JP2681952B2 - Sewing machine settling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a feed dog lowering device for a sewing machine and is used for a feeding mechanism of a domestic sewing machine. (Prior Art) As a device of this type known in the past, as shown in FIG.
The technique described in Japanese Patent Publication No. 55-25892 is known. That is, for the operating arm 22 that engages with the vertical feed cam 21 and swings, the switching arm 25 that supports at one end a roller 24 that engages with the lower surface of the feed base 23 has one of two different relative movement positions. To be selectively retained. The feed dog 26 makes a regular feed movement at one of the moving positions of the switching arm 25, and the feed tooth 26 is located below the upper surface of the needle plate 27 at the other position. (Problems to be Solved by the Invention) However, in the above technique, when the cloth is set on the needle plate surface and the presser foot is lowered, in order to shift the feed dog from the subsidence to the normal state, There is a problem that the movement operation force becomes extremely heavy. Further, it is necessary to additionally provide a height adjusting member for the feed dog, which results in high cost. In the present invention, the above-mentioned drawbacks are eliminated and the structure and the assembly adjustment are rationalized. [Structure of the Invention] (Means for Solving Problems) In order to solve the above problems, the present invention takes the following means. That is, a support plate 2 fixed to the machine frame 1, a support shaft 4 fixed to the support plate 2, a feed cam shaft 6 arranged in parallel to the support shaft 4, and a mounting on the feed cam shaft 6. The vertical feed arm 3 and the vertical feed arm 3 mounted on the support shaft 4 so as to be swingable and axially movable so as to be linked to the feed cam 7 and the vertical feed base 8 mounted on the support shaft 4. This is to configure the feed dog sinking device of the sewing machine, which is provided with the switching lever 11 that moves the upper and lower feed arms 3 and the feed cam 7 to engage and disengage. (Operation) When the vertical feed arm 3 is engaged with the feed cam 7 by operating the switching lever 11, the vertical feed arm 3 swings by the action of the feed cam 7, and this swing moves the vertical feed base 8 up and down. Move it. Further, when the vertical feed arm 3 is detached from the feed cam, the vertical feed base 8 sinks. (Embodiment) An embodiment of the present invention will be described with reference to the accompanying drawings.
In the figure, 1 is a machine frame, 2 is a support plate fixed to the machine frame 1, 3 is a vertical feed arm (hereinafter referred to as feed arm), and its base forms a U-shape 3a. The feed arm 3 is fitted so that its U-shaped base 3a can rotate and move in the axial direction (bending side of the spring 5) with a spring 5 interposed on a support shaft 4 that is fixed to the support plate 2. To be done. Then, by a biasing force of a spring attached to the end of the feed base 8 (not shown), the feed cam 7 contacts the feed cam 7 on the feed adjusting cam shaft 6, and the middle portion abuts the feed base 8 to transmit the vertical movement. A member 9 is provided. 10 is a vertical feed switching lever (hereinafter referred to as a switching lever)
In addition, it has a knob 11 on the front side, a step portion 10a and a cutout portion 10b in the middle portion, and is inserted into the guide elongated hole 2a of the support plate 2, and the other end portion 10c forming an L shape is U-shaped. It is sandwiched between the feed arm bases 3a and is loosely fitted on the support shaft 4. Thus, the switching lever 10 is urged in the front direction by the spring 12 stretched between the end portion of the lever and the support plate 2, and normally the position on the front side (the position of the front side by the engagement of the step portion 10a ( Reign in A). When this switching lever 10 is pushed in against the spring 12, the notch 10b engages with the support plate 2, and the lever 10 secures the forward (B) position. With this forward movement, the feed arm 3 compresses the spring 5, and the cam contact portion 3b at the tip thereof moves on the feed cam 7. The feed table 8
One end of is attached swingably to a support shaft 14 provided on the horizontal feed arm 13, and the feed dog 15 is fixed to the other end. Next, the vertical feed motion will be described. (1) Normal regular vertical feed motion The rotation of the vertical feed cam 7 causes the feed arm 3 to swing and the feed dog 15 to move up and down via the feed base 8. (2) To avoid the regular feed and to sink the feed dog,
Push the switching lever 10 forward to bring it to the position (B). As a result, the feed cam contact portion 3b of the feed arm 3 is brought into and out of contact with the cam surface 7, and the swing of the feed arm 3 is made inoperative. (3) To operate the vertical feed, return the switching lever 10 to the (A) position,
The feed arm 3 is pushed back to the front side by the spring 5, and the contact portion 3b of the feed arm comes into contact with the cam surface 7 of the vertical feed cam 7 to operate the vertical feed properly. In this return switching operation, it is possible that the abutment part of the feed arm hits the lift shape (height) of the cam at the beginning of the rotation stationary angle of the vertical feed cam, preventing the movement. Absorbed with a deflection of 5,
Immediately solved by rotating the vertical feed cam. [Advantages of the Invention] (1) The device configuration is simply assured, it can be assembled from the same direction as other hook structure parts, the work is easy, and the cost is advantageous. (2) When adjusting the height of the feed dog, when assembling the vertical feed device to the bed, it can be adjusted at the same time in the long hole portion, and no other adjusting member is required. (3) Since the raising of the feed dog is always switched when the feed dog is lower than the needle plate, there is an effect that needle breakage does not occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view for explaining an embodiment of the device of the present invention, and FIG.
FIG. 4 is a plan view of the drawing, FIG. 3 is an operation explanatory view of a switching lever, and FIG.
The figure is an explanatory view of the prior art. 1 …… machine frame, 2 …… support plate, 3 …… upper and lower feed arms, 7 …… feed cam, 8 …… feed base, 10 …… switch lever, 15 …… feed teeth.

Claims (1)

(57) [Claims] A support plate fixed to the machine frame, a support shaft whose one end is fixed to the support plate, a feed cam shaft arranged in parallel with the support shaft, a feed cam mounted on the feed cam shaft, The upper and lower feed arms mounted on the support shaft so as to be capable of swinging and movable in the axial direction so as to be linked to the upper and lower feed bases, and the upper and lower feed arms are moved on the support shaft to move the upper and lower feed arms and the feed cam. Sewing machine feed dog subsidence device equipped with a switching lever that engages and disengages.