JPS64218Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a tape feeding device for a sewing machine, and more particularly to a feeding device capable of adjusting the amount of tape feeding.

When sewing tape material such as rubber tape (hereinafter simply referred to as tape) to fabric, the tape guided by the tape guide and the fabric on the throat plate are both sent to the seam forming area by a feeding mechanism. However, if excessive tension is applied to the tape being fed, or if the tape is fed more than the cloth,
After sewing, the fabric stretches and contracts, producing undesirable results. Therefore, conventionally, a tape feeding device has been provided, which consists of a drive roller that rotates intermittently in synchronization with the fabric feeding mechanism of the sewing machine, and a presser roller that sandwiches the tape between the roller.The device is driven according to the type of tape and sewing conditions. The amount of tape feed was changed by adjusting the amount of intermittent rotation of the roller. In order to rotate the drive roller intermittently, a one-way clutch is usually provided on the feed shaft to which the roller is fixed, and the crank of the clutch is connected with an eccentric cam provided on the main shaft using a rod.
The feed amount can be adjusted by changing the amount of eccentricity of an eccentric cam installed on the main shaft by changing the amount of eccentricity, and by changing the connection position of the rod and crank in the radial direction of the crank. There is a way to do this. However, with the former method, it is not possible to determine the distance from the axis of the spindle to the eccentric center, that is, the amount of eccentricity, and therefore it is not easy to set the desired feed amount. It is located between the pulley at the end of the main shaft and the sewing machine body, making the work space narrow and difficult to see, resulting in poor workability.

On the other hand, when using the latter method, it is easy to grasp the distance between the connecting part and the center of rotation of the crank, and there is no obstacle to adjust the connecting part, so it is easier to work with. However, if the connecting part between the rod and the crank is changed, the phase of the feed axis with respect to the main shaft will change, and the timing of cloth feeding and tape feeding will be different. The problem became more serious as the distance from the center was moved and the feed amount was reduced.

This idea combines both of the above methods, allowing the feed amount to be adjusted in several stages using an eccentric cam mechanism, and adjustments between these can be made by changing the position of the connecting part. This is an attempt to eliminate the drawbacks of the conventional method by narrowing the adjustment range and setting the amount of eccentricity at each adjustment stage in the eccentric cam mechanism.

An embodiment of the present invention will be described below with reference to the drawings.A drive roller 4 and a presser roller 5 are pivotally supported on a bracket 3 fixed to the arm head of the sewing machine 1, and the presser roller 5 is supported by an elastic device attached to the bracket 3. 6 against the drive roller 4, and the pressing pressure can be adjusted depending on the properties of the tape. The bracket 3 is also provided with a tape guide 8 for positioning and guiding the tape into the seam forming area.

A feed shaft 9 that fixes the drive roller 4 and is rotatably supported by the sewing machine body at the rear has a one-way clutch 10 (another intermittent feed mechanism may be used) attached to its end, and the one-way clutch 10 has a crank 11. , the rocking motion of the crank 11 is transmitted to the feed shaft 9 by a one-way clutch 10 as an intermittent rotational movement in one direction. crank 1
1 has a long hole 12 formed in its longitudinal direction, and a stepped screw 13 is inserted into the long hole 1.
The stepped screw 13 is fitted so that it can slide inside the crank 11, and the protruding end thereof is fitted with a claw portion 14 into an elongated hole to prevent rotation. Pointer 16 indicating the position within the long hole
The indicator plate 17 formed with the same shape as shown in FIG. A rod 21 is pivotally attached to the crank 11 so as to be rotatable and swingable. Also screwed onto the stepped screw 13 is a stepped screw 25 which is passed through the crank 11, projects into the elongated hole 12, and is pivotally supported by a stopper 24 so that it can only be rotated. When operated, the stepped screw 13 moves within the elongated hole and its position is adjusted.

On the other hand, a first eccentric cam 28 and a second eccentric cam 29 in the form of a flange tube are fitted onto the main shaft 27 in sequence, and the first eccentric cam 28 has a pin 31 protruding from a pulley 30 fixed to the end of the main shaft. The second eccentric cam 29 is fitted with a fitting hole 32 formed in the pulley 30 so as to rotate together with the main shaft 27, and the second eccentric cam 29 has a protruding pin 33 formed in the pulley 30. The pin 33 is fitted into the semicircular groove 34 of the groove 34 so that it can rotate 180 degrees on the first eccentric cam 28, and the second eccentric cam 29 is rotated until the pin 33 reaches one end of the groove 34. When turning , the amount of eccentricity of the first eccentric cam 28 from the axis c of the main shaft 27 is set as e ₁ , and the amount of eccentricity of the second eccentric cam 29 from the eccentric center of the first eccentric cam is set as e ₂ . When (set to e ₂ < e ₁ ) the amount of eccentricity from the axis c becomes the minimum e ₁ - e ₂ , and when turned 180° until reaching the other groove end, the eccentricity becomes the maximum e ₁ + e ₂ . , the maximum eccentricity e ₁ +e ₂ and the minimum eccentricity e ₁ −
As shown in FIG. 5, each eccentric center of e ₂ is located on the same line as the axis c, and is arranged to be displaced only in the Y direction. and a set screw 36 at each position.
is fixed on the first eccentric cam, and the upper end of the rod is externally fitted thereon via a bow bearing 37. Therefore, the crank 11 is linked to the main shaft 27.
swings, and the drive roller 4 is intermittently rotated by the one-way clutch 10 via the feed shaft 9.

