US3771325A

US3771325A - Element position detector system

Info

Publication number: US3771325A
Application number: US00139104A
Authority: US
Inventors: J Sweeney; G Dyer; R Johnson
Original assignee: Rockwell International Corp
Current assignee: Boeing North American Inc
Priority date: 1971-04-30
Filing date: 1971-04-30
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: CH549677A; BR7202579D0; FR2136749A5; ES402249A1; DE2220786A1; NL7204154A; ZA721520B; GB1367731A; BE782879A; IT952383B; CA956716A

Abstract

An apparatus and detector system for sensing whether moving element of a series of elements are in a selected position which apparatus comprises sensor means mounted adjacent the path of travel of the series of elements, the sensor means being capable of projecting and receiving light, means for converting received, reflected light into a voltage pulse and means, including selected gating, for comparing the voltage pulse with other command or related derived signals.

Description

ESQ- 961123 Unite Staes 1 WW,

Sweeney et al.

SUBSTITUTE FOR MISSING XR ELEMENT POSITION DETECTOR SYSTEM 3,529,445 9/1970 Brose 66/i57 3,577,750 5/1971 V l 66/157 [75] lnvemm James Sweeney Laguna Beach; 3,646,542 2/1972' Artistr 66/157 George A. Dyer, San Juan Capistrano; Ronald Johnson FOREIGN PATENTS OR APPLICATTONS Anaheim, all Of Calif. I 1,583,356 10/1969 France 66/154 A [73] Assignee: Rockwell International Corporation, OTHER PUBLICATIONS Pittsburgh Rottmann, IBM Technical Disclosure Bulletin, Vol. 9, [22] Filed: Apr. 30, 1971 N0. 5, Oct. 1966, pp. 540 & 541

[21] Appl' l39l04 Primary ExaminerWm. Carter Reynolds Anorrieylohn R. Bronaugh, Floyd S. Levison, E. [52] U.S. Cl. 645/50 R, 66/157, 250/222 R, Dennis OConnor and Richard A. Speer 250/227, 340/213 Q, 340/267 R, 340/282 [5i] Int. Cl. D04b 15/78, D04b 35/18 [57] ABSTRACT 52 Field of Search 66/50 R, 501;, 25, An apparatus and detector system for Sensing whether 66/50 1 157; 250/222 RI moving element of a series of elements are in a se- 2273 340/213 267 282 lected position which apparatus comprises sensor means mounted adjacent the path of travel of the se- [561 Relemnces cued ries of elements, the sensor means being capable of UNITED STATES PATENTS projecting and receiving light, means for converting 2,493,543 1/1950 Merchant 340/258 B x received, reflected light into a voltage Pulse and 3,646,542 2/1972 Anthony 66/157 X means, including selected gating, for comparing the "3,313,128 4/1967 Schmidt et a1 66/50 A voltage pulse with other command or related derived 3,365,699 H1968 Foster 250/227 X signal 3,449,928 6/1969 Schmidt et al. 1 66/50 R 3,449,931 6/1969 Kawakami et al. 66/157 2 Ch 6 D'awmg mgulms 7 /0 H flWZ'f/fll/ 0/" /i Z!) II,

flflffil/T 5764/41 Z/ 20 f/fi/f/fll fliflt'cffiflfi SEARCH ROOM PATENFEE MW 13 I975 SHEET 18F 2 kmwmwmu S PMENFEUHUV 13 ms SHEET 2 [IF 2 ELEMENT POSITION DETECTOR SYSTEM BACKGROUND OF THE INVENTION While this invention relates broadly to a sensing apparatus or system, for detecting the relative positioning of individual elements of a series of elements, it will be discussed in connection with a specific environment. Specifically, in the operation of various types of rotary knitting machines, particularly those in which pattern changes are to be effected by other than mechanical alteration of the equipment, malfunctioning of pattern jacks many times occurs. These errors result primarily from variations in cylinder eccentricity, speed of cylinder rotation, and, where the electro-magnetic or similar actuating means is used, from variations in electromagnetic phasing or in permanent magnet field strength. Obviously, if these variations result in the production of imperfect fabric due to improper knitting, loss of both time and money results. It is therefore desirable for the machine user to have some instant or ready indication that there is malfunctioning in the pattem jack operation.

