Sewing Machine

Abstract

Illuminating device includes a plurality of LEDs positioned at intervals so as to form a linear LED array generally corresponding to an array line along which needle bars are provided, and a lens for gathering emitted light from the LEDs to thereby generate a linear light beam corresponding to the array line. The illuminating device provided in each machine head is controlled, independently of the illuminating devices of the other machine heads, in response to an operating state of the machine head. Thus, it is possible to not only generate, at low cost, a linear light beam suited to illumination of areas around the points of a plurality of needles arranged in a linear array, but also appropriately control the needle point illumination for the plurality of machine heads.

Description

TECHNICAL FIELD [0001] The present invention relates to sewing machines provided with an illuminating device for illuminating areas around needle points immediately beneath a machine head. BACKGROUND ART [0002] Heretofore, there have been known sewing machines provided with an illuminating device for illuminating areas around the points of needles (i.e., needle points) and surface of a sewing fabric so that needle threading operation and inspection of a pattern sewn on a sewing fabric can be performed with ease. Japanese Patent Application Laid-open Publication No. HEI-11-253685 discloses a sewing machine which includes a plurality of needle bars provided on a machine head, and an illuminating device for illuminating an area around the point of a needle fixed to the lower end of each needle bar and surface of a sewing fabric. The illuminating device, which is capable of emitting a linear light beam generally along an array line along which the needle bars are disposed, comprises, fo...

AI Technical Summary

Benefits of technology

[0006] In view of the foregoing, it is an object of the present invention to provide a sewing machine provided with an illuminating device that can generate, at low cost, a linear light beam suited to illumination of areas around the points of individual needles disposed in a linear array (i.e., needle point illumination). It is another object of the present invention to provide a sewing machine which can appropriately control needle point illumination for a plurality of machine heads.

[0009] By the provision of the illuminating device constructed in the aforementioned manner, the emitted light from the plurality of the unitary light sources disposed at intervals can be gathered, via the lens, to be converted into a linear light beam so that the areas around the points of the individual sewing needles can be illuminated evenly over a wide range with a small number of the unitary light sources, which can thereby minimize the manufacturing cost of the illuminating device. Further, in cases where the present invention is applied to a multi-head sewing machine, the necessary manufacturing cost can be reduced synergistically. Furthermore, where chip LEDs (Light Emitting Diodes) are used as the unitary light sources, the unitary light sources not only can be reduced in size and increased in operating life but also can effectively prevent undesired heat production.

[0010] By controlling each of the machine heads in response to an operating state of the machine head, it is possible to perform optimal needle-point illumination control on each of the machine heads, independently of the other machine heads, in the multi-head sewing machine, in response to the operating state of the machine head. For example, when only one or some of the plurality of machine heads are to be caused to operate with the other machine heads in a non-operating state, it is possible to perform control for illuminating the illuminating devices of only the machine heads that are to be caused to operate. Alternatively, when the sewing machine has stopped operating or shut down due to occurrence of a thread breakage, it is possible to perform control for illuminating only the illuminating device of the machine head where the thread breakage has occurred. In this way, a human operator is allowed to advantageously identify, at a glance, each operating or non-operating machine heads, and perform sewing operation and illumination control with no waste.

Problems solved by technology

However, because illumination (light emission) by the LED lamp as a unitary light source is limited to a small spot-shaped range, a multiplicity of LED lamps have to be disposed in a linear array with almost no gap in order to illuminate areas around the points of the individual needles of a multi-needle sewing machine, which would inevitably require an increased cost.

With a multi-head, multi-needle type sewing machine including a plurality of multi-needle type machine heads, the necessary cost would increase in proportion to the number of the machine heads.

Thus, in multi-head sewing machines provided with a plurality of machine heads, it has of course been impossible to control the illuminating device of each of the machine heads independently of the illuminating devices of the other machine heads, and it has also been impossible to control the individual illuminating devices in response to operating states of the corresponding machine heads.

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