Claims
- 1. A rotary loop taker for high speed rotation about a bobbin basket maintained in a substantially fixed position in a lock-stitch sewing machine below the take-up device of said machine, in which sewing machine the needle provides one of the two threads that together form said lock-stitch, said needle thread being taken off the needle in the form of a loop by the loop seizing point of said rotary loop taker as the loop taker rotates about the bobbin basket, the side wall of said bobbin basket carrying a radially extending rib for engaging the loop taker as the latter rotates about said bobbin basket, which rotary loop taker comprises:
- (a) a frame of substantially annular construction, said frame having an axis of rotation located generally perpendicular to the frame, the radially inner wall of said frame defining the lower ledge of the middle and final portions of a raceway to receive said radially extending rib on the side wall of said bobbin basket, said frame having a cut-away portion along one segment of its circumference to provide space for the needle thread to exit from the loop seizing point of the rotary loop taker as said thread is pulled off the loop seizing point, said cut-away portion being defined by an end wall of said frame and the forward portion of said loop seizing point facing upon said cut-away portion;
- (b) a frame support member extending crosswise of said substantially annular frame, with one edge portion of said support member facing said cut-away portion of the frame;
- (c) means for supporting said substantially annular frame for rotation of the same about its said axis of rotation, and about said bobbin basket, during operation of said sewing machine;
- (d) a gib secured to said frame to define the upper ledge of said middle and final portions of said bobbin case raceway,
- (e) a loop seizing point having a tapered forward end including a base and a free end, with the largest transverse dimensions of said tapered forward end being at said base, said base lying immediately adjacent said substantially annular frame, and the smallest transverse dimensions of said tapered forward end being at its said free end, said free end extending circumferentially forward into said cut-away portion of said substantially annular frame; and
- said tapered forward end of the loop seizing point including on its surface radially inner and outer lower quadrants, and radially inner and outer upper quadrants, each of said quadrants extending from said base to said free end of said tapered forward end,
- said substantially annular frame forming a smoothly curved junction, free of any seams or joints, with the two lower quadrants of said tapered forward end of the loop seizing point, for guiding said loop of needle thread as it moves from said free end of the tapered forward end down to the rearwardmost position assumed by said loop on the portion of said tapered forward end adjacent its base, and back to said free end again,
- said rotary loop taker being formed of two different materials, one of which is metal of a predetermined type,
- said free end of said tapered forward end of the loop seizing point being formed of solid metal of said predetermined type, said solid metal free end extending circumferentially rearward a distance at least equal to a substantial fraction of the distance from the free end to the base of said tapered forward end,
- the radially outer wall of the tapered forward end of the loop seizing point including a first surface portion of metal of said predetermined type extending from said solid metal free end through the above described smoothly curved junction, said metal surface portion forming the entire exterior surface of that part of said radially outer lower quadrant of said tapered forward end that lies circumferentially rearward of said solid metal free end, and forming the exterior surface of at least that part of the approximate bottom one-quarter of said radially outer upper quadrant that lies circumferentially rearward from said solid metal free end,
- the radially inner wall of said tapered forward end of the loop seizing point including a second surface portion of metal of said predetermined type extending from said solid metal free end through said smoothly curved junction, said metal surface portion forming the entire exterior surface of that part of said radially inner lower quadrant of said tapered forward end that lies circumferentially rearward of said solid metal free end, and forming the exterior surface of at least about the forward one-half of the part of said radially inner upper quadrant that lies circumferentially inward of said solid free end,
- said first and second metal surface portions each having a substantial thickness relative to the maximum transverse dimension of said base of the tapered forward end of the loop seizing point,
- said solid metal free end and said first and second metal surface portions being integrally formed with each other and with the above described smoothly curved junction,
- (f) means formed of metal for anchoring said loop seizing point to said crosswise support member, said metal anchoring means being integrally formed with said solid metal free end and said first and second metal surface portions of said tapered forward end of the loop seizing point and with said smoothly curved junction, said anchoring means extending inward toward the central portion of the crosswise support member from the bottom portion of said annular frame for a substantial distance away from said tapered forward end of the loop seizing point, and being embedded in said crosswise support member, with a plurality of contact surfaces lying within said support member,
- a substantial part of said rotary loop taker being formed of a second material other than said metal of a predetermined type, said second material comprising a flowable, hardenable material surrounding all said contact surfaces of said metal anchoring means that lie within said crosswise extending support member of the rotary loop taker, in full, intimate contact with said surfaces, and filling all portions of said rotary loop taker not occupied by components thereof that are formed of metal, in full, intimate contact with said metal components, to form a secure, permanent attachment between said metal components and the remainder of the rotary loop taker, the resulting exterior surface of said loop seizing point being smooth throughout its entire area.
