ways at each traversal of the field of view 20 past a spindle location at which an end of yarn is present The operation of the circuitry of FIG. 8 depends upon distinguishing between two such difiering responses.

Upon movement of the field of view of the photosensitive means 30 past a spindle location, there is a general shift in the electrical characteristics of the photosensitive means 30 occasioned by the relative brightness of the bobbin cap or of the body of yarn wound about the bobbin as compared with the space between adjacent spindles. Such a shift in level of electrical characteristics is distinct from the relatively rapid fluctuation caused by the rotating balloon of yarn.

In FIG. 8, the photosensitive means 30 is coupled through a coupling capacitor C1 and a setpoint potentiometer PI to an amplifier 32 functioning as a portion of signal conditioning circuit means 31. Electrical pulse signals passing through the amplifier 32 are screened by a tank circuit 33 which passes pulse signals having a frequency indicative of the presence of a rotating balloon of yarn. This operation is similar to the balloon detecting circuitry described hereinabove with reference to FIG. 6.

The photosensitive means 30 is additionally coupled, through a coupling capacitor C6 and a second setpoint potentiometer P2, to logic circuit means 36 including an amplifier 60. By selection of appropriate settings and values for the coupling capacitor C6 and the setpoint potentiometer P2, the logic circuit means 36 is rendered responsive to shifts in the photosensitive means response level. That is, the coupling capacitor C6, setpoint potentiometer P1 and amplifier 60 cooperate for distinguishing between a first level of photosensitive means response which is indicative of traversal of a location where ends of yarn normally are not present (such as between adjacent spindles) and a second level of response indicative of traversal of a location where ends of yarn normally are present. The greater relative brightness of a bobbin cap or wound body of yarn brings about such a shift in responsive levels.

The level shifts thus recognized are then employed in a manner similar to the pulse electrical signals derived from the photoresistor PR1 in FIG. 5, to reach a gate device 38 through a bistable multivibrator 42 and inverter 51.

In a fifth embodiment of circuitry in accordance with this invention, the photosensitive means 30 is coupled, through a capacitor C1 and a setpoint potentiometer P1, to an amplifier 32. Through means of the amplifier and a pair of pulse-shaping transistors TRl and TR2, pulse signals appear on a conductor 61 as the photosensitive means 30 is moved past a spindie location at which an end of yarn is present. The appearance of a pulse signal on the conductor 61 resets a distance counter 62 as will now be described, in accomplishing position based cadencing.

The distance counter 62 receives and counts pulses originating from a traveling unit pulse generator 64, preferably a rotation signaling device. By interconnection of the device to an idler wheel 65 of tlne traveling pneumatic cleaner 10, through means of an idler wheel shaft 66, movement of the idler wheel 65 along the track 11 by which the traveling cleaner is supported results in generating of pulses by the signaling device which indicates the rotational movement of the shaft 66. By selection of the pulse train passed from the device to the linear distance counter 62, pulses received at the linear distance counter 62 are correlated in a predetermined manner to the rotation of the idler wheel 65 and are thereby correlated to movement of the traveling cleaner 10 along the track 1 1. The traveling unit pulse generator 64 thus functions as a movement signaling means or as a movement controlled oscillator.

With such correlation of pulse transmittal from the traveling unit pulse generator 64 to the linear distance counter 62, a predetermined relationship is established with regard tothe distance between adjacent spindle locations along the spinning frame 12 at which ends of yarn normally are formed. Thus, where spindle locations are on a 3 inch gauge, for example, 300 pulses may be delivered to the linear distance counter 62 from the traveling unit pulse generator 64 during movement of the photosensitive means 30 from a position where a first spindle location is monitored to a position where a second, adjacent, spindle location is monitored. During such movement, the linear distance counter 62 counts the 300 pulses received from the movement signal generator 64 and, upon a pulse being passed through the conductor 61, is reset to zero and begins a next count.

