JPH04371190A - Differential feed mechanism for sewing machine - Google Patents

Abstract

PURPOSE:To reduce loads exerted on a main feed bar and to simplify the structure of the main feed bar by designing a main feed bar to which the main feed dog of a differential feed mechanism is affixed and an auxiliary feed bar to which an auxiliary feed dog is affixed in such a manner that the bars are capable of independent horizontal movement. CONSTITUTION:A main feed cam 15 and an auxiliary feed cam 16 are mounted on a drive shaft 4 freely rotatably supported to a sewing machine frame and a main feed horizontal link 17 and an auxiliary feed horizontal link 19 have their respective ends 18, 20 fitted over the main feed cam 15 and the auxiliary feed cam 16, respectively. A main feed oscillating arm 23 and an auxiliary feed oscillating arm 27 are freely oscillatably supported to the shaft portion 30 of the sewing machine frame and a main feed bar 21 having a main feed dog 13 affixed at one end thereof and an auxiliary feed bar 35 having an auxiliary feed dog 14 affixed at one end thereof are connected to the respective upper end portions 24, 31 of the main feed oscillating arm 23 and the auxiliary feed oscillating arm 27 and also the main feed horizontal link 17 and the auxiliary feed horizontal link 19 are connected to the respective lower end portions of the oscillating arms 23, 27 via a main feed link 48 and an auxiliary feed link 57, respectively. The auxiliary feed bar 35 is freely oscillatably sandwiched between the pressar bar 40 of the main feed bar 21 and a rectangular top 39 which is supported in such a manner as being freely oscillatable in its longitudinal direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential feed mechanism for a sewing machine.

0002

[Prior art] The differential feed mechanism of conventional sewing machines was
3-136698 (Utility Model Application Publication No. 2-59781), since the movement of the main feed table causes the sub feed table to move horizontally, a large load is collected on the feed generation mechanism of the main feed table, The rotational torque at the location where the feed motion of the feed table is generated is too large, and the accuracy of the related parts of the mechanism must be particularly improved.

0003

SUMMARY OF THE INVENTION The present invention aims to reduce torque by simplifying the structure of a differential feed mechanism of a sewing machine and reducing the weight of moving parts, and also eliminates excessive load on the main feed table. The purpose is to improve productivity by eliminating the need for high-precision parts.

0004

[Means for Solving the Problems] The present invention is directed to a differential feed mechanism of a sewing machine, in which a main feed table to which a main feed dog is fixed and a sub feed table to which a sub feed dog is fixed are capable of independent horizontal movement. This structure reduces the load on the main feeder and simplifies the structure of the main feeder.

[0005]

[Operation] The present invention includes a drive shaft rotatably supported on the sewing machine frame, and a main feed link connected to the other end of the main feed horizontal link whose one end is fitted to the main feed cam fixed to the drive shaft. , a sub-feed link connected to the other end of the sub-feed horizontal link, one end of which is fitted into the sub-feed cam fixed to the drive shaft;
a shaft supported by the sewing machine frame; a main feed swinging arm that is swingably supported by the shaft and connected to one end of the main feed link; and one end connected to the upper end of the main feed swing arm. A main feed table having a main feed dog fixed to its tip and a square piece slidably held in the center thereof, and a sub-feed swing that is swingably supported by the shaft and connected to one end of the sub-feed link. The arm is connected to the upper end of the sub-feed swinging arm via a sub-feed table link, has a sub-feed dog fixed to the tip, and is held by the main feed plate and a presser plate whose central portion is provided on the main feed plate. It is composed of a sub-feed that is slidably held between the top surface of the square piece, and the main feed and sub-feed are configured to allow independent horizontal movement, thereby reducing the load. Another feature is that the structure of the main feed table and the sub feed table is simplified.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of an embodiment of the present invention will be described below with reference to the drawings. The sewing machine frame 1 consists of an arm machine frame 2 and a bed machine frame 3. A drive shaft 4 driven by a motor (not shown) is supported on the bed machine frame, and a pulley 5 is mounted outside the machine frame of the drive shaft. Some of them are exposed. A needle bar 6 is supported by the arm frame 2 so as to be movable up and down, and is moved by the drive shaft 4 via a transmission shaft.

A plurality of thread tension devices (
7, 7, . . . ) are provided, and the thread tension device adjustably applies tension to the thread of the thread rod attached to the thread stand 8 provided at the rear of the arm machine frame 2. A looper cover 9 is pivotally attached to the lower front side of the arm frame so as to be openable and closable.

