Overlock sewing machine

Patent metadata

Field	Value
Publication number	US-9695536-B2
Application number	US-201514796967-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Jan 26, 2015
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

In an overlock sewing machine, a main shaft fixing operating shaft is provided with a differentiation ring that can be swung in a predetermined range such that, when the rotation of a main shaft is to be enabled, it is set to an enable state in a stationary state, and when the rotation of the main shaft is disabled, it is swung and shifted from the enable position. Furthermore, a looper cover open/closed detection configuration is configured by modifying a part of a typical known configuration. Such an arrangement provides an overlock sewing machine having a simple configuration that requires only a single micro switch to detect the switching between the threading mode and the sewing mode and to detect the open/closed state of the looper cover.

First claim

What is claimed is:

1. An overlock sewing machine comprising:
a swing lever portion arranged such that the swing lever portion can be swung in a predetermined range such that the swing lever is set to an enable position in a stationary state when rotation of a main shaft is to be enabled, and such that the swing lever is swung and shifted to a position away from the enable position when the rotation of the main shaft is to be disabled;
a switch that switches a motor configured to drive the main shaft between a driving enable state and a driving disable state;
a detection lever arranged such that the detection lever can be swung with a swinging axis that extends in a direction that differs from the direction in which a swinging axis of the swing lever portion extends, and configured to be swung between an operation enable position at which the switch is set to the motor driving enable state and an operation disable position at which the switch is set to the motor driving disable state, wherein the swinging axis of the detection lever is configured at a skew position with respect to the swing axis of the swing lever portion;
a detection lever spring that applies a force to the detection lever toward the operation disable position;
a cover detection shaft arranged such that it extends along a direction in which the swinging axis of the swing lever portion extends, and configured such that it can be shifted to a position so as to press and shift the detection lever from the operation disable position to the operation enable position;
a cover detection shaft spring that applies a force to the cover detection shaft so as to increase a distance between the cover detection shaft and the detection lever;
a looper cover arranged so as to cover at least a part of the looper, and configured to be opened and closed;
a pressing portion configured to be shifted together with the looper cover as a single unit, and to press the cover detection shaft such that the cover detection shaft approaches the detection lever when the looper cover is set to a closed position;
a looper cover spring that applies a force to the looper cover such that, when the looper cover is set to a closed state, the cover detection shaft is shifted against the force applied by the cover detection shaft spring and the force applied by the detection lever spring so as to shift the detection lever from the operation disable position to the operation enable position; and
an operation limiting portion that limits an operation of the detection lever according to the position of the swing lever portion such that, when the swing lever portion is set to the enable position, the detection lever can be swung and shifted to the operation enable position, and such that, when the swing lever portion is not set to the enable position, the detection lever cannot be swung and shifted to the operation enable position.

2. The overlock sewing machine according to claim 1 , comprising:
at least one looper having a receiving opening that receives a looper thread and having a hollow structure through which the looper thread can pass;
a thread insertion opening into which the looper thread is to be inserted such that the looper thread passes through the looper;
a looper conducting pipe that guides the looper thread inserted into the looper inserting opening to the receiving opening;
a slide pipe arranged between the looper conducting pipe and the receiving opening such that one end thereof is slidably fitted to the looper conducting pipe, such that the other end thereof can be shifted between a threading position at which the other end thereof is connected to the receiving opening and a sewing position at which the other end thereof is distant from the receiving opening;
a slide member configured to hold the slide pipe and to be shifted together with the slide pipe between the threading position and the sewing position, and having a long hole portion that extends along a direction in which the slide member is to be shifted, and a wide hole portion configured to have a width that is greater than that of the long hole portion, and to communicate with the long hole portion;
a slide member spring that applies a force to the slide member and the slide pipe toward the receiving opening side;
a main shaft to be rotationally driven;
a main shaft fixing plate fixed to the main shaft and having a notch at a position on an outer circumferential face that corresponds to a threading phase at which the receiving opening can be connected to the aforementioned other end of the slide pipe;
a first shaft configured such that one end thereof can be shifted between an engagement position at which the aforementioned one end thereof is engaged with the notch so as to set the main shaft to the threading phase and a retracted position at which there is a sufficient distance between the aforementioned one end thereof and the main shaft fixing plate, and such that the other end thereof has a small-diameter portion to be engaged with the long hole portion of the slide member and a large-diameter portion to be engaged with the wide hole portion of the slide member, and configured such that the small-diameter portion and the large-diameter portion can respectively be engaged with the long hole portion and the wide hole portion so as to allow the position of the slide member to be set to the threading position and otherwise the sewing position;
a second shaft configured to be relatively shifted along the axial direction of the first shaft;
a shaft spring that applies a force so as to increase a distance between the first axis and the second axis;
a shaft pin configured such that it protrudes from the second shaft, or is otherwise configured as a shaft pin engaged with the second shaft such that it can be shifted together with the second shaft as a single unit in an axial direction of the second shaft;
an engaging portion provided to the first shaft, and engaged with the shaft pin and/or the second shaft so as to receive a force that shifts the first shaft toward the main shaft fixing plate side,
wherein the swing lever portion comprises a main shaft fixing operating arm portion including a shaft pin engaging portion engaged with the shaft pin or otherwise the shaft pin itself, and a switch limiting portion that can be swung together with the main shaft fixing operating arm portion as a single unit,
and wherein the overlock sewing machine further comprises:
a main shaft fixing operating spring configured to apply a force in a direction that is switched between both directions in which the swing lever portion can be swung when the swing lever portion is swung across a neutral position;
a switch operating portion provided so as to allow a user to perform an operation; and
a switch interlocking portion comprising a switch engaging portion engaged with the switch limiting portion, and configured to operate so as to swing the swing lever portion according to an operation performed via the switch operating portion, and a slide member engaging portion that can be engaged with the slide member so as to shift the position of the slide member to the sewing position when the switch operating portion is set to the sewing position.

Assignees

• Janome Sewing Machine Co Ltd

Inventors

• Shomura Eiichi

Classifications

• D05B87/02 Primary

  with mechanical means for moving thread through needle {or looper} eye · CPC title

• D05B69/36

  Devices for stopping drive when abnormal conditions occur, e.g. thread breakage · CPC title

• D05B57/02

  for chain-stitch sewing machines, e.g. oscillating · CPC title

• D05B87/00 Primary

  Needle- {or looper-} threading devices · CPC title