Abstract:
A bobbin hanger enabling the use of a mechanical bobbin changing apparatus. The bobbin hanger is constructed so as to provide an allowance for the movement of a weight for controlling a bobbin holding mechanism in the range of 4 to 10 mm so that the mechanical bobbin changing apparatus is able to achieve bobbin hanging and bobbin removing operations without fail. The bobbin hanger employs bobbin holding fingers formed in a shape which will not allow the bobbin holding fingers to be retracted easily into a bobbin hanging tube by a horizontal force acting on the bobbin holding fingers so that the accidental removal of the bobbin hung on the bobbin hanger is prevented.

Description:
BACKGROUND ART 
     The present invention relates to a bobbin hanger for use in the textile industry and, more specifically, to a bobbin hanger for holding a yarn package or a roving package on a textile machine or for conveying a yarn package, a roving package or an empty bobbin. 
     Various bobbin hangers are used in the textile industry. Shown in FIG. 10 is a typical currently and widely used bobbin hanger capable of smooth rotation and slight swing. This bobbin hanger has a bobbin hanging tube 1 having an expanded section 1a having a larger diameter and a reduced section 1b having a smaller diameter, and joined to a tubular holding member 2. A bobbin B is fitted on the reduced section 1b. As shown in FIG. 11, longitudinal grooves 1c (only one of them is shown in FIG. 11) are formed diametrically in the reduced section 1b. An opening 1d is formed at the upper end of each groove 1c so as to connect with a longitudinal, bottomed square hole 1e formed coaxially in the central portion of tee reduced section 1b. Grooves 1q are formed, respectively, in the opposite surfaces of the square hole 1e so as to correspond to the grooves 1c respectively. Longitudinal slots 1i are formed diametrically at an angular distance of 90° from the grooves 1c in the lower end of the reduced section 1b so as to connect with the square hole 1e to receive retractable bobbin holding fingers 6 therein. A weight 3 having inner projections 3a is put on the reduced section 1b  with the inner projections 3a received, respectively, in the grooves 1c for axial movement along the reduced section 1b. A pin 1h is fitted in a hole 1p penetrating the lower ends of the bottom walls of the grooves 1c so that the opposite ends thereof project into the grooves 1c to prevent the weight 3 from falling off the reduced section 1b. A sliding member 4 shown in FIG. 12 is fitted slidably in the square hole 1e of the reduced section 1b. The bobbin holding fingers 6 are joined pivotally to the lower end of the sliding member 4 with a pin 6a. A retaining member 5 is supported pivotally on the upper part of the sliding member 4 with a pin 5d. The retaining member 5 has a square ratchet 5a and a base block 5b formed integrally with the square ratchet 5a. Projections 5c are formed, respectively, on a pair of opposite sides of the base block 5b. Grooves 4a are formed diametrically in the upper end of the sliding member 4. Sliding member 4 is provided with flanges 4b in the upper portion thereof. The flanges 4b rest on the upper end 1f (FIG. 11) of the reduced section 1b to limit the downward movement of the sliding member 4. Splines 4d extending downward from the flanges 4b engage the grooves 1q formed in the square hole le and project through the openings 1d into the grooves 1c so as to engage the projections 3a of the weight 3, respectively. A ratchet operating member 7 is formed by bending a single spring strip and has an operating leg 7a, a head 7b and a stopping lug 7c. In assembling the bobbin hanger, the ratchet operating member 7 is put in the grooves 4a of the sliding member 4, the bobbin holding fingers 6 are retracted into the sliding member 4, the sliding member 4 is inserted in the square hole 1e of the bobbin hanging tube 1, a compression spring 8 is placed on the flanges 4b, a holding plate 9 is placed on top of the compression spring 8, and then a pin 2a is inserted in through holes 1g formed in the wall of the expanded section 1a of the bobbin hanging tube 1, through holes 2b formed in the wall of the holding member 2 and a through hole 9a formed in the holding plate 9 to join together the bobbin holding tube 1 and the holding member 2 as shown in FIG. 13. When the bobbin hanger is thus assembled, the stopping lug 7c of the ratchet operating member 7 rests on the upper end 1f of the reduced section 1b, and the head 7b of the ratchet operating member 7 is received in a recess 9b (FIG. 13) formed in the lower surface f the holding plate 9. When placed substantially in a horizontal position, the projections 5c of the base block 5b engage the upper end lf to retain the sliding member 4 at an upper position as shown in FIG. 13. In this state, the bobbin holding fingers 6 are retracted into the reduced section 1b of the bobbin hanging tube 1, and the weight 3 rests on the pin 1h. 