- 2. The rotary loop taker of claim 1 in which said solid metal free end on said tapered forward end of the loop seizing point extends circumferentially rearward from the forwardmost portion of said free end at least a distance approximately equal to 1/4 the distance from said forwardmost portion to said base of the loop seizing point.
- 3. The rotary loop taker of claim 1 in which said first metal surface portion that forms at least a part of the exterior surface of the radially outer upper quadrant of said tapered forward end of the loop seizing point extends throughout the entire area of said quadrant that lies between said solid metal free end and said base of the loop seizing point.
- 4. The rotary loop taker of claim 1 in which said second metal surface portion that forms at least a part of the exterior surface of the radially inner upper quadrant of said tapered forward end of the loop seizing point extends throughout the entire area of said quadrant that lies between said solid metal free end and the base of the loop seizing point.
- 5. The rotary loop taker of claim 1 in which said first and second metal surface portions extend throughout the entire exterior surface of said tapered forward end of the loop seizing point that lies between said solid metal free end and said base of the tapered forward end adjacent said substantially annular frame.
- 6. The rotary loop taker of claim 5 in which the entire tapered forward end of the loop seizing point is formed of solid metal of said predetermined type from its free end to its base adjacent said substantially annular frame.
- 7. The rotary loop taker of claim 6 in which said substantially annular frame includes a supporting lug integrally formed with said solid metal tapered forward end of the loop seizing point and with said metal anchoring means, which lug extends directly downward from immediately adjacent and circumferentially rearward from said tapered forward end base, the circumferentially forward portion of said lug comprising a portion of said above described smoothly curved junction.
- 8. The rotary loop taker of claim 6 in which the radially inner wall of said tapered forward end of the metal loop seizing point carries the leading edges of (a) an upper ledge that defines the upper part of the initial portion of said bobbin basket raceway, and (b) a lower ledge that defines the lower part of the initial portion of said bobbin basket raceway, said ledges being integrally formed with said tapered forward end of the metal loop seizing point.
- 9. The rotary loop taker of claim 7 in which:
- (a) said downwardly extending supporting lug includes a foot that extends from the lower portion thereof, from immediately behind said base of said tapered forward end of the loop seizing point, inwardly towards the center of said annular frame to provide a smoothly curved junction between said lug, said foot and said two lower quadrants of said tapered forward end, the surface of said smoothly curved junction being free of any joints or seams and extending radially inward beyond the base of said tapered forward end of the loop seizing point, said lug foot having a rearwardly facing surface and an inwardly facing surface,
- (b) said crosswise extending support member defines a notch, in its edge portion that faces the cut-away portion of said annular frame, in a position adjacent the radially inner wall of said frame, and
- (c) said lug foot extends inwardly and rearwardly into said notch in nesting relationship therewith, with said rearwardly and inwardly facing surfaces of said lug foot in intimate contact with the walls of said notch, to form a smooth junction between said notch and said lug foot.
- 10. The rotary loop taker of claim 7 in which:
- said downwardly extending supporting lug has a continuation portion integrally formed therewith of said metal of said predetermined type and extending below and adjacent the bottom end of said smoothly curved junction, said curved junction merging smoothly into said continuation portion, the forward portion of said continuation portion that faces said cut-away portion of the annular frame being located circumferentially forward of said edge portion of the crosswise extending support member that faces said cut-away portion of the annular frame and having a smoothly shaped guide surface for any needle thread loop that falls slack from said loop seizing point and moves downward to the lowest position it occupies during normal operation of the sewing machine, to provide a smoothly shaped barrier to keep any such slack loop that moves downward to said lowest position from passing partly or entirely beneath said supporting lug which extends downward from behind said tapered forward end of the loop seizing point.
