US3557377A

US3557377A - Device for electro-optically monitoring filiform material

Info

Publication number: US3557377A
Application number: US791738*A
Authority: US
Inventors: Hans Raasch
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-01-20
Filing date: 1969-01-16
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19
Also published as: CH485586A; GB1241084A; ES360019A1; FR1600953A; BE727069A

Abstract

Device for electro-optically monitoring filiform material alternately stationary and traveling in the longitudinal direction thereof includes a light-sensitive element disposed back of the filiform material, means located in front of the filiform material for subjecting the filiform material to light beams extending in at least two directions thereto, and means for spacing the filiform material, in the traveling condition thereof, closer to the light-sensitive element than when the filiform material is in stationary condition thereof.

Description

United States Patent lnventor Hans Raasch Rheydt, Germany Appl. No. 791,738 Filed Jan. 16, 1969 Patented Jan. 19, 1971 Assignee Walter Reiners Monchengladbach, Germany Priority Jan. 20, 1968 Germany 1,710,131

DEVICE FOR ELECTRO-OPTICALLY MONITORING FILIFORM MATERIAL 6 Claims, 3 Drawing Figs.

US. Cl 250/219, 356/200 Int.Cl ..G01b11/10 Field of Search 250/2195,

(inquired), 219L, 219TH; 356/199, 200, 237, 238; 66/163 [56] References Cited UNITED STATES PATENTS 2,413,486 12/1946 Denyssen 250/219X 2,438,365 3/1948 Hepp etal. 66/163 3,016,207 1/1962 Comstock 250/219X 3,461,299 8/1969 Felix 250/219 3,053,986 9/1962 Loepfe et al 250/239X Primary Examiner-Walter Stolwein Att0rneys-Curt M. Avery, Arthur E. Wilfond, Herbert L.

Lerner and Daniel J. Tick ABSTRACT: Device for electro-optically monitoring filiform material alternately stationary and traveling in the longitudinal direction thereof includes a light-sensitive element disposed back of the filiform material, means located in front of the filiform material for subjecting the filiform material to light beams extending in at least two directions thereto, and means for spacing the filiform material, in the traveling condition thereof, closer to the light-sensitive element than when the filiform material is in stationary condition thereof.

DEVICE FOR ELECTRO-OPTICALLY MONITORING FILIFORM MATERIAL My invention relates to device for electro-optically monitoring filiform material and more'particularly such devices wherein the material is subjected from at least two directions to light influencing a light-sensitive element.

Devices of this general type are employed, for example, for ascertaining the presence of abnormalities in the filiform material, such as thick or thin spots therein or for inspecting the regular knotting or tying of two ends of the filiform material. These devices are generally associated with a severing device which severs the filiform. material if a dimension thereof, such as the diameter, cross section, volume or the like deviates from a given nominal value.

If the filiform material is a textile yarn, it is known, of course, that it cannot have any exact uniform cross section but rather is subject to certain variations in cross section. A specific valueof these variations is looked upon as being permissible or tolerable. Thus, the device for monitoring textile yarn is so adjusted that deviations within a predetermined tolerance value do not produce any actuating pulse that would otherwise result insevering the yarn. Moreover, the length of the yarn portion of abnormal dimension. such as a thickened portion or the like, is of significance. Thus, for example greatly thickened yarn portions that are very short in length may nevertheless be tolerable, whereas slightly thickened yarn portions of relatively great length can have a disturbing effect. In order to take such a situation into account, delay circuits for example have been provided which permit the yarn severing device to be activated only after the predetermined maximum value of a shading for a specific time period is exceeded. Since the speed of the yarn traveling through themonitoring device is known, the tolerable length of a yarn portionof given deviating thickness is ascertained in this manner.

A trouble-free operating device of this type for the traveling yarn, however, produces fault shadows when the yarn is at rest i.e. is 'not traveling in the longitudinal direction thereof through the monitoring device.

It has therefore been proposed that the monitoring of the filiform material be interrupted during the time interval in which the filiform material is at rest. This proposal demands considerable expense, however, requiring the monitoring device to be activated immediately upon start-up of the machine without permitting an inadmissible or intolerable length of the filiform material to travel therethrough untested.

It is accordingly an object of my invention to provide device for electro-optically monitoring filiform material which avoids the foregoing disadvantages of the heretofore known devices of this general type and which, more specifically, avoids the undesired insert cuts or unintentional severances of the filiform material at relatively low cost.

