JPH0728966B2 - Cylinder-bed sewing machine differential feed device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed device of a sewing machine that performs a feed movement with a feed dog kept horizontal, and more particularly to a differential feed device suitable for use in a cylinder bed sewing machine. .

2. Description of the Related Art As a differential feed device of a sewing machine, a main feed bar with a main feed dog and a differential feed bar with a differential feed dog are pivotally supported by a machine frame at each end. A square piece that slidably fits, and a square piece that slidably fits to an eccentric ring attached to the main shaft at the middle part or the other end is slidably fitted and also interlocks with the main shaft. It is known that a main feed crank and a differential feed crank, which are fixed to a swinging feed front-rear shaft, are respectively connected via links. In this type of device, the main feed and differential feed swing up and down with the corner piece at one end as a fulcrum due to the rotation of the spindle, and reciprocate back and forth due to the swing of the feed forward and backward shafts to move forward and backward and up and down. However, since the feed table swings up and down, the feed dog also tilts and appears on and off the upper surface of the needle plate, and a step is formed between the feed dog upper surface of the main feed tooth and the differential feed tooth. This step difference is small when the square piece that supports one end of each feed table is far away from the sewing part, and does not affect sewing as much as left, but due to space restrictions such as a small diameter cylinder bed. If the above-mentioned square piece must be provided near the sewing portion, it will be relatively large and will affect sewing.

As shown in Japanese Patent Publication No. 60-6675, the above problem is caused by vertically moving both the front and rear ends of the main feed plate and the differential feed plate at the same time to keep the feed motion while always keeping the upper faces of the main feed plate and the differential feed dog. This can be solved by adopting a mechanism that makes it possible to improve the feed efficiency, but in the known device described above, it is often necessary to move both the main feed table and the differential feed table forward and backward and up and down. Since the link mechanism is used, the structure is complicated and it is difficult to make it compact, so when trying to use it for a cylinder bed sewing machine, the tube diameter of the bed becomes quite large, and a tubular part with a small diameter like children's clothes It was not possible to sew a material to be sewn.

Problems to be Solved by the Invention The first invention is to improve a known differential feed device that performs feed movement with the main and differential feed dogs kept horizontal to a more compact one, thereby improving the size of the cylinder bed having a small diameter. The second aspect of the invention is such a differential feed device that the differential feed amount can be adjusted easily and even during sewing, and the bed diameter of the bed is increased because of this. It's something that wasn't done.

Means for Solving Problems The first aspect of the invention is to mount a differential feed base having a differential feed dog attached thereto and a main feed dog so that the differential feed rack can slide in the front-back direction. It is supported or slidable in the front-back direction to the main feed table that supports the differential feed table slidably in the front-rear direction, and one end of either one of the differential feed table and the main feed table. And a first vertical movement mechanism having a square piece externally fitted to an eccentric wheel that rotates in synchronism with the main shaft, and is provided at the other end of the one feed base so as to project laterally. One of the above-mentioned one slider having a first pin having a slider and a first bifurcated portion that swings up and down in conjunction with a main shaft, the bifurcated portion being provided on the first pin A second vertical movement mechanism that is fitted to the first pin to vertically move the first pin, and a second forked portion that swings back and forth in conjunction with the main shaft. A first slider that is fitted to the other slider of the pin to move the first pin back and forth
A forward / backward moving mechanism, a differential feed crank that swings in the forward / backward direction in conjunction with a main shaft, a first adjusting slider that slidably fits on an arm of the crank, and the adjusting slider. A second front-rear moving mechanism having a link connecting to the differential feed base and an adjusting mechanism for moving the position of the adjusting slider on the arm of the crank along the arm. is there.

Here, the first pin may be provided so as to project to one side of the main feed table, but preferably, it is provided so as to penetrate the main feed table and project to both sides of the feed table, and at one end thereof. One slider is provided and the other slider is provided at the other end.

As the slider, a square piece can be cited as a preferable example. In this case, it is desirable that the square piece fitted to the second forked portion further has a sliding surface formed on the cylindrical surface so as to be rotatable. Twisting due to assembly error between the shaft attached to the main feed bar and the main feed bar is eliminated, and even if the differential feed crank and the main feed crank are closely formed integrally This makes it easier to process.