- 11. The rotary loop taker of any of claims 1, 5, 7 or 8 in which said loop seizing point includes a metal portion extending rearwardly from said tapered forward end of the loop seizing point, said rearwardly extending portion being integrally formed with the metal portions of said tapered forward end and with said metal anchoring means, and said rearwardly extending portion having an integral shoulder on its bottom inward edge forming the upper ledge of the initial portion of said raceway.
- 12. The rotary loop taker of any of claims 1, 5, 7 or 8 in which all parts of the rotary loop taker that are not formed of metal are formed of said second material, which comprises a flowable, hardenable plastic that forms a hard polymeric material having a smooth, slippery exterior surface.
- 13. The rotary loop taker of claim 12 in which said flowable, hardenable plastic material includes a solid lubricant dispersed therein.
- 14. The rotary loop taker of claim 12 in which said crosswise frame support member is formed in part of metal.
- 15. The rotary loop taker of claim 12 which includes a metal arcuate member that together with said gib forms a retaining ring extending substantially around the outer wall of said loop taker on the exterior thereof, to restrain radial expansion of the plastic material included in said substantially annular frame.
- 16. The rotary loop taker of claim 6 in which said metal anchoring means has at least one side wall that (a) extends in a first predetermined direction away from said tapered forward end of the loop seizing point, then (b) extends in at least one other direction with respect to said tapered forward end, said at least one other direction extending away from said first predetermined direction.
- 17. The rotary loop taker of claim 16 in which said at least one other direction extends both away from said first predetermined direction and away from said tapered forward end of the loop seizing point.
- 18. The rotary loop taker of claim 16 in which said first predetermined direction in which said at least one side wall of the metal anchoring means extends and said at least one other direction in which said side wall extends both lie in a plane perpendicular to the axis of rotation of the rotary loop taker.
- 19. The rotary loop taker of claim 1 in which said metal anchoring means extending away from said tapered forward end of the loop seizing point has (a) a first predetermined cross-sectional area measured, in a first plane perpendicular to the direction in which the anchoring means extends from said tapered forward end, at a given distance from said tapered forward end, and (b) a larger cross-sectional area measured, in a second plane perpendicular to the direction in which the anchoring means extends from said tapered forward end, at a greater distance than said given distance from said tapered forward end.
- 20. The rotary loop taker of claim 1 in which said metal anchoring means extending away from said tapered forward end of the loop seizing point has (a) a first predetermined cross-sectional area measured in a first plane that includes the axis of rotation of the rotary loop taker, and (b) a larger cross-sectional area measured in a second plane that includes said axis of rotation and is located at a greater angular distance about said axis than said first plane from said tapered forward end of the loop seizing point.
- 21. The rotary loop taker of claim 1 in which at least a portion of said inwardly extending metal anchoring means is fully embedded in and fully encased by said crosswise support member.
- 22. The rotary loop taker of claim 1 in which said inwardly extending metal anchoring means extends in a direction away from said tapered forward end to a point adjacent the opposite side of the annular frame.
- 23. The rotary loop taker of claim 1 which includes a second metal anchoring means integrally formed with said loop seizing point, said second anchoring means extending rearwardly from said tapered forward end of the loop seizing point in the circumferential direction and fully embedded in and fully encased by said substantially annular frame, said rearwardly extending portion having a plurality of contact surfaces lying within said annular frame with which said second, flowable, hardenable material lies in full, intimate contact.
- 24. The rotary loop taker of claim 23 in which said rearwardly extending metal anchoring means has (a) a predetermined cross-sectional area measured in a first plane, said first plane being located at a given angular distance from said tapered forward end of the loop seizing point and including the axis of rotation of the rotary loop taker, and (b) a larger cross-sectional area measured in a second such plane located at a greater angular distance about said axis of rotation than said given distance from said tapered forward end of the loop seizing point.
- 25. The rotary loop taker of claim 1 in which said means for supporting said substantially annular frame for rotation about said bobbin basket comprises a hub formed of said metal of a predetermined type, and said inwardly extending metal anchoring means is integrally formed with said hub.
- 26. The rotary loop taker of claim 5 in which said tapered forward end of the loop seizing point includes a forwardly tapered slot in its interior and a forwardly tapered tongue extending from and integral with said substantially annular frame, with the external walls of said tongue in full, intimate contact with the internal walls that define said slot, said tongue being formed of said flowable, hardenable second material.