SUMMARY OF THE INVENTION As noted earlier the detector system of this invention is particularly applicable for use in conjunction with circular knitting machines in which the pattern jacks can be automatically changed through the application of an appropriately applied magnetic field, although the concept is applicable with other types of equipment where similar sensing is of value and should, therefore, not be narrowly interpreted. The detector system utilizes a sensor element, capable of projecting and receiving light which is located on the knitting machine with one face operably adjacent the tricks of the needle cylinder so that light projected from the emitter and receptor face will strike the edges of the pattern jacks as they move past the sensing site. At least a pair of light c o n dgcting fibre cables one of which trams Em from asTtitabl' smefo the emitter-receiver face of the element and the other of which is operably joined to a light receiving voltage generatonThe signal derived from the voltage generator is appropriately shaped and amplified so that a usable signal can be fed to a comparator logic system. in the logic system the signal derived from the voltage generator is compared with the signal from the jack actuator command to determine the presence of any malfunctioning. The system also provides for comparison between the command output and other signals derived from the voltage generator output to determine what particular type of malfunctioning has occurred.

It is a principal object of this invention to provide a new sensor device for sensing the relative positioning of individual elements in a series of elements as they pass a sensing site.

Another object of this invention is to provide a sensor device for use in conjunction with electro-magnetically operated jack positioning devices on rotary knitting equipment.

It is an additional object of this invention to provide an improved sensing device in which light is reflected from the edges of the pattern jacks and the received reflected light is converted into a signal that can be used to determine the presence or absence of machine malfunctioning.

Another object of this invention is to provide an improved detector system which can determine whether a pattern jack has passed its operating stage in either a knit or a non-knit position erroneously.

Other objects and advantages of this invention will, in part, be obvious and in part explained by reference to the accompanying specification and drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the general relationship between the edges of the pattern jacks, the light emitting and receiving sensor and associated reflected light receiving voltage generating means.

FIG. 2 is an enlarged perspective showing the general construction of the light emitting and receiving sensor of FIG. 1.

FIG. 3 is a schematic diagram illustrating the manner in which the output sensed from the moving elements can be compared with a command input signal.

FIG. 4 is a series of graphs showing the relationship between proper jack positioning and the various derived outputs on a 1X1 select jack pattern.

FIG. 5 is a schematic similar to that of FIG. 4 showing the signals derived when a jack passes the sensing site at an erroneous elevated level.

FIG. 6 is a schematic similar to that of FIG. 5 but showing the outputs derived when a jack passes the sensing site below the selected level.

'It was ealier mentioned that the detector system of this invention is useful in determining the relative positioning of any sort of element moving past a detecting site. However, in outlining the invention, it will be described with particular application toa rotary knitting machine.

The type of knitting machine with which this invention is most applicable is one in which the pattern jacks can be automatically adjusted to either a position where it will cause the knitting needles to knit or not to knit. This is accomplished through the use of an electro-magnetic control system including an electromagnetically functioning jack actuator which is operated by a command system, specifically a computer input. Machines of this type generally comprise a large number of knitting stations or feeds, although it would also be applicable to relatively small diameter machines with a small number of yard feed stations. In the co-pending application of R. G. Wolfshagen, Ser. No. 135,3l9, filed Apr. 19, I971, (docket 1676) there is described a complete jack actuator system as used on a machine'having 48 feed stations and therefore 48 jack actuator arrays. In this sort of knitting machine the electromagnetic jack actuators are positioned reasonably critically. with respect to the edges of the pattern jacks as they pass by a selecting site. If during the course of operation misalignmentshould occur it opens the possibility of jack actuation not occurring as it should in response to a command input. When this happens it is of course essential that the malfunctioning be located promptly and the cause for the malfunctioning appropriately corrected.

