US2664114A - Auxiliary beam letoff mechanism for looms - Google Patents

Description

Dec. 29, 1953 Filed Jan. 4, 1952 J. A. BRADSHAW 2,664,114 AUXILIARY BEAM LE'IQFF mcHANI su FOR Locus 3 Sheets-Sm 1 Fi i INVENTOR.

JOHN A BRADSHAW Dec. 29, 1953 R DsH w 2;664 ',l1 4

AUXILIARY BEAM LETOFYF MECHANISM FQR gous Filed Jan. 4, 1952 s SheetQ-Sheet 2 IN VEN TOR.

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Dec. 29, 1953 2,664,114

J. A. BRADSHAW AUXILIARY BEAM LETOFF MECHANIM LOQMS Filed .Jan. 4, 1952 s Shani-she p's A INVENTOR.

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Patented Dec. 29, 1953 AUXILIARY BEAM LETOFF MECHANISM FOR LOOMS John A. Bradshaw, Greenville, S. 0., assignor to J. P. Stevens & 00., Inc., a corporation of Dela.-

ware

Application January 4, 1952, Serial No. 264,931

Claims.

This invention relates to letoff mechanisms for looms and more particularly to an improved mechanism of this sort for use in looms on which an auxiliary warp beam is employed for supplying supplementary warp ends in addition to the warp ends fed from a main beam to the loom.

In weaving fabrics such as Seersucker cloth and the like, which are characterized by a puckered effect in the fabric, it is necessary to provide slack in certain of the warp ends in order to produce this puckered fabric texture, This is commonly done by feeding certain of the warp ends to the loom from a main warp beam in the usual manner and at the usual tension, and the providing an auxiliary warp beam from which supplementary warp yarns are fed separately to the loom at the necessary degree of slack. Usually the auxiliary warp beam is mounted above the main warp beam, and is therefore referred to as a top beam, and the letoff mechanism of the present invention is uniquel adapted for unwinding the warp ends from a top beam of this sort at a regular rate for the degree of slack feeding desired or found necessary in any particular case.

The letoff mechanism of the present invention is described in detail below in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation illustrating the manner in which a letoff mechanism constructed in accordance with the present invention is installed on a loom, the loom being represented only fragmentarily.

Fig. 2 is a fragmentar detail view related to Fig. 1 to show the manner in which the letoff mechanism of the present invention may be connected for actuation from a main operating element of the loom;

Fig. 3 is a fragmentary elevation taken from jiggle Jrear of the loom as seen from the left in Fig. 4 is a further detail view related to Fig. 3 to show the other end of the letoff mechanism driving drum;

Fig. 5 is a sectional detail taken substantially on the line 5--5 in Fig. 3;

Fig. 6 is a further detail taken substantially on the line 66 in Fig. 3; and 1 Fig. 7 is a sectional detail taken substantially on the line '!-'I in Fig. 1.

Referring now in detail to the drawings, and more particularly at first to Fig. l, the-letoff mechanism of the present invention is shown as comprising a frame structure as indicated generally by the rcference numeral l0, which is .ar-

ranged for attachment to a conventional loom frame illustrated fragmentarily at F, and which may be provided with bracing arms [2 for further support from the loom arch indicated at A.

This frame structure I0 is adapted according to the present invention for carrying a driving drum I4, as will be explained more in detail presently, and is formed with guideways as at I6 for positioning an auxiliary warp beam B so that a warp end package P wound thereon will rest in peripheral driving contact on the driving drum I l. The guideways l6 are also preferably formed with a lip portion I8 at their upper ends to provide an elevated rest position for the warp beam B free of the driving drum I4 to facilitate its handlin upon installation and threading in the loom. The guideways l6 otherwise extend downwardly in the frame structure In with a reach suflicient to accommodate the full displacement of the warp beam B while supported peripherally on the driving drum M as it moves from full position (as shown by full lines in Figs. 1 and 3) to the empty position indicated by dotted lines at B.

It should also be noted that the guideways l5 are not arranged radiall with respect to the driving drum id, but are offset so as to be aligned more nearly in a tangent relation with the driving drum [4 at the side thereof that moves downwardly as the drum [4 rotates in order to obtain an increasing wedging effect between the rotating driving drum l4 and the opposing face of each guideway [6 as a warp end package P is unwound from the warp beam B, and thereby compensate for the loss in weight of the unwinding warp beam B so that an effective driving contact is maintained with driving drum [4 until the warp beam B is completely exhausted. In particular cases, it may be desirable to provide very accurately for obtaining this increasing wedging effect in relation to the weight loss of the beam B, and

for this purpose the guideways l6 might be arranged with a calculated curvilinear form having the upper portion thereof at a more or less radial relation to reduce the wedging effect to a minimum at .full position of the warp beam B and arrangement for the guideways l6 as illustrated in the drawings will provide satisfactory results.

The driving drum M is formed in a length less than the spacing between the end flanges of the warp beam B, so as to operate in driving contact only with the warp end package P wound between these end flanges, and is invested with a surface covering as at formed of cork or other suitable material to provide it with a satisfactory surface driving action. Also, particularly where filament yarns are to be handled in the warp end package P carried by the warp'beam -.B, there is considerable advantage in relieving this surface covering 20 in a pattern such as is provided by the spiral grooves 20', and by which the effective supporting portion of the surface covering 20 is continuously shifted laterally as the driving drum I4 is rotated. By this arrangement, the peripheral driving contact of the drum I4 with the package P is continuously shifted in relation to the individual ends of the package P so that an opportunity is afforded for distribution of any inequalities in tension between the individual ends such as must often be dealt with in handling filament yarns. The spiral grooves 28' may start at each end of the driving drum I4 as illustrated in the drawings, so as to meet in a V-formati'on midway thereof, or the spiral may run continuously from one end of the drum I4 to the other, or any other comparable relieved pattern that will provide the laterally shifting support by the surface covering 20 as described above may be used as desired. The manner in which the driving drum I4 is carried on the frame structure I0 is illustrated best in Figs. 3 and 4, in which the driving drum I4 is shown journalled in housings 22 and 22 that are supported on tie rods 24 and 26 forming part of the frame structure I0, the tie rod 24 extending entirely across the frame structure I0 while the tie rods 26 extend only from each side to the adjacent housings 22 or 22.

Actuation 0f the letoff mechanism of the present invention is accomplished directly from a main operating element of the loom with which it is associated, and for this purpose the embodiment shown in the drawings is equipped with an actuating rod 28 (compare Figs. 1 and 2) .fitted at one end with an eccentric collar 30 assembled on an eccentric 32 adapted to be fixed on the loom cam shaft C as illustrated in Fig. 2. At its other end, this actuating rod 28 is connected to the purchase arm 34 of a bell crank 36 for a pick mechanism 38, the other arm 40 of which carries the shifting pawl 42 of the pick mechanism 38. The purchase arm 34 is formed with an elongated slot 44 allowing the actuating rod 28 to be connected at varying distances from the axis of the bell crank so that the pick mechanism 38 is rendered adjustable to vary the speed of rotation transmitted to the driving drum I4 as desired. The shifting pawl arm 40 of the bell crank 36 is also formed with an elongated slot 48 to allow the shifting pawl 42 to be positioned therein properly for smooth operation in relation to the ratchet or pick Wheel 48 of the pick mechanism 38. The ratchet 48 is fixed on a shaft 50 that also carries the bell crank 36 at its outer end, and that is journalled on the frame structure III in a bearing bracket 52 formed with an upstanding arm portion 54 adjacent the ratchet 48, in which arm portion 54 an elongated slot 58 is provided for receiving and positioning a, holding pawl 58 for the pick mechanism 38 (compare Figs. 3 and 7).

The inner end of the ratchet shaft 50 extends beyond the bearing bracket 52 to carry a pinion 60 disposed to engage a gear 62 on a countershaft 64 (compare Figs. 3 and 5). This countershaft 64 runs to the adjacent housing 22 in which the driving drum I4 is journalled, as already mentioned above, and carries a pinion 66 engaging an intermediate gear 68 that is also journalled in this adjacent housing 22 to run in direct engagement with a drive gear I0 carried on the adjacent end of the mounting shaft I2 for the driving drum I4. Through this geared arrangement, the driving drum I4 .is rotated directly and regularly from the motion of the loom cam shaft C, or other operating element of the loom, for slack feeding of Warp ends from the warp end packageP on the warp beam B at a desired degree of slack as adjusted by the pick mechanism 42 in relation to the conventional feeding of warp ends from a main beam (not shown) to the loom.

In order to stabilize the geared drive for the winding drum I4 to operate smoothly as the letoff mechanism of the present invention is actuated through the pick mechanism 42, the previously mentioned countershaft 64 which runs to the adjacent driving drum support housing 22 is fitted at its other end with a brake mechanism as at 1-4. This brake mechanism (as shown best in-Fig. 6) comprises a brake cylinder 16 on which are assembled a pair of pivoted clamping arms I8 and both of which are fitted with brake shoes as at 82 and 84. These clamping arms 18 and 88 extend from their common pivot joint at 86 to receive a pressure rod 88 at their extending ends. The extending end of the clamping arm 80 is formed to receive this pressure rod 88 through a retaining face as at 98 against which a compression spring 92, disposed over the pressure rod 88, is confined by a nut 94 engaging the extending threaded end of pressure rod 88. The other clamping arm 18 is formed to rovide a contact face as at 96 for a cam-like portion 98 of a manipulating lever I00 that is pivoted on the other extending end of the pressure rod 88 as at I02 for disposition at a retracted position gainst the adjacent clamping arm I8 to apply the brake mechanism I4, or for pivoting outwardly from the adjacent clamping lever I8 towards a horizontal position so that its cam-like portion 98 releases the brake mechanism '14 when desired.

The present invention has been described above for purposes of illustration only and is not intended to be limited by this description or otherwise except as defined in the appended claims.

I claim:

1. An auxiliary beam letoff mechanism for slack feeding of supplementary warp ends in a 100m, said letoif mechanism comprising an auxiliary frame structure adapted for attachment to a loom frame, a driving drum carried by said frame structure, guideways formed in said frame structure for positioning a warp beam to rest a warp yarn package wound thereon in peripheral driving contact on said driving drum, said guideways being arranged to extend from their remote ends in a path diverging from a radial direction with respect to said driving drum whereby the lateral reaction force from said driving drum against the opposing face of said guideways increases upon decrease in diameter of said warp yarn package and thereby compensates for loss in weight of said package on said driving drum during unwinding, and means for rotating said driving drum from the motion of a main operating element of said loom at a speed providing a degree of slack feeding of warp ends from said auxiliary beam as desired in relation to the warp 'ends fed from a main beam to said loom.

2. An auxiliary beam letofl mechanism for slack feeding of supplementary warp ends in a loom, said letoff mechanism comprising an auxiliary frame structure adapted for attachment to a loom frame for positioning an auxiliary warp beam thereon, a driving drum carried by said frame structure and formed in a length less than the spacing between the end flanges on said auxiliary warp beam for supporting said auxiliary warp beam in peripheral driving contact with a warp yarn package wound thereon, means connecting said driving drum for rotation from the motion of a main operating element of said loom, and an adjustable pick mechanism interposed in said connecting means for varying the speed of rotation of said driving drum and thereby adjusting the slack feeding of warp ends from said auxiliary beam as desired in relation to the warp ends fed from a main beam to said loom.

3. An auxiliary beam letoif mechanism for slack feeding of supplementary warp ends in a loom, said letoff mechanism comprising a peripheral driving drum, means for mounting said driving drum in relation to the main frame of a loom and for supporting an auxiliary warp beam with a warp end package wound thereon resting on said driving drum, and means for rotating said driving drum from the motion of a main operating element of said loom at the desired speed of slack feeding of the supplementary warp ends from said auxiliary Warp beam in relation to the warp ends fed from a main Warp beam to said loom, said driving drum being formed with a peripheral surface that is relieved in a pattern by which the effective supporting portion of said surface is continuously shifted laterally as said driving drum is rotated.

4. An auxiliary beam letoff mechanism for slack feeding of supplementary warp yarns in a loom, said letoif mechanism comprising a peripheral driving drum, means for rotatably mounting said driving drum in relation to the main frame of a loom and for supporting an auxiliary warp beam with a warp end package wound thereon resting on said driving drum, an adjustable pick mechanism geared to said driving drum, and means connecting said pick mechanism to follow continuously the motion of a main operating element of said loom for rotating said driving drum through said adjustable pick mechamsm.

5. An auxiliary beam letoff mechanism for slack feeding of supplementary warp yarns in a loom having a camshaft for actuating the cyclic weaving operation thereof, said letoif mechanism comprising an auxiliary frame structure adapted for attachment to the frame of said loom for positioning an auxiliary warp beam thereon, a driving drum carried by said frame structure for supporting said auxiliary warp beam in peripheral driving contact with a warp yarn package wound thereon, an adjustable pick mechanism disposed on said frame structure and geared to said driving drum, and an actuating rod connecting said adjustable pick mechanism for operation continuously from said camshaft to rotate said driving drum at the rate desired for slack feeding of warp ends from said auxiliary beam in relation to the warp ends fed from a main beam to said loom.

JOHN A. BRADSHAW.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,517,930 Wells Dec. 2, 1924 1,698,497 Gunning Jan. 8, 1929 2,290,628 Alderfer July 21, 1942 2,489,609 Amidon Nov. 29, 1949

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