US 3904529 A
The admission of a gas to a reaction chamber which has been previously evacuated is followed by its excitation by either a high-frequency electrostatic field or an electromagnetic field, formed by capacitor plates or a coil, respectively, which envelops the outer wall of the reaction chamber. A perforated metallic cylinder is disposed within the chamber concentrically with the long axis of the chamber and comprises the material-handling zone of the chamber. The activated gas reacts with material placed within the perforated cylinder, during which reaction inactive gas and resultant gaseous byproducts are continuously withdrawn. The construction of the chamber and the internal perforated metallic cylinder are such as to provide very uniform distribution of gaseous excited species throughout the entire material-processing volume within the cylinder thereby promoting very uniform chemical conversions of practical interest.
Claims available in
Description (OCR text may contain errors)
United States Patent 1 Nakamura Sept. 9,1975
 NEEDLE DEFECT DETECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES [75) Inventor: Isao Nakamura, Nishinomiya,
Japan  Assignee: Kazumasa Ashida and Shinko Electric and Instrumentation Co., Ltd., Osaka, Japan v  Filed: Apr. 24, 1974 ] Appl. No.: 463,536
 Foreign Application Priority Data Apr. 27. 1973 Japan .1 51441  U.S. Cl 250/561, 66/165, 250/227  Int. Cl. G01N 21/30  Field of Search 250/559, 561, 562, 563,
[5 6] References Cited UNITED STATES PATENTS 3,631,690 1/1972 Findlay et al 66/165 3,599,586 8/1071 Newman 242/36 3,772,524 11/1973 Erbstein 250/561 3,496,739 2/1970 Motin et al 250/571 3,688,526 9/1972 Worner 66/165 11/1969 Kottman ..250/563 8/1972 Flaczynski ..250/560 Primary Examiner-Eli Lieberman Assistant Examiner- D. C. Nelms Attorney, Agent or Firm-James E. Nilles 1 ABSTRACT This invention relates to an apparatus for detecting defects of needles for a circular knitting machine.
Said apparatus comprises at least an optical fiber having an end of a small sectional area and disposed to detect light reflections from one of hooks or latch portions of dial and cylinder needles mounted on the circular knitting machine, a light receiver unit operatively coupled to the other end of said optical fiber and including a photo-electric converter element, and an electric circuit for transforming a variation in signal representative of said light reflections produced by said light receiver unit into a corresponding variation of an electrical quantity.
In this invention possible breaking or bending of the hook or defects of the latch or like undesirable conditions of the knitting needles are detected to thereby prevent knitting defects from being produced in the knitted web.
3 Claims, 7 Drawing Figures PATENTED SEP 9 I975 SHEET FIG. I
PATENTED SEP 9 I975 SHEET HRDQ hr D FIG. 3A
PATENTED 9l975 3,904,529
SHEET 3 FIG. 5
9 l I 27 28 30 3| 32 f $229 j SWITCHING CIRCUIT AMPLIFlER AND 5% j END OF FIBER CIRCUIT 2 BUNDLE AND GATE Z CONV/TER 29 RECEIVER CIR T 30 9 I I 27 28 DISPLAY UNIT NEEDLE DEFECT DETECTOR APPARATUS FOR CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION otherwise occurring defects from being produced in.
the knitted web.
Lately, a photo-electric detection system is rather increasingly used for automatically detecting defects in a web knitted by a circular knitting machine. However, it is difficult to perform such detection for the knitted web itself in case of a pattern knitting or av colored pattern knittingwhich is widely employed in the circular knitting field. Considering the fact that most of the knitting defects or defective stitches are attributable to malfunctions or defects of the knitting needles, it is apparently more advantageous to instantly stop the operation of the machine by detecting the defects or malfunctions of the knitting needles themselves to thereby previously exclude the possibility of the defects being produced in the knitted stitches than to detect the defects in the knitted web to thereby stop the machine operation. In order to monitor heads or points of the knitting needles, the detection has to be performed when the knitting needles are projected. In case of the circular knitting machine, the detection must be made at a position adjacent to the yarn feeder or at the position where the needles are at least partially projected. Accordingly, it is necessary to use a detector of a very small size. Particularly, in case of a circular knitting machine which has needles arranged at a high density and is rotated at a relatively high speed, the thickness of the needle head is only of 0.3 to 0.4 mm and therefore a detector head of a special design was required for the valid detection. I
The present invention has overcome the above difficulties by using an optical fiber or fiber bundle having a diameter of ca. 0.5 mm as the detector head.
