US2882848A - Rotary thread take-ups for sewing machines - Google Patents

Description

2,882,848 ROTARY THREAD TAKE-UPS FOR SEWING MACHINES! Filed April 3, 1956 E. o. MAYER ET AL April 21, 1 959 3 Sheets-Sheet 1 INVENTORS Eugene 0. Mayer BY Fr aqcl's L. Walling WI/lldfll C. Van Ness W 7- ATTORNEY SEWING MACHINES April 21, 1959 E. o. MAYER ET AL ROTARY THREAD TAKE-UPS FOR Filed April 3, 1956 5 Sheets-Sheet 2 a. 0 e e T N mmm w Z LC e .5 mm u mw E M /2 Q ATTORNEY WITNESS I W? @M 'April 21, 1959 f o. MAYER ET AL 2,832,848

ROTARY THREAD TAKE-UPS FOR SEWING MACHINES Filed April a, 1956 3 Sheets-Sheet 3 INVENTORS' Eugene 0. Mayer By Franc/ls L. Walling Mil/am C. Van Ness United States Patent f ROTARY THREAD TAKE-UPS FOR' SEWING MACHINES Eugene O. Mayer, South Norwalk, Francis L. Walling, I

Trumbull, and William C. Van Ness, Devon, Conn., assignors to The Singer Manufacturing Company, Elizabeth, NJ a corporation of New Jersey Application April 3, 1956, Serial No. 575,738

4 Claims. (Cl. 112-248) This invention relates to a thread take-up mechanism 3 h April 28, 1953, illustrates a rotary needle thread takeup to which the present invention may be applied advantageously, The Van Wagener-et a1. construction has proven highly successful; its single thread engaging member which rotates at constant velocity provides practically vibrationless operation, and its compact construction is accommodated convenientlyinto a sewing head as compared with its awkward, oversized predecessors. Perhaps the most important attribute of the Van Wagener et al. take-up to the sewing machine operator, however, is the factthat it acts with, smooth and gradual action onthe needlethread and therefore, it can sew with threads that would'break if used with other types of .take-upmechanisms.

Itis an object of this invention to provide a modified form of the VanWagener et al. rotary take-up having an easier and gentleraction on the needle thread so as to further minimize thread breakage and to enable a sewing machine to operate with threads which are. more .delicate than has been heretofore'possible. 'In the Van Wagener et 'al. construction of US. Pat.- ent No. ,636,464, the thread controlling' edge which controls the needle thread during-stitch setting is arcuate and is disposed so that atistitchsettingtime, the needle thread loop distended by the. takeaup can be in engagement with the thread controlling edge anywhere .along its length Without requiring more or. less thread. "With this wide range of possible positions of the thread loop along the thread controlling edge the stitches will beset each in the same fashion when the thread controlling edge reaches the predetermined stitch setting position.

It is an object of this invention to provide a rotary thread engaging member having a thread controlling edge formed to provide an, extremely narrow range of positions of a thread loop at the stitch setting point,

2,882,848 Patented Apr. 21, 1959 ICC and showing the rotary hook diagrammatically, illustrating the position of the stitch-forming and threadcontrolling elements at the stitch setting point and at a point immediately subsequent to stitch setting respectively,

Fig. 5 represents a rear elevational view of the take up member per se, that is, a view of the take-up member taken from the right in Fig. l,

Fig. 6 represents an enlarged front elevational view of the take-up member per se with the thread confining finger being sectioned to expose the thread controlling edge, and

Fig. 7 represents an enlarged front elevational view of the thread controlling arm portion of a modified form of take-up member.

Referring to Figs. 1 and 2, the rotary thread take-up of this invention is applied to a sewing machine having a conventional frame including a work supporting bed 11 and a hollow bracket arm 12 overhanging the bed and sustained by a standard 13. A main shaft 14 journaled in the bracket arm is drivingly connected with whereby Without impairing the consistency with which v the stitches are set, a gentler and smoother action on the thread is obtained.

With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which: Fig. 1 represents a vertical cross-sectional view ofthe sewing head portion ofa sewing machine having our improved form of rotary thread take-up mechanism apz plied thereto.

