US2457954A - Pneumatic thread holder for weft replenishing looms - Google Patents

Description

Jan. 4, 1949. R. G. TURNE 2,457,954

PNEUMATIC THREAD HOLDER FOR WEF'I' REPLENISHING LOOMS Filed Oct. 1, 1947 .INVENTOR RIGHARD a TURNER ATTORNEY aw Jan. 4, 1949- THREAD HOLDER FOB Wm BEPLENISHING 1100115 Richard G. Turner, Worcester, Mala. Illinoito PNEUMATIC (irompton & Knowles Loom Works, Masa. a corporationof Massachusetts Worcester,

Application Oetobcr 1, 1041, Serial No. nuns Claims. (of. 139-247) This invention relates to improvements in weft replenishing looms and it is the general object of the invention to provide a. pneumatic thread holder for the weft ends'of the reserve bobbins effective to continue a partial vacuum within the thread holder after completion of the working stroke of the air pump which creates the partial vacuum.

In weft replenishing looms the weft ends extending from the reserve bobbins must be held taut and it is also desirable that the weftend of a transferred bobbin be removed when out at the selvage. Heretoi'ore I have proposed pneumatic means for accomplishing these results by a pneumatic system utilizing a reciprocating air pump to create subatmospheric pressures during backward movement of the lay within a thread holder into which the weft end extends. When the pump reaches the end of its backward stroke there is a rise in pneumatic pressure and the weft ends are likely to move in a direction from the thread holder toward the bobbin holding magazine with consequent chafing and fraying.

It is an important object of my present invention to provide a pneumatic thread holding system wherein an auxiliary air cylinder or chamber acts to continue the condition of subatmospheric pressures within the thread holder after the air pump has completed its backward stroke. This result I accomplish by connecting the auxiliary chamber in such manner that it can be partially evacuated during the working stroke of the pump and then become effective to draw air into the thread holder while the air pump is having its idle or return stroke.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein two forms of the invention are shown,

Fig. 1 is a side elevation of part of a weft replenishing loom, partly in section, showing the preferred form of the invention applied thereto,

Fig. 2 is a diagrammatic view showing the manner of operation of the preferred form of the invention, and

Fig. 3 is a diagrammatic view illustrating the modified form of the invention.

Referring to Fig. l, the loom frame 1' supports a magazine M having reserve bobbins not shown from which weft ends W extend to a pneumatic thread holder H. The latter is connected pneumatically to the interior of a thread collecting cylinder or the like II the upper part of which is connected by a pipe or hose II to an air pump I2. The latter has a piston it reciprocating in the cylinder I4 and driven by a holder.

connector I! attached to the upper end of a lay driven operating lever It The cylinder M has a head ll receiving the pipe II and provided with a valve II which normally tends to close and remain in the dotted line position shown in Fig. 2. The piston has escape ports I! which can be opened by valves 20 when air within the cylinder between the piston and valve II is under compression and closed when a partial vacuum is being formed in the cylinder.

The loom is also provided with a lay L s pporting a shuttle S provided with a bobbin B the condition of which with respect to weft supply is detected periodically by a weft detector D. When the weft supply is exhausted the detector calls into operation mechanism which operates transfer mechanism T to move a bobbin from the magazine M into the shuttle S. As this bobbin moves down into the shuttle its weft end is lowered, but still extends into the thread At some later time in the operation of the loom this thread is cut at the selvage and is then drawn pneumatically through the thread holder into the cylinder Ill.

The piston I3 is moved rearwardly to create a partial vacuum within the cylinder I l and pipe II when the lay L moves from its front center or detecting position to its back center position. During this time valve I8 is open as shown in full lines in Fig. 2 and valves 20 are closed. At the end of the backward stroke of the lay piston I3 is momentarily at rest and then starts forwardly, whereupon valve II is closed to the dotted line position of Fig. 2. and valves 20 open to permit escape of air through the ports is.

The matter thus far described is of common construction and may be as set forth in my prior Patent No. 2,199,353.

As already stated, the weft ends which extend through the thread holder H and into the cylinder in are subjected to pneumatic attraction during backward movement'of the lay and are then slackened as the lay moves forwardly. As a consequence of this condition the threads move back and forth with respect to the holder and when they are of very fine denier are likely to become chafed or frayed to such an extent that they will be broken during the transferring operation.

