US2422911A - Electric weft detector for looms - Google Patents

Description

Patented June 24, 1947 ELECTRIC WEFT DETECTOR FOR LOOMS Charles B. Keenan, Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application March 18, 1946, Serial No. 655,103

9 Claims.

This invention relates to improvements in electric weft detectors for looms and it is the general object of the invention to provide a detector in which the bobbin engaging detector finger is mounted for sliding movement in a support or base and is permanently connected to the spring which holds it normally in rearward detecting position.

Weft detectors employing sliding detector fingers are customarily equipped with small compression springs surrounding the fingers to hold the latter in detecting position. These springs occasionally become part of the current conducting circuit and are injured by heating. It is an important object of my present invention to use a sheet metal spring having ample cross section for conducting the electric current needed for the detecting circuit, and attach the spring to the detector finger permanently so that the connection between the spring and the finger will ofler a minimum of resistance to the flow of electric current.

The base which supports the detector finger is ordinarily provided with binding posts or the like for connection with wires of the external loom controlling detecting circuit. In order that there may be a minimum of resistance between these binding posts and the spring it is a further object of my present invention to fasten the spring permanently to its binding post to provide a continuous metallic circuit from the tip of the detector finger through the spring to the binding post.

In order that the spring and its attached detector finger and binding post may be readily assembled on the detector it is another object of my invention to provide a base having a large enough opening to permit placement of the binding post through a part of the base. Another part of the base is provided with a removable bearing element such as a cap bearing for the detector finger. In a modified form of the invention the detector finger passes through the sheet metal spring so that it may have a bearing surface at two points on the base which are behind the binding post.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein two forms of the invention are set forth,

Fig. l is a plan view of the preferred form of my improved weft detector,

Fig. 2 is a side elevation looking in the direction of arrow 2, Fig. l,

Fig. 3 is a vertical section on line 33 of Fig. 1,

Fig. 4 is a transverse vertical section on line 4-4 of Fig. 1,

Fig. 5 shows the detector and binding post and the spring connected thereto with the spring in its normal form prior to application to the detector,

Fig. 6 is a plan view of a detector made according to the modified form of my invention,

Fig, 7 is a longitudinal vertical section on line l| of Fig. 6,

Fig. 8 is a vertical section on line 8-4 of Fig. 6, and

Fig. 9 is a view similar to Fig. 5 but showing the modified form of detector finger used with the modified form of the invention.

Referring particularly to Figs. 1 and 5 which show the preferred form of the invention, Ill indicates a support mounted on the loom and having the detector D secured thereto by bolts II. The detector includes a base I! made of insulating material having side members [3 and H, a rear bearing l5, and a front cross bar l6. These parts inclose a substantially rectangular elongated opening l'l extending between the bolts H. The base may be cut from fiat material or may be molded. The bearing I5 is drilled to provid two parallel slide bearing bores 20 and 2| extending in the direction of the length of slot or opening H.

The base I2 is provided with two detector elements designated generally at 25 and 26, and since these detectors are alike only one of them will be described in detail. The detector element 25 includes an electric detector finger 21 made preferably of metal and slidable in bearing bore 20 and having a tip 28 driven thereon for engagement with the ferrule F of a bobbin B when the latter is depleted of weft during a detecting operation of the loom. The detector finger, which is shorter than the length of slot 11, extends forwardly through the bearing l5 and has brazed, soldered, welded, or otherwise permanently attached to the forward end thereof the rear end 29 of a sheet metal spring 30. The forward end 3| of the spring is permanently connected to a metallic binding post or electrode 32 preferably attached to the spring in the same manner that the rear end 29 is attached to the detector finger. The binding post is sufilciently long to extend forwardly from the cross wall or bar ii to have attachment with a wire forming part of the detecting circuit. The latter is not indicated in the drawings but will include wires 33 and 34 attached to the detector elements 25 and 26, respectively.

After the two detecting elements have been made as shown in Fig. 5, the detector fingers 21 will be placed in slot l1 and slid rearwardly through their respective bores 20 and 2|, after which the tips 28 will be driven onto the rear ends of the fingers 21. The forward ends of the springs are then bent so that their binding posts can be slipp d through holes 35 formed in the cross wall or bar l6, after which the circuit wires can be attached. The spring 30 operates normally to hold the detector in rearward position for engagement with the bobbin B, and when a ferrule engages both the tips 28 the wires 33 and 34 will be electrically connected to each other, the circuit through the detector elements being unbroken and continuously metallic. The opening I1 is sufiiciently long to permit a considerable forward movement of the detector fingers, and is also long enough to permit insertion of the binding posts through the cross bar IS. The bearing I5 is of sufiicient width to afford adequate support for the fingers 21.

In the modified form of the invention shown. in Figs. 6 to 9 the detector D' has a base 40 somewhat similar to base I2 and having a rear bearing 4| corresponding to bearing I5 and provided with a cap 42. The front part of the base 40 is provided with a cross bar 43 corresponding to cross bar |6. The base 40 is made of insulating material and is provided with front and back openings 45 and 46, respectively, which are separated by a transverse bearing 41 in which are located two horizontal parallel spaced bores 48 which serve as slide bearings.

The detector element for the modified form of the invention is shown in Fig. 9 and includes a sheet metal spring 50 which in its normal form is fiat. Secured to the forward end of spring 50 is a binding post 5| corresponding to the binding post 32, while the rear end of the spring is permanently connected to a detector finger 52 having a bobbin engaging tip 53. The finger 52 extends on both sides of the spring and is permanently connected to the latter, as is also binding post 5| in the same manner as that described for the preferred form of the invention.