In the event that the linear distance counter 62 is not reset to zero by the appearance of pulse on the conductor 61, as when the photosensitive means 30 moves past the spindle location at which an end is down, the distance counter 62 continues to count pulses originating from the traveling unit pulse generator 64. Thereafter, when the count reaches a predetermined number greater than that correlated to the gauge distance of the spindle locations, such as 3l0, a pulse signal is passed from the distance counter 62 through a first exit gate 68. A pulse passing through the first exit gate 68 appears on a conductor 70, to accomplish two purposes. The first is passage of an output pulse through an ends down signal or gate 38 to appear on a conductor 61, resetting the distance counter 62. The pulse appearing on the conductor 70, through the first exit gate 68, additionally sets a flipflop formed by a pair of interconnected gates 71, 72, to present a continuing signal at an and gate 74.

In the event that an end is down at two adjacent spindle locations, the distance counter 62 would again fail to be reset by the appearance of a pulse on a conductor 61 from the photosensitive means 30. Thereafter, as the count in the distance counter 62 reached the number of pulses correlated to the gauge distance of the spinning frame 12 (or 300 in the present example), a second exit gate 75 passes a pulse from a distance counter 62 to the and gate 74. Upon appearance at the and gate 74 of a continuing signal from the flipflop formed by the gates 71 and 72 and a pulse signal passed through the second exit gate 75, a pulse is passed through the or gate 38 to appear on the output conductor. Thus, no cumulative error is introduced in continuing recognition of successive spindle locations at which ends are down.

In the drawings and specification, there have been set forth preferred embodiments of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

What is claimed is:

1. In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, an electrical circuit combination particularly adapted for traversal of a photosensitive means field of view along a portion of a spinning frame wherein ends of yarn normally are ballooned between stationary and rotating guides and comprising:

photosensitive means having a predetermined field of view and generating a pulse electrical signal in response to variations in illumination in said field of view indicative of the presence of an end of yarn, said photosensitive means being mounted for traversal of said field of view along a plurality of locations where ends of yarn normally are present,

signal conditioning means comprising pulse shaping circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for shaping the characteristics of received pulse signals, said pulse shaping circuit means comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals which originate from said photosensitive means and have varying pulse characteristics, and said signal conditioning means further comprising a frequency responsive circuit electrically connected to said amplifier for receiving shaped pulse signals therefrom and for passing substantially unimpeded a pulse signal indicative of variations in illumination in said field of view of said photosensitive means occurring at a predetermined frequency coordinated to the rotational speed of the ballooned ends of yarn, and

logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations and for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should normally be present.

2. An electrical circuit combination according to claim 1 wherein said frequency responsive circuit comprises a tuned tank circuit of inductance and capacitance elements selected to attenuate pulse signals having repetitive frequencies other than said predetermined frequency.

3. An electrical circuit combination according to claim 1 wherein said frequency responsive circuit comprises an integrator circuit of resistance and capacitance elements selected to attenuate pulse signals having repetitive frequencies below said predetermined frequency.

4. An electrical circuit combination according to claim 1 wherein said signal conditioning means further comprises a difierentiator circuit of. resistance and capacitance elements electrically connected to said frequency responsive circuit for receiving a pulse signal passed therethrough and for smoothirng such a received pulse signal to a standardized shaped characteristic.

5. In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, electrical circuit means for determining the absence of ends of yarn comprismg:

signal conditioning means comprising pulse shaping circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for shaping the characteristics of received pulse signals, and

logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should nonnally be present, said logic circuit means comprising a resettable, freerunning oscillator normally generating output pulse electrical signals at a predetermined time interval coordinated to normal traversal of said photosensitive means field of view and responsive to receipt of a shaped pulse signal from said pulse shaping circuit means for initiating timing of said predetermined interval, said predetermined time interval being slightly greater than the interval at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present, so that cadenced resetting of said oscillator by shaped pulse signals indicative of ends of yarn being present at traversed locations inhibits generation of an output pulse signal by said oscillator.