To describe the invention in greater detail, reference is made to FIG. 1 of the drawings where the numeral 10 illustrates diagrammatically the edges of pattern jacks as they would be in a 1X1 select position. That is at the given site only every other one of the needles will be caused to move to the knit position and the alternate needles will remain in the non-knit position. Situated operably adjacent the edges of the pattern jacks is a sensor 11 which comprises a head 12 and a pair of fib reoptic cables 13 and 14 which are capable of transmitting oiconducting light from and to the head 12. On

the side of the head 12 adjacent the edges of the pattern jacks 10 is an emitter-receiving face 15 where the signal and the output signal from the sensor means, that light source which is to supply light to the lowermost operably adjacent the other of the optic fibre cables 1 (14) is a receiver 21 for the light which is being emitted from the cable 14. This receiver 21 may appropriately be a photocell which will take the light being conducted to it and convert it into a voltage pulse. The photocell 21 is connected to a signal processor 22 which serves to sharpen and improve the nature of the voltage pulse received from photocell 21. Signal processer 22 may advantageously be a saturating amplifier which will shape the analog signal and square it to deliver a cleaner signal. The signal processer 22 then delivers an output signal which is connected to additional apparatus. I

f The operation of that part of the senso'r described thus far is as follows. Light from source 20is displayed to the fibre cable 13 and this light is emitted from the face 15 of head 12, so that it willstrike any of the jacks 10 which are in the lowered or non-knit position, as viewed in FIG. 1. When light strikes one of the pattern jacks, a certain percentage of it is reflected back and is transmitted through the fibres that are contained in the uppermost cable 14 to then activate the photocell 21. The photocell 21 then delivers a voltage pulse to the signal processer for subsequent application. When there is no jack present opposite the emittor-receptor face of head 12 then insufficient light will be reflected back to activate the voltage generating photocell 21. In the case of knitting equipment the light reflected from the emittor-receptor face can be adjusted to strike the needle or jack butts so that reflection from the needle cylinder is not a significant factor. The system can then differentiate between the presence or absence of any given jack (or other type of passing element) by means of determining whether or not light is being reflected back to result in the generation of a-voltage pulse.

Since malfunctioning may occur by having a jackactuator in either an erroneous knit or an erroneous nonknit position, that is, in a raised or lowered position as shown in the drawings, it is obvious that means should be provided to determine the specific nature of the malfunctioning that is occurring. This is accomplished by means of the circuit illustrated in the diagram shown in FIG. 6 of the drawings. Here the output signal derived'from signal processor 22 in FIG. 1 is fed into the jack position sensor output and then connected to a one-shot multivibrator 25 that will deliver a pulse of constant amplitude and length regardless of machine speed. The other input to the comparator system of FIG. 6 is the actuator command, which comes from the central command system that controls the actuation or pulsing of the individual jack actuator mechanisms at each yarn feed station.

The overall system then comprises first gating means 26 for receiving as input signals the actuator command is, the signal derived from processor 22. If a signal is received from the output sensor and the actuator command coincidentally, then no output signal will come from gating means 26 and proper operation of the apparatus will be indicated. Second gating means 27 re ceives the output signal from gate 26 and the actuator command signal to give a first error signal indicating that a jack has passed the sensor means 11 in an improper position. Specifically, it identifies the error as one where a jack is in the non-knit wrongly.

Third gating means 28 receives the output signal from gate 26 and the output signal from the command system to indicate that a jack has passed the sensor means 11 in the knit or uppennost position erroneously. The output of the

gating elements

27 and 28 are indicated in FIG. 6 to deliver a down error signal and an up-error signal, respectively. An additional gate 29 is provided which receives as input signals those derived from

gate elements

27 and 28 and has been labelled as an OR gate29. As indicated, this gate will give a positive indiction of all errors that have occurred, whether up or down.

