JPS6324711B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an inner cutter of a rotary electric shaver, and particularly to a structure of a connecting portion with a push-up spring for biasing the inner cutter toward the outer cutter. .

[Background technology]

The inner cutter 2 in the rotary electric shaver is the sixth
As shown in the figure, the outer cutter 1 is attached to an inner cutter base 5 which is connected to the output shaft of a motor and rotationally driven within the outer cutter frame 4 to which the outer cutter 1 is attached, and one end is attached to the inner cutter base 5. Fixed push-up spring 3
By engaging with the tip of the inner cutter 2, the edge 20 formed on the upper edge of the inner cutter 2 comes into sliding contact with the inner surface of the outer cutter 1.
The part that engages with the push-up spring 3 is the conventional seventh part.
As shown in the drawings and FIG. 8, a vertical groove 21 that opens downward is formed in the lower part of the inner cutter 2, and the upper end of this vertical groove 21 is used as the engagement part of the push-up spring 3.
When the inner cutter 2 is assembled into the inner cutter base 5 from above, the tip of the push-up spring 3 automatically fits into the vertical groove 21, and the inner cutter 2 and push-up spring 3 are connected. In order to prevent the inner cutter 2 from coming off due to vibrations caused when cleaning beard debris or shaving, a protrusion 22 is provided protruding from the middle of the side wall of the vertical groove 21, and the protrusion 22 and the push-up spring 3 are partially overlapped in the left-right direction in the figure, and the upward movement of the inner cutter 2 relative to the inner cutter base 5 is restricted by the push-up spring 3 hitting the tip of the protrusion 22. be. However, in this case, due to variations in parts during assembly, deformation of the push-up spring 3 during use, etc., the push-up spring 3 moves to the right in the figure, and the overlap amount A between the inner cutter 2 and the protrusion 22 disappears. As shown in FIG. 8, the push-up spring 3 sometimes slipped out from the vertical groove 21 of the inner cutter 2. As shown in FIG. 9, a vertical groove 21 opens downward at the engagement portion of the inner cutter 2 with the push-up spring 3.
If the hole 23 is provided instead of a hole 23, unlike the case described above, the inner cutter 2 will not come off, but in this case, the inner cutter 2 may not be attached to the inner cutter base 5. When the push-up spring 3 is inserted from above and assembled, the push-up spring 3 is pushed by the lower edge of the inner cutter 2 and bent greatly before its tip fits into the hole 23, as shown in FIG. Therefore, plastic deformation occurs in the push-up spring 3, resulting in a problem of poor yield.

[Purpose of the invention]

The present invention has been made in view of these points, and its purpose is to enable smooth assembly and to prevent the push-up spring from being plastically deformed. To provide an inner blade of an electric shaver that does not come out of engagement with a spring.

[Disclosure of the invention]

Therefore, the present invention has an edge on the upper edge that makes sliding contact with the inner surface of the outer blade, and a vertical groove that opens downward at the lower part, and the side walls of the vertical groove are in the biasing direction of the push-up spring. A plurality of protrusions protrude toward the other side wall at vertically shifted positions, and a passage is formed between the protrusions and the other side wall where the tip of the protrusion faces, and The width of the passage in the direction orthogonal to the longitudinal direction of the push-up spring is made larger than the width of the push-up spring that contacts the upper end of the vertical groove, and the width of the passage section is made larger than the width of the push-up spring that contacts the upper end of the vertical groove, and the above-mentioned orthogonal relationship is established between the tips of the protrusions that are vertically offset and protrude from each side wall. The spacing in this direction is characterized by being smaller than the width of the push-up spring, and during assembly, the push-up spring is moved along the vertical groove that opens downward to the mounting position at the top of the vertical groove. In addition, no matter which direction the push-up spring moves, the push-up spring comes into contact with a protrusion protruding from either side wall.

The present invention will be described in detail below based on an illustrated embodiment. FIGS. 1 to 4 show an embodiment of the present invention, in which an outer cutter frame 4 holding an outer cutter 1 is A plurality of inner cutters 2 are mounted at equal intervals in the circumferential direction on an inner cutter base 5 which is rotationally driven by being connected to a motor. In addition, the outer cutter 1 here has a bent strip 10 that dips downward on its upper surface circumference, and correspondingly, the inner cutter 2 also has an inner cutter 2A on the inner circumferential side than the bent strip 10.
and an inner cutter 2B on the outer peripheral side.
In the figure, 6 is a comb and 7 is a cover. The push-up spring 3 that urges each inner cutter 2 upward and brings the edge 20 of the upper edge of the inner cutter 2 into contact with the inner surface of the outer cutter 1 is integrated into each inner cutter 2 as shown in FIG. The inner cutter base 5 is fixed to the lower surface of the inner cutter base 5 by a heat seal portion 9. The tip of this push-up spring 3 is connected to the inner cutter insertion opening 15 of the inner cutter base 5.
The inner cutters 2 are inserted into the vertical grooves 21 that open downward and are formed at the bottom of the inner cutters 2 from above, and are engaged with the upper ends of the respective longitudinal grooves 21.
Although the vertical groove 21 in the inner cutter 2A located on the inner peripheral side has the same form as the conventional example, the inner cutter located on the outer peripheral side The vertical groove 21 in 2B has protