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

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

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, for example, a cold cathode fluorescent lamp or planar light-emitting member formed in a linear shape, or a plurality of high-intensity dot-shaped light-emitting members (e.g., LEDs) disposed in a linear array. With such an illuminating device capable of emitting a linear light beam, it is possible to sufficiently illuminate the area around the point of each needle and surface of the sewing fabric.

Also known are sewing machines constructed to control the illuminating device in response to an operating state of the machine. Japanese Patent No. 2900549 discloses a sewing machine which, when an anomaly or abnormal condition has been detected by an abnormal condition detection means that detects false operation, accident (e.g., thread breakage) or the like, changes the color of the light emitted from the illuminating device to inform of the abnormal condition. Further, Japanese Patent Application Laid-open Publication No. HEI-6-91085 discloses another type of automatic sewing machine which detects a start and end of automatic sewing so as to deilluminate the illuminating device upon detection of the start of automatic sewing and illuminate the illuminating device upon detection of the end of the automatic sewing; in this way, this sewing machine can spare a human operator the trouble of operating the switch of the illuminating device in order to save power consumption.

In recent years, there has been a tendency to use, as the illuminating device for illuminating an area around a needle point and surface of a sewing fabric, an LED lamp that can be significantly reduced in size and increased in operating life and that can effectively prevent undesired heat production. 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.

On the other hand, in the conventionally-known sewing machine of the type constructed to control the illuminating device in response to an operating state of the sewing machine as disclosed in Japanese Patent No. 2900549 or Japanese Patent Application Laid-open Publication No. HEI-6-91085, only one illuminating device is controlled in response to an operating state of the machine. 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.

DISCLOSURE OF THE INVENTION

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.

The present invention provides an improved sewing machine provided with a multi-needle machine head having a plurality of needle bars disposed in a straight or curved linear array, which includes an illuminating device for illuminating an area around a point (needle point) of a sewing needle fixed to the lower end of each of the needle bars. The illuminating device comprises: a plurality of unitary light sources disposed at intervals, or with some gaps therebetween, so as to form a linear array of the light sources generally corresponding to a needle bar array line along which the needle bars are disposed; and a lens provided for covering the plurality of unitary light sources to gather light emitted from the individual unitary light sources, to thereby generate a linear light beam corresponding to the needle bar array line.

According to another aspect of the present invention, there is provided a sewing machine provided with a plurality of machine heads, which comprises: an illuminating device provided for each of the machine heads for illuminating an area around a point of a sewing needle of the machine head; and a control section for controlling the illuminating device of each of the machine heads in response to an operating state of the machine head.

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.

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.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing an outer appearance of a multi-head, multi-needle embroidery sewing machine in accordance with an embodiment of the present invention;

FIG. 2 is a front view of the machine head in the embodiment;

FIG. 3 is a side view, partly in section, of the machine head in the embodiment;

FIG. 4 is a perspective view showing an example of an illuminating device in the embodiment;

FIG. 5(A) is a sectional side view of the illuminating device in the embodiment, and FIG. 5(B) is a sectional side view showing a modification of the illuminating device; and

FIG. 6 is a block diagram showing a control system of a control device and illuminating devices in the embodiment of the embroidery sewing machine.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will hereinafter be described with reference to the accompanying drawings.

FIG. 1 is a view showing an outer appearance of a multi-head, multi-needle embroidery sewing machine in accordance with an embodiment of the present invention, where reference numeral 1 indicates a machine frame, and 2 a table. A plurality of (four in the illustrated example) machine heads 3 are disposed at equal intervals along a left-right horizontal direction of the sewing machine, and a needle plate 4 is disposed immediately beneath each of the machine heads 3 and at generally the same height position as the table 2. On the upper surface of the table 2, there is placed an embroidery frame 5 that is driven in front-rear and left-right horizontal directions via an X-axis drive mechanism and Y-axis drive mechanism (not shown).

FIG. 2 is a front view of the machine head 3, and FIG. 3 is a side view (partly in section) of the machine head 3. As clear from these figures, each of the machine heads 3 comprises an arm 6 fixed to the machine frame 1, and a needle bar case 7 slidably supported on the front surface of the arm 6. A plurality of (nine in the illustrated example) needle bars 8 are vertically-movably provided in the needle bar case 7, and a sewing needle 9 is fixed to the lower end of each of the needle bars 8. The needle bar case 7 is caused to slide by a not-shown change mechanism, so that a desired one of the needle bars 8 can be located at a selected position and the thus-selected needle bar 8 is driven vertically via a not-shown needle bar drive mechanism. Sewing is performed in the conventionally-known manner through cooperation between the vertically-driven needle bar 8 (sewing needle 9) and a not-shown rotary hook provided beneath the needle plate 4, and embroidery sewing is performed, on the basis of embroidery data, by the embroidery frame 5 being driven in the front-rear and left-right directions as well as by the cooperation between the vertically-driven needle bar 8 (sewing needle 9) and the rotary hook.

Illuminating device 10 is provided on a front lower surface portion of the needle bar case 7. As shown in a perspective view of FIG. 4 and sectional side view of FIG. 5(A), the illuminating device 10 generally has a semi-cylindrical shape. The illuminating device 10 includes a base plate 12 having a plurality of (four in the illustrated example) chip LEDs 11 provided at equal intervals thereon, a base member 13 fixing the base plate 12, and a lens 14 provided to cover the base plate 12. The number of the chip LEDs 11 on the base plate 12 is smaller than the number of the needle bars 8 arranged in the needle bar case 7, and the chip LEDs 11 are disposed on the base plate 12 at intervals to form a linear array (straight linear array in the illustrated example) substantially corresponding to a needle bar array line along which the needle bars 8 are disposed on the base plate 12. The lens 14 is in the form of a substantially-semicylindrical lens that can gather incoming light through its flat surface portion and emit a linear light beam through its cylindrical surface portion, and the lens 14 is formed of, for example, an acrylic material. The semicylindrical lens 14 has a total length corresponding to a total length of the needle bar array line along which the needle bars 8 are arrayed in the needle bar case 7, and the lens 14 has a shape corresponding to the array line (straight line in the illustrated example) along which the needle bars 8 are disposed. This lens 14 gathers respective emitted light from the plurality of chip LEDs 11 to thereby emit a linear light beam that can evenly illuminate areas around the points of the individual sewing needles 9. Thus, the light emission from the small number of (four in this case) chip LEDs 11 of the illuminating device 10 can evenly illuminate the areas around the points of the nine sewing needles 9 greater in number than the four chip LEDs 11 of the illuminating device 10. Whereas, in the illustrated example, the needle bars 8 are disposed in the needle bar case 7 in a straight linear array, the needle bars 8 are sometimes disposed in a curved array, such as a circular array, in which case the longitudinal shape of the illuminating device 10 is formed into a curved shape corresponding to the shape of the array of the needle bars 8; thus, an array line along which the plurality of chip LEDs 11 are arranged and the longitudinal shape of the semicylindrical lens 14 are also set to a curved line and curved shape, respectively.