In order to prevent this back and forth movement of the threads in the thread holder I propose to use an auxiliary air cylinder or chamber connected pneumatically to the pump it in such manner as to continue movement of air into the thread holder and cylinder l during a part at least of the forward movement of the lay.

In the preferred form of the invention an auxiliary cylinder 30 is connected by a relatively large pipe 3| to the tube or hose I i and has an internal transverse plate 32 provided with a port 53 which can be closed by a valve 34. The air chamber 35 of the auxiliary cylinder 35 above plate 32 is connected by a pipe 36 of relatively small diameter to the pipe H at a point between the thread.

collecting cylinder I0 and the pipe 3|. Although pipe 36 is shown as being connected to the pipe II I am not necessarily limited to this construction since it is suflicient if it be pneumatically connected to the interior of the thread collecting cylinder It).

In the operation of the preferred form of the invention, and assuming that the lay is on front center as shown in Fig. 1, backward movement of the lay will cause the piston l3 to move to the right as viewed in Fig. 2, thereby opening valve l8 and closing valves and creating a partial vacuum in the pipe H the effect of which is to draw air through the thread holder H into the cylinder l0 and also move the valve 34 from the normally closed dotted to the open full line position shown in Fig. 2. The pump it therefore creates subatmospheric pressures within the chamber 35 of the auxiliary tank at the same time that it performs its normal function of drawing air into the thread holder. When the lay reaches its back center position it ceases to create subatmospheric pressures and then starts forwardly. Valveit closes and the subatmospheric pressures existing within the chamber 3'5 will draw the valve 3% upwardly to its closed position as indicated in dotted lines in Fig. 2. Under these conditions the only way by which air can get into chamber to relieve the subatmospheric pressures therein is through the thread holder, cylinder it, part of pipe ii and the small pipe 36. Because of the small diameter of the latter an appreciable time is required to permit enough air to move through it into the chamber 35 to restore the latter to normal atmospheric pressure, and during this time air is moving into the holder H to prevent outward or retrograde movement of the weft ends and the aforesaid chafing and fraying is avoided.

In the modified form of the invention shown in Fig. 3 the cylinder l0 and pump 12 may be as already described, but the auxiliary cylinder 40 is connected by a pipe 4! similar to pipe II to the thread cylinder i0 and by a second pipe 42 to the pump i2. A pipe 43 having a diameter much smaller than that of pipe 4| connects the left end of cylinder 40 with pipe 4i and is similar in function to small diameter pipe 35 of the preferred form of the invention.

Cylinder 40 can be sealed from pipe 4| by a valve 45 shown herein as of the slide type. A small ball crank lever 46 is connected to valve 45 and is pivoted as at 41 to a fixed part of the 100m structure. The upright arm 48 'of lever 48 has a pin 49 fitting in a slot 50 on the left end of a rod 5i which is pivoted as at 52 to the previously mentioned operating lever l6. The slot 55 provides a lost motion connection between the valve 45 and the lay.

end of slot 50 engages pin 48, whereupon con tinned backward movement of the lay will cause bell crank lever 45 to rock in a clockwise direction as viewed in Fig. 3 to raise valve 45 to closed position. This closure may come either at back center or preferably slightly before back center so that the last part of the backward stroke of piston l3 will create additional subatmospheric pressures within the cylinder 40. Thereafterair moving from the thread holder into the cylinder Ill will be drawn upwardly through the small diameter pipe 43 into the cylinder 40 to continue movement of air into the thread holder during forward movement of the piston i5.

As the layapproaches front center the right end of slot 50 will engage pin 49 and rock lever 45 in a counter-clockwise direction, thereby moving slide valve 45 downwardly as viewed in Fig. 3 to open the cylinder 40 to the pipe 4i. Valve 45 will remain in this open position during the greater part of the next backward stroke of the lay and enable the pump to draw air in the usual manner through the thread holder andinto the cylinder ID to place the weft ends W under tension.

From the foregoing it will be seen that I have provided simple means by which an auxiliary air cylinder or the like is utilized as storage means for subatmospheric pressures which are utilized to continue movement of air into the thread holder after the piston It has reached its rcarmost position and completed its working stroke. In both forms of the invention the subatmospheric pressure created within the auxiliary cylinder acts through a relatively small diameter pipe or tube to continue movement of air into the thread holder. In the first form of the invention valve 34 acts automatically and due to the partial vacuum existing within the air chamber 35. In the modified form of the invention valve is opened and closed positively by operation of the loom and may be closed slightly before the lay reaches back center position so that'the pump it can create additional subatmospheric pressures within auxiliary cylinder 4@. Valve 55 will then remain closed so that air can continue to i move through the holder and thread collector I0 into cylinder 40 through the'small diameter pipe as. In both forms of the invention the diameter of the small pipes 36 and 43 is so chosen as to prolong the time required to restore atmospheric pressures within the auxiliary cylinder and thereby prolong the time during which the weft ends are subject to pneumatic forces during forward movement of the lay.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do. not wish to be limited to the details herein disclosed, but what I claim is:

1. In a pneumatic control for the weft ends of reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures. a pneumatic holder for the weft ends, an air pump, hollow means of relatively large internal cross sectional area interconnecting the In operation of the modified form, backward movement of the lay from its front center posi- 7 pressures created within the storage 'means by tion will move rod 5i rearwardly until the left air pump, storage means and pneumatic holder, the pump eflective on a working stroke thereof to create subatmospheric pressures within the storage means and pneumatic holder, and hollow pneumatic means of relatively small internal cross sectional area connecting the storage means and pneumatic holder enabling the subatmospheric awaeu said pump to create subatmospheric pressures within the pneumatic holder subsequent to completion 01 said working stroke.

2. In a pneumatic control for the weft ends or" reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures, a pneumatic holder for the weft ends, an air pump, hollow means of relatively large internal cross sectional area connecting the storage means pneumatically with the pump and holder, the pump effective on a working stroke thereof to create subatmospheric pressures within the storage means and pneumatic holder, and hollow pneumatic means of relatively small internal cross sectional area connecting the storage means and pneumatic holder enabling the subatmospheric pressures created within the storage means by said pump to create subatmospheric pressures within the pneumatic holder subsequent to completion of said working stroke.

3. In a pneumatic control for the weft ends of reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures, a pneumatic holder for the weft ends, an air pump having a working stroke during loom operation to create subatmospheric pressures, hollow means of relatively large internal cross sectional area pneumatically connecting the pump and holder and storage means together, the pump on a working stroke thereof creating subatmospheric pressures within the storage means and holder, an airvalve for the storage means between the storage means and pump opened by pneumatic pressure when the pump has a working stroke and closing upon completion of said stroke due to subatmospheric pressures within said storage means, and hollow means of relatively small internal cross sectional area connecting the storage means and pneumatic holder and enabling the subatmospheric pressures within the storage means to create subatmospheric pressures within the pneumatic holder subsequent to completion of said working stroke.

4. In a pneumatic control for the weft ends of reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures, a pneumatic holder for the weft ends, an air pump having a working stroke during loom operation to create subatmospheric pressures, hollow means of relatively large internal cross sectional area pneumatically connecting the pump and holder and storage means together, the pump on a working stroke thereof creatin subatmospheric pressures within the storage means and holder, an air valve for the storage means between the storage means and the pump open when the pump has a working stroke and closing upon completion of said stroke, and hollow means of relatively small internal cross sectional area connecting the storage means and pneumatic holder and enabling the subatmos-- pheric pressures within the storage means to create subatmospheric pressures within the pneumatic holder subsequent to completion of said working stroke.

5. In a pneumatic control for the weft ends of reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures, a pneumatic holder for the weft ends, an air pump having a working stroke during loom operation to create subatmospheric pressures,

V beginning of said working stroke and closing the valve prior to completion of said working stroke to enable the pump to create subatmospheric pressures within the storage means only, and hollow means of relatively small internal cross sectional area pneumatically connecting the storage means and pneumatic holder to enable the subatmospheric pressures within the storage means to create subatmospheric pressures within the pneumatic holder subsequent to completion of said working stroke.

6. In a pneumatic control for the weft ends of reserve bobbins in a weft replenishing loom, storage means for air under subatmospheric pressures, a pneumatic holder for the weft ends, an air pump having a working stroke during loom operation to create subatmospheric pressures, hollow means pneumatically, connecting the pump to the storage means and other similar hollow means connecting the storage means to the phone.

matic holder, an air valve in the second named hollow means, the pump on a working stroke thereof when the valve is open creating subatmospheric pressure in the storage means and holder,

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date I 57,412 Vander Weyde Aug; 21, 1866 186,408 Blunt Jan. 23,, 1877 Turner Feb. 26,, 1946

Images