US2711759A - Circular looms - Google Patents

Description

` 'June 28, 1955 R. N. Low Em zal-1,759

- CIRCULAR LooMs Filed Feb. 24, 1955 lNvENT'oRs i 'ATTORNEYS CIRCULAR LOOMS Robert Norrie Low, Dundee, Scotland, and Jean Catry,

Flixecourt, France, assignors to Fairwest (U. K.) Limited, London, England, a British company Application February 24, 1953, Serial No. 338,454

Claims priority, application Great Britain February 22, 1952 4 Claims. (Cl. 139-13) This invention relates to circular looms of the kind disclosed for example, in United States Patent No. 2,248,- 281, granted July 8, 1941, in which the Shuttle traverses a circular path within a Warp-shed which opens and closes respectively in front of and behind the Shuttle as the latter progresses.

It has been found desirable, in certain circumstances, to introduce an additional supply of weft from such a Shuttle into the material being woven, at some particular point whilst the loom is in motion and it is the object of the present invention to provide means for efecting this desideratum.

According to this invention, the Shuttle carries a movable needle or like rod capable of Supporting the weftend and normally held in its retracted position, means being provided for moving the needle from its retracted position into an extended position so that the additional weft-end may be introduced between the Warp threads as they cross behind the Shuttle and, by being locked therebetween, may be held in position.

Preferably the needle is carried at its real' end by a guide block which is slidably mounted on the stem of the Shuttle in such manner that when said block is released from a retracted position, the drag thereon due to the movement of the Shuttle across the Warp threads will cause said block to slide towards the outer extremity of said stem thus projecting the needle from its position within the confines of the stem to its operative position.

The needle, or its guide block, may be retained in its retracted position by mechanical means such as a latch adapted to be released by operation of a weft stop motion,

In an alternative method the needle or a part attached to the needle is the armature of an electromagnet which is retaned in its retracted position by means of a Spring and adapted to be moved into its operative position by operation of an electromagnet which is operated by the weft stop motions.

Two forms of the invention will be described with reference to the accompanying diagrammatic drawings of which,

Figure 1 is a plan of a Shuttle to which the invention is applied.

Figure 2 is a plan of the outer end portion of a Shuttle stem, to an enlarged Scale, showing the weft stop motion.

Figure 3 is an elevation corresponding to Figure 2 looking in the direction of arrow A and Figure 4 is a sectional elevation of an alternative arrangement.

As shown in the drawings, a Shuttle a having a stem b is adapted to travel in the direction indicated by the arrow (Fig. 1) across warp threads indicated by the broken lines c, c.

The outer end portion of the stem b is constituted by two parallel rods d, d, slightly spaced apart and bent towards each other at their extremities so as to be able, without hindrance, to pass, in light contact therewith, between the threads c, c, of the Warp shed, which shed closes immediately behind said stem b so that the threads nited States Patent O ICC Shuttle.

Slidably mounted upon the stem rods d, d, is a smoothly rounded guide block e which carries, projecting from its rearward end, a needle the outer extremity of which is formed with a slot or other means for lightly holding the end of the additional weft g coming from the Shuttle a. I

The guide block e is provided With a projection `h which is engaged by a spring loaded latch j which forms the armature of an electromagnet k mounted on the shuttle the arrangement being such that when the electromagnet is energised the latch is Withdrawn against the action of the spring l and this releases the guide block e.

The arrangement is such that when the latch j is Withdrawn by the action of the electromagnet k the drag due to the passage of the block e across the Warp threads c, c, will cause said block to travel to the outer end of the rods d, d, of the stem b whereby the outer end of the needle together With the weft end g is projected beyond the outer end of the stem into the closing Warp shed, at which point the coming together of the Warp threads c, c, nips the weft end g and draws it from the needle after which the weaving process continues in normal manner.

In an alternative method shown in Figure 4 the needle m is provided With an enlarged rear portion n which forms the armature of a spring loaded electromagnet p fixed to the rods d of the stem b.

When the electromagnet is excited the armature n is drawn into the electromagnet against the action of the spring q and the needle m is projected into the closing Warp shed for the thread to be withdrawn by the nipping action of the Warp threads.

The electrornagnet k in the one arrangement and p in the other arrangement is arranged to be operated by the weft stop motion shown in Figures 2 and 3.

In such an arrangement the normal supply of weft yarn on its passage from the cop to the fell of the cloth passes around a freely rotatable centrifugal switch r and by means of a freely rotatable spring-loaded tension disc s fulcrumed at t drives the switch r. When switch r is rotated an electrical circuit is broken and remains so as long as the weft thread remains intact.

If the weft thread breaks, the switch r comes to rest, an electrical Circuit is complete and by existing means the drive to the loom is stopped and the electromagnet k or p is operated.

The switch r is of the centrifugal type which when rotated at a predetermined speed sustains an open circuit by means of weighted contacts which are moved by centrifugal force away from a central contact, the weighted contacts being influenced by Springs towards the co- Operating contact. An example of such a switch is disclosed in U. S. Patent No. l,224,420, granted May l, 1917.

Between the time when the switch r operates and the time when the Shuttle is exposed by the Warp threads being moved to one extreme position and the shuttles brought to rest, there is usually a short time lag which causes a fault known as lack of weft The operation of the electromagnet k or v With the consequential op eration of the additional weft supplying device described herein provides a reserve of weft which fills the gap and eliminates the lack of weft fault.

What is claimed is:

1. In a circular loorn, a Shuttle, a stem member extending from the Shuttle, a needle slidable on said stem member between a retracted position near to the Shuttle and an extended position away from the Shuttle, and means for moving the needle and retaining it in its retracted position.

2. In acircular loom, a Shuttle, a stem member extending from the Shuttle, a guide block slidable on said Patented June 28, 1955 stem member between a retraeted position near to the shuttle and an extended position away from the Shuttle, and means for retaining the guide block in its retracted position.

3. In a circular loom, a Shuttle, a stem member extending from the Shuttle, a guide block slidable on said stem member between a retracted position near to the Shuttle and an extended position away from the Shuttle, and an electromagnet having an armature which constitutes a latch engageable with said guide block when said guide block is in retracted position, said electromagnet being operatve, when energized, to Withdraw the latch from engagement with the guide block.

4. In a circular loom, a Shuttle, a stem member extending from the Shuttle, a guide block slidable on said stem member between a retracted position near the shuttle and an extended position away from the shuttle, an clectromagnet having an armature member fixed to said needle, and a spring dsposed between said armature member and one end of said electromagnet, said electromagnet being operative, when energized, to pull the armatura against the action of said spring and thereby 10 move the needle to the extended position.

NQ reterences citd.

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