As shown in FIG. 6, an illuminating drive control signal is supplied from a control device 20 of the embroidery sewing machine separately to the illuminating device 10 of each of the machine heads 3 (the four machine heads 3 are indicated in the figure by #1 to #4 for clearer distinction) via a driver 21. Illumination and deillumination (i.e., turning-on and turning-off) of each of the illuminating devices 10 is controlled by the control device 20 in accordance with an operating state of the sewing machine and an operating state of the corresponding machine head 3. For example, the control is performed in such a manner that the illuminating device 10 is deilluminated when the sewing machine is in the operating state because there is no need to illuminate the areas around the needle points, but the illuminating device 10 is illuminated when the sewing machine has stopped operating. In some case, the multi-head type sewing machine is operated with only one or some of the machine heads 3 in the operating state with the remaining machine head(s) 3 in the non-operating state. If, in such a case, the sewing machine has stopped operating, the control is performed, independently for each of the machine heads, in such a manner only the illuminating device 3 of each machine head 3 set in the operating state is illuminated with the illuminating device 10 of each machine head 3 set in the non-operating state kept deilluminated. In this way, the human operator not only can advantageously identify, at a glance, each machine head 3 to be in the operating state, but also can avoid a waste of, for example, illuminating the illuminating device 10 of any of the non-operating machine heads 3 which does not need to be illuminated. Further, by performing the illumination control independently for each of the machine heads as noted above, the control can be performed so that, when the sewing machine has stopped operating or shut down due to a thread breakage, only the illuminating device 10 of the machine head 3 where the thread breakage has occurred is illuminated. Thus, when the sewing machine has stopped operating or shut down due to a thread breakage, the human operator not only can easily identify in which of the machine heads the thread breakage has occurred, but also can avoid a waste of illuminating the illuminating device 10 of any of the other machine heads 3 where the thread has not been broken and hence there is no need to illuminate the illuminating device 10. In order to perform such head-by-head illumination control, it is only necessary to prepare and install a necessary computer program and cause a CPU of the control device 20 of the sewing machine to execute the program. In such a case, information for setting operation (i.e., activation/deactivation) of each of the machine heads 3, thread breakage detection signal of each of the machine heads 3, information indicative of a current operating state of the sewing machine, etc. are input to the control device 20 of the sewing machine, and the aforementioned illumination control is performed independently for each of the machine heads 3 by the control device 20 referring to these input signal and information. However, the present invention is not limited to such program-based illumination control, and necessary hardware circuitry for performing the illumination control may be fabricated and incorporated into the control device 20 of the embroidery sewing machine.

FIG. 5(B) shows a modification of the illuminating device. Although this modified illuminating device 15 functions similarly to the aforementioned illuminating device 10, the flat surface portion of the cylindrical lens has a slightly different shape from that of the aforementioned illuminating device 10. Namely, whereas the flat surface portion of the cylindrical lens 14 of the illuminating device 10 shown in FIG. 5(A) has a groove formed therein for positioning the chip LEDs 11, the entire flat surface portion of the cylindrical lens 16 of the illuminating device 15 shown in FIG. 5(B) is formed flat, and a spacer 17 is interposed between the flat surface portion and the base member 13 so that a slight space is formed, by the provision of the spacer 17, for appropriately positioning the chip LEDs 11. While the cylindrical lens 14 shown in FIG. 5(A) requires formation of the groove in the flat surface portion, the cylindrical lens 16 shown in FIG. 5(B) does not require formation of such a groove and thus can be simplified in construction.

Whereas, in the above-described embodiment of the invention, the illuminating device 10 (or 15) corresponding to one of the machine heads 3 is constructed as a one-piece unit, the present invention is not so limited, and a plurality of units of the illuminating device 10 (or 15) may be provided, depending on the number of the needle bars per machine head 3, by combining the units into a horizontal array along the array line of the needle bars, to thereby provide an illuminating means for the machine head 3. For example, two chip LEDs 11 may be used to provide an illuminating device unit having about half of the length of the illuminating device 10 shown in FIG. 4, and only one such short-length illuminating device unit may be provided per machine head 3 where the machine head 3 has just four or five needle bars; however, two such short illuminating device units may be provided horizontally per machine head 3 where the machine head 3 has nine needle bars. In another alternative, the illuminating device unit having about a quarter of the length of the illuminating device 10 shown in FIG. 4 may be constructed using only one chip LED 11. In such case, one chip LED 11 is positioned centrally in the longitudinal or length direction of the lens 14 (or 16), and one or more short illuminating device units, each comprising the one chip LED 11 and corresponding cylindrical lens 14 (or 16), may be provided horizontally on the base plate 12, depending on the number of the needle bars in the machine head 3. Needless to say, illuminating device units of various different lengths may be provided in a horizontal array on the base plate 12.