- 27. The rotary loop taker of claim 1 in which said metal anchoring means extends inward toward the central portion of said crosswise support member from said tapered forward end of the loop seizing point for at least a distance substantially equal to the internal radius of said annular frame.
- 28. The rotary loop taker of claim 1 in which the cross-section of said metal anchoring means, measured transverse to the direction in which the said anchoring means extends away from said tapered forward end of the loop seizing point, is elongated in shape.
- 29. The rotary loop taker of claim 1 which includes means for balancing the distribution of the weight of the rotary loop taker angularly and radially about its said axis of rotation, said balancing means being positioned generally on the opposite side of said substantially annular frame from said tapered forward end of the loop seizing point.
- 30. The rotary loop taker of claim 29 in which said balancing means positioned on the opposite side of said substantially annular frame from said loop seizing point is a metal counterweight.
- 31. The rotary loop taker of claim 30 in which said crosswise frame support member includes a part formed of metal, which metal part and said metal counterweight, said metal anchoring means, said downwardly extending supporting lug, and said solid metal tip are all integrally formed with each other.
- 32. The rotary loop taker of claim 29 in which said balancing means is comprised of metal and is integrally formed with said metal anchoring means.
- 33. A rotary loop taker for high speed rotation about a bobbin basket maintained in a substantially fixed position in a lock-stitch sewing machine below the take-up device of said machine, in which sewing machine the needle provides one of the two threads that together form said lock-stitch, said needle thread being taken off the needle in the form of a loop by the loop seizing point of said rotary loop taker as the loop taker rotates about the bobbin basket, the side wall of said bobbin basket carrying a radially extending rib for engaging the loop taker as the latter rotates about said bobbin basket, which rotary loop taker comprises:
- (a) a frame of substantially annular construction, said frame having an axis of rotation located generally perpendicular to the frame and having a cut-away portion along one segment of its circumference to provide space for the needle thread to exit from the loop seizing point of the rotary loop taker as said thread is pulled off the loop seizing point, said cut-away portion being defined by an end wall of said frame and the forward portion of said loop seizing point facing upon said cut-away portion, the radially inner wall of said frame defining the lower ledge of the middle and final portions of a raceway to receive said rib that extends radially from the side wall of said bobbin basket;
- (b) a frame support member extending crosswise of said substantially annular frame, with one edge portion of said support member facing said cut-away portion of the frame, said edge portion defining a notch adjacent the radially inner wall of said substantially annular frame;
- (c) means for supporting said substantially annular frame for rotation of the same about is said axis of rotation, and about said bobbin basket, during operation of said sewing machine;
- (d) a gib secured to said frame to define the upper ledge of said middle and final portions of said bobbin basket raceway;
- (e) a loop seizing point having a tapered forward end including a base and a free end, with the largest transverse dimensions of said tapered forward end being at said base, said base lying immediately adjacent said substantially annular frame, and the smallest transverse dimensions of said tapered forward end being its said free end, said free end extending circumferentially forward into said cut-away portion of said substantially annular frame,
- said loop seizing point having generally the same circumferential curvature as said substantially annular frame,
- said tapered forward end of the loop seizing point being formed entirely of solid metal from its free end to its base adjacent said substantially annular frame and being integrally formed with the hereinafter described smoothly curved junction;
- (f) a downwardly extending supporting lug included in said substantially annular frame, said lug being integrally formed with said tapered forward end of the loop seizing point and extending directly downward from immediately behind said tapered forward end base,
- said downwardly extending supporting lug forming a smoothly curved junction, free of any seams or joints, with said tapered forward end of the loop seizing point, for guiding said loop of needle thread as it moves from said free end of said tapered forward end down to the rearwardmost position assumed by said loop on the portion of said tapered forward end adjacent its base, and back to said free end again,
- the radially inner walls of said solid metal tapered forward end of the loop seizing point and of said downwardly extending metal supporting lug carrying the leading edge of (i) an upper ledge that defines the upper part of the initial portion of said bobbin case raceway and (ii) a lower ledge that defines the lower part of the initial portion of said bobbin case raceway, said ledges being integrally formed with said tapered forward end of the loop seizing point and said metal supporting lug;
- (g) a metal portion extending rearwardly from said tapered forward end of the loop seizing point at the upper portion of said substantially annular frame, said rearwardly extending portion having an integral shoulder on its bottom inward edge forming the initial portion of said upper ledge;
