US3380483A

US3380483A - Thread cutter and clamping mechanism for looms

Info

Publication number: US3380483A
Application number: US557957A
Authority: US
Inventors: Noyes W Bridgham
Original assignee: HORACE L BOMAR
Current assignee: Draper Corp; HORACE L BOMAR
Priority date: 1966-06-16
Filing date: 1966-06-16
Publication date: 1968-04-30
Anticipated expiration: 1985-04-30

Description

April 30, 1968 N. w. BRIDGHAM 3,330,483

THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMS Filed June 16, 1966 2 Sheets-Sheet 1 IN VENTOR NOYES W.BR|DGHF\M 2mm W ATTORNEY P 1968 N. w. BRIDGHAM 3,380,483

THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMS Filed June 16. 1966 2 Sheets-Sheet 2 IN VENTQR. NOYES W. BRIDGHAM BYQMOW ATTORNEY United States Patent 3,380,483 THREAD CUTTER AND CLAMPING MECHANISM FOR LOOMS Noyes W. Bridgham, Meudon, Mass., assignor, by mesne assignments, to John Donald Marshall and Horace L.

Bomar, trustees Filed June 16, 1966, Ser. No. 557,957 3 Claims. (Cl. 139263) ABSTRACT OF THE DISCLOSURE An adjusting means for the cutting and clamping members of a thread cutter in a bobbin-change loom with which independent adjustments may be made to the cutting and clamping edges. The possibility of overadjusting to an excessive pressure is eliminated by using an internally threaded pivot stud having flat-sided flange members separating its pivotal surface.

This invention pertains to automatic filling replenishing looms and more particularly to cutting and clamping means for effectively controlling the outgoing filling, or that end of filling which extends between the selvage and the nearly exhausted bobbin prior to transfer.

It is a general object of the invention to provide improvements in the loom thread cutter of the type described, thereby rendering increased efiiciency to that device and simplification to the proper setting of parts.

It is a more specific object of the invention to provide adjusting means for the cutting and clamping members which may be controlled to exert sufficient but not excessive opposing pressure.

It is a further object of the invention to provide an additional adjusting means for a thread cutter to compensate for tolerance stack up in manufacture or normal wear of parts.

These and other objects of the invention will become apparent as further details are disclosed.

Thread cutters of the Stafford type which both cut and hold the filling are often applied to fly-shuttle looms for use at the time of bobbin transfer. As is well known, these cutters are moved into position to accept the filling yarn between opened jaws, which then perform a severing action, releasing that end which extends to the depleted bobbin and retaining hold of the end extending from the selvage. It is highly important to proper loom operation that the cutter perform a decisive action and that the clamping member retain its grip upon the yarn until a subsequent cycle is commenced.

These devices have in the past performed most satisfactorily provided the individual parts were correctly set and those settings were maintained. Difficulty was occasionally experienced in the setting of both new and worn parts. Where new parts were combined in which the components might have had their allowable tolerances stacked in one direction, the total overall dimension would have been excessive. Adjustment in this case became difiicult and overadjusting by tightening of the connecting bolt would likely occur. With malfunction due to worn parts, there is often the tendency for a loom fixer to merely tighten the bolt upon which the movable blade pivots in an attempt to correct the 'fault. This will often result in overadjusting to a point where the parts will wear excessively or be broken.

The instant invention discloses simple but effective means for setting and locking the parts in a proper relationship and overcomes the tendency to overadjust. The invention will be described by reference to a specific embodiment thereof as illustrated in the accompanying figures of drawing wherein:

ice

FIG. 1 is a perspective view of an assembled thread cutter and bracket with a portion shown in section; and

FIG. 2 is an exploded view of the parts shown in FIG. 1.

Now referring to the drawings, a bracket 10 has a slide arm 11 by which the mechanism is moved in a well known manner and a carrying arm 12. A stationary cutter blade 13 is snugly carried by arm 12 in a slot 14 and fixedly secured by a screw 15 threaded through a hole 16 in the blade 13. An angular hole 17 through the blade 13 is adapted to receive one of two flat sided ends 18 and '19 of a stud generally designated 20. The intermediate portion 21 of the stud 20 is circular for pivotally supporting a movable blade broadly indicated 22. The functioning end of the blade 13 has a sharpened edge 23 and a shoulder 24 which will position the yarn to be cut (not shown).

A stationary clamping blade 25 is held generally parallel with the blade 13 by the flat sided end 19 being inserted into an angular hole 26. A shoulder 27 coacts with the shoulder 24 in maintaining the yarn properly for cutting and clamping.

The movable blade 22 is pivotally supported upon the circular portion 21 by the stud 20 being inserted through a hole 28 shaped for that purpose. A clamping member 29 which may be of a fiber or laminated plastic type of material is secured to the movable blade 22 by a screw 30. Pivotal movement is furnished to the blade 22 by various camming arrangements (not shown) which are well known in the weaving art, any of which might function upon the cam follower end 31 to cause a scissors-like action between the blades above mentioned.

The movable blade 22 has a sharpened edge 32 which will contact with the edge 23 to effect a cutting action. A rounded edge 33 of the clamping member 29 will coact with a smooth rounded edge 34 of the clamping blade 25 to squeeze and hold the yarn therebetween While the scissors-like ends are closed.

Leaf springs

35 and 36 are applied outwardly of the

stationary blades

13 and 25 with the

bent spring ends

37 and 38, respectively, exerting pressure to constantly urge the

edges

23 and 34 toward each other. The assembly is drawn snugly together by a bolt 39 threaded through the stud 20 and the nut 40 (FIG. 2). It will be seen that by taking up the bolt 39 within the stud 20, the blade 22 will be drawn into closer contact with the cutter blade 13. By tightening the nut 40, the clamping blade 25 may be adjusted toward the movable blade 22. These adjustments may be, and often are, made in an excessive manner to a point where the clamping member 29 may be damaged or the movable blade may bind.

To overcome the tendency to overadjust the blades, a set screw 41 is threaded into the arm 12 (FIG. 2) to bind downwardly upon the upper edge 42 of the clamping blade 25. By pressing the

edges

23 and 34 toward each other and then tightening the set screw 41, the

stationary blades

13 and 25 may be locked into a fixed position. When adjustment is made by tightening the bolt 39 and nut 40, the blades are drawn together at the pivot point of the stud 20 and will be held in generally parallel relationship. This may not act to correct the need for a slight angularity between the cutter and clamping edges. As the parts wear it is possible to loosen the set screw 41 and pivot the clamping blade 25 through a slight horizontal :arc to a position nearer the sharpened edge 23. If the set screw 41 is then tightened down, the

stationary blades

13 and 25 will stand apart in an angular relationship.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in :a number of ways. This invention is, therefore, not to he limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. In a Stafford type thread cutter for looms, a slide bracket, cutter and clamping means carried by said bracket, said cutter and clamping means comprising stationary cutting and clamping blades fixed to said bracket, a movable blade pivotally supported for scissors-like movement between said stationary blades, resilient means for urging said cutting blade and said clamping blade into engagement with said movable blade, means for drawing said stationary blades, said movable blade and said resilient means into close mutual proximity whereby said stationary blades stand apart by a distance of separation, said drawing means including a stud having an intermediate surface for pivotally supporting said movable blade and flanged ends separated by said intermediate surface, and means for locking said stationary blades to control said distance of separation.

2. Mechanism as defined in claim 1 wherein said lock- 20 ing means includes a set screw carried by said bracket for ch-angeably maintaining the lateral position of said clamping blade relative to said cutting blade.

3. Mechanism as defined in claim 2 wherein said stud has an internal threaded surface the full length of an opening extending therethrough for adjustably receiving a tightening screw therein.

References Cited UNITED STATES PATENTS 2,515,045 7/1950 Kielczewski et a1. 139267 2,676,620 4/1954 Urquhart 139-263 2,684,085 7/1954 Harris et al. 139-263 X 2,720,225 10/1955 Moon 139263 3,112,774 12/1963 Bostic 139-263 2,711,193 6/1955 Consoletti 139263 3,200,851 8/1965 Cadorette 139-263 MERVIN STEIN, Primary Examiner.

ROBERT R. MACKEY, Examiner.

J. KEE CHI, Assistant Examiner.