By the control device 20 variously setting illuminating styles (illuminating time length, blinking style, illuminating color switching style, etc.), the sewing machine of the present invention can also perform various informing functions. For example, the sewing machine of the present invention can warn the human operator that a thread breakage has occurred, by first blinking the illuminating device 10 of the machine head 3, where a thread breakage has occurred, for several seconds and then illuminating the illuminating device 10. In another alternative, when the sewing machine has shut down, for example, due to some error, all of the illuminating devices 10 may be blinked to inform the human operator of the error. In this case, the illuminating devices 10 are brought back to the normal state once the human operator clears the error on an operation panel or the like. In an alternative, there may be provided chip LEDs of a plurality of colors, so as to allowing the chip LEDs to perform various informing functions by switching between emitted light colors of the LEDs. Note that each of the unitary light sources may be any other suitable light source than the chip LEDs. Further, the present invention may be applied to any other types of sewing machines than embroidery sewing machines.

In the preferred embodiment, as having been described above, the emitted light from the chip LEDs 11 disposed at intervals or with some gaps therebetween is gathered via the lens 14 to be converted into a linear light beam so that areas around the points of the plurality of sewing needles 9 disposed in a linear array are illuminated by the linear light beam. As a result, the areas around the points of the plurality of sewing needles 9 can be illuminated appropriately by a small number of the chip LEDs 11, which can thereby minimize the necessary manufacturing cost of the illuminating devices, and the necessary manufacturing cost of the sewing machine of the multi-head, multi-needle type too can be reduced synergistically. Further, by performing illumination/deillumination control on the illuminating devices 10 of the individual machine heads 3 in accordance with the respective operating states of the machine heads 3, it is possible to illuminate only the illuminating device 10 of each operating machine head 3 or only the illuminating device 10 of a particular machine head 3 where a thread breakage has occurred, with the result that the human operator is allowed to not only readily identify each operating or particular machine head 3 but also prevent wasteful illumination of the illuminating device 10 of any of the machine heads 3 where no illumination is unnecessary.

Claims

1. A sewing machine provided with a multi-needle machine head having a plurality of needle bars disposed in a straight or curved linear array, said sewing machine including an illuminating device for illuminating an area around a point of a sewing needle fixed to a lower end of each of the needle bars, said illuminating device comprising: a plurality of unitary light sources disposed at intervals so as to form a linear array of said light sources generally corresponding to a needle bar array line along which the needle bars are disposed; and a lens provided for covering said plurality of unitary light sources to gather light emitted from individual ones of said unitary light sources, to thereby generate a linear light beam corresponding to the needle bar array line.

2. A sewing machine as claimed in claim 1 wherein said lens of said illuminating device is a single elongated cylindrical lens of a predetermined length, and said plurality of unitary light sources are disposed at intervals along a longitudinal direction of the cylindrical lens.

3. A sewing machine as claimed in claim 1 wherein said lens of said illuminating device comprises a single elongated cylindrical lens of a predetermined length, and a plurality of illuminating device units disposed in an array along the needle bar array line, each of said illuminating device units including at least one said unitary light source provided in correspondence with said illuminating device.

4. A sewing machine as claimed in any one of claims 1 wherein each of said unitary light sources is a chip LED.

5. A sewing machine as claimed in claim 1 wherein a number of said unitary light sources is smaller than a number of said needle bars in said machine head.

6. A sewing machine as claimed in claim 1 which is provided with a plurality of the machine heads each including said illuminating device.

7. A sewing machine as claimed in claim 6 which further comprises control means for controlling said illuminating device of each of the machine heads in response to an operating state of the machine head.

8. A sewing machine provided with a plurality of machine heads, said sewing machine comprising: an illuminating device provided for each of the machine heads for illuminating an area around a point of a sewing needle of the machine head; and control means for controlling said illuminating device of each of said machine heads in response to an operating state of the machine head.

9. A sewing machine as claimed in claim 8 wherein, when only one or some of said plurality of machine heads are to be caused to operate with other of said machine heads in a non-operating state, said control means performs control for illuminating the illuminating devices of only the machine heads that are to be caused to operate.

10. A sewing machine as claimed in claim 8 wherein, when said sewing machine has stopped operating due to occurrence of a thread breakage, said control means performs control for illuminating only said illuminating device of the machine head where the thread breakage has occurred.

11. A sewing machine as claimed in claim 8 wherein said control means performs control for illuminating said illuminating devices in any of different illuminating styles corresponding to a plurality of kinds of informing functions.