US 5,474,004 AGranted

Rotary loop taker with a detachable loop seizing point

AssigneeBakron Corp.

InventorPaul Badillo

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Abstract

A rotary loop taker for a lock-stitch sewing machine having a detachable loop seizing point and detachable raceway-defining portion. The inwardly facing vertical wall in the middle and final portions of the bobbin case raceway is defined by a replaceable member that in all cases is formed separately from the annular frame. The lower ledge in the middle and final portions of the raceway is defined by a member that may be formed separately from the annular frame, or may be formed integrally with the frame. In the preferred embodiments of the rotary loop taker, the two members referred to may both be formed integrally with the detachable loop seizing point, or only the member that defines the vertical wall may be formed integrally with the loop seizing point. If desired, neither of the two members mentioned may be formed integrally with the detachable loop seizing point.

Claims30

Dependent claims

A rotary loop taker for rotation about a generally cylindrical bobbin case maintained in a fixed position in a lock-stitch sewing machine below the take-up device of said machine, a side wall of said bobbin case carrying a radially extending rib for engaging an inwardly facing raceway on said loop taker as the loop taker rotates about said bobbin case, said raceway having a downwardly facing upper ledge, an upwardly facing lower ledge, and an inwardly facing vertical wall located between said upper ledge and said lower ledge, which comprises:

(a) a frame of substantially annular construction, said frame having a cut-away portion along one segment of its circumference, said cut-away portion being defined by opposing end walls of said frame facing upon said cutaway portion;
(b) means for rotatably supporting said frame in said lock-stitch sewing machine;
(c) a detachable loop seizing point with spaced ends mounted on said frame having generally the same curvature as said substantially annular frame, said detachable loop seizing point:
(i) being integrally formed from one end of said detachable loop seizing point to the other end of said detachable loop seizing point,
(ii) having a single tapered, smoothly shaped, integrally formed forward end,
(iii) having a supporting lug that extends directly downward from immediately behind said forward end into said cut-away portion of said frame, and
has a rear surface that abuts at all times, throughout substantially the entire height of the lug, the surface of the one of said frame end walls that is at a trailing end of said cut-away portion during forward rotation of said frame,
said forward end of the detachable loop seizing point extending forwardly of said downwardly extending lug into said cut-away portion of said frame,
(iv) having a rear portion extending rearwardly of said lug along said annular frame, and
(v) having an inner wall and an outer wall, said inner wall:
defining an initial portion of said upper ledge of said raceway,
defining an initial portion of said lower ledge of said raceway, and
defining an initial portion of said vertical wall of said raceway;
(d) raceway-defining means carried by said substantially annular frame to define said lower ledge and said vertical wall in at least a middle portion of said raceway, at least the part of said raceway-defining means that defines said vertical wall being formed separately from said annular frame;
(e) a gib detachably secured to said frame to define said upper ledge of a final portion and said middle portion of the raceway;
and
(f) means for detachably securing said loop seizing point to said frame, said means being located entirely rearward of said tapered forward end of said loop seizing point.

14 more elements

A detachable loop seizing point in combination with raceway-defining means for use in a rotary loop taker mounted to rotate about a generally cylindrical bobbin case maintained in a fixed position in a lock-stitch sewing machine below the take-up device of said machine, a side wall of said bobbin case carrying a radially extending rib for engaging an inwardly facing raceway on said loop taker as the latter rotates about said bobbin case, said raceway having a downwardly facing upper ledge, an upwardly facing lower ledge, and an inwardly facing vertical wall located between said upper ledge and said lower ledge, said rotary loop taker including a frame of substantially annular construction, said frame having a cut-away portion along one segment of the circumference of the frame, said cut-away portion being defined by opposing end walls of said frame facing upon said cut-away portion, and also including a gib detachably secured to said frame to define the upper ledge of a middle portion and a final portion of said raceway, which comprises:

(a) a detachable loop seizing point with spaced ends that includes:
(i) a single tapered, smoothly shaped, integrally formed forward end,
(ii) a supporting lug that:
extends directly downward from immediately behind said forward end into said cut-away portion of said frame, and
has a rear surface that abuts at all times, throughout substantially the entire height of the lug, the surface of the one of said frame end walls that is at a trailing end of said cut-away portion during forward rotation of said frame,
said forward end of the detachable loop seizing point extending forwardly of said downwardly extending lug into said cut-away portion of said frame,
(iii) a rear portion extending rearwardly of said lug, said forward end, supporting lug and rear portion of the loop seizing point having generally the same over-all curvature as said substantially annular frame and being integrally formed from one end to the other end of the loop seizing point,
(iv) an inner wall and an outer wall, said inner wall:
defining an initial portion of said upper ledge of said raceway,
defining an initial portion of said lower ledge of said raceway, and
defining an initial portion of said vertical wall of said raceway;
(b) raceway-defining means defining at least one of said vertical wall and said lower ledge in said middle portion of the raceway, said means being integrally formed with said loop seizing point;
and
(c) means for detachably securing said integrally formed loop seizing point and raceway-defining means to said frame, said means being located entirely rearward of said tapered forward end of the loop seizing point.

11 more elements

Dependencies are inferred from the claim text.