With the foregoing and other objects in view l provide in accordance with my invention device for electro-optically monitoring filiform material comprising a light-sensitive element, and means for spacing the filiform material closerto the lightsensitive element, when the filiform material is traveling in the longitudinal direction thereof, than when the filiform material is at a standstill. It should be understood that by the term standstill it is meant not only the absolute rest of the filiform material but also the faulty movement of the filiform material in the longitudinal direction thereof i.e. the interrupted or broken travel of the filiform material. A movement of the filiform material, such as a yarn, transversely to the longitudinaltravel direction thereof, for example when inserting the filiform material into the monitoring device, does not result in any travel of the filiform material in thelongitudinal direction thereof, and is consequently relegated to the category of the standstill of the filiform material.

In accordance with further features of my invention, the spacing means defines the spacing of the filiform material from the light-sensitive element so that the light beams coming from different directions and impinging on the filiform material cast orderly shadows thereof on'the light-sensitive element. When the filiform material is at standstill as when the filiform material is being inserted in the monitoring device, the spacing of the filiform material from the light-sensitive element is increased, however, so that the shadow effects produced on the light-sensitive element by the individual light beams that extend in different directions produce no switching pulse due to their insignificance.

, To permit trouble-free measurement, l provide in accordance with a further feature of my invention a translucent cover for the light-sensitive element which is spaced at given distance therefrom, the filiform material being disposed in abutment with the translucent cover when the filiform material is traveling in its longitudinal direction so as to define thereby the spacing of the filiform material from the light-sensitive element.

In accordance with yet another feature of my invention, the translucent cover is provided with inclined end faces so that the path of the filiform material at the ends of the cover is angled off, and thus attaining not only a reliable abutment for the filiform material at the translucent cover but also simultaneously assuring that when several filiform materials are being monitored together, they will be disposed parallel to one another in front of the light -scnsitive element and will in this way be uniformly strongly illuminated.

In accordance with additional features of my invention, in addition to the cover of the light-sensitive element serving as an abutment member for the traveling filiform material, l provide an abutment means for the stationary filiform material which is preferably disposed parallel to the abutment surface of the translucent cover. When a prism or a diffused lightproducing disc are employed for providing light beams extending along different paths, the prism or disc can then serve as the abutment means for the stationary filiform material. To insure that the filiform material will actually abut this abutment means, I further provide in accordance with my invention at least one air nozzle acting on the stationary filiform material. I also provide, in accordance with my invention, at least one contour member at the translucent cover, against which the traveling filiform material abuts for providing a lateral limit to the motion of the filiform material whereby all or at least the predominant portion of the light beams impinging on the filiform material from different directions have an exciting effect on the light sensitive element.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in device for electro-optically monitoring filiform material, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIGS. l and 2 are respective plan and side elevational views of the electro-optical device for monitoring filiform material according to my invention; and I FIG. 3 is an enlarged fragmentary view of FIG. 1.

Referring now to the drawing and first, particularly, to FIGS. 1 and 2 thereof, there is shown a light bulb I from which light is passed through a lens 2 and a prism 3 to a photoelectric cell 4 protected by a translucent cover 5. The filiform material that is being monitored is inserted between the translucent cover 5 and the prism 3. The aforementioned components are so assembled that when the filiform material travels in the iongitudinal direction thereof it follows a path corresponding to the dot-dash line E whereas when the filiform material is at rest such as for example after the filiform material has been inserted in the measuring device, the filiform material adopts a course corresponding to the dot-dash line F It can be observed from the enlarged fragmentary view of FIG. 3 that light beams extend from the prism 3 in two different directions so that the inserted filiform material such as yarn, casts a shadow in both of these directions. Thus, as clearly seen in FIG. 3, only the shadows F, and F," of the yarn F, located closer to the photoelectric cell 4 excites or impinges on the cell. while the shadows F and F produced by the yarn F laterally pass by the cell 4. In order to define the position F or F of the yarn more clearly, the yarn when traveling along the path represented by the dot-dash line F lies right at the translucent cover 5, whereas it lies in abutting engagement with the prism 3 when the yarn is at standstill. As can be seen from H0. 2, the path of the yarn corresponding to the dot-dash line F is angled off at the inclined end faces 50 and 5b of the translucent cover 5 so that, for example, when two yarns are inserted, assurance is afforded that both of these yarns will travel parallel to one another over the translucent cover 5 and will therefore have uniform spacing from the photoelectric cell 4.

Two

air nozzles

6 and 7 are also provided as shown in FIG. 2. in the form of suction nozzles which act on the stationary yarn F and assure the abutment of this yarn F against the prism 3. There can furthermore be seen in FIG. 3, two lateral contour members 8 and 9 which extend between the prism 3 and the translucent cover 5 so as to limit the lateral movement of the yarn F to a range within which both shadows F. and F," will safely fall on the photoelectric cell 4. The lateral limiting contour member 8 is formed with an insert opening 8a through which the yarn can be inserted in the measuring device.

The hereindescribed and illustrated device for monitoring the orderly knotting of yarn in an automatic yarn-winding machine, for example, operates in the following manner: The yarn coming from the take up coil or from the supply coil is inserted through the insert slot 8a into the measuring device by means of a gripper arm simultaneously inserting the yarn into the knotting device, and thereby assumes the position represented by the dot-dash line F in which the shadow image on the photoelement of the cell 4 is at least so small that even upon accidental insertion of a deviating thick portion of the yarn, no activating pulse for the non nonillustrated yarn-severing device will be produced. The

suction nozzles

6 and 7 thereby hold the yarn tightly against the prism 3, at startup of the winding station of the automatic winding machine, the yarn tension increases so that the yarn, by being drawn taut between the nonillustrated yarn guiding members of the station. adopts the course represented by the dot-dash line F Thus the full shadow formation or shading action upon the photoelement of the cell 4 is immediately attained.

As aforementioned, my invention is not limited to the illustrated and aforedescribed embodiment only. In the figures, the light emanating from the lamp 1 impinges on the filiform material from two directions by means of the prism 3. However, a prism can also be employed which directs light beams from more than two directions onto the yarn. Furthermore, my invention is also suited to the use of several light sources for producing the plurality of light beams. It is in fact also possible to employ diffused light which will impinge on the yarn from a virtually infinite number of directions. Also in such a case, it would be found, in accordance with the invention. that the shadow effect of the yarn in the position F is considerably less than in the the position F,, and accordingly no switching or activating pulse is released by the photoelectric cell 4 when the yarn is in the position F I claim:

l. Device for electro optically monitoring continuous filiform material alternately stationary and traveling in the longitudinal direction thereof. comprising a light-sensitive element disposed back of the continuous filiform material. means located in front of the continuous filiform material for subjecting the continuous fi iform material to light beams extending in at least two directions thereto. and means for spacing the continuousfiliform material in the travelin condition thereof closer to said light-sensitive element than w en the continuous filiform material is in the stationary condition thereof.

2. Device according to claim I, comprising a translucent cover for said light-sensitive element spaced a predetermined distance therefrom, the filiform material in said traveling condition thereof being in abutting relation to said translucent cover so as to determine the spacing from said light-sensitive element of the filiform material in said traveling condition thereof.

3. Device according to claim 2 wherein said translucent cover has inclined end faces, and the filiform material in said traveling condition thereof follows a path that is angled away at said inclined end faces.

4; Device according to claim 2 including abutment means spaced from said said light-sensitive element and being adopted for engagement in abutting relationship therewith by the filiform material in said stationary condition thereof.

5. Device according to claim 4 including air nozzle means coordinated with said abutment means for acting on the filiform material in said stationary condition thereof.

6. Device according to claim l including at least one contour member coordinated with said means for spacing from said light-sensitive element the filiform material in the traveling condition thereoffor limiting a lateral movement of the filiform material.

Claims

1. Device for electro-optically monitoring continuous filiform material alternately stationary and traveling in the longitudinal direction thereof, comprising a light-sensitive element disposed back of the continuous filiform material, means located in front of the continuous filiform material for subjecting the continuous filiform material to light beams extending in at least two directions thereto, and means for spacing the continuous filiform material in the traveling condition thereof closer to said light-sensitive element than when the continuous filiform material is in the stationary condition thereof.

2. Device according to claim l, comprising a translucent cover for said light-sensitive element spaced a predetermined distance therefrom, the filiform material in said traveling condition thereof being in abutting relation to said translucent cover so as to determine the spacing from said light-sensitive element of the filiform material in said traveling condition thereof.

4. Device according to claim 2 including abutment means spaced from said said light-sensitive element and being adopted for engagement in abutting relationship therewith by the filiform material in said stationary condition thereof.

6. Device according to claim l including at least one contour member coordinated with said means for spacing from said light-sensitive element the filiform material in the traveling condition thereof for limiting a lateral movement of the filiform material.