A throat plate 10 is horizontally disposed on the upper surface of the bed machine frame 3, and the periphery of the throat plate is surrounded by a rotatable bed cover 11. The throat plate 10 is provided with a feed dog window 12 that is long in the front-rear direction, and a main feed dog 13 and a sub feed dog 14 are exposed in the feed dog window.

Next, the differential feed mechanism will be described in detail. A main feed cam 15 and a sub feed cam 16 are screwed to the drive shaft 4 with their opposing end surfaces 15a and 16a spaced apart from each other by screws. One end 18 of the main feed horizontal link 17 is fitted into the main feed cam 15, and one end 20 of the sub feed horizontal link 19 is fitted into the sub feed cam 16, respectively.

The main feed table 21 having the main feed dog 13 fixed to its front end has its rear end 22 connected to the upper end 24 of the main feed swing arm 23.
A window portion 26 is provided at a vertical portion in the substantially central portion, and a square piece, which will be described later, is fitted into the window portion so as to be slidable in the front-rear direction. The main feed swing arm 23
is swingably supported along with the sub-feed swinging arm 27 by a shaft portion 30 provided horizontally on support plates 29, 29 planted on both sides of the swinging arm stand 28 fixed to the bed machine frame 3. ing.

One end 33 of a sub-feed link 32 is connected to the upper end 31 of the sub-feed swing arm 27 via a pin shaft 34. A sub-feed table 35 having the sub-feed dog 14 fixed to its front end has a rear end 36 connected to the other end 37 of the sub-feed plate link 32 via a pin shaft 38. A square piece 39 which is wide and has a protruding portion from the window portion is fitted into the window portion 26 of the main feed table 21 so as to be slidable in the front and rear direction.

The sub-feed table 35 is capable of sliding in the front-rear direction between the lower surface of a presser plate 40 fixed to the upper surface of the main feed table 21 and the upper surface 41 of the square piece 39 protruding from the window. It's like being held in place.

A hole 42 is formed in the center of the square piece 39, and a vertical feed cam 43 integrally provided with the sub feed cam 16 is fitted into the hole. On both sides of the square piece 39, seat plates 44, 44, which fit onto the drive shaft 4, are arranged, and protrusions 45, 45 protruding from the seat plates are formed into recesses 46, which are bored into the square piece 39. , 46 to prevent rotation is mounted between the end surface 15a of the main feed cam 15 and the end surface 16a of the sub feed cam 16.

One end 49 of a main feed link 48 is connected via a pin 51 to the other end 47 of the main feed horizontal link 17, which has one end 18 fitted around the outer periphery of the main feed cam 15. The other end 50 is connected to the lower end 52 of the main feed swing arm 23 by a pin 53. The pin 51
One end 55 of the main feed adjustment link 54 is rotatably supported above.

A sub-feed link 57 is attached to the other end 56 of the sub-feed horizontal link 19 whose one end 20 is fitted to the sub-feed cam 16.
One end 58 is connected via a pin 59, and the other end 60 of the sub-feed link 57 is connected to the lower end 61 of the sub-feed swing arm 27 via a pin 62. One end 64 of a sub-feed adjustment link 63 is rotatably supported on the pin 59.

Next, FIG. 4 shows an adjustment device for the differential feed mechanism.
This is explained with reference to. F indicates the entire differential feed mechanism, and A indicates the other end 6 of the main feed adjustment link 54.
5 and the tip 67 of the main feed transmission arm 66, and B shows the connection axis between the other end 68 of the sub-feed adjustment link 63 and the tip 70 of the sub-feed adjustment arm 69.

The base end of the main feed transmission arm 66 is fixed to one end of a shaft portion 71 rotatably supported on the sewing machine frame 1, and a feed arm 72 is fixed to the other end of the shaft portion. There is. The feed arm has one end 73 connected to a feed rod 74 connected to a feed amount adjustment operation section 90, and the other end 75 connected to one end of a connecting rod 76 connected to a differential adjustment mechanism.

In the differential adjustment mechanism, a differential rod 77 connected to a differential adjustment operation section 91 regulates the movement of a pin 79 planted at the lower end by a groove formed in a guide plate 78 fixed to the sewing machine frame 1. The pin 79 of the differential rod 77 has an elongated hole 81 formed in a converting arm 80 that is connected at its lower end to the other end of the connecting rod 76 and connected to the sub-feed adjustment arm 69 at its upper end. It is slidably fitted, and the feed amount adjustment operation section 90
When the converting arm 80 is operated, the converting arm 80 is rotated about the pin 79 in the direction of arrow CD.

