U.S. patent number 3,659,409 [Application Number 05/077,101] was granted by the patent office on 1972-05-02 for electric circuit means for textile strand ends down detecting apparatus.
This patent grant is currently assigned to Parks-Cramer Company. Invention is credited to David W. Saunders.
United States Patent |
3,659,409 |
Saunders |
May 2, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ELECTRIC CIRCUIT MEANS FOR TEXTILE STRAND ENDS DOWN DETECTING
APPARATUS
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.
Inventors: |
Saunders; David W. (Fitchburg,
MA) |
Assignee: |
Parks-Cramer Company
(Charlotte, NC)
|
Family
ID: |
26758882 |
Appl.
No.: |
05/077,101 |
Filed: |
October 1, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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866265 |
Oct 14, 1969 |
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Current U.S.
Class: |
57/265; 57/304;
57/81 |
Current CPC
Class: |
D01H
13/145 (20130101) |
Current International
Class: |
D01H
13/14 (20060101); D01h 013/26 (); D01h 013/16 ();
D01h 013/32 () |
Field of
Search: |
;57/34R,56,52-54,78-81
;250/219 ;15/312 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Watkins; Donald E.
Parent Case Text
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.
Claims
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 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.
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 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.
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 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.
Description
It has heretofore been proposed that the efficiency 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
distinguishing 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 11 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. 11, 1970 entitled "Apparatus and Method for
Detecting and Reporting 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 to other 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
spindles 14 spaced along the length of the machine, in that each
end of yarn passes from 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 formed 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 16 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 15 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 signals 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 15 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 16
and travelers on the rings 18. It is contemplated by the present
invention that the electrical circuit means herein disclosed for
determining the absence of ends of yarn from locations along 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 20 in 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 15 to the
pigtail 16 as well as in that portion where the ends of yarn follow
ballooned paths between the pigtail 16 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 U.S. 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 detail, but 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. 3,523,413, 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 U.S. 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 differentiator 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 TA1 and TA2. The
transistors TA1 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 10 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 retro-reflective 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 PR1 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,
TA5, 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 one-half 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 TA1 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 42, 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 TA3, TA4, TA5,
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 TA1 and TA2 to
be applied to the other element 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 U.S. 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. 5 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 differentiator 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 C1 and a set point potentiometer
P-1 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 TR1 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 TR1 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
frequencies 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
short-to-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 differentiator 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 TR5 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 timing capacitor C5 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 TR5 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 37.
In operation of the circuit of FIG. 6, movement of the field of
view 20 of the photosensitive means 30 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 determination 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 the present 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
differing levels of response. More particularly, it will be noted
from 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 differing
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 P1 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 TR1 and TR2, pulse signals appear on a conductor 61 as
the photosensitive means 30 is moved past a spindle 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 the 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 10 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 11. 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 to the
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
310, 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.
* * * * *