Describingthe operation of the system of FIG. 6 slightly differently, the actuator command signal is fed into NAND gate 26'with the jack position sensor output so. that no signal occurs at pulse coincidence but signals do occur for all other combinations. The output signal from NAND gate 26 is then forwarded to AND gate 27 with the jack position input pulse to yield a down errorsignal. The output signal from NAND gate 26 is also forwarded to AND gate 27 with the actuator command signal and from this is derived the up error signal. By forwarding the

signals from'ANl gate

27 and 28 to OR gate 29 all errors are detected, as noted earlier.

The manner in which the pulses interact to deliver the indication of malfunction can best be described by referring to FIGS. 3, 4 and 5 of the drawings. Referring first to FIG. 3 there is shown a vertical series of five outputs which occur at various edges of the detecting operation. The uppermost of the six vertical elements present in FIG. 3 is representative of the positions the jacks should correctly assume in a 1X1 pattern select. In this case it can be seen that every other jack is in the down or non-knit position with alternating jacks being in the upper or knit position. When the jacks are in the non-knit lowered position the light being emitted and received through sensor head 12 will cause the photocell 21 to generate pulses which coincide with the passage of a lower jack past the detecting site. Again, as earlier described, the voltage pulse coming from the photocell 21 goes through signal processor 22 and is processed to deliver an improved signal. The fourth vertical line from the top of the vertical series of curves represents the input derived from the actuator command or input signal system. It can be seen that the pulses received, as generated by photocell 21, coincide with the clocking pulses received from the command system. When this occurs the lower two lines indicate that there are no detector output signals that would indicate any sort of machine malfunction. Comparing the curves of FIG. 3 with those of FIG. 4 it will be noted that the jack numbered 30" is in a raised position, whereas. to be properly located it should be in a lower position. This, of course, results in the absence of a pulse from the jack position sensor output while the jack actuator command as indicated with a pulse should be present. Operating through the system of FIG. 6 then, the inputs would result in NAND gate 26 and AND gate 28 combining to produce an up error signal.

Conversely the curves of FIG. 5 demonstrate what the condition of the system is when a jack 31 is in a lower or down position erroneously. Here an extra pulse is produced by the jack position sensor while one is not called for the command system. When this occurs, NAND gate 26 and AND gate 27 should deliver an indication of a down error.

This detector is far less sensitive to cylinder eccentricity and cylinder to detector Spacing than the conventional magnetic sensors which are adversely affected by cylinder velocity and jack to sensor distance and the presence of magnetic fields.

Although the present invention has been described in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

We claim:

1. A detector system for use with a circular knitting machine on which the pattern jacks carried within the tricks of the needle cylinder are selected by electronically regulated jack actuators controlled by an actuator command system to be either raised to a knit position by jack raising cams or left in a lower non-knit position, as desired, said detector system comprising:

sensor means for positioning operably adjacent the needle cylinder for projecting light against the edges ofjacks in the non-knit position and for collecting a portion of the light reflected by the edges; and

means associated with said sensor means to generate a voltage output signal indicative of the passage of a jack in the non-knit position past said sensor means.

2. A detector system as described in claim 1 wherein aid sensor means comprises at least two light conductng fibre cables terminating in an emitter and receptor face fofiio's idoning adjacent the edges of said jacks, one of said cables being operably connected to a source of light and the other of said cables being operably joined to a light responsive voltage generator.

it t a e

Claims

1. A detector system for use with a circular knitting machine on which the pattern jacks carried within the tricks of the needle cylinder are selected by electronically regulated jack actuators controlled by an actuator command system to be either raised to a knit position by jack raising cams or left in a lower non-knit position, as desired, said detector system comprising: sensor means for positioning operably adjacent the needle cylinder for projecting light against the edges of jacks in the non-knit position and for collecting a portion of the light reflected by the edges; and means associated with said sensor means to generate a voltage output signal indicative of the passage of a jack in the nonknit position past said sensor means.

2. A detector system as described in claim 1 wherein said sensor means comprises at least two light conducting fibre cables terminating in an emitter and receptor face for positioning adjacent the edges of said jacks, one of said cables being operably connected to a source of light and the other of said cables being operably joined to a light responsive voltage generator.