US2808071A - Circular looms - Google Patents

Description

Oct. 1, 1957 I J. CATRY ETAL 2,808,071 CIRCULAR LOQMS Filed Dec 11, 1953 United States Patent CIRCULAR LOOMS Jean Catry and Robert Hnmblot, Flixecourt, France, assignors, by mesne assignments, to Fairbairn Lawson Combe Barbour Limited, Leeds, England Application December 11, 1953, Serial No. 397,733

Claims priority, application France December 15, 1952 1 Claim. (Cl. 139-13) The present invention concerns circular looms in which the heddle frames may be held at one of their extreme positions by a system of hooks. More particularly, the present invention concerns a control device for these hooks and its purpose is to effect the hooking and unhooking of the heddle frames without any weave fault in the fabric.

The device according to the invention is characterized in that the hooks are controlled by auxiliary cams, equal in number to the hooks the keying angle of which on the control shaft is dependent upon the keying of the main cams controlling the motions of the frames. The auxiliary cams are stationary during the normal operation of the loom, and in such a position that they keep the hooks out of contact with the hooking parts but are driven at a speed which depends on that of the main cams in case of the breaking of a weft yarn. The auxiliary cams then release the hooks which hold the frames at their low positions until the loom stops, shuttles uncovered, and are again driven at the same speed as previously when the loom starts again stopping after a complete revolution. Thus the shuttles enter the shed after a pre-determined number of revolutions, their entrance point being a function of their outlet point, and so located that there is no fault of re-entrance in the shed. It is possible, in particular, to have the shuttles re-enter at the place where they came out.

The motion of the shafts controlling the auxiliary cams is controlled by a one-turn clutch, i. e. once clutched in, it can be released only after one complete revolution. The engagement of this clutch is automatically effected by the detector for detecting a weft break or the end of a spool, which then stops the loom, shuttles uncovered.

The appended drawing shows, by way of example, and diagrammatically, two modes of embodiment of the present invention.

Figure 1 shows a frame control.

Figure 2 shows a modification thereof.

The heddle frame 1 is controlled by the main cam 2 through a linkage system including the rocker 3, the hooking part 4, the connecting rods 5 and 6 and bell crank lever 7. The spring 8 holds the cam follower rocker 3 in contact with the main cam 2. The hook 9 is controlled by the auxiliary cam 16 keyed on the control shaft 17 through a spring 14. The spring 15 presses the hook 9 towards the hooking part 4.

The auxiliary cams 16 are equal in number to the hooks 9 and their keying angle on the control shaft 17 depends on the keying of the main cams 2.

In normal operation, the auxiliary cams 16 are stationary, at the position shown in the diagram, i. e. they hold the hooks 9 in inoperative position out of contact with the hooking parts 4. When a break occurs in the weft, the control shaft 17 is driven at a speed which depends on that of the main cams 2 and earns 16 then turn and release the hooks 9 which move under action of springs 15 to an operative position engaging the hooking parts 4 to hold the frames at their low positions. On the other hand, the break detector has caused the stopping of the loom which stops when the frames are at their low positions with the shuttles uncovered. After the weft yarn has been repaired, the loom is started again, the cams 16 continue their rotation, compress the springs 14 and finally stop in the normal operation positions shown in the diagram.

Due to the provision of a one-turn clutch, the auxiliary cams 16 have moved exactly one revolution for causing the shuttles to come out of the shed, to turn outside the shed and finally to re-enter the shed. As the speed of the auxiliary cams 16 depends on that of the main cams 2, the shuttles carry out, outside the shed, a predetermined number of revolutions and it is easy to design the contours of the cams 16 to obtain the result that the re-entrance point of the shuttles is dependent on their exit point and that there be no fault of reentrance in the shed. In particular, the shuttles may be made to re-enter at the place where they came out.

In the form of embodiment shown in Fig. 2, the hook 9 is located underneath the cams 2 and works under pressure, and the spring 14 is controlled by the auxiliary cam 16 which is placed under the horizontal connecting rod 5 and the return spring 8 for the rocker 7. This arrangement offers the advantage of a smaller size of the loom, and of a greater accessibility.

It should be understood that the two modes of embodiment of the invention described above are given as indicative and non limitative examples, and that numerous modifications may be made without departing from the scope of the present invention.

What we claim is:

A device for controlling the heddle frames of a circular loom, comprising, in combination, rotary main cams; linkage systems including hooking parts and cam follower means respectively cooperating with said main cams, said linkage systems being respectively connected to the heddle frames for moving the same between a higher position and a lower position; hooks respectively movable between inoperative positions and operative positions, and engaging in said operative positions the associated hooking portions for blocking said linkage systems when the same are in a position corresponding to said lower position of said heddle frames; auxiliary cams cooperating with said hooks, respectively, and controlling the movement of said hooks between said operative and inoperative positions, said auxiliary cams being normally in a holding position in which said hooks are held in said inoperative position while said linkage systems and heddle frames are operated by said main cams, said auxiliary cams being connected to said main cams so as to turn through one complete revolution in the event of a weft break at a speed depending on the rotary speed of said main cams, and at a predetermined relative time with respect to said main cams so that said auxiliary cams are in said holding position when operation of said heddle frames is resumed.

References Cited in the file of this patent UNITED STATES PATENTS 2,248,281 Pelce July 8, 1941 2,592,820 Moessinger Apr. 15, 1952 2,671,472 Low 1 Mar. 9, 1954 2,715,915 Catry et al Aug. 23, 1955 FOREIGN PATENTS 615,739 Great Britain Ian. 11, 1949

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