6 In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, electrical circuit means for determining the absence of ends of yarn comprising:

logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations and for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should normally be present, said logic circuit means comprising cadence signal generating means for producing cadence pulse signals correlated to the intervals at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present and further wherein said logic circuit means further comprises means for receiving both shaped pulse signals from said pulse shaping circuit means and cadence pulse signals from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn at a traversed location and receipt of one signal indicating the absence of an end of yarn from a traversed location.

7. An electrical circuit combination according to claim 6 wherein said cadence signal generating means comprises reflective indicia means spaced in predetermined relation to said traversed locations at which ends of yarn are normally present, and second photosensitive means mounted for movement with said first photosensitive means and along said reflective indicia means for generating said cadence pulse electrical signals in response to reflection therefrom, said indicia and second photosensitive means being so positioned relative to said locations of ends of yarn and said first photosensitive means that said cadence pulse signals are produced in coordination with generation of pulse electrical signals by said first photosensitive means in response to viewing of present ends of yarn.

8. An electrical circuit combination according to claim 6 wherein said cadence signal generating means comprises an oscillator generating pulse signals at a predetermined frequency.

9. An electrical circuit combination according to claim 6 wherein said cadence signal generating means comprises level shift recognition circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for distinguishing between a first level of photosensitive means response which is indicative of traversal of a location where ends of yarn normally are not present and a second level of photosensitive means response which is indicative of traversal of a location where ends of yarn normally are present, whereby said photosensitive means cooperates in the origination of both shaped pulse signals and cadence pulse signals.

10. An electrical circuit combination according to claim 6 wherein said cadence signal generating means comprises movement signaling means for generating a train of pulses correlated to the movement of said photosensitive means along said plurality of locations and further wherein said signal distinguishing means includes counter means for counting said train of pulses and thereby detennining the position of said photosensitive means relative to said locations.

1 1. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising:

photosensitive means having a predetermined field of view and being mounted for movement with a traveling pneumatic cleaner for traversal of said field of view along a portion of said textile apparatus where ends of yarn normally are present, said photosensitive means generating a pulse electrical signal in response to movement of said field of view across a location at which an end of yarn is present,

sigrnal conditioning means electrically connected to said photosensitive means for receiving pulse signals therefrom and comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals originating from said photosensitive means and having varying shaped pulse characteristics, and

logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising a resettable, freerunning oscillator normally generating output pulse electrical signals at a predetermined time interval coordinated to normal traversal of said photosensitive means field of view and responsive to receipt of a shaped pulse signal from said signal conditioning means for irnitiating timing of said predetermined interval, said predetermined interval being slightly greater than the interval at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present, so that cadenced resetting of said oscillator by shaped pulse signals indicative of ends of yarn being present at traversed locations inhibits generation of an output pulse by said oscillator.

12. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising:

logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising cadence signal generating means for producing cadence pulse signals correlated to the intervals at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present and further wherein said logic circuit means further comprises means for receiving both shaped pulse signals from said signal conditioningmeans and cadence pulse signals from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn at a traversed location and receipt of one signal indicating the absence of an end of yarn from a traversed location. 13. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising:

photosensitive means having a predetermined field of view and being mounted for movement with a traveling pneumatic cleaner for traversal of said field of view along a portion of said textile apparatus where ends of yarn normally are present, said photosensitive means generating a pulse electrical signal in response to movement of said field of view across a location at which an end of yarn is present, v

signal conditioning means electrically connected to said photosensitive means for receiving pulse signals therefrom and comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals originating from said photosensitive means and having varying shaped pulse characteristics, and

logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising movement signaling means for generating a train of pulses correlated to the movement of said traveling pneumatic cleaner along a traversed textile apparatus and counter means electrically connected to said signal conditioning means and to said movement signal means for counting said train of pulses and for distinguishing between receipt of a shaped pulse signal prior to a count indicative of the movement of said traveling pneumatic cleaner adjacent a n'aversed location and absence of a shaped pulse signal at such count.

14. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising:

detector means mounted for movement with a traveling pneumatic cleaner and for traversal along a portion of said textile apparatus where ends of yarn normally are present, said detector means generating an electrical signal in response to movement across a location on a traversed textile apparatus at which an end of yarn is present, and

logic circuit means mounted for movement with said traveling pneumatic cleaner and op'eratively electrically connected to said detector means for receiving signals therefrom and comprising cadence signal generating means for producing an electrical sigrnal correlated to the interval at which said detector means normally traverses locations at which ends of yarn are normally present and means for receiving both signals passing from said detector means and signals gnassingnfrorn said cadence signal generating means and or dis gurshrng between receipt of both sigrnals indicating the presence of an end of yarn and the receipt of one signal indicating the absence of an end of yarn from a traversed location.

15. Apparatus according to claim 14 wherein said cadence sigrnal generating means comprises indicia means spaced in predetermined relation to said traversed location at which ends of yarn are normally present and second detector means mounted for movement with said first detector means and along said indicia means for generating said cadence electrical signals in response to traversal of a location at which an indicia means is present, said indicia means and second detector means being so positioned relative to said locations of ends of yarn and said first detector means that said cadence electrical sigrnals are produced in coordination with generation of electrical signals by said first detector means in response to traversal of present ends of yarn.

16. Apparatus according to claim 14 wherein said first and second detector means comprise radiant energy level responsive devices for remotely detecting the respective presence of an end of yarn and of an indicia means.

17. Apparatus according to claim 14 wherein said cadence signal generating means comprises level shift recognition circuit means electrically connected to said detector means for receiving signals therefrom and for distinguishing between a first level of detector means response which is indicative of traversal of a location where ends of yarn normally are not present and a second level of detector means response which is indicative of traversal of a location where ends of yarn normally are present, whereby said detector means cooperates in the origination of said both signals.

18. In an apparatus which travels along textile strand processing apparatus such as spinning frames, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising:

detector means mounted for traversal along a portion of said textile apparatus where ends of yarn normally are present and for generating an electrical signal in response to movement across a location on a traversed textile apparatus at which an end of yarn is present, and

logic circuit means operatively electrically connected to said detector means for receiving signals therefrom and comprising cadence signal generating means for producing an electrical sigrnal at the interval at which said detector means normally traverses locations at which ends of yarn are normally present and means for receiving both a signal originating from said detector means and a signal originating from said cadence signal generating means and for distinguishing between receipt of botln signals indicating the presence of an end of yarn and the receipt of one signal indicating the absence of an end of yarn from a traversed location.

i t i i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 659,409 Dated May 2, 1972 lnventofls) David W. Saunders It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

C01. 16, line 28, "Claim 14" Should be Claim 15 Signed and sealed this 5th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents USCOMM-DC GUSTO-P59 0.! GOVIINHINY PRINTING OFFICI: IIII 0JCl-.\Jl

FORM F'O-105O (0-69)

Claims

1. In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, an electrical circuit combination particularly adapted for traversal of a photosensitive means field of view along a portion of a spinning frame wherein ends of yarn normally are ballooned between stationary and rotating guides and comprising: photosensitive means having a predetermined field of view and generating a pulse electrical signal in response to variations in illumination in said field of view indicative of the presence of an end of yarn, said photosensitive means being mounted for traversal of said field of view along a plurality of locations where ends of yarn normally are present, signal conditioning means comprising pulse shaping circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for shaping the characteristics of received pulse signals, said pulse shaping circuit means comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals which originate from said photosensitive means and have varying pulse characteristics, and said signal conditioning means further comprising a frequency responsive circuit electrically connected to said amplifier for receiving shaped pulse signals therefrom and for passing substantially unimpeded a pulse signal indicative of variations in illumination in said field of view of said photosensitive means occurring at a predetermined frequency coordinated to the rotational speed of the ballooned ends of yarn, and logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations and for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should normally be present.