According to a second aspect of the present invention, in the above device, the adjusting mechanism in the second forward / backward moving mechanism is pivotally supported about an axis that coincides with or substantially coincides with the swing center of the arm of the differential feed crank,
A lever having a first sliding guide portion in the radial direction and a sliding guide portion of the lever are slidably engaged, a second pin is projectingly provided on one side, and a drive guide body is provided on the other side. The second adjusting slider provided and the drive guide body are formed, and the first adjusting slider is along an arc having a center of curvature on a line orthogonal to the axis or along a chord of the arc. A first sliding guide part for guiding the first adjusting slider to move, and to move along the arm when the first adjusting slider is in one position during a swinging movement. Guide means for guiding the second pin to
The second pin is moved in accordance with the guide means, and the drive guide body is used to move the first adjusting slider along the arm.

The arms of the differential feed crank may be linear, but are preferably arcuate.

As the guide means, for example, when the differential feed crank is located at the swing center, the guide means is rotatably supported around an axial center that coincides with the center of curvature of the arm formed in an arc shape, and the free end is provided with the above-mentioned first portion. Examples thereof include a lever to which the two pins are attached, a linear or arc-shaped long hole or long groove formed on a bed or a guide plate fixed to the bed.

The operating means is an operating shaft and an operating lever fixed to the shaft and having an elongated hole or a fork into which the second pin fits, a lever for rotating the lever, a manual operating member such as a dial, or the lever. It is desirable to be able to remotely control from a position such as the cylinder base side so as not to hinder the sewing of the tubular cloth in any case.

Embodiment FIG. 1 shows a differential feed device arranged in the cylinder bed of the cylinder bed sewing machine shown in FIG. 5, and FIG. 2 shows an exploded view of the same device. An eccentric wheel with a differential feed dog 23 attached with a differential feed dog 23 fitted slidably in the front-rear direction and fixed to a main shaft 26 at a rear bifurcation. A square piece 28 that fits over 27 is slidably fitted in the front-rear direction, and the front part has a pin.
29 is fitted and a slider 31 made of a square piece attached to one end of the pin is slidable in the fore and aft direction on a fork 33 fixed to a feed vertical shaft 32 that swings in conjunction with the main shaft 26. Is fitted to. Therefore, the main feed table 22 and the differential feed table 24 are respectively provided with vertical movement mechanisms at the front and rear sides thereof, so that the main feed table 22 and the differential feed table 24 are simultaneously lifted or lowered at the front and rear sides to move vertically. Reference numeral 34 denotes a presser foot of the differential feed base 24. The pin 29 also has a sliding surface formed on the other end of the sliding surface in the form of a cylindrical surface.
Of the set of cranks consisting of a main feed crank 37 and a differential feed crank 38 fixed to the feed front-rear shaft 36, the slider 35 is attached, and the slider 35 swings in conjunction with the main shaft.
It is fitted on two forks so that it can slide vertically and rotate horizontally. As described above, the main feed table 22 is vertically driven by the square piece 28 and the slider 31 while being kept horizontal, while the swing of the main feed crank 37 causes the slider 35 and the pin 29 to swing.
It is transmitted to the main feed table 22 via and is also driven back and forth.
Although not shown, guides are provided on both sides of the main feed table 22 and the differential feed table 24 to prevent the left and right swings of the two feed tables when they are moved back and forth. The main feed crank 37 and the differential feed crank 38 standing in parallel are formed in an arc shape, and a slider 39 is slidably fitted therein. The slider 39 and the shaft 41 protruding from the differential feed base 24 are linked by a link 42.
The differential feed crank 24 is guided by the main feed base 22 to move back and forth by the swing of the differential feed crank 38. It is adjusted by moving along the feed crank 38 and changing its position. An adjusting mechanism is provided for moving the slider 39 to change the differential feed amount. Next, this mechanism will be described.

A bifurcated lever 45 is rotatably supported on a shaft 44 attached to the cylinder bed 43 as an extension of the front-rear shaft 36.
A second portion fixed to the drive guide body 46 at the forked portion of the forked lever 45.
Is slidably fitted to the adjusting slider 47 of FIG. 1, and an arc-shaped guide groove 48 is formed in the drive guide body 46, and the groove has a center of curvature located on a line orthogonal to the axial center of the feed front-rear axis. And then the slider
An arcuate slider 49 pivotally supported by 39 is slidably fitted. The drive guide body 46 is also a pin protruding from the slider 47.
The pin 51 is provided so that its axis coincides with the center of the spindle of the slider 49 and the center of the axis connecting the slider 39 and the link 42. And a cylinder bed on the extension of the shaft 41 when the differential feed crank 38 is located at its swing center
A shaft 52 is pivotally supported by 43, a lever 53 is pivotally mounted on this shaft, and a pin 51 is pivotally mounted on a free end of the lever 53.
The distance between the pin 51 and the shaft 52 is matched with the distance between the shaft 41 and the center of the spindle of the slider 39. Further, the pin 51 is slidably fitted in a long hole 56 provided in an operation lever 55 fixed to an operation shaft 54 pivotally supported by the sewing machine frame. Operation axis
Reference numeral 54 extends along the main shaft 26 to the right in the drawing, and an appropriate operating means such as a manual lever (not shown) is fixed to the shaft end.

In the above-described embodiment, the guide member 46 is formed with the circular arc groove 48, and the slider 49 is adapted to be fitted in the guide groove 46.However, the drive guide member is formed as an arc-shaped guide member and the slider 49 is formed. An arc-shaped guide groove may be formed, and the drive guide body formed as a guide body may be fitted into the guide groove.

Although the lever 53 guides the movement of the pin 51 in the above-described embodiment, the movement of the pin 51 may be guided by an arc-shaped long hole or long groove. FIG. 4 shows an example of the guide plate 61 fixed to the sewing machine frame.
An arcuate elongated hole 62 having the center of curvature of the shaft 52 as a center of curvature is provided to guide the movement of the pin 51.

Action As the differential feed crank 38 swings, the slider 49
Reciprocally slides in the guide groove 48 of the guide body 46 to draw an arcuate trajectory, which is in contact with an arc whose center of curvature is the front-rear axis of feed at the center. Therefore, the deviation between the actual track of the slider 49 and the circular arc becomes extremely small, and the vibration of the slider 49 on the crank 38 becomes minute.

Next, the differential feed amount is adjusted by rotating the operation lever 55 up and down by an operation means such as a manual lever. That is, the upward rotation of the operation lever 55 causes the guide body 46 to
While rotating around 52, it moves along the bifurcation of the bifurcated lever 45, or along the arcuate long hole 62 of the guide plate 61 and the bifurcation of the bifurcated lever 45, and feeds the slider 39 differentially. Push up along the crank 38 (Fig. 3A). On the other hand, when the operation lever 55 is rotated downward, the slider 39 is pressed down along the differential feed crank 38 (FIG. 3B).

As described above, in the first aspect of the present invention, in the differential feed device in which the vertical movement mechanism is provided at both ends of both feed bases, either one of the main feed base and the differential feed base can slide to the other. Two sliders are provided on one pin that is supported and protruded from the main feed table, and one slider has a vertical movement mechanism.
By connecting the back-and-forth moving mechanism to the other slider, respectively, one pin receives two movements and transmits them to the main feed bar. Therefore, the individual mechanism is connected to each feed bar. Compared to the above, the number of connecting points in the feed table is reduced, so that the structure is simplified, the feed table can be downsized, and the bed tube diameter can be reduced.

According to the second aspect of the invention, in the above-mentioned device, the adjustment of the differential feed amount can be performed easily and even during sewing. Moreover, when adjusting the differential feed amount, the movement of the guide body does not affect the length of the lever. In order to fit the differential feed amount adjusting device in the cylinder bed so that it fits within the range of the height, it is basically sufficient that the cylinder diameter is such that the lever fits.
Therefore, the cylinder diameter of the cylinder bed does not increase.

[Brief description of drawings]

1 is a perspective view of a differential feed device provided in a cylinder bed, FIG. 2 is an exploded perspective view of the same device, and FIGS. 3A and 3B are front views of a feed amount adjusting device when the feed amount is changed, Fourth
FIG. 5 is a front view of a modification of the device, and FIG. 5 is a perspective view of a cylinder bed sewing machine. 22 …… Main feed stand, 24 …… Differential feed stand 26 …… Spindle, 32 …… Feed vertical axis 37 …… Main feed crank, 38 …… Differential feed crank 39 …… Slider, 43 …… Cylinder Bed 44 …… Axis, 45 …… Bending lever 46 …… Drive guide, 48 …… Guide groove 49 …… Slider, 53 …… Lever, 55 …… Operating lever 61 …… Guide plate, 62 …… Arc-shaped long hole

Claims (8)

