ROTARY SHUTTLE FOR SEWING MACHINE

Abstract

The present invention relates to a rotary shuttle for a sewing machine, wherein a shuttle tension spring having a lower thread separation-prevention end for facilitating threading the lower thread (A) supplied from the center is coupled to the outer circumferential edge of a lower thread case (30).

Claims

1. A rotary shuttle for a sewing machine comprising: a hook body (10) having a lower part to which a drive shaft is rotatably coupled; a lower thread base (20) that is coupled to an inner circumference of the hook body (10) to rotate in a direction opposite to the hook body (10) when the drive shaft rotates and includes a concave groove (21) recessed in a downward direction on an upper part of a main wall, and a lower thread case (30) surrounding upper and lateral parts of a lower thread (A) that is inserted into the lower thread base (20) to expose an upper part thereof, wherein: the lower thread case (30) includes a protrusion (31) that protrudes to be inserted into the concave groove (21) by spring elastic force, a hook (32) having one end coupled to a hook coupling hole (31a) formed in the protrusion (31) and moving the protrusion (31) in an inward direction when a remaining end is lifted, a case body (33) that includes a protrusion inlet (33a) formed on an upper part thereof to allow opposite lateral parts of the protrusion (31) to be inserted thereinto and to be supported by spring elastic force and is shaped like a cylinder with an opened lower surface to insert the lower thread (A) thereinto, and a bobbin shell (34) coupled to one side of an outer circumference of the case body (33) and including a lower thread hanger (34a) bent inward at one end to guide the lower thread (A) when the lower thread (A) is pulled out; and the protrusion inlet (33a) includes a lower thread concave groove (33a′) formed in one end thereof to be positioned inward to guide the lower thread (A) when the lower thread (A) is pulled out.

2. The rotary shuttle for a sewing machine according to claim 1, wherein the lower thread case (30) includes a lower thread outlet hole (30a) formed through centers of the case body (33), the protrusion (31), and the hook (32) to easily pull out the lower thread (A), and an outlet hole channel (30b) formed on the protrusion (31) and the case body (33) to connect the lower thread outlet hole (30a) to an outer lateral part thereof.

3. The rotary shuttle for a sewing machine according to claim 1, wherein the bobbin shell (34) includes a case fixing unit (34b) that extends from the lower thread hanger (34a) and is coupled to the outer circumference of the case body (33), and an elastic insert unit (34c) that extends from the case fixing unit (34b) and is in close contact with an outer circumference of the lower thread case (30) by elastic force, and the elastic insert unit (34c) includes a lower thread separation prevention end (341) that is bent inward to prevent separation of the lower thread (A).

4. The rotary shuttle for a sewing machine according to claim 3, wherein: the lower thread separation prevention end (341) includes an upper prevention end (341′) bent from an upper part thereof and a lower prevention end (341″) bent from a lower part thereof to pull out the lower thread (A) from a center of an end thereof; and the case body (33) includes a prevention end concave groove (33c) through which the lower thread separation prevention end (341) is positioned inward.

5. The rotary shuttle for a sewing machine according to claim 1, wherein a lower thread hanger (33b) that rotates spirally and extends to position the lower thread (A) at a center thereof and to pull out the lower thread (A) from the center is provided at one side of an upper surface of the case body (33).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 is a diagram for explaining a conventional rotary shuttle for a sewing machine.

[0025] FIG. 2 is an exploded perspective view of a rotary shuttle for a sewing machine according to the present invention.

[0026] FIG. 3 is a diagram for explaining a bobbin shell according to the present invention.

[0027] FIG. 4 is a diagram showing a plane and side of a lower thread case according to the present invention.

[0028] FIG. 5 is a diagram for explaining a state in which a lower thread is pulled out from a lower thread case according to the present invention.

BEST MODE

[0029] Hereinafter, a rotary shuttle for a sewing machine according to the present invention will be described in detail with reference to the accompanying drawings.

[0030] As shown in FIGS. 2 to 5, the rotary shuttle for a sewing machine according to the present invention includes a hook body 10 having a lower part to which a drive shaft is rotatably coupled, a lower thread base 20 that is coupled to an inner circumference of the hook body 10 to rotate in a direction opposite to the hook body 10 when the drive shaft rotates and includes a concave groove 21 recessed in a downward direction on an upper part of a main wall, and a lower thread case 30 surrounding upper and lateral parts of a lower thread A that is inserted into the lower thread base 20 to expose an upper part thereof and is drawn out from the center thereof.

[0031] That is, the lower thread A may be drawn out from the center, and a larger amount of the lower thread A may be wound than in the case in which a separate bobbin is used.

[0032] The lower thread case 30 may include a protrusion 31 that protrudes to be inserted into the concave groove 21 by spring elastic force, a hook 32 having one end coupled to a hook coupling hole 31a formed in the protrusion 31 and moving the protrusion 31 in an inward direction when the other end is lifted, a case body 33 that includes a protrusion inlet 33a formed on an upper part thereof to allow opposite lateral parts of the protrusion 31 to be inserted thereinto and to be supported by spring elastic force and is shaped like a cylinder with an opened lower surface to insert the lower thread A thereinto, and a bobbin shell 34 coupled to one side of an outer circumference of the case body 33 and including a lower thread hanger 34a bent inward at one end to guide the lower thread A when the lower thread A is pulled out.

[0033] When the hook 32 is lifted, the protrusion 31 may be positioned inward and may be inserted into the concave groove 21, and when the hook 32 is released, the protrusion 31 may protrudes outward by spring elastic force and may be caught on an inner end of the upper part of the concave groove 21.