To adjust the tape feed amount, loosen the set screw 36, turn the second eccentric cam 29 until the cam 33 touches one groove end, tighten the set screw 36, and then adjust the front and rearward steps using the stepped screw 25. This is done by sliding the stepped screw 13 along the elongated hole 12 through a rotational operation.

In the above embodiment, the tape feed amount is adjusted in two stages by the eccentric cam mechanism. In the known type in which the rod is vertically displaced by the rotation of the cam, the eccentric cam itself has a scale or has a scale around it, or a locking means consisting of a notched groove and a spring-loaded ball or pin. It is also possible to provide an arrangement in which the feed amount is adjusted in several stages by rotating the eccentric cam. In this case, the range of adjustment by the crank is narrower than in the above embodiment, and therefore the length of the crank can be further shortened to reduce changes in the phase of the feed shaft.

As described above, the tape feeding device of the present invention is equipped with an eccentric cam mechanism that can adjust the amount of eccentricity, and also allows the position of the joint between the rod and the crank to be adjusted. This is done by adjusting the position of the connecting part.With an eccentric cam mechanism, if the amount of eccentricity at each stage can be grasped, adjustment work on the mechanism will be extremely easy, and adjustment of the connecting part will be easier. The range is also narrower compared to the conventional method in which adjustment is made only by this, and therefore there is little change in phase and timing deviation can be reduced, eliminating the drawbacks of the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a sewing machine equipped with a tape feeding device according to the present invention, Fig. 2 is an exploded perspective view of a feed rate adjustment mechanism in the device, Fig. 3 is a sectional view of an eccentric cam mechanism, and Fig. 4 is a perspective view of a sewing machine equipped with a tape feeding device according to the present invention. - Line sectional view of Fig. 3, No. 5
The figure shows a line diagram, and FIG. 6 shows a side view of the main part of the adjustment mechanism. 4... Drive roller, 5... Presser roller, 9...
Feed shaft, 10...One-way clutch, 11...
Crank, 12... Long hole, 13... Stepped screw, 2
1...Rod, 25...Stepped screw, 27...Main shaft, 28...First eccentric cam, 29...Second eccentric cam, 30...Pulley, 33...Pin, 34...
…groove.

Claims (1)

[Claims for Utility Model Registration] (1) An eccentric cam mechanism provided on the main shaft of the sewing machine, an intermittent rotation mechanism provided at one end of the feed shaft, and a rod connecting the crank of the mechanism and the eccentric cam mechanism;
A sewing machine having a drive roller fixed to the other end of a feed shaft and driven to rotate intermittently through an intermittent rotation mechanism by the oscillating motion of a crank interlocking with the main shaft, and a presser roller that sandwiches a tape between the drive roller and the drive roller. In the tape feeding device, the eccentric cam mechanism is provided with an eccentric cam 29 in which the amount of eccentricity with respect to the main shaft is adjusted in several stages, and the rod 21 is displaced in the vertical direction at each adjustment stage. A tape feeding device whose position can be adjusted toward the center of rotation of the crank. (2) The eccentric cam 2 provided in the eccentric cam mechanism
Reference numeral 9 is rotatably fitted onto the first eccentric cam 28 fixed to the main shaft 27, and its rotation range is restricted within a range of 180° by a regulating means. 2. A tape feeding device for a sewing machine according to claim 1, wherein the attachment to the cam 28 is performed at one end of said range. (3) The tape feeding device for a sewing machine according to claim 2, wherein the regulating means is a semicircular groove 34 and a pin 33 slidably fitted into the groove. (4) The eccentric cam provided in the eccentric cam mechanism is rotatably fitted onto the main shaft and fitted into the elongated hole, and the vertical position of the rod is adjusted by the rotation of the eccentric cam using a positioning means. A tape feeding device for a sewing machine according to claim 1, wherein the tape feeding device is operated in several steps. (5) The tape feeding device for a sewing machine according to claim 4, wherein the positioning means is a scale displayed in the circumferential direction. (6) The tape feeding device for a sewing machine according to claim 4, wherein the positioning means is a notch groove and a spring-loaded ball or pin that fits and locks in the notch groove.