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| United States Patent |
6,170,325
|
|
Hinchliffe
|
January 9, 2001
|
Measuring instrument
Abstract
An instrument is provided with several sensing elements to enable several
parameters of a processed yarn to be measured or determined. In order to
minimize the total sensing element/guide contact with the yarn within the
complete process threadline, the yarn is guided through the instrument by
contact only with the inlet and outlet guiding elements of the instrument
and contact operative sensing elements. One particular instrument
consists, in succession, of an interlace sensing device, a tension sensing
device and an oil content sensing device. The electrical resistance of the
yarn is measured between two pins of the oil content sensing device and in
this case, the first pin is also a tension sensing pin of the instrument,
and the second pin of the oil content sensing device is also the outlet
guide of the instrument.
| Inventors:
|
Hinchliffe; Malcolm Geoffrey (Macclesfield, GB)
|
| Assignee:
|
Fibrevision Limited (Isle of Man, GB);
The Merlin Partnership (Isle of Man, GB)
|
| Appl. No.:
|
369531 |
| Filed:
|
August 6, 1999 |
Foreign Application Priority Data
| Intern'l Class: |
G01L 005/04; G01L 005/06; G01L 001/26 |
| Field of Search: |
73/160,159,862.391,862.42,862.451,862.471,862.73
|
References Cited
U.S. Patent Documents
| 5140852 | Aug., 1992 | Bonigk et al. | 73/160.
|
| 5462094 | Oct., 1995 | Josefsson et al. | 139/194.
|
| 5718854 | Feb., 1998 | Nguyen | 264/40.
|
| 5956994 | Sep., 1999 | Schoni | 73/159.
|
| 5966919 | Oct., 1999 | Tsou | 57/264.
|
| 5996925 | Dec., 1999 | Iwade et al. | 242/413.
|
Primary Examiner: Williams; Hezron
Assistant Examiner: Loo; Dennis
Attorney, Agent or Firm: Schwegman, Lundberg, Woessner & Kluth, P.A.
Claims
What is claimed is:
1. A yarn parameter measuring instrument comprising an inlet yarn guiding
element and an outlet yarn guiding element, and a plurality of sensing
devices mounted successively within the instrument, each sensing device
having at least one operative sensing element adapted to be responsive to
a respective yarn parameter, wherein the yarn is guided through the
instrument by contact only with the inlet and outlet guiding elements and
the sensing elements that are contact operative, the contact operative
sensing element of one sensing element device serving to guide the yarn to
a successive sensing device.
2. An instrument according to claim 1, comprising a yarn tension sensing
device.
3. An instrument according to claim 2, wherein the yarn tension sensing
device has a contact operative sensing element which comprises a tension
sensing pin.
4. An instrument according to claim 3, wherein the tension sensing pin has
stress measuring means secured thereto responsive to the deflection of the
tension sensing pin due to the tension in a yarn passing therearound.
5. An instrument according to claim 4, wherein the tension sensing pin
comprises a supporting stem and the stress measuring means comprises at
least one strain gauge secured to the stem.
6. An instrument according to claim 1, comprising an interlace sensing
device.
7. An instrument according to claim 6, wherein the interlace sensing device
has operative sensing elements comprising a laser beam generating device
and a photo diode operable to receive the laser beam.
8. An instrument according to claim 1, comprising an oil content sensing
device.
9. An instrument according to claim 8, wherein the oil content sensing
device has contact operative sensing elements which comprise a first pin
to which an electrical voltage is applied and a second pin adapted to
measure the voltage on the yarn to determine the electrical resistance of
the yarn between the first pin and the second pin.
10. An instrument according to claim 9, wherein substantially 200 volts are
applied to the first pin.
11. An instrument according to claim 1, comprising, in succession, an
interlace sensing device, a tension sensing device and an oil content
sensing device.
12. An instrument according to claim 11, wherein the oil content sensing
device has contact operative sensing elements which comprise a first pin
to which an electrical voltage is applied and a second pin adapted to
measure the voltage on the yarn to determine the electrical resistance of
the yarn between the first pin and the second pin, and wherein the first
pin is a tension sensing pin, and the second pin is the outlet guiding
element.
Description
FIELD OF THE INVENTION
This invention relates to a measuring instruments for measuring the various
parameters of a textile yarn, and in particular to instruments for
measuring yarn parameters whilst the yarn is running through a textile
machine during the processing of the yarn.
BACKGROUND OF THE INVENTION
There is a requirement to measure various parameters of a textile yarn
during and subsequent to the processing of the yarn, to determine the
efficiency and effectiveness of such processing and the quality of the
processed yarn. To this end, there are many sensing instruments available,
each adapted to measure a specific parameter. A typical yarn process on
POY or DTY may require the measurement of interlace, oil level and tension
and the determination of the presence of broken filaments. To perform all
of these measuring or sensing functions requires the use of at least three
sensing instruments. Whilst some of the actual operative sensing elements
may be non-contact, e.g. optical sensors, each sensing instrument requires
two or more yarn contacting sensing elements and/or yarn guides to locate
the running yarn in the sensor relative to the operative sensing elements.
