US3312253A - Pickers for looms for weaving - Google Patents

Description

April 4, 7 R. M. SEDDEN 3,312,253

PICKERS FOR LOOMS FOR WEAVING Filed May 7, 1965 INVENTOR:

ROBERT MAXWELLfiEDDEN T ORNEYS United States Patent 3,312,253 PICKERS FUR LOOMS FOR WEAVING Robert M. gedden, Knaresborough, England, assignor to Unitex Limited, Knaresborough, England, a company of Great Britain Filed May 7, 1965, Ser. No. 453,992 4 Claims. (Cl. 139-159) This invention relates to improvements in pickers for looms for weaving and more particularly to loop pickers for underpick looms.

It has been proposed to make loop pickers i.e. pickers having a bore through which the picking stick passes, of a relatively hard polyurethane elastomer and pickers made from this material when fitted correctly to matching picking sticks give very good results over long periods.

It has been found, however, that the dimensions of sticks even for the same loom vary in size particularly because of the lack of close control on the manufacture of the picking sticks. Furthermore, a picker may be forced down a stick, more or less, according to the general setting of the stick to the loom. For example, a picker may be fitted to a stick with an excessive force fit which has an adverse effect on the life of the picker since stresses are set up in the nose portion of the picker and it is an established fact that most materials and particularly polyurethanes may be cut or abraded much more readily if the material is in a state of tension. Furthermore, the harder the polyurethane, the more pronounced is this effect.

It is the object of this invention to provide loop pickers which will reduce considerably the effect of too tight at fit on the stick and yet retain sufiicient grip on the stick to prevent undue movement thereon.

According to the invention :a picker for an underpick loom is formed of polyurethane characterised by an internal bore or loop for fitting over the picking stick the bore being so shaped that spaces are provided for local deformation of the material of the bore under the stresses induced by force fitting the picker over the picking stick.

The invention will be described with reference to the accompanying drawings:

FIG. 1 is a longitudinal section through a picker on line 11 FIG. 2.

FIG. 2 is a side view of same.

FIG. 3 is a longitudinal section of a further picker on line 3-3 FIG. 4.

FIG. 4 is a side view of same.

A picker A consists of a body a of hard polyurethane provided with a through bore b that is continuously lined with an internal sleeve b of softer deformable polyurethane that has its external periphery b bonded integrally to the body.

In the form of the invention illustrated in FIGS. 1 and 2 that one of the internal walls a of the bore b located adjacent the nose a of the picker tapers in the direction X- X with a taper of approximately 1 to 20 which has been found to be most suitable for the majority of pick- Patented Apr. 4:, I967 ing sticks. The internal surfaces of sleeve b may be moulded with ribs a in the direction of the taper so that when the picker is fitted local deformation of the ribs a prevents transfer of high stresses to the nose portion of the picker. This may be advanced further by making the ribbed portion and a supporting wall around the loop in a softer'material b than the remaining portion of the picker.

In a further form as illustrated in FIGS. 3 and 4 where a taper on the bore b or loop is undesirable the walls of the loop for a portion of the thickness may be moulded with a liner in the softer material b as described above, for example of a softer polyurethane or a cellular polyurethane.

The nose of a shuttle is engaged by the recess c in the nose end a of the picker in known manner.

In addition to increasing life as a result of decreasing the transferred stresses in the nose of the picker, the constructions described above result in reduced shock to both the picking sticks and the pickers thereby extending the lives of both.

What I claim is:

1. A picker for :an underpick loom for weaving comprising an integral body of relatively hard non-deformable polyurethane having a shuttle engaging nose and formed with a through bore, and a sleeve of softer deformable polyurethane having its outer periphery integrally surface bonded to said bore so as to completely continuously line said bore, said sleeve being adapted to deform to accommodate to the picker stick dimensions when the picker bore is force-fitted onto the picker stick and thereby prevent said force-fit from inducing stresses in said hard body while providing sufiicient grip to retain the picker against undue movement on the stick.

2. The picker defined in claim 1, wherein said sleeve is internally formed with grooves extending in the direction of the axis of said bore.

3. The picker defined in claim 1, wherein the internal surface of said sleeve adjacent the nose side of said picker is inclined relative to the bore axis.

4. The picker defined in claim 1, wherein said sleeve is an integral element of cellular polyurethane.

References Cited by the Examiner UNITED STATES PATENTS 2,968,322 1/1961 Downs 139159 3,021,307 2/1962 Csendes 28-1 FOREIGN PATENTS 1,032,392 3/1953 France.

1,348,520 12/1963 France.

359,263 10/ 1931 Great Britain. 703,857 2/ 1954 Great Britain. 839,135 6/ 1960 Great Britain.

MERVIN STEIN, Primary Examiner.

I. KEE CHI, Assistant Examiner.

Claims (1)

1. A PICKER FOR AN UNDERPICK LOOM FOR WEAVING COMPRISING AN INTEGRAWL BODY OF RELATIVELY HARD NON-DEFORMABLE POLYURETHANE HAVING A SHUTTLE ENGAGING NOSE AND FORMED WITH A THROUGH BORE, AND A SLEEVE OF SOFTER DEFORMABLE POLYURETHANE HAVING ITS OUTER PERIPHERY INTEGRALLY SURFACE BONDED TO SAID BORE SO AS TO COMPLETELY CONTINUOUSLY LINE SAID BORE, SAID SLEEVE BEING ADAPTED TO DEFORM TO ACCOMMODATE TO THE PICKER STICK DIMENSIONS WHEN THE PICKER BORE IS FORCE-FITTED ONTO THE PICKER STICK AND THEREBY PREVENT SAID FORCE-FIT FROM INDUCING STRESSES IN SAID HARD BODY WHILE PROVIDING SUFFICIENT GRIP TO RETAIN THE PICKER AGAINST UNDUE MOVEMENT ON THE STICK.

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