     In hanging a bobbin B on the bobbin hanger, the weight 3 is pushed up by the bobbin B, while the projections 3a of the weight 3 engage the lower ends of the splines 4d of the sliding member 4 projecting into the openings 1d to push up the sliding member 4 to an uppermost position against the resilience of the compression spring 8 as shown in FIG. 14. Consequently, the tooth of the ratchet 5a of the retaining member 5 engages the lower end of the operating leg 7a of the ratchet operating member 7, and thereby the retaining member 5 is turned through an angle of 90° and the projections 5c are placed in a vertical position as shown in FIG. 14 as the sliding member 4 is moved upward. Then, an upward force applied to the bobbin B is removed. Consequently, as shown in FIG. 15, the bobbin B drops together with the weight 3 to a hanging position, where the retaining member 5 is received in the square hole le, the flanges 4b of the sliding member 4 rest on the upper end 1f of the reduced section 1b, and the bobbin holding fingers 6 are caused to swing outward by the pin 1h and engage the stepped par B 1  of the bobbin B to hold the bobbin B on the bobbin hanger. 
     In removing the bobbin B from the bobbin hanger, the bobbin B is pushed up again to move the sliding member 4 to the uppermost position, whereby the retaining member 5 is turned through an angle of 90° and the bobbin holding fingers 6 are retracted into the bobbin hanging tube 1 to release the bobbin B. 
     In hanging the bobbin B on this conventional bobbin hanger, the bobbin B is put on the reduced section 1b of the bobbin hanging tube 1 and pushed up by hand together with the weight 3 to an uppermost position, where the upper end of the weight 3 is in abutment with the lower end 1r of the expanded section 1a. Thus, the bobbin hanger is designed so that the retaining member 5 pivotally supported on the sliding member 4 has been turned through an angle of 90° by the operating leg 7a of the ratchet operating member 7 before the bobbin B arrives at the uppermost position where the upper end of the weight 3 is in abutment with the lower end 1r of the expanded section 1a, and an allowance C, namely, the distance between the upper end of the weight 3 and the lower end 1r of the expanded section 1a at the completion of turning of the retaining member 5 through an angle of 90°, is very small. Thus, the bobbin B is pushed up to the uppermost position in hanging the bobbin B on and removing the same from the bobbin hanger by hand. 
     Recently, bobbin changing apparatus have been introduced into spinning mills for the mechanical bobbin changing operation on spinning frames and roving frames. The bobbin changing apparatus puts bobbins on bobbin hangers and removes the same from the bobbin hangers individually or simultaneously with arms 10 (FIG. 10). When such a mechanical bobbin changing apparatus is used for mechanically putting bobbins on and removing the same from bobbin hangers, it is difficult to position bobbins in alignment with the bobbin hanging tubes of the bobbin hangers unless the bobbin hangers are disposed very accurately. Furthermore, since the stroke of the arm of the mechanical bobbin changing apparatus is fixed, the bobbin hangers must be arranged on the same level, and it is difficult to achieve mechanical bobbin changing operation satisfactorily if the bobbin hangers are arranged on different levels or the bobbin hangers are supported on an easily bendable support. 
     Since the lower end 1j of the reduced section 1b of the bobbin hanging tube 1 is flat as shown in FIG. 13, sometimes, the bobbin hanging tube 1 fails to enter the bore of the bobbin B smoothly. Particularly, since the result of the mechanical bobbin changing operation is not confirmed by the operator, it is possible that the bobbin is not hung on or removed from the bobbin hanger successfully or the bobbin hanger is damaged by a faulty mechanical bobbin changing operation. 
     When a horizontal force acts in the direction of an arrow F 1  on the bobbin holding finger 6 engaging the inner stepped part B 1  of the bobbin B, FIG. 15, to cause the bobbin holding finger 6 to be moved in the direction of an arrow M 1  by the pin 1h engaging the inclined surface 69 of the bobbin holding finger 6 and the bobbin B falls off the bobbin hanger, which is possible to occur when the bobbin conveying apparatus is braked abruptly or started suddenly, because the downward pressure applied to the sliding member 4 by the compression spring 8 is small to facilitate bobbin hanging operation and bobbin removing operation, and the inclined surface 69 of the bobbin holding finger 6 is liable to slide upward along the pin 1h. 