A pin 82 implanted at the upper end of the conversion arm 80 is connected to an upper end 85 of a sub-feed transmission arm 84 fixed to one end of a shaft 83 rotatably supported on the sewing machine frame 1. A sub-feed connecting arm 86 fixed to the other end of the shaft 83 is connected at its tip 87 to the other end 88 of the sub-feed adjusting arm 69 via a sub-feed connecting rod 89.

Since the configuration of the present invention is as described above, by operating the feed amount adjustment operation section 90, the feed rod 74 is moved in the direction of arrow E, and the feed arm 72 and the main feed transmission arm 66 are moved. Main feed horizontal link 1 through rotation of
The horizontal momentum of the main feed table 21 is adjusted by changing the center of motion of the sub-feed horizontal link 7, and the center of movement of the sub-feed horizontal link 19 is changed through the rotation of the converting arm 80 and the sub-feed adjusting arm 69 to adjust the horizontal momentum of the sub-feed table 35. The horizontal momentum is adjusted, and the differential adjustment operation section 9
1, the differential rod 77 moves in the direction of arrow G.
When moved in the direction, the pin 7 in the elongated hole 81 of the conversion arm 80
9 is changed, and the center of rotation of the conversion arm 80 is changed.

For example, when the pin 79 of the differential rod 77 is lowered and the feed rod 74 is rotated, the amount of transmission to the sub-feed table side is greater than the amount of transmission to the main feed plate side. The position of the pin 62 of the sub-feed link 57, which is the center of movement of the sub-feed horizontal link 19, is the same as the pin 5 of the main feed link 48, which is the center of movement of the main feed horizontal link 17 on the main feed table side.
Since it is moved in the direction of arrow H (FIG. 2) from position 3, the feed amount of the sub feed table becomes larger than the feed amount of the main feed table, and the ratio of the two feed amounts is changed.

In the present invention, the main feed table 21 and the sub-feed table 35 are given independent motion, and the main feed table 21 is given horizontal movement by the main feed cam 15 and the main feed horizontal link 17, The feed table 35 is given horizontal movement by the sub-feed cam 16 and the sub-feed horizontal link 19, and the sub-feed table 35 is held by a holding plate 40 attached to the main feed plate 21 and a window portion 26 of the main feed plate 21. It has a simple shape with parallel upper and lower surfaces that are sandwiched between the upper surface of the square piece 39.

[0023]

[Effect] Since the present invention has the above structure and function, the main feed table and the sub feed table are driven independently, so the load on the main feed table is significantly reduced compared to the conventional one. Since it is possible to simplify the structure,
Since the structure is such that the sub feed table is held between the presser plate of the main feed table and the top surface of the square piece held by the main feed table, the structure of the sub feed table can be simplified and vibrations are significantly reduced. This has great practical effects.

[0024]

[Brief explanation of the drawing]

FIG. 1 is an external view of a sewing machine incorporating the device of the present invention, FIG. 2 is a side view of the main parts of the device of the invention, FIG. 3 is an exploded perspective view of the structure of the main parts of the device of the invention, and FIG. 4 is a main part of the device of the invention. Slope view of the partial structure. 4...Drive shaft 15...Main feed cam 16...Sub feed cam 17...Main feed horizontal link 19...Sub feed horizontal link 21...Main feed table 23...Main feed swing arm 27...Sub feed swing arm 30...Shaft portion 32 ...Sub feed link 35...Sub feed stand 39...Square piece 40...Press plate 48...Main feed link 57...Sub feed link

Claims (1)

[Claims] A drive shaft rotatably supported on the sewing machine frame, a main feed link connected to the other end of a main feed horizontal link whose one end is fitted to a main feed cam fixed to the drive shaft, and a main feed link fixed to the drive shaft. a sub-feed link connected to the other end of the sub-feed horizontal link whose one end is fitted into the sub-feed cam; a shaft supported by the sewing machine frame; a main feed swing arm connected to one end of the main feed link; one end connected to the upper end of the main feed swing arm and a main feed dog fixed to the tip;
A main feed base that slidably holds a square piece in the center, a sub-feed swinging arm that is swingably supported by the shaft and connected to one end of the sub-feed link, and A sub-feed table connected to an upper end via a sub-feed plate link, a sub-feed dog fixed to the tip, and a central portion slidably sandwiched between a presser plate provided on the main feed plate and the upper surface of the square piece; A differential feed mechanism for a sewing machine characterized by comprising: