JPS6016370Y2 - Jig-jig sewing machine pattern sewing cam device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a resin pattern sewing cam device for a zigzag sewing machine.

The conventional patterned cam of this type is a silver-gold laminated cam as shown in Fig. 5, and one cam is formed from a mild steel sheet material by precision press punching, and after laminating multiple cams, they are integrated with a caulking pin 18. Therefore, during assembly, due to variations in plate thickness, the cumulative pitch between the cams is large and it is necessary to prepare seam washers 15 of several thicknesses and adjust the pitch depending on the combination. Due to the combined assembly, there were drawbacks such as phase shift between the cams.

Therefore, in order to eliminate the above-mentioned drawbacks, we devised a resin integral cam as shown in Figs. 6 and 7. However, due to the shrinkage of the molded special rib 14, it deformed into a polygonal shape as shown by the dotted line in Fig. 7. Correct machining of the cam outer circumference was required.

Also, as shown in Figure 6, if the resin cam uses insert metal fittings 15' (mild steel, copper alloy, aluminum alloy), the linear expansion will be significantly different, so when the temperature rises, deformation will occur at both ends as shown by the dotted line. In addition, stress at the time of the bottom shape was concentrated on the outer periphery of the insert and the contact area, causing cracks 16 to occur.

Therefore, the present invention attempts to eliminate these defects and provides a resin integrally molded cam group that is robust, has improved molding accuracy, and eliminates deformation due to temperature changes.

An embodiment embodying the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 has cams 3 with a radial mountain range pattern on the outer periphery, grooves 6 are formed between each cam 3, and a large number of cams 3a, 3b, 3c, . . . are formed in the axial direction. ...3n
The main body of the cam group is integrally formed and has an opening on the minus side and a closed part on the other side, and is fixed to the cam shaft 2.

Into this opening, an inner diameter 8 having the same diameter as the outer diameter of the bearing part 7 or slightly smaller than the outer diameter and an inner diameter 5 of the cam group main body 1 are fitted, and the lid 4 is fixed concentrically with the cam group main body 1.

Further, in the closed part on the other side of the cam group main body 1, there is a gear 9 which is integrally connected to a bearing part 7 inserted into the cam shaft 2 supported on the sewing machine frame and receives the driving force of the cam group. It is integrally formed on the circumference.

This suppresses deformation due to the contact finger load applied to the cam group body 12, and forcibly ensures concentricity between the outer periphery of the cam group body 1 and the cam shaft.

The material of the lid 4 is the same resin as that of the cam group body 1, or other rigid resin or metal.

The groove 6 serves to eliminate the influence of shrinkage and deformation of the adjacent cam during integral resin molding, and also prevents contact fingers from interfering with the adjacent cam.

FIG. 3 shows another embodiment, in which a straight lid 4' is fitted and fixed to the inner circumference 5 of the cam group body 1 and the outer circumference 8 of the bearing part.

FIG. 4 shows another modified embodiment, in which the cam group body 1
A bearing part 7' is provided only on the other side, and the camshaft is supported by the inner diameter part 7'' of the lid 4'' on the negative side.

As explained above, the present invention includes a plurality of cams each having a radial cam shape in the axial direction on the outer circumference, a gear, and a groove provided between each cam and a bearing portion on the inner diameter of the cam group body. Since it has an integral bottom shape, it is no longer necessary to deform the polygon due to contraction of the rib 14 during molding and to modify the cam outer periphery as in the conventional device.

In addition, the risk of cracking caused by the difference in linear expansion in the case of insert metal fittings has been eliminated.

Unlike silver-gold laminated cams, where cumulative errors occur during assembly due to variations in plate thickness, there is no need to adjust the pitch using seam washers of different thicknesses and assemble. A cam group body can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the device of the present invention, FIG. 2 is a cross-sectional view of the device of the present invention, FIGS. 3 and 4 are cross-sectional views showing modified embodiments of the device of the present invention, and FIG. The figure shows a conventional device in which silver-gold cams are laminated, FIG. 6 shows a conventional device including a boss insert also integrally molded with resin, and FIGS. 7 and 8 are side views showing defects in the conventional resin cam. 1...Cam group main body, 2...Cam shaft 'i
39 3av3 b, 3 e = 3 n =
Cam, 69 6a, 6b. 6et6n・・・groove, 7.7', 7″ 7 //
/...Bearing section.

Claims (1)

[Scope of utility model registration request] A plurality of cams arranged in a row in the axial direction, grooves interposed between the cams, and gears are provided on the outer periphery, and an opening and a closing portion are respectively formed on one side and the other side, and the closing portion is provided on the outer periphery. A cam group main body having an integral bottom shape and having a bearing portion mounted on a cam shaft rotatably supported on a sewing machine frame, and an opening of the cam group main body are closed, and the cam group A pattern sewing cam device for a zigzag sewing machine, comprising an outer periphery ε of a main body and a lid fixed between the bearing parts, and the cam group main body is molded with resin.