     DISCLOSURE OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a bobbin hanger capable of surely functioning in combination with a mechanical bobbin changing apparatus, which moves a bobbin through a fixed distance in hanging the bobbin on and removing the bobbin from the bobbin hanger, regardless of slight deviation or variation of the position thereof from a predetermined position relative to the mechanical bobbin changing apparatus, and retractable bobbin holding fingers capable of reliable operation. 
     It is another object of the present invention to provide a bobbin hanger having a bobbin hanging tube capable of surely entering the bore of a bobbin even if the axis of the bobbin hanger and that of the bobbin are dislocated relative to each other. 
     It is a further object of the present invention to provide a bobbin hanger having bobbin holding fingers which are not readily retracted to release the bobbin hung on the bobbin hanger even if a horizontal force acts thereon when the bobbin hanger conveying apparatus is braked abruptly or started suddenly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially cutaway side elevation of a bobbin hanger in a first embodiment according to the present invention, in which the parts are shown in positions for hanging a bobbin; 
     FIG. 2 is a partially cutaway side elevation of a bobbin hanger in a second embodiment according to the present invention, in which the parts are shown in positions during a bobbin hanging operation; 
     FIG. 3 is a partially cutaway side elevation of a bobbin hanger in a third embodiment according to the present invention; 
     FIG. 4 is an enlarged fragmentary longitudinal sectional view of a bobbin hanger in a fourth embodiment according to the present invention; 
     FIG. 5 is a fragmentary longitudinal sectional view showing the bobbin holding fingers of the bobbin hanger of FIG. 4 in a retracted position; 
     FIG. 6 is a diagrammatic illustration of bobbin holding fingers incorporated into a bobbin hanger in a fifth embodiment according to the present invention; 
     FIG. 7 is a bottom view of the bobbin hanger of FIG. 2; 
     FIG. 8 is an exploded perspective view of a portion of a bobbin hanger in a sixth embodiment according to the present invention; 
     FIG. 9 is a fragmentary longitudinal sectional view of assistance in explaining a bobbin hanger in a seventh embodiment according to the present invention; 
     FIG. 10 is a partially cutaway side elevation of a conventional bobbin hanger, in which the parts are shown in positions for hanging a bobbin; 
     FIG. 11 is an exploded perspective view of the bobbin hanging tube assembly of the bobbin hanger of FIG. 10; 
     FIG. 12 is an exploded perspective view showing the component parts of the bobbin hanger of FIG. 10; and 
     FIGS. 13, 14 and 15 are fragmentary longitudinal sectional views illustrating the successive positions of the bobbin hanger of FIG. 10 during a bobbin hanging operation. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Representative embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. 
     Referring to FIG. 1, showing a bobbin hanger in a first embodiment according to the present invention, a holding member 2 has a spherical upper wall 15 having a central hole and is provided internally with a spherical seat. A bolt 12 is passed through the center hole of the upper wall 15, a dust cover 16 having a shape conforming to the outer surface of the upper wall 15 and placed on the upper wall 15, a brake spring 13 placed on the dust cover 16, and a cap 14 placed on the brake spring 13, and a nut is screwed on the bolt 12 to fasten together the holding member 2, the dust cover 16, the brake spring 13 and the cap 14. A ball bearing is mounted on the bolt 12 between the head of the bolt 12 and the spherical seat formed in the upper wall 15 to allow the holding member 2 to move for rotation and slight swing motion on the bolt 12. The bolt 12 is fastened to a support member 11 for supporting the bobbin hanger. 
     A bobbin hanging tube 1 has an expanded section 1a and a reduced section 1b. The length of the expanded section 1a is greater than that of the expanded section of the bobbin hanging tube of the conventional bobbin hanger shown in FIGS. 13, 14 and 15. The length of the operating leg 7a of a ratchet operating member 7 is longer by a length C 1  than the operating leg of the ratchet operating member of the conventional bobbin hanger shown in FIGS. 13, 14 and 15. When a bobbin B is applied to the lower end of the bobbin hanging tube 1 and moved upward by a bobbin changing apparatus to hang the bobbin on the bobbin hanger, a weight 3 engages the splines 4d of a sliding member 4 at a position S 1 . When the weight 3 is pushed up further together with the sliding member 4 to a position S 2 , a retaining member 5 pivotally supported on the sliding member 4 is turned substantially through and angle of 90° by the operating leg 7a of the ratchet operating member 7, so that the projections 5c of the retaining member 5 are placed in a vertical position as shown in FIG. 1. In this state, a gap Ca, namely, an allowance for the upward movement of the weight 3, is secured between the upper end of the weight 3 and the shoulder 1r of the expanded section 1a of the bobbin hanging tube 1. Accordingly, the weight 3 never collides against the shoulder 1r even if the bobbin B is pushed up excessively. The size of the gap Ca is determined taking into consideration errors in the height of the bobbin hanger and in the stroke of the bobbin pushing mechanism of the bobbin changing apparatus. Generally, the size of the gap Ca is in the range of 4 to 10 mm. 
