US2707975A

US2707975A - Shuttle threading block

Info

Publication number: US2707975A
Application number: US336216A
Authority: US
Inventors: James M Tuten
Original assignee: Draper Corp
Current assignee: Draper Corp
Priority date: 1953-02-11
Filing date: 1953-02-11
Publication date: 1955-05-10
Anticipated expiration: 1972-05-10

Description

May 10, 1955 J. M. TUTEN SHUTTLE THREADING BLOCK Filed Feb. 11, 1953 FIJI 15 324 f izfi" A TTORNE Y 39 INVENTOR. JAMES M. TUTE N United States Patent 2,707,975 SHUTTLE THREADIN G BLOCK James M. Tuten, Greenville, S. C., assignor to Draper Corporation, Hopedale, Mass., a corporation of Maine Application February 11, 1953, Serial No. 336,216 4 Claims. (Cl. 139-223) .This invention pertains to improvements in threading blocks for loom shuttles.

It is a general object of the invention to devise a threading block for loom shuttles which shall be easily molded from a non-ductile metal such as cast iron and then formed into a completed article by simple and easily accomplished machining operations.

It is a further object to devise a shuttle threading block which shall serve effectively to shed all kinds of loops occasioned by the unusual behavior of the filling as it comes from the bobbin, including so-called back loops and double front loops.

It is another object of the invention to devise a threading block of very rugged design and having an integrally cast scroll which is of uniform cross-secti0n throughout its length and which shall be easily threaded, reasonably effective against unthreading and strong enough to resist the damaging tendencies to which it may be subjected by a trapped bobbin.

Other objects will become apparent from the following disclosure.

In loom shuttles, especially the type used in automatic looms, the filling is theaded through a threading block, sometimes referred to as a shuttle eye, and which must serve to control the filling as it is drawn from the bobbin and delivered by the shuttle during Weaving.

In some shuttles, blocks are used which are integrally cast to comprise the body, horn, side eye notch, scroll and, in fact, all parts except a steel pin or pins which are inserted in the finished block after it has been machined. Examples of such eyes are evident in U. S. Patents 2,336,937 and 2,470,064. While these function with a degree of success, they are not adapted to shed all kinds of undesirably encountered loops and in the case of a scroll with a continuous taper as in the former patent, problems of manufacture are encountered which it is desired to avoid.

According to the instant invention, a threading block is so devised as to be cast from non-ductile material and machined by simple, straight forward metal cutting operations to provide a finished block having a longitudinal thread passage defined in part by an integrally cast scroll of substantially uniform cross section to avoid the added production difficulties attendant upon machining a corresponding part with a continuous taper. The said scroll is inclined at an angle to the path of the filling through the block and toward the horn end of the same.

A thread entrance slot is formed which is preferably of uniform width and cut on an arc the radius of which is centered at the center of the longitudinal thread channel, and which terminates at the approximate vertical center plane of that channel, and a second slot cut from the channel downwardly to enter the arcuate slot at its terminus.

This scroll is formed at an angle to the horizontal path of the filling through the block by casting and/or machining as will be described. The angle is such as to permit all types of unintended but unavoidable loops to be shed, that is, to slip off the scroll rather than catching or hanging thereon. These loops also slip from the scroll as herein formed without developing appreciable extra tension on the filling which, of course, would easily break if that were done.

The details of the block, the method of manufacture and its operation will be described in detail in the following description which refers to the accompanying figures of drawing wherein:

Fig. 1 is a plan view of a shuttle to which a block according to the invention has been applied.

Fig. 2 is an elevation of the shuttle of Fig. 1.

Figs. 3-8 are end views of the threading block showing progressive steps in its manufacture.

Fig. 9 is a view of the completed block as seen from the horn end.

Fig. 10 is a sectional view showing further details of the scroll which forms a part of the block.

Now referring to Figs. 1 and 2, a shuttle 20 of conventional design carrying a bobbin 21 with filling F Wound thereon is provided at its front end with a suitable recess 22 within which is retained a threading block generally denoted by numeral 23. This block is cast from a nonductile material such as a good grade of cast iron and comprises a body portion 24, Fig. 9, for example, a horn 25 having a lip 26, an apron 27 extending toward the front side of the shuttle, and a scroll 28 defining in part a longitudinal thread channel 29. The thread or filling is threaded into channel 29 through

slots

30 and 31, the first following an arc concentric with the channel and the second being cut vertically from the channel to the terminal part of the arcuate slot.

As seen in Figs. 1 and 2, the forward end of the shuttle is grooved at 32 and 33 to assist in threading the filling beneath the scroll and also down under the horn 25 at the first pick after replenishment whereupon the filling will pass through the longitudinal thread channel and under lip 26. At the following or return pick the filling will be cammed under horn 25 and apron 27 to enter side eye E in the shuttle, at the same time being snapped under point 34 and and into upwardly directed notch 35, Fig. 10. A pin 36 of hardened steel is inserted through appropriate apertures in the block and is of such height as to hold the filling, when taut, at about the level of the bottom of the longitudinal thread channel. When threaded automatically, the filling snaps under the scroll and then runs through the thread channel 29 being elevated by pin 36 so it is virtually impossible for it to become unthreaded.

The scrol 28 defines one side or about of the circumference of the channel 29 and is inclined as more clearly shown in Fig. 10 at an angle of approximately 45 to the horizontal or path of the filling at that location. That inclines the back face 37 of the scroll and of the block adjacent the scroll so that a filling loop resulting from improper release of the filling from the bobbin will be shed or permitted to slip over that part of the block and scroll with no tendency to catch. With a much steeper angle of face at this point such loops are not shed and, of course, filling breakage results. After shedding, the filling immediately rethreads itself.

