JPS627262Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a presser foot lifting device for a sewing machine, and more particularly to a presser foot lifting device for a sewing machine equipped with a pedal operated by a worker's knee or foot.

Conventionally, with sewing machines that sew thick fabrics such as tents and jeans, the frictional resistance between the needle and the fabric is large.
Furthermore, since an external force acting on one end of the fabric affects the entire fabric, making it easy for the fabric to shift during sewing, the presser foot pressure is made stronger than in general sewing machines. For this reason, the method of raising the presser foot by manually rotating a lever placed in the jaw of the sewing machine requires strong physical strength. Conventionally, this type of sewing machine was equipped with a pedal operated by the foot or knee instead of the hand.
In order to replace or adjust the throat plate or hook, or to clean the area around the hook, the pedal must be kept pressed against a strong spring force while the presser foot is held in the raised position, resulting in worker fatigue. The disadvantage was that the amount of water was significantly increased compared to other sewing machines.

Additionally, if a hand-operated lever is provided in addition to a foot-operated pedal, the presser foot can be mechanically locked in the raised position, but in order to lock the presser foot in the raised position, the pedal must be pressed. In addition, in order to lower the presser foot from that position, you must rotate the lever by hand in the opposite direction while pressing the pedal, and then press the pedal. This type of operation has the disadvantage of being complicated, as it requires the complicated work of turning the lever by hand in addition to operating the pedal to raise or lower the presser foot. Ta.

The purpose of this invention is to eliminate the above-mentioned conventional drawbacks with a simple configuration.

Examples of this invention will be described below with reference to the drawings.

In the figure, 1 is a machine frame, 2 is a hollow adjustment screw screwed vertically into the upper wall of the machine frame 1, and 3 is a bush that is fitted and fixed perpendicularly to the lower wall of the machine frame 1 with respect to the adjustment screw 2. A presser bar 4 is loosely fitted into the hollow portion of these adjusting screws 2 and within the bush 3 so as to be movable up and down.

5 is a presser foot fixed to the lower end of the presser bar 4; 6 is a presser bar holder fixed to the presser bar 4 in the hollow of the machine frame 1; The coil spring 7 is compressed and arranged so that the presser foot 5 always has the upper surface 1 of the bed.
Apply force to press a downward. 8
9 is a lifting body integrated with the presser bar holder 6, and 9 is a forked link, whose middle part is rotatably supported on a horizontal fixed shaft 10, and whose one end is similar to that of the plate described in Japanese Utility Model Publication No. 25-1098, for example. It is connected to an operating body (not shown) operated by the knee or foot via a connecting rod 11, and the other end is loosely fitted into a long hole 12 formed in the pulling body 8. In addition, the pulling body 8, the forked link 9, the connecting rod 1
1. The operating body constitutes a presser foot lifting means. 1
3 is a support shaft rotatably supported on the side wall of the machine frame 1 and movable in the axial direction; 14 is a locking body fixed to one end of the support shaft 13 extending inside the hollow of the machine frame 1;
Reference numeral 5 denotes a lever fixed to the other end of the support shaft 13 extending outward from the machine frame 1, and these constitute a locking means. 1
Reference numeral 6 denotes a coil spring as an elastic body which is compressed and arranged between the lever 15 and the machine frame 1 so as to press the support shaft 13 outward of the machine frame 1, and is generated by the acting force of the pressing spring 7. The frictional force between the lower surface of the presser bar holder 6 and the upper surface of the locking body 14 is weak. Reference numeral 17 denotes a cam body fixed to one end of the spindle 13 in line with the locking body 14. By rotating the cam body 90 degrees clockwise from the state shown in FIGS. 3 and 4, the presser foot 5 is moved to the position shown by the solid line in FIG. A cam surface is formed on the outer periphery so that it can be moved and locked from the working position to the non-working position indicated by the two-dot chain line.

Since this device has the above-described structure, when the operating body is pressed with the knee or foot from the state shown by the solid line in FIGS. It is pulled upward against the presser spring 7, and the presser foot 5 rises from the bed upper surface 1a as shown by the two-dot chain line in FIG. So lever 1
When the support shaft 13 is pressed to the right in FIG.
The entry position is directly below. After that, when the pressure of the operating body is released, the lower surface of the presser bar holder 6 comes into contact with the upper surface of the locking body 14 at a slightly lowered inactive position due to the acting force of the presser spring 7, as shown in FIG. As a result, a frictional force greater than the acting force of the elastic body 16 is generated between the presser bar holder 6 and the locking body 14.
Even when the pressure on the lever 15 is released, the above-mentioned relationship between the presser bar holder 6 and the locking body 14 is maintained, and the presser foot 5 continues to be held in the inactive position.

Next, from the state shown in FIG. 2, when you press the operating body again with your knee or foot, the presser bar holder 6
As the locking body 14 and the presser bar holder 6 are disengaged from each other, the locking body 14 returns to the position shown in FIG. 1 due to the acting force of the elastic body 16. The rod 4 is lowered by the force of the presser spring 7, and the presser foot 5 comes into pressure contact with the bed upper surface 1a.

As described above, this invention has a structure that includes a lever placed outside the machine frame and an elastic body that lightly presses the presser bar holder out of the movement path when the lever is operated in two directions. With the presser foot raised to the inactive position, the presser foot can be locked in the raised position simply by lightly pressing the lever against the elastic body, and from this state, the presser foot can be locked by pressing the presser foot lifting means again. Since the above locking of the presser foot can be released, the presser foot can be easily raised to the inactive position and locked in that position even in sewing machines for thick materials, and this type of operation can be simplified. It has excellent practical effects.

[Brief explanation of the drawing]

1 and 2 are partial vertical sectional views of the main parts, and FIG. 3 is an explanatory view of the operation.

Claims (1)

[Scope of Claim for Utility Model Registration] A presser foot 5 supported at the lower end of a presser bar with a presser bar holder in the middle, and a presser spring 7 that always presses the presser foot downward.
, presser foot lifting means 6, 8, 9, 11 for raising the presser foot against the action of the presser spring, and locking means for holding the presser foot at the position raised by the presser foot lifting means. In the sewing machine, the locking means always includes: a lever 15 disposed outside the machine frame; and a locking body 14 that is moved in and out of the movement path of the presser bar holder by two-way operation of the lever. consists of an elastic body 16 that presses the locking body out of the movement path of the presser bar holder, and when the locking body is moved out of the movement path of the presser bar holder, the presser foot is allowed to descend by the presser spring, and the lock is stopped. A presser foot lifting device for a sewing machine, characterized in that the presser foot is engaged with a lower surface of the presser bar holder to lock the presser foot in the raised position when the body is within the movement path of the presser foot holder.