- (h) means formed of metal for anchoring said loop seizing point to said crosswise support member, said metal anchoring means being integrally formed with said tapered forward end of the loop seizing point, said downwardly extending supporting lug and said smoothly curved junction, said anchoring means (i) extending inward from the bottom portion of said substantially annular frame and away from said tapered forward end of the loop seizing point at least a distance substantially equal to the internal radius of said frame, and (ii) being embedded in and fully encased by said crosswise extending support member of the rotary loop taker, with a plurality of contact surfaces lying within said crosswise extending support member,
- said anchoring means having (i) a first predetermined cross-sectional area measured, in a first plane perpendicular to the direction in which the anchoring means extends away from said tapered forward end, at a given distance from said tapered forward end, and (ii) a larger cross-sectional area measured, in a second plane perpendicular to the direction in which the anchoring means extends away from said tapered forward end, at a greater distance than said given distance from said tapered forward end;
- (i) means for balancing the distribution of the weight of the rotary loop taker angularly and radially about its said axis of rotation, said balancing means being positioned generally on the opposite side of said substantially annular frame from said tapered forward end of the loop seizing point; and
- (j) a metal arcuate member that together with said gib forms a retaining ring extending entirely around the outer walls of said rotary loop taker on the exterior thereof, with all portions of said retaining ring being positively connected to each other, to restrain radial expansion of the hereinafter mentioned polymeric material included in said substantially annular frame,
- said rotary loop taker being formed of two different materials, the first of which is a metal of a predetermined type and the second comprising a flowable, hardenable plastic that forms a hard polymeric material having a smooth, slippery exterior surface,
- said tapered forward end of the loop seizing point, downwardly extending supporting lug, leading edges of raceway ledges, lug foot, rearwardly extending portion, and anchoring means all being integrally formed of said metal of said predetermined type, and a substantial part of the rotary loop taker being formed of said flowable, hardenable plastic, said flowable, hardenable plastic material surrounding all said exposed contact surfaces of said metal anchoring means that lie within said crosswise extending support member, in full, intimate contact with said surfaces, and filling all portions of said rotary loop taker not occupied by components thereof that are formed of metal, in full, intimate contact with said metal components, to form a secure, permanent attachment between said metal components and the remainder of the rotary loop taker, the resulting exterior surface of said loop seizing point being smooth throughout its entire area.
- 34. A rotary loop taker for high speed rotation about a bobbin basket maintained in a substantially fixed position in a lock-stitch sewing machine in which the sewing machine needle provides one of the two threads that together form said lock-stitch, said needle thread being taken off the needle in the form of a loop by said rotary loop taker as the rotary loop taker rotates about the bobbin basket, which rotary loop taker comprises:
- (a) a substantially annular frame with a cut-away portion along tis circumference;
- (b) means for supporting said substantially annular frame for rotation about the bobbin basket during operation of the sewing machine;
- (c) a loop seizing point attached to the substantially annular frame with a tapered forward end extending into said cut-away portion for taking said loop off the needle, said tapered forward end having a solid metal free end and a substantially metal surface from said free end to a base end attached to the annular frame;
- (d) a substantially annular metal ring attached to the outer wall of said substantially annular frame for retaining the loop taker against radial expansion and creep during rotation about said bobbin basket, a portion of said annular ring being a metal gib attached to the substantially annular frame for retaining said bobbin basket and another portion of said annular ring being a metal arcuate member the inner wall of which conforms approximately to the outer wall of said annular frame, said metal arcuate member having a cam in the axial direction of said frame for facilitating the passing of said loop over the bobbin basket during rotation of the loop taker; and
- (e) a fin attached to said metal arcuate member and extending circumferentially rearwardly and radially inwardly into said cut-away portion for directing air radially inwardly between said annular frame and said bobbin basket during operation of the sewing machine,
- said loop taker being substantially of a flowable, hardenable polymeric material.
Parent Case Info
This application is a continuation of application Ser. No. 07/025,452, filed Mar. 13, 1987 and now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (5)
Number |
Date |
Country |
933601 |
Sep 1955 |
DEX |
1213898 |
Nov 1959 |
FRX |
60-261490 |
Dec 1985 |
JPX |
88625 |
Nov 1956 |
NOX |
872822 |
Jul 1961 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
25452 |
Mar 1987 |
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