In assembling the modified form of the invention the cap bearing 42 will be removed and the forward ends 55 of the detectors will be inserted into the rear ends of the bores or slide bearings 48 with the rear end of spring 50 in opening 45. The detector fingers 52 are resilient and can be bent sufiiciently to permit this assembly with respect to the cross bearing 41. The binding posts 5| are then placed in opening 45 and inserted through the front cross bar 43 as already described for the preferred form of the invention. The binding posts of both detector elements 52 may then be connected to wires 56 and 51 forming part of the detecting circuit. In this modified form of the invention it will be understood that the detector fingers are supported by two spaced slide bearings between which is located the rear end of springs 50.

From the foregoing it will be seen that I have provided an electric weft detector including a detector element made up essentially of three parts the first of which is the bobbin engaging detecting finger, the second of which is the sheet metal spring, and the third of which is the binding post. These three parts are permanently connected to each other as by the methods already described so that a continuous uninterrupted electric circuit can be established between the detector finger tip and the binding post. In the preferred form of the invention the bearing I5 is made sufflciently wide to afford ample support 4 for the detector fingers 21, but in the modified form of the invention the bearing 4| may be narrower than bearing |5 due to the forward bearing 41. Also, in the modified form of the invention, the detector finger 52 extends on opposite sides of the spring 50 and the openings 45 and 43 are of sumcient length to permit insertion of the binding posts 5| through the front cross bar 43 and accommodate normal forward movement of the detector fingers during engagement of the tips 53 with a full bobbin. The forward ends 55 of the detector fingers 52 may project through the bores 48 during certain at least of the de tecting operations, but will not strike the binding posts 5|. In the preferred form of the invention slot H is longer than either the detector fingers 21 or binding posts or electrodes 32 thereby permitting entry of these parts into their respective bearing bores and holes 35 from within the slot.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. A detector element for an electric weft detector, said element comprising a normally fiat elongated sheet metal spring, a metallic detector finger permanently connected to one end of the spring and extending laterally therefrom, and a binding post permanently connected to the other end of the spring and projecting laterally therefrom.

2. A detector element for an electric weft detector, said element comprising a normally fiat elongated sheet metal spring, a metallic detector finger permanently connected to one end of the spring and extending laterally therefrom on opposite sides of the spring, and a binding post permanently connected to the other end of the spring and projecting laterally therefrom.

3. A detector element for an electric weft detector, said element comprising a normally fiat elongated sheet metal spring, a metallic detector finger permanently connected to one end of the spring, and a binding post permanently connected to the other end of the spring, said finger and bindin post both extending laterally of said spring on the same side thereof.

4. In an electric weft detector for looms, said detector having two spaced electric detector fingers, a base made of electric insulating material having an opening therein, a front wall on the base forward of said opening, rear slide bearings on the base behind said opening, the detector fingers being slidable in the bearings, a binding post for each finger extending through and secured to said front wall, and a sheet metal spring for each finger, each spring having a rear end permanently connected to the corresponding finger and normally in front of the associated bearing and having a front end permanently connected to the corresponding binding post behind said front wall, said springs normally vvul u having a front end against said front wall and in said opening and having a rear end in front of the corresponding bearing and in said opening, and a binding post for each spring extending through said front wall and secured therein. each post being permanently connected to the front end of the corresponding spring, each detector finger slidably mounted in the bearing corresponding thereto and having the forward end thereof permanently connected to the rear end of the associated spring, said fingers being movable forwardly into said opening against the action of said springs and toward said binding posts.

6. In an electric weft detector for looms, a base made of electric insulating material, a front wall forming part of said base, a pair of rear slide bearings formed on the rear of the base, an intermediate bearing between said rear front wall and said bearings and formed with said base, a pair of detector fingers each slidable in a rear bearing and said intermediate bearing, a pair of binding posts secured in said front wall, one for each finger, and a pair of sheet metal elongated springs, each spring having the front end thereof permanently connected to a binding post and having the rear end thereof permanently secured to a finger between said intermediate and rear bearings, said springs normally pressing against said rear bearings and normally maintaining the fingers in rear position, said fingers being slidable forwardly in said bearings each toward the corresponding binding post against the action of the associated spring.

7. In an electric weft detector for looms, said detector having two electric detector elements, a base made of insulating material and having an elongated horizontally extending slot therein, a bearing on said base behind one end of said slot, each electric detector element comprising an elongated sheet metal spring to one end of which an electric detector finger is permanently connected, and means securing the other end of each spring to said base, said detector fingers being slidably mounted in said bearing and being of less length than the length of said slot to facilitate rearward sliding of said detector fingers from a position in said slot into said bearing.

8. In an electric weft detector for looms, said detector having two electric detector elements, a base made of insulating material and having an elongated horizontally extending slot therein, a front wall on said base in front of one end of said slot, and a slide bearing on said base behind the other end of said slot, each electric detector element comprising an elongated sheet metal spring to one end of which a metallic detector member is permanently connected and to the other end of which an electrode member is permanently connected, said detector members being slidable in said bearing and said electrode members extending through said wall and the ends of said springs being between said wall and bearing, said slot being longer than either of said members to enable the detector member to be inserted into said bearing and said electrode member through said wall from within said slot.

9. In an electric weft detector for looms, said detector having two spaced electric detector fingers, a base made of electric insulating material, a front wall forming part of said base, spaced front and back bearings formed on the base behind the front wall, said detector fingers slidably mounted in said bearings, a. pair of sheet metal elongated springs, one for each member, each spring having a rear end permanently connected to the corresponding finger between said bearings, and a pair of binding posts secured to said front wall, each post permanently connected to the front end of one of said springs.

CHARLES B. KEENAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'EN'IS Number Name Date 2,392,913 Geier Jan. 15, 1946 FOREIGN PATENTS Number Country Date 525,997 Germany June 1, 1931 IIUUI H

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