US 4,589,364 AGranted

Sewing machine top feed

AssigneePegasus Sewing Machine Mfg. Co., Ltd.

InventorsKhoichi Yamamoto, Takashi Kasuda

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Abstract

A top feed device for a sewing machine has an upper feed dog movable horizontally and vertically in synchronism with operation of a lower feed dog. The upper feed dog is vertically moved by a spring for depressing an upper feed arm to which the upper feed dog is attached, and a crank engages the upper feed arm and is vertically swingable, the crank being held in engagement with the upper feed arm at all times to prevent striking engagement therewith. A swingable shaft to which the crank is fixed and a lever angularly movably mounted on the swingable shaft and swingable in coaction with a drive shaft have abutments projecting axially in confronting relation. The abutments on the shaft are urged by a spring to angularly move in one direction. The abutments on the lever which are held against the other abutments are disengaged therefrom in a circumferential direction when the upper feed dog reaches a throat plate and stops its downward movement. Then, the abutments on the lever are reversed and brought into engagement with the abutments on the shaft. A substantial portion of the swingable shaft and the lever are accommodated in a closed sewing machine body.

Claims17

Dependent claims

A top feed device for coaction with a bottom feed device having a lower feed dog in a sewing machine, said top feed device comprising:

(a) an upper feed arm supported for vertical swinging movement on a drive member adapted to be operatively coupled to the bottom feed device and movable for horizontal reciprocation, said upper feed arm having an upper feed dog mounted on a free end thereof and positioned to confront the lower feed dog;
(b) spring means for depressing the upper feed arm;
(c) a mechanism for vertically moving said upper feed dog, said mechanism including a crank swingable vertically in response to movement of a drive shaft, the crank having a slider means held in slidable engagement with said upper feed arm for vertically moving said upper feed arm in coaction with said spring means, a swingable shaft having an end, said crank being fixed to said end, a lever angularly movably supported on said swingable shaft and swingable in response to rotation of said drive shaft, and clutch means for disconnectably transmitting swinging movement of said lever to said swingable shaft, said clutch means comprising engagement portions disposed on said swingable shaft and said lever and disengageable from each other in a circumferential direction, said engagement portions on said swingable shaft being normally held against said engagement portions on said lever under the action of said spring means;
and
(d) retainer means for supporting said slider means against movement away from said upper feed arm.

2 more elements

Dependencies are inferred from the claim text.