The result of adding three sensing instruments to a typical process
threadline can add over 45.degree. of sensing element/guide wrap, thereby
undesirably increasing by a considerable amount the tension in the yarn
downstream of those instruments. Hence the quality of the processed yarn
is often compromised by the act of monitoring its quality. For this
reason, and having regard to the high process speed with some processes,
it is desirable or even essential to minimise the total sensing
element/guide contact with the yarn within the complete process
threadline.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a yarn parameter
measuring instrument which minimises the abovementioned problem.
SUMMARY OF THE INVENTION
The invention provides a yarn parameter measuring instrument comprising an
inlet yarn guiding element and an outlet yarn guiding element, and a
plurality of sensing devices mounted successively within the instrument,
each sensing device having at least one operative sensing element adapted
to be responsive to a respective yarn parameter, wherein the yarn is
guided through the instrument by contact only with the inlet and outlet
guiding elements and contact operative sensing elements.
The instrument may comprise a yarn tension sensing device, having an
operative sensing element which may comprise a tension sensing pin. The
tension sensing pin may have stress measuring means secured thereto
adapted to be responsive to the deflection of the tension sensing pin due
to the tension in a yarn passing therearound. The stress measuring means
may comprise at least one strain gauge secured to a stem which supports
the tension sensing pin.
The instrument may comprise an interlace sensing device having operative
sensing elements which may comprise a laser beam generating device and a
photo diode operable to receive the laser beam.
The instrument may comprise an oil content sensing device, having a first
operative sensing element which may comprise a first pin to which an
electrical voltage is applied and a second operative sensing element which
may comprise a second pin adapted to measure the voltage on the yarn to
determine the electrical resistance of the yarn between the first pin and
the second pin.
The instrument may comprise, in succession, an interlace sensing device, a
tension sensing device and an oil content sensing device. In this case the
first pin may be the tension sensing pin, and the second pin may be the
outlet guiding element.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention will now be further described with
reference to the accompanying drawing in which:
FIG. 1 is a side view of a parameter measuring instrument, and
FIG. 2 is a front view of the instrument of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the Figures, there is shown a yarn parameter measuring
instrument 10, having a housing 11 in which there is mounted in succession
in the direction of passage of a yarn 12, an inlet guiding element 13,
three sensing devices 14, 15 and 16, and an outlet guiding element 17 as
described below.
Sensing device 14 is an interlace sensing device which comprises
non-contact sensing elements in the form of laser beam generating device
18 and a laser beam receiving photo-diode 19, between which the yarn 12
passes from the inlet guiding element 13. The photo-diode 19 senses
changes in the width of the yarn 12 passing through the laser beam, and
the resulting signal from the photo-diode 19 is representative of the
presence or absence of interlace nodes in the yarn 12.
Sensing device 15 is a tension sensing device which comprises a contact
operative sensing element in the form of a tension sensing pin 20 having
at least one strain gauge 21 secured to a stem 22 which supports the pin
20 in the housing 11. The signal provided by the strain gauge 21 is a
measure of the deflection of the pin 20 under the tension of the yarn 12
passing in contact with it, and hence a measure of that tension.
Sensing device 16 is an oil content sensing device which comprises two
contact operative sensing elements in the form of a first pin 20 to which
an electrical voltage, e.g. 200 V, is applied and a second pin 17 adapted
to measure the voltage on the yarn 12 as it reaches the pin 17 to
determine the electrical resistance of the yarn 12 between the pins 20 and
17. This resistance depends upon the oil content of the yarn 12, being
high when no oil is present on the yarn 12 and reducing with increasing
oil content. In this case the first pin 20 is the tension sensing element
of the tension sensing device 15, and the second pin 17 serves also as the
outlet guiding element 17.
By means of the invention an instrument is provided which enables several
parameters of a processed yarn 12 to be measured or determined. In the
above described embodiment, interlace, tension and oil content are
measured, but other parameters may be measured or determined in addition
to or instead of the those parameters. In order to measure the three
parameters as described above using separate instruments, two yarn
guides/contact operative elements would normally be provided for each of
the interlace and oil content measuring instruments, and three yarn
guides/contact operative elements would normally be provided for the
tension measuring instrument. These seven yarn guides/contacting elements
could require at least 35.degree. and probably over 45.degree. of yarn
wrap. In the present case however there are only three yarn
guiding/contact operative elements requiring some 15.degree. to 20.degree.
of yarn wrap, a reduction of 57%. This will lead to a considerable
reduction in output tension in use of the instrument of the present
invention by comparison with the use of three separate instruments, and
hence considerably less detrimental effect on the quality processed yarn
12 as a consequence of monitoring that quality than has been the case in
the past.
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