     As shown in FIG. 2, both the expanded section 1a and reduced section 1b of the bobbin hanging tube 1 may be formed, respectively, in lengths L 1  and L 2  greater than those of the expanded section and reduced section of the bobbin hanging tube of the conventional bobbin hanger, and the length of the operating leg 7a of the ratchet operating member 7 may be increased accordingly to secure the gap Ca of a size in the range of 4 to 10 mm. 
     As shown in FIG. 3, the position where the sliding member 4 is retained may be lowered within a range in which the bobbin holding fingers 6 are held in a retracted position, by lowering only the upper end 1f of the reduced section 1b of the bobbin hanging tube 1 on which the projections 5c of the retaining member 5 rest and extending the operating leg 7a of the ratchet operating member 7. When the bobbin hanger is thus constructed, the length of the opening 1d formed in the reduced section is increased. 
     The bobbin hanger of the present invention may be a swingable bobbin hanger as those shown in FIGS. 1 and 2 or a bobbin hanger mainly for conveying a bobbin as shown in FIG. 3. The bobbin hanger shown in FIG. 3 is attached to a support member 11 with a compression spring 17 between the holding tube 2 thereof and the support member 1, and the holding tube 2 is unable to rotate and capable of automatic alignment. Since the bobbin hanger shown in FIG. 3 is unable to swing, the lower end 1k of the reduced section 1b of the bobbin hanging tube 1 is tapered to facilitate inserting the bobbin hanging tube 1 into the bore of a bobbin B. The holding tube 2 may be directly and fixedly attached to the support member 11. In such a case, the bobbin B is hung on the bobbin hanger in an inclined position and is handled in the inclined position for mechanical bobbin changing operation. 
     FIG. 4 shows bobbin holding fingers 6 embodying the present invention. When the bobbin holding fingers 6 are caused to swing outward by a pin 1h, portions 61 of the bobbin holding fingers 6 in contact with the pin 1h extend vertically. Accordingly, the portions 61 do not slide along the pin 1h and hence the bobbin holding fingers 6 are not pushed upward even if a horizontal force F 1  acts on the bobbin holding fingers 6. When a sliding member 4 pivotally supporting the bobbin fingers 6 is moved upward, the portions 61 are separated from the pin 1h and the bobbin holding fingers 6 are retracted by gravity into the reduced section 1b of a bobbin hanging tube 1 as shown in FIG. 5. 
     FIG. 6 shows a modification of the bobbin holding finger 6 shown in FIG. 4. Bobbin holding fingers 6 shown in FIG. 6, similarly to those shown in FIG. 4, have portions 61 which extend vertically when the bobbin holding fingers 6 are projected fully from the reduced section 1b by the pin 1h. The portions 61 of the bobbin holding fingers 6 shown in FIG. 6 is longer than those of the bobbin holding fingers shown in FIG. 4. The bobbin holding fingers 6 shown in FIG. 6 can be surely retracted by gravity as indicated by broken lines 6A in FIG. 6. 
     FIG. 7 is a bottom view of the bobbin hanging tube 1 of the bobbin hanger shown in FIG. 1. The lower end 1k of the bobbin hanging tube 1 is tapered to facilitate the insertion of the bobbin hanging tube 1 into the bore of a bobbin B. The lower end 1k may be formed in a substantially tapered shape having a portion formed of a concave surface 1m as shown in FIG. 9. The tapered lower end may be a separate tapered tip member 18 as shown in FIG. 8. The tapered tip member 18 may be attached adhesively to the lower end 1j of the reduced section 1b or the tapered tip member 18 may be provided with lugs 18a as shown in FIG. 8; the lugs 18a are fitted in grooves 1c formed in the lower end of the reduced section 1b and joined to the reduced section 1b with the pin 1h. 
     The lower end 1k of an acute angle facilitate the insertion of the bobbin hanging tube 1 into the bore of a bobbin B. 
     The bobbin hangers thus constructed in accordance with the present invention ensure successful mechanical bobbin changing operation regardless of slight variations in the horizontal and vertical positions between the bobbin hangers or regardless of variation in the height of the bobbin support member. Furthermore, the bobbin hangers of the present invention hold bobbins securely even if a horizontal force acts on bobbins hung on the bobbin hangers.