[0034] The protrusion inlet 33a may include a lower thread concave groove 33a′ formed in one end thereof to be positioned inward to guide the lower thread A when the lower thread A is pulled out, and thus the lower thread A may be stably pulled out through an upper part of the case body 33.

[0035] The lower thread case 30 may include a lower thread outlet hole 30a formed through the centers of the case body 33, the protrusion 31, and the hook 32 to easily pull out the lower thread A, and an outlet hole channel 30b formed on the protrusion 31 and the case body 33 to connect the lower thread outlet hole 30a to an outer lateral part thereof, and thus the lower thread A may be positioned inside the lower thread concave groove 33a′ and may be pulled out through a lower part of the hook 32.

[0036] The bobbin shell 34 may include a case fixing unit 34b that extends from the lower thread hanger 34a and is coupled to the outer circumference of the case body 33, and an elastic insert unit 34c that extends from the case fixing unit 34b and is in close contact with an outer circumference of the lower thread case 30 by elastic force, and the elastic insert unit 34c may include a lower thread separation prevention end 341 that is bent inward to prevent separation of the lower thread A. The lower thread A may be pulled out while being positioned between the bobbin shell 34 and the case body 33 by lifting the lower thread separation prevention end 341 of the bobbin shell 34.

[0037] Here, the lower thread separation prevention end 341 may include an upper prevention end 341′ bent from an upper part thereof and a lower prevention end 341″ bent from a lower part thereof to pull out the lower thread A from the center of an end thereof, and the case body 33 may include a prevention end concave groove 33c through which the lower thread separation prevention end 341 is positioned inward, and accordingly, the lower thread A may be pulled out through a space between the upper prevention end 341′ and the lower prevention end 341″.

[0038] A lower thread hanger 33b that rotates spirally and extends to position the lower thread A at the center thereof and to pull out the lower thread A from the center may be provided at one side of an upper surface of the case body 33, and accordingly, even if the hook body 10 rotates rapidly, the upper thread and the lower thread A may be prevented from becoming entangled.

[0039] An operation of the rotary shuttle for a sewing machine according to the present invention as configured above will be described below.

[0040] As shown in FIGS. 2 to 5, the rotary shuttle for a sewing machine according to the present invention may be accommodated in the lower thread case 30 inserted into the lower thread base 20 to supply the lower thread A from the center while being wound without a bobbin. The lower thread base 20 may be accommodated inside the hook body 10 to rotate in a direction opposite to the hook body 10.

[0041] The lower thread A may be wound more using a space between a central axis and upper and lower plates of a bobbin (not shown) as a winding space than in the case in which a bobbin is used, and accordingly, maintenance costs may be reduced when a mass-operated sewing machine is used.

[0042] The lower thread outlet hole 30a may be formed through the center of an upper surface of the lower thread case 30, and the outlet hole channel 30b may be cut to connect the lower thread outlet hole 30a to the lateral part, and thus the lower thread A may be easily pulled out.

[0043] That is, the lower thread A pulled out from the center may be positioned between a lower surface of the hook 32 and an upper surface of the protrusion 31 and may be pulled out from the lateral part through the lower thread outlet hole 30a and the outlet hole channel 30b. The lower thread A may be pulled out from the bobbin shell 34 through the lower thread concave groove 33a′ of the protrusion inlet 33a.

[0044] The bobbin shell 34 may be bolted to the outer circumference of the lateral part of the case body 33 through the case fixing unit 34b, and the lower thread A may be pulled out from the upper part through the lower thread hanger 34a and the elastic insert unit 34c. In this case, the lower thread separation prevention end 341 bent inward may be provided at an end of the elastic insert unit 34c, thereby preventing separation of the lower thread A.

[0045] The lower thread A positioned between the bobbin shell 34 and the case body 33 may be pulled out from an upper plate of the sewing machine through the lower thread hanger 33b having a spiral shape to maintain tension when being pulled out from the upper plate through the lower thread separation prevention end 341, and thus may be completely mounted.

[0046] As such, the rotary shuttle according to the present invention may be rapidly mounted through the lower thread outlet hole 30a, the outlet hole channel 30b, the lower thread concave groove 33a′, the lower thread hanger 34a, the lower thread separation prevention end 341, and the lower thread hanger 33b in order to easily mount the lower thread A supplied from the center, and accordingly, when the rotary shuttle is applied to a large-scale sewing machine, the sewing machine may be efficiently managed with limited manpower and productivity may be improved.

[0047] It is clearly understood that the same is by way of illustration and example only and is not to be taken as limiting the present invention, and it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the subject matter and scope of the present invention.

EXPLANATION OF REFERENCE NUMERALS

[0048] 10: hook body [0049] 20: lower thread base [0050] 21: concave groove [0051] 30: lower thread case [0052] 30a: lower thread outlet hole [0053] 30b: outlet hole channel [0054] 31: protrusion [0055] 31a: hook coupling hole [0056] 32: hook [0057] 33: case body [0058] 33a: protrusion inlet [0059] 33a′: lower thread concave groove [0060] 33b: lower thread hanger [0061] 33c: prevention end concave groove [0062] 34: bobbin shell [0063] 34a: lower thread hanger [0064] 34b: case fixing unit [0065] 34c: elastic insert unit [0066] 341: lower thread separation prevention end [0067] 341′: upper prevention end [0068] 341″: lower prevention end [0069] A: lower thread