JPS64872Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use This invention relates to a vertical movement mechanism that provides vertical movement to a feed dog in a feed device of a sewing machine.

PRIOR TECHNOLOGY In conventional feeding devices, the vertical movement of the feed dog is often caused by an eccentric cam attached to the vertical feed shaft disposed inside the bed, and caused by the lift difference of the cam. It is supported by two bearings, and its rotation is performed from the upper shaft via a bevel gear and a vertical shaft, or via a timing belt.

The problem that the invention aims to solve This can be said about devices in general,
One of the technical challenges for sewing machines is to reduce costs by simplifying the structure and making each part easier to manufacture. In a conventional vertical movement mechanism, the vertical feed shaft equipped with an eccentric cam has a transmission mechanism such as a bevel gear and a vertical shaft or a sprocket and a timing belt that transmit rotational motion to the shaft, and a bearing part for supporting the vertical feed shaft. In addition to requiring a lot of machining, such machining also requires considerable precision, it is desirable to provide a vertical movement mechanism that has a relatively simple structure and is easy to manufacture in place of such a mechanism. .

Means to Solve the Problems The present invention uses a link mechanism that has a relatively simple structure and is easy to manufacture for the vertical movement mechanism of the feed, and attempts to move the feed dog up and down by the movement of a lever that swings in the vertical direction. A cam fixed to the upper shaft, an intermediate lever that swings left and right by the cam, and a feed bar that engages with the intermediate lever and swings up and down as the lever swings left and right. It is characterized by a swinging lever that moves it up and down.

Embodiment The intermediate lever 1 has a pin 2 protruding from its upper end engaged with a grooved cam 4 fixed to an upper shaft 3, and the rotation of the grooved cam 4 causes it to swing left and right about a fulcrum 5. , the pin 6 protruding from the bottom has a bed B.
One side of the swinging lever 7 (formed as a cam 8 as shown in the figure in order to provide a vertical movement synchronized with the forward and backward movement of the feed dog, which will be described later) is engaged, and the intermediate part of the swing lever 7 is pivotally supported within the center. The swinging of the lever causes the swinging lever 7 to swing vertically, and the feed bar 9, which the other end of the swinging lever engages with, swings up and down about the pivot shaft 10. Then, the feed dog 12 fixed to the feed table 9 is given vertical movement. Note that the forward and backward movement of the feed table 9 is achieved by the swinging of an arm 14 that is fixed to a feed back and forth shaft 13 that swings in conjunction with the upper shaft 3, and that connects the feed table 9 with a pivot shaft 10. (See Figure 2).
A rack 15 is also connected to the lower end of the intermediate lever 1 with a pin 16, and the rack engages with a pinion (not shown) that is coaxial with a driver 17 in the cauldron, so that the intermediate lever 1 can be reciprocated in the left and right direction by swinging. This causes the driver 17 to swing via the pinion. In the figure, reference numeral 19 denotes a spring that urges the intermediate lever 1 in the clockwise direction in the figure.

In the above embodiment, the vertical movement of the feed dog and the drive of the driver are performed by the swinging of the intermediate lever, but the driver is driven by a separate mechanism, so that only the vertical movement of the feed dog is performed. Good too. In this case, the pin 6 can be omitted by directly engaging the lower end of the intermediate lever with the swing lever.

In the above embodiment, the intermediate lever is oscillated by a grooved cam fixed to the upper shaft, but an end cam may be used instead of the grooved cam, or an eccentric cam, plate cam, etc. Any cam can be used; in the case of an eccentric cam, the intermediate lever is oscillated via a lever, a bell crank-shaped lever, etc. that is fitted onto the cam;
Furthermore, when using a plate cam and wanting to operate the intermediate lever directly from the plate cam, the plate cam should be rotated around an axis perpendicular to the upper shaft.

Effects of the invention As described above, in this invention, the vertical movement of the feed dog is performed by a link mechanism, so the structure is simpler than the conventional one which required bearings, gears, sprockets, timing belts, etc. It is relatively simple, and the machining accuracy is also relaxed compared to the conventional method, which requires centering and requires considerable precision for machining. In addition, the intermediate lever and the swing lever that constitute the link mechanism can be press-molded, making it simple to manufacture and further reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a front view of the internal mechanism of a sewing machine equipped with a vertical feed mechanism according to the present invention, and FIG. 2 is a side view of the feed mechanism. 1... Intermediate lever, 3... Upper shaft, 4... Groove cam, 7... Rocking lever, 8... Cam, 9... Feed base, 12... Feed dog.

Claims (1)

[Scope of utility model registration request] The intermediate part is pivotally supported by the sewing machine frame, and there is an intermediate lever that swings left and right in conjunction with the rotation of a cam fixed to the upper shaft. and a swinging lever whose other end is connected to a back-and-forth movement mechanism so as to be movable back and forth, and which is engaged with a feed base which is pivotable in the vertical direction, and which swings in the vertical direction by the swinging of the intermediate lever. A vertical movement mechanism in a feed device of a sewing machine.