Fig. 2 represents a left end elevational view of the sewing machine of Fig; 1 with portions of the machine frame; and of the take-up guard in section,-

- Figs. 3 and 4 are left end elevational views of -the sewing machine head with the take-up guard removed and rotated at one half the speed of a'bed shaft 15 journaled in the bed 11. A counterbalanced crank member 16 fast' on the main shaft is embraced by one extremity of a driving link 17 of which the opposite extremity is constrained to reciprocatory motion by a guide slot 18 in the bracket arm and is pivotally secured to a needle bar 19. The needle bar is journaled for endwise reciprocation in bushings 20-20 in the bracket arm and carries at its lower extremity a needle 21. Cooperating with the needle in the formation of lock-stitches is a rotary hook 22 fast on the bed shaft 15. Also carried beneath the bed is a conventional drop feed mechanism including a serrated feed dog 23 which operates through slots in a throat plate 24 set into the bed and is opposed by a presser foot 25 carried by a spring loaded presser bar 26 supported in the bracket arm.

v The free extremity of the hollow bracket arm 12 is closed by a cover plate 27 secured by screws 2828. A circular aperture 29.formed in the cover plate is disposed substantially concentric about the axis of the main shaft 14 and accommodates a supporting disk 30 to which a take-up member, indicated generally as 31, is secured by three. screws 32. The take-up supporting disk 30 is gripped between a clamp block 33 and the shouldered extremity 34 of the needle bar driving crank member by which arrangement an angular or timing adjustment of the take-up member 30 maybe effected and r the parts locked in selected position of adjustment by fastening screws 3535. This clamp arrangement for providing timing adjustments to the take-up member is more fully described in the US. patent of Hale No. 2,686,486, August 17, 1954, to which reference may be had for a complete description thereof. y

Secured on the exposed face of the cover plate 27 beneath the take-up member as by fastening .bolts 36-36, is an annular take-up guard 37 which extends upwardly of the fastening bolts 36 in spaced relation to the cover plate to define therebetween an upwardly open slot 38 through which the needle thread gains access to the take-up member. As illustrated in Fig. 1, the outer face of the annular guard 37 may be covered by a dished plate 39 preferably of transparent material supported by a proboscis 40 which may be hinged or otherwise secured to the top of the annular guard so as to be readily displaceable for cleaning or adjustment of the take-up member. 1

Figs. 2, 3 and 4 illustrate the path of the needle thread through the thread controlling instrumentalities and into the seam being stitched. The needle thread is directed from a source of supply (not shown) alternately through the eyelets of a thread guide 41, through a passageway between the cover plate 27 and the bracket arm to a conventional spring-loaded thread tension device 42, over a check spring 43, around a thread guide 44, around a thread guiding pin 45 extending from the annular guard ring 37, and then into the slot 38 between the take-up guard 37 and the cover plate 27 and thus to the take-up member. From the take-up, the thread is directed through a thread guide 46 carried on the cover plate 27 and a thread guide 47 secured on the needle bar bushing 20, to the needle and thence to the work being stitched.

The take-up member 31, as best illustrated in Figs.

and 6, is preferably made of a single stamping blanked from sheet metal and then bent into appropriate shape. The take-up member comprises a body portion 50 drilled and countersunk at 51 to receive the fastening screws 32 and apertured at 52 to accommodate the clamp block 33. Extending in a direction radially outwardly from the body portion 50 is a spoke-like projection composed preferably of a pair of arms 53 and 54 which terminate in a bridge piece 55 bent outwardly at substantially a right angle from the plane of the body portion 50 and that of arms 53 and 54. The take-up member rotates in the direction indicated by the arcuate arrow in Figs. 3 and 4, and projecting from the leading end of the bridge piece 55 is a curved thread confining arm 56, and extending from the trailing end of the bridge piece is a thread confining tail 57. At the base of the spoke-like arm 53, the body portion 50 is formed with a freely projecting thread guard member or extension 58, while at the base of the arm 54 the body portion is formed with a thread guard member or finger 59 of which the free end is bent inwardly and buried in an aperture 60 in the take-up supporting disk when the take-up member is applied to the machine.