4. An electrical circuit combination according to claim 1 wherein said signal conditioning means further comprises a differentiator circuit of resistance and capacitance elements electrically connected to said frequency responsive circuit for receiving a pulse signal passed therethrough and for smoothing such a received pulse signal to a standardized shaped characteristic.

5. In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, electrical circuit means for determining the absence of ends of yarn comprising: photosensitive means having a predetermined field of view and generating a pulse electrical signal in response to variations in illumination in said field of view indicative of the presence of an end of yarn, said photosensitive means being mounted for traversal of said field of view along a plurality of locations where ends of yarn normally are present, signal conditioning means comprising pulse shaping circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for shaping the characteristics of received pulse signals, and logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should normally be present, said logic circuit means comprising a resettable, freerunning oscillator normally generating output pulse electrical signals at a predetermined time interval coordinated to normal traversal of said photosensitive means field of view and responsive to receipt of a shaped pulse signal from said pulse shaping circuit means for initiating timing of said predetermined interval, said predetermined time interval being slightly greater than the interval at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present, so that cadenced resetting of said oscillator by shaped pulse signals indicative of ends of yarn being present at traversed locations inhibits generation of an output pulse signal by said oscillator. 6 In an apparatus which travels detector means along textile strand processing apparatus such as spinning frames for locating and reporting ends down thereon, electrical circuit means for determining the absence of ends of yarn comprising: photosensitive means having a predetermined field of view and generating a pulse electrical signal in response to variations in illumination in said field of view indicative of the presence of an end of yarn, said photosensitive means being mounted for traversal of said field of view along a plurality of locations where ends of yarn normally are present, signal conditioning means comprising pulse shaping circuit means electrically connected to said photosensitive means for receiving pulse signals therefrom and for shaping the characteristics of received pulse signals, and logic circuit means electrically connected to said pulse shaping circuit means for receiving shaped pulse signals therefrom and responsive to normal traversal of said photosensitive means field of view for distinguishing between absence and presence of ends of yarn at traversed locations and for generating an output pulse electrical signal upon an end of yarn being absent from a location at which the same should normally be present, said logic circuit means comprising cadence signal generating means for producing cadence pulse signals correlated to the intervals at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present and further wherein said logic circuit means further comprises means for receiving both shaped pulse signals from said pulse shaping circuit means and cadence pulse signals from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn at a traversed location and receipt of one signal indicating the absence of an end of yarn from a traversed location.

10. An electrical circuit combination according to claim 6 wherein said cadence signal generating means comprises movement signaling means for generating a train of pulses correlated to the movement of said photosensitive means along said plurality of locations and further wherein said signal distinguishing means includes counter means for counting said train of pulses and thereby determining the position of said photosensitive means relative to said locations.

11. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising: photosensitive means having a predetermined field of view and being mounted for movement with a traveling pneumatic cleaner for traversal of said field of view along a portion of said textile apparatus where ends of yarn normally are present, said photosensitive means generating a pulse electrical signal in response to movement of said field of view across a location at which an end of yarn is present, signal conditioning means electrically connected to said photosensitive means for receiving pulse signals therefrom and comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals originating from said photosensitive means and having varying shaped pulse characteristics, and logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising a resettable, freerunning oscillator normally generating output pulse electrical signals at a predetermined time interval coordinated to normal traversal of said photosensitive means field of view and responsive to receipt of a shaped pulse signal from said signal conditioning means for initiating timing of said predetermined interval, said predetermined interval being slightly greater than the interval at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present, so that cadenced resetting of said oscillator by shaped pulse signals indicative of ends of yarn being present at traversed locations inhibits generation of an output pulse by said oscillator.

12. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising: photosensitive means having a predetermined field of view and being mounted for movement with a traveling pneumatic cleaner for traversal of said field of view along a portion of said textile apparatus where ends of yarn normally are present, said photosensitive means generating a pulse electrical signal in response to movement of said field of view across a location at which an end of yarn is present, signal conditioning means electrically connected to said photosensitive means for receiving pulse signals therefrom and comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals originating from said photosensitive means and having varying shaped pulse characteristics, and logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising cadence signal generating means for producing cadence pulse signals correlated to the intervals at which said photosensitive means field of view normally traverses locations at which ends of yarn are normally present and further wherein said logic circuit means further comprises means for receiving both shaped pulse signals from said signal conditioning means and cadence pulse signals from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn at a traversed location and receipt of one signal indicating the absence of an end of yarn from a traversed location.

13. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising: photosensitive means having a predetermined field of view and being mounted for movement with a traveling pneumatic cleaner for traversal of said field of view along a portion of said textile apparatus where ends of yarn normally are present, said photosensitive means generating a pulse electrical signal in response to movement of said field of view across a location at which an end of yarn is present, signal conditioning means electrically connected to said photosensitive means for receiving pulse signals therefrom and comprising an amplifier for shaping to a substantially uniform shaped pulse characteristic pulse signals originating from said photosensitive means and having varying shaped pulse characteristics, and logic circuit means electrically connected to said signal conditioning means for receiving shaped pulse signals therefrom and for determining from received pulse signals the presence and absence of ends of yarn, said logic circuit means comprising movement signaling means for generating a train of pulses correlated to the movement of said traveling pneumatic cleaner along a traversed textile apparatus and counter means electrically connected to said signal conditioning means and to said movement signal means for counting said train of pulses and for distinguishing between receipt of a shaped pulse signal prior to a count indicative of the movement of said traveling pneumatic cleaner adjacent a traversed location and absence of a shaped pulse signal at such count.

14. In an apparatus which travels a pneumatic cleaner along textile strand processing apparatus such as spinning frames for removing lint and the like therefrom, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising: detector means mounted for movement with a traveling pneumatic cleaner and for traveRsal along a portion of said textile apparatus where ends of yarn normally are present, said detector means generating an electrical signal in response to movement across a location on a traversed textile apparatus at which an end of yarn is present, and logic circuit means mounted for movement with said traveling pneumatic cleaner and operatively electrically connected to said detector means for receiving signals therefrom and comprising cadence signal generating means for producing an electrical signal correlated to the interval at which said detector means normally traverses locations at which ends of yarn are normally present and means for receiving both signals passing from said detector means and signals passing from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn and the receipt of one signal indicating the absence of an end of yarn from a traversed location.

15. Apparatus according to claim 14 wherein said cadence signal generating means comprises indicia means spaced in predetermined relation to said traversed location at which ends of yarn are normally present and second detector means mounted for movement with said first detector means and along said indicia means for generating said cadence electrical signals in response to traversal of a location at which an indicia means is present, said indicia means and second detector means being so positioned relative to said locations of ends of yarn and said first detector means that said cadence electrical signals are produced in coordination with generation of electrical signals by said first detector means in response to traversal of present ends of yarn.

18. In an apparatus which travels along textile strand processing apparatus such as spinning frames, electrical circuit means for locating ends down by determining the absence of ends of yarn normally present thereon comprising: detector means mounted for traversal along a portion of said textile apparatus where ends of yarn normally are present and for generating an electrical signal in response to movement across a location on a traversed textile apparatus at which an end of yarn is present, and logic circuit means operatively electrically connected to said detector means for receiving signals therefrom and comprising cadence signal generating means for producing an electrical signal at the interval at which said detector means normally traverses locations at which ends of yarn are normally present and means for receiving both a signal originating from said detector means and a signal originating from said cadence signal generating means and for distinguishing between receipt of both signals indicating the presence of an end of yarn and the receipt of one signal indicating the absence of an end of yarn from a traversed location.