[Claims] 1. A differential feed base 24 to which a differential feed dog 23 is attached,
The main feed dog 22 is attached to the main feed dog 21 and supports the differential feed base 24 so as to be slidable in the front-rear direction. Eccentric wheel that rotates in conjunction
A first vertical movement mechanism having a square piece 28 which is fitted to the outside of the main body 27, and two sliders 3 which are provided at the other end of the main feed base so as to project laterally.
It has a first pin 29 having 1, 35 and a first bifurcated portion 33 which is fixed to a shaft 32 which pivots interlockingly with a main shaft and which pivots up and down. A second vertical movement mechanism for vertically driving the first pin 29 by fitting one of the sliders 31 provided on the pin 29 and a shaft 36 that is oscillated in conjunction with the main shaft and fixed in parallel And has a second forked portion 37 which swings back and forth and a differential feed crank 38, and the other slider 35 of the first pin 29 is fitted to the second forked portion 37 to A first forward / backward movement mechanism that drives the first pin 29 back and forth, a first adjustment slider 39 slidably fitted on the arm of the differential feed crank 38, and a difference from the adjustment slider. A second forward / backward moving mechanism having a link 42 connecting the moving feed 24 and an adjusting mechanism for moving the position of the adjusting slider 39 on the arm of the crank along the arm. Cylinder bed Shin of the differential feed device. 2. The differential feed device for a cylinder bed sewing machine according to claim 1, wherein the first pin 29 is a pin that penetrates the feed base 22 and projects to both sides of the feed base. 3. The claim according to claim 1, wherein a fitting portion between the other slider 35 of the first pin 29 and the forked portion 37 of the first forward / backward movement mechanism is formed in a cylindrical surface shape. Cylinder bed sewing machine differential feeder. 4. A differential feed base 24 to which a differential feed dog 23 is attached,
The main feed dog 22 is attached to the main feed dog 21 and supports the differential feed base 24 so as to be slidable in the front-rear direction. Eccentric wheel that rotates in conjunction
A first vertical movement mechanism having a square piece 28 which is fitted to the outside of the main body 27, and two sliders 3 which are provided at the other end of the main feed base so as to project laterally.
It has a first pin 29 having 1, 35 and a first bifurcated portion 33 which is fixed to a shaft 32 which pivots interlockingly with a main shaft and which pivots up and down. A second vertical movement mechanism for vertically driving the first pin 29 by fitting one of the sliders 31 provided on the pin 29 and a shaft 36 that is oscillated in conjunction with the main shaft and fixed in parallel And has a second forked portion 37 which swings back and forth and a differential feed crank 38, and the other slider 35 of the first pin 29 is fitted to the second forked portion 37 to A first forward / backward movement mechanism that drives the first pin 29 back and forth, a first adjustment slider 39 slidably fitted on the arm of the differential feed crank 38, and a difference from the adjustment slider. A second forward / backward moving mechanism having a link 42 connecting the movable feed base 24 and an adjusting mechanism for moving the position of the adjusting slider 39 on the arm of the crank along the arm;
The adjusting mechanism is rotatably supported around an axis that coincides with or substantially coincides with the swing center of the arm of the differential feed crank 38, and has a lever 45 having a first sliding guide portion in the radial direction, A second adjusting slider 47 slidably engaged with a sliding guide portion of the lever, a second pin 51 protruding from one side and a drive guide body 46 provided on the other side; A first adjusting slider formed on the guide body 46 so that the first adjusting slider 39 moves along an arc having a center of curvature on a line passing through the axis or along a chord of the arc. Second sliding guide for guiding 39
48 and the second pin 51 so as to move along the arm when the first adjusting slider 39 is in one position during the swinging motion.
Cylinder bed comprising guide means 53 and 62 for guiding the second guide pin, and operating means for moving the second pin according to the guide means and moving the first adjusting slider along the arm by the drive guide body 46. Sewing machine differential feed device. 5. An arm of a differential feed crank is formed in an arc shape, and when the differential feed crank is located at the swing center, the guide means is rotatable about an axis that coincides with the center of curvature. A lever that is pivotally supported and has the second pin 51 attached to its free end.
The differential feed device for a cylinder bed sewing machine according to claim 4, which comprises 53. 6. The differential feed device for a cylinder bed sewing machine according to claim 4, wherein the guide means is a long hole 62 or a long groove formed in the bed. 7. The operating means is an operating shaft 54 and is fixed to the shaft,
The differential feed device for a cylinder bed sewing machine according to claim 4, further comprising an operation lever 55 having a long hole 56 into which the second pin 51 is fitted or a forked portion. 8. The differential feed device for a cylinder bed sewing machine according to claim 5, wherein the operating means is a device for rotating the lever 53.