When the take-up member 31 is applied to the sewing machine as illustrated in Figs. 1 to 4, the take-up may be threaded simply by placing the thread laterally into the slot 38. The bent thread guard finger 59 and the curved thread confining arm 56 serve to guide the loop of thread to a position around the spoke-like arms 53-54 and thus act not only to keep the thread loop about the arms 53-54 during operation of the machine but also to facilitate proper insertion of the thread loop on the take-up member when the machine is threaded. When the take-up member is rotated, the thread loop on the take-up is alternately expanded and permitted to reduce as it plays back and forth lengthwise of the spoke-like arms 53-54 between the thread guard members 58 and 59 and the bridge piece 55, with the leading edge 61 of arm 53 providing a cam-like control of the size of the thread loop while the thread loop is being expanded, as illustrated in Figs. 2 and 3, and the trailing edge 62 of arm 54 providing a cam-like controlled reduction of the size of the thread loop during the thread-slackening portion of the take-up cycle.

The leading edge 61 of the thread controlling arm 53 is bounded at its outer extremity by an outer thread confining throat'63 defined by the juncture of the arm 53 with the curved thread confining arm 56 and at its inner extremity by an inner thread confining throat 64 defined by the juncture of the arm 53 with the thread guard extension 58 of the body portion of the take-up member. When expansion of the loop of needle thread is begun by the take-up, as illustrated in Fig. 2, the bridge piece 55 of the take-up member is at the bottom of its circular path of motion and the thread loop is arranged over the thread controlling edge 61 of the arm 53 and constrained in the outer thread confining throat 63. As the stitching cycle progresses and rotary motion of the take-up member continues, the thread loop moves in a direction inwardly along the thread controlling edge 61 first to the stitch setting position illustrated in Fig. 3 and thereafter to the position illustrated in Fig. 4 in which the thread loop has been shifted into the inner thread confining throat 64 and in which slack thread is provided suflicient to allow formation of the succeeding stitch.

In accordance with this invention, the precise and consistent action of the take-up on the thread by which the stresses in the thread may be maintained at a minimum is derived by virtue of the form and arrangement of the leading edge 61 of the take-up arm 53. As best illustrated in the enlarged view of the take-up member illustrated in Fig. 6, the leading edge 61 does not follow a continuous arcuate path as does the leading edge in the disclosure of the Van Wagener et a1. Patent No. 2,636,464. In the present invention, the leading edge 61 is formed between its extremities as defined by the outer and inner thread confining throats 63 and 64, respectively, with a thread detaining means which has for its purpose the definition of a precise point along the leading edge at which the loop of thread will cross when stitch setting occurs. In the preferred embodiment of the invention, the leading edge 61 is divided into three distinct portions, that is, an inner portion 71 extending from the inner thread confining throat 64 to a point intermediate the throats 64 and 63, an outer portion 81 extending from the outer throat 63 to a point intermediate the throats 63 and 64, and a thread detaining portion 91 joining the inner and outer portions 71 and 81. The slope or inclination of the thread detaining portion 91 is difierent from that of either the inner or outer portions so that the thread detaining portion 91 will form, in effect, a shelf along the leading edge 61 onwhich the thread loop will be caught during expansion of the thread loop and detained until immediately after stitch setting.

As indicated in Fig. 3 in which the parts are illustrated in the position occupied during the stitch setting period, the thread detaining portion 91 of the thread controlling edge is disposed substantially normal to an imaginary line bisecting the angle formed by the limbs of the thread loop on the take-up as defined by the thread guides 45 and 46 and, therefore, the sum of the distances from the edge 61 to the thread guides 45 and 46 is substantially constant for any point along the thread controlling portion 91. During stitch setting, however, the inner and outer portions 71 and 81 of the thread controlling edge 61 are inclined sharply with respect to the imaginary line bisecting the limbs of the thread loop and, therefore, the sum of the distances from said edge portions 71 and 81 to both of said thread guides 45 and 46 decreases along said edges toward the inner thread confining throat 64. It follows, therefore, that when the take-up member arrives at stitch setting position, as illustrated in Fig. 3, the thread loop will be moved to a point where it crosses the edge 61 at the thread detaining portion 91 because along the outer portion 81 of the thread controlling edge, the summation of lengths of thread from the thread guides 45 and 46 to the portion 81 will decrease inwardly along the edge. The inclination of the outer portion 81 will, in effect, urge the thread loop with a cam-like action onto the thread detaining portion 91. The detaining portion 91 will exert no camming action on the thread until after stitch setting and then, as illustrated in Fig. 4, the thread detaining portion 91, having moved to a position inclined with respect to the imaginary line bisecting the angle formed by the link of thread loop as defined by the thread guides 45 and 46, will spill the thread loop quickly into the inner thread confining throat 64. Since with this construction, the thread detaining portion 91 constitutes only a small portion of the entire thread controlling edge 61, any delay in the spilling of the thread loop after stitch setting because of differences in friction or the like will be exceedingly small and insignificant.