The front face 38 is exactly parallel to face 37 insofar as is possible in commercial-production. This front face is formed during molding while the face 37 is preferably produced by machining.

Now having described the general characteristics of the block, a brief description of the machine operations performed thereon will be given. After the casting, Fig. 3, has been snagged and preferably annealed, the longitudinal thread channel 29 is formed by drilling, Fig. 4. This hole is drilled substantially on the horizon- 3 tal, but possibly at a slight downward angle toward the front or horn end of the block.

The recess at the rear of the block is then cut by end milling. Fig. 5, so that the face 37 will be parallel to face 33, Fig. 10. According to preferred practice the cut is made so face 37 will be inclined at about 45 to the horizontal.

The arcuate slot 3%, Fig. 6, is not started as such, but a straight, vertical cut is first made down to the horizontal center plane of the hole 29. This cut is parallel with the back wall 24 and facilitates the start of the arcuate cut which, of course, is more difficult and more delicately accomplished.

A band saw is preferably utilized to make the arcuate cut, and at that time the block is located on a jig pin passing into the hole for the longitudinal thread passage. The block is turned on this jig pin as a center so that the saw must cut slot 3%) concentrically disposed to the hole. This actually forms the scroll 28 which will thus be bounded by concentric cylindrical surraces and parallel end faces; thus it will have a cross-section of substantially uniform area as desired. The arcuate cut may be carried slightly past the vertical center plane of the longitudinal thread channel.

it remains to interconnect the hole 29 and arcuate slot 30, Fig. 7, and that may be done by use of a saw or a broach. The block is at that time removed from the pin and held rigidly in a fixture while the cut is made from the hole downwardly into the slot. The cut is evenly spaced to either side of the vertical center plane of the channel 29 or slightly toward the back wall.

The hole for pin 36 is drilled and the pin may be inserted at any convenient time.

The entire block is sand blasted to smooth it, and sharp corners which might harm a thread, interfere with its threading or the shedding of an undesired but unavoidable loop in the filling are all rounded in any convenient manner.

At Fig. 3 the finished block is shown after all operations have been performed including insertion of the pin 36 and drilling of a hole 39, Figs. 9 and 10, through which a retaining bolt, l, is passed.

in u this blQCrZ will thread easily and has a maximum ct res. lance to unthreading especially when pin 36 is placed so its top edge is about even with the horizontal plane of the bottom of channel 29, or slightly higher.

The very solid and rugged construction makes it virtu'clly impossible for a trapped bobbin to damage the bloclt in any way. The smooth surfaces and the angular disposal of the scroll facilitate the shedding of all types of loops as above mentioned, this being accomplished without subjecting the filling to added tension such as might cause it to break.

While cast iron has been mentioned as a preferred material, it is to be understood that any metal normally classified as non-ductile may be used. The order of machining operations and the manner of performing them may be varied so long as the ultimate result is the formation of a threading block as described.

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 be 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. A threading block for loom shuttles comprised as a non-ductile metal casting and having means defining a longitudinal thread channel of circular cross-section, a

side eye recess, a horn with a thread confining lip, said means defining the longitudinal thread channel including a scroll integral with the cast block, said scroll being of substantially uniform cross-section and inclined at an angle toward the horn end of the block, and means defining thread entrance slots leading to the longitudinal thread channel, one said slot leading downwardly and then arcuately on a radius concentric with the longitudinal thread channel and a second slot leading from the terminal portion of said arcuate slot vertically toward the center of the longitudinal thread channel.

2. A threading block for loom shuttles comprised as a non-ductile metal casting and having means defining a longitudinal thread channel of circular cross-section. a side eye recess and a horn with a thread confining lip, said means dc 1c he longitudinal thread channel ineluding a scroll integral with the cast block, said scroll h 3g of substantially uniform cross-section and inclined at an angle of substantially 45 to the longitudinal thread channel and toward the horn end of the block, and means defining thread entrance slots leading to the longitudinal thread channel, one said slot leading downwardly and then arcuately on a radius concentric with the longitudinal thread channel and a second slot leading from the terminal portion of said arcuate slot vertically toward the center of the longitudinal thread channel.

3. A. threading block for loom shuttles comprised as a nonductile metal casting and having means defining a longitudinal thread channel of circular cross-section, a side eye recess, and a horn with a thread confining lip, said means defining the longitudinal thread channel including a scroll integral with the cast block, said scroll being of substantially uniform cross-section and inclined at an angle toward the horn end of the block, the front and rear transverse faces of said scroll being parallel and the rear said face forming with adjacent perpendicular bounding walls, an indentation at the thread entrance portion of the block for facilitating entry of the thread and shedding of a back loop of filling, and means defining thread entrance slots leading to the longitudinal thread channel, one said slot leading downwardly and then arcuately on a radius concentric with the longitudinal thread channel and a second slot leading from the terminal portion of said arcuate slot vertically toward the center of the longitudinal thread channel.

4. A threading block for loom shuttles comprised as a non-ductile metal casting and having means defining a longitudinal thread channel of circular cross-section, a

' side eye recess, and a horn with a thread confining lip,

said means defining the longitudinal thread channel including a scroll integral with the east block, said scroll being of substantially uniform cross-section and inclined at an angle toward the horn end of the block, and means i defining thread entrance slots leading to the longitudinal thread channel, one said slot leading downwardly and then arcuately on a radius concentric with the longitudinal thread channel and a second slot leading from the terminal portion of said arcuate slot vertically toward the center of the longitudinal thread channel, and a pin disposed transversely of the block and forwardly of the scroll, said pin being at a height to hold filling threaded through the block at substantially the level of the lowest part of the longitudinal thread channel.

References Cited in the file of this patent