Accordingly, an object of the present invention is to provide a needle defect detection apparatus comprising an optical fiber bundle for detecting the defects of the needles as variations in light reflected from the needle head and impinging onto the exposed end of the optical fiber.
In a lately developed circular knitting machine operated at a higher rotating speed as compared with prior machines, oil mist is used for lubrication. Because no optical lens system is employed in conjunction with the optical fiber bundle in the apparatus of the present invention, the use of oil mist will provide substantially noobstacle for the light receiving function, since the'adhesion of oil mist to the optical lens does not come into question. Additionally, the apparatus according to the invention may be operated under sufficiently stabilized condition without being subjected to disturbance by dispersed yarn dusts.
The apparatus according to the present invention allows the use of all electronic components for an electric signal processing circuit as well as alarming circuit for a control section except for a mechanism which serves to stop the operation of the knitting machine by means of relay contacts. Furthermore, according to the present invention, the electronic signal processing circuit includes a means for converting the interval period between succeeding adjacent pulses produced by two adjacent knitting needles into a voltage wave form having a corresponding amplitude and a circuit for producing a signal to stop the operation of the knitting machine when there occurs a voltage of an abnormal amplitude twice as great as said corresponding amplitude. Due to such circuit arrangement, the detector apparatus of the present invention is prevented from being operated during the initiation phase of the machine operation until the machine attains a predetermined constant speed. The time span of the initiation phase may be arbitrarily selected. Additionally, the detector apparatus does not function during the deceleration phase of the machine operation as brought about by the signal representative of a defect of the needle.
A plurality of detector channels are provided, each having a display device such as a lamp so that the defective needle detected by a detector channel may be easily identified by the associated display lamp.
For a knitting machine of a single needle type, the
.provision of a single detector head will be sufficient.
For a knitting machine of a double needle type in which no needle selecting operation is required, two detector heads, i.e. one for dial needles and the other for cylinder needles will be sufficient. In case of the machine where the needle selection is to be made, four detector heads are required. For the circular knitting machine the cylinder needles of which are operated in the so-called tuck position, three detector heads, namely one for cylinder needles and two for dial needles are required.
The above and other objects as well as novel features and advantages of the present invention will become more apparent from the following description of a preferred embodiment of the invention. The description makes reference to drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially sectioned fragmental side view of a knitting portion of a circular knitting machine of a double needle type illustrating a detector apparatus according to the present invention mounted for monitoring hook portions of cylinder needles;
FIG. 2 schematically illustrates a relationship between needles and actuating cams;
FIGS. 3A and 3B are front and side views, respectively, of a detector head for the hooks of cylinder needles mounted on a dial needle exchange cover;
FIGS. 4A and 4B are front and side views, respectively, of a detector head mounted on an inherent yarn feeder of the machine for monitoring the hooks of dial needles; and
Fig. 5 is a block diagram of an electric circuit having two detector heads or channels.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, reference numeral 1 indicates a dial provided with a dial cover 2. Numeral 3 denotes dial cams for controlling the operation of dial needles 4. Reference numeral 5 denotes a needle cylinder provided with a cylinder cover 6. Cylinder cams 7 are also arranged for operating cylinder needles 8. Further, reference letter A represents hook portions of the needles 4 and 8, respectively, while character B denotes latch portions of the respective needles 4 and 8. Letter C denotes bretts each of which constitutes a part of the needles 4 and 8 and is adapted to cooperate with the associated cam to move the needle reciprocately. Usually, the dial'l and'the cylinder 5 are rotated with the needles 4 and 8 placed in the needle grooves, while the dial cover2 and the cylinder cover 6 remain stationary and serve to support the associated cams 3 and 7. Reference numeral 9 indicates an end portion of an optical fiber bundle which end portion is held in a position apart from the hook portion A for a distance less than a few millimeters and serves as a sensor or detector head. The optical fiber bundle 9' is accommodated within a holding metal tube 10 and operatively coupled to a light signal receiver unit '11 comprising a photoelectric converter element and an amplifier in a form of an integrated circuit. The receiver unit 11 in'turn is electrically connected to a control section for processing electric signals, as will be hereinafter described. Numeral 12 indicates a light emission or illuminating element energized by dc. current from which ripple components have been completely removed. The light emission element12 as well as the light receiver unit 11 are supported by a frame 13 which is mounted on the cylinder cover 2 at 14 removably so that the frame 13 together with the light emission element 12 and the receiver unit 11 may be removed or moved away from the needle heads so as to facilitate manual works such as exchange of yarns or the like. An arrow D indicates the direction into which knitted web is fed or forwarded.
Referring to FIG. 2, which illustrates a relationship between the needles 4 and 8 and earns for pushing and withdrawing them, numeral 15 denotes cams for pushing the needles 4 and 8 to respective middle or intermediate positions generally called tuck posi tion, while numeral 16 indicates cams for returning these needles 4 and 8 from the tuck positions to the starting positions. Further, cams 17 serve to push the needles to the outermost positions, which needles are then moved backwards by respective cams 18. Dots 19 schematically indicate the positions of the bretts. The outermost positions of the needles for latching yarns into the hooks are indicated by numeral 20 and the tuck positions are denoted by reference numeral 21. Arrow E indicates the direction in which the dial 1 or cylinder 5 carrying its needles is rotated.
FIGS. 3A and 3B show a detector head for the hooks of cylinder needles.
In FIGS. 3A and 38, reference numeral 22 indicates an inherently provided portion of the machine for exchanging the dial needles. When the head portions of needles for a pattern knitting machine are to be monitored, the detector head may be easily mounted on this dial needle exchange portion 22 in a simple manner. To this end, a plate 23 is provided for mechanically connecting the detector head to the dial needle exchanging cover 22. The light receiver unit 11 and the light emission element 12 are supported and secured to the plate 23 by means of a member 24.
The light receiver unit 11 is electrically connected to a control section by way of an electric cable 25.
FIGS. 4A and 4B show a detector head for the hooks of dial needles.
In FIGS. 4A and 4B, yarn fed to the knitting machine is indicated by reference numeral 26.
Referring to FIG. 5, blocks 27 indicate amplifier and shaper circuits in which electric signalsproduced by the units 11 in response to the optical inputs from the detector. head or optical fiber bundles are converted into rectangular wave pulses of narrow pulse width. Connected to the outputs of the circuits 27 are converter circuits 28 which are arranged so as to transform normally a distance or interval between the succeeding adjacent pulses into an analog voltage signal of a corresponding magnitude and produce a voltage of the amplitude twice as high as said magnitude when a failure or defect is detected in a single needle. Blocks 29 represent limiter. circuits which are switched fromone state to another state when the associated output voltages from the circuits 28 vary from the normal amplitude to the high level as above stated. The circuits. 29 have respective display units 30 suchas alarm lamps which are activated when the failure signals are produced in the associated channels. The. outputs from the limit or switching circuits 29 are coupled. to a coincidence comparator suchas an AND gate 31 which in turn is connected to another switchingcircuit 32 for producing a signal to stop the operation of the knitting machine or an alarm signal.
The circuit 29 is constructed in a form of a priority the pulse interval becomes disordered, any defect representative outputs of the circuits 28 will not exert any influences on this stopping phase of the machine operation. I
Upon initiation of the circular knitting machine, the switching circuit 32 is automatically released from the locked state. However, a timer relay maybe employed in order to inhibit the defect detecting function of the photo-electronic systems until the machine has attained a predetermined constant speed.
Although the invention has been illustrated and described with reference to a preferred embodiment by way of an example, it will be appreciated by those skilled in the art that modifications and changes may be made in the form of the invention without departing from the spirit and scope of the invention.
What is claimed is:
1. Apparatus for detecting defects of needles for unit into a corresponding variation of an electrical signal, whereby a possible defect of said component is detected to thereby prevent knitting defects from for stopping the operation of the circular knitting machine when the voltage from said circuitry attains a level greater than said predetermined amplitude.
3. Apparatus as set forth in claim 2, further comprisr ing a circuit for inhibiting stoppage of the said machine after starting of the circular knitting machine until the machine has attained a predetermined constant speed.
UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent 3,904 ,529 Dated September 9 1975 Inventor(s) I530 Nakamura It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
On the cover sheet the illustrative figure should appear as shown below:
Signed and Scaled this eleventh of May 1976 [SEAL] A ties I:
RUTH C. M A SON C. MARSHALL DANN AIH'SIHIX ()fjujvr ('mnmissimwr uflarenls and Trademarks