In order for the thread detaining portion 91 to define a shelf forthe retention of the thread loop until after er the leading edge'be disposed entirely on the trailing side of a line whichis anoutward continuation of the inner portion 71 of the leadingedge. As illustrated in Fig. 6 the line xx represents the continuation of the inner portion 71 of the thread controlling edge 61. It will be noted in Fig. 6 that the outer portion 81 is disposed entirely on the trailing side of theline .x-x taken with respect to the normal direction of rotation of the take-up member as indicated bythe arcuate arrow.

Fig. 7 illustrates the spoke-like arm 53' of a modified form of take-up element embodyingthe features of this invention. The version illustrated in Fig. 7 is intended for use on a sewing machine similar to that illustrated in Figs. 1 to 4 but in which the thread guiding pin 45 is removed so that the thread loop to the take-up member is {defined by the thread guides 44 and 46.

The parts illustrated in Fig. 7 will be indicated by prime numbers corresponding to the counterparts in the version of Figs. 1 to 6. Although the configuration of the leading edge 61' of the version illustrated in Fig. 7 differs from that of the remaining figures, a counterpart exists for each of the portions discussed above in connection with the form illustrated in Fig. 6. Thus, in the form illustrated in Fig. 7, the leading edge 61' is bounded at its outer extremity by an outer thread confining throat 63' and at its inner extremity by an inner thread confining throat 64'. A thread detaining portion 91' is provided on the leading edge 61 between an outer portion 81' and in inner portion 71'. As in the embodiment of Figs. 1 to 6, the inner portion 71 of the modified form illustrated in Fig. 7 is preferably formed adjacent to the thread detaining portion 91' with a contour substantially coincident with a straight line x-x, while the outer portion 81 is formed slightly concave having a radius of curvature as indicated at R The outer portion 81, moreover, is disposed on the trailing or rearward side of the line xx considered in the direction of rotation of the take-up member 31 as indicated by the arrow in Fig. 7.

In the version illustrated in Fig. 7, the inner portion 71" of the leading edge 61' is cut away slightly from 00- incidence with the line x-x at the inner thread confining throat 64' thus making the throat 64' more pronounced. The purpose of this cut-away portion is to provide for a more rapid giving up of the thread loop on the take-up immediately after the needle has penetrated the work fabrics, since after needle penetration, the addi tional slack thread may be accommodated in the system without the danger of the needle penetrating the needle thread. In other respects, however, the relationships bea tween the portions 71', 81 and 91 of the leading edge 61, correspond to the relationships discussed above with regard to the embodiments illustrated in the Pigs. 1-6.

This concept of providing a distinct thread detaining portion along the thread controlling edge of a rotary take-up member may be readily applied to take-ups of various and differing designs, and it will be understood that numerous changes in the construction and arrange- (ment of parts may be made from that of the preferred form illustrated and described in considerable detail herein without departing from the principles and scope as defined by the accompanying claims.

Having thus set forth the nature of the invention, what we claim herein is:

1. A sewing machine having in combination a frame, a thread carrying needle supported in said frame for end-wise reciprocatory motion, a rotary hook journaled in said frame and disposed to cooperate with said needle in the formation of lock stitches, a needle thread take-up member rotatable about a fixed axis and at a uniform angular velocity, a pair of thread guides fixed in said frame and adapted each to direct one limb of a loop of needle thread to said take-up member, and an arm extending outward from the center of movement of said take-up member and formed with a thread controlling edge in the direction of rotation thereof along which edge the loop of thread directed by said thread guides can slide, means forming an inner and outer thread confining throat on said arm one at each extremity of said thread controlling edge, said thread'controlling edge having inner and outer portions and a thread detaining portion disposed therebetween, said thread detaining portion being disposed during the stitch setting period such that the summation of the distances from said edge to both of said thread guides is constant for any pointon said thread detaining portion, the inner portion of said thread controlling edge extending from said inner thread confining throat to said thread detaining portion, and the outer portion of said thread controlling. edgeextending from said thread detaining portion to said outer thread confining throat, said inner and outer portions each being disposed during the stitch setting period such that the summation of the distances from said portions to both of said thread guides decreases along said portions toward said inner thread confining throat.

2. A rotary needle thread take-up mechanism for a sewing machine having an endwise reciprocating needle cooperating in the formation of stitches with a rotary loop taker rotating twice for each reciprocation of the needle, said take-up mechanism comprising a rotary thread take-up member, means for imparting a complete revolution to said rotary take-up member once for each needle reciprocation, a pair of thread guides carried on said sewing machine, said take-up member being adapted to act on a thread between said thread guides, an arm extending outwardly with respect to the axis of rotation of said take-up member and formed with a thread controlling edge in the direction of rotation thereof along which edge said thread can slide, means forming a thread confining throat on said arm at each extremity of said thread controlling edge, and thread loopdetaining means formed along the thread controlling edge of said arm intermediate said thread confining throats for maintaining a thread loop of constant size between said thread guides and said loop detaining means during the stitch setting period.

3. A rotary needle thread take-up mechanism for a sewing machine having an endwise reciprocating needle cooperating in the formation of stitches with a rotary loop taker rotating twice for each reciprocation of the needle, said take-up mechanism comprising a rotary thread take-up member, means for imparting a complete revolution to said rotary take-up member once for each needle reciprocation, a pair of thread guides carried on said sewing machine, said take-up member being adapted to act on a thread between said thread guides, an arm extending outwardly with respect to the axis of rotation of said rotary take-up member and formed with a thread controlling edge in the direction of rotation thereof, means forming thread confining throats on said arm one at the outer and one at the inner extremity of said thread controlling edge, an inner portion of said thread controlling edge extending from said inner thread confining throat to a point intermediate said throats, an outer portion of said thread controlling edge extending from said outer thread confining throat to a point intermediate said throats, and a thread detaining portion of said thread controlling edge joining said inner and outer portion, said thread detaining portion having an inclination different from that of either said inner or outer portions.

4. A rotary needle thread take-up mechanism for a sewing machine having an endwise reciprocating needle cooperating in the formation of stitches with a rotary loop taker rotating twice for each reciprocation of the needle, said take-up mechanism comprising a rotary thread take-up member, means for imparting a complete revolution to said rotary take-up member once for each needle reciprocation, a pair of thread guides carried on said sewing machine, said take-up member being adapted to act on a thread between said thread guides, an arm extending outwardly with respect to the axis of rotation of said rotary take-up member and formed with a thread controlling edge in the direction of rotation thereof, means forming thread confining throats on said arm one at the outer and oneat the inner extremity of said thread controlling edge, an inner portion of said thread controlling edge extending frorn'said inner thread confining throat to a point intermediate said throats, an outer portion of said thread controlling edge extending from said outer thread confining throat to a point intermediate said throats, and a thread detaining portion of said 10 thread controlling edge joining said inner and outer portions and defining a thread detaining means, said thread detaining portion having an inclination different from either said inner or outer portions, said inner portion'of the thread controlling edge having adjacent to said thread 15 2,686,486

' member and substantially parallel thereto.

References Cited in the file of this patent UNITED STATES PATENTS 705,221 Diehl et a1. July 22, 1902 705,327 Diehl et a1. July 22, 1902 739,157 Diehl et al. Sept. 15, 1903 2,636,464 Van Wagener et al. Apr. 28, 1953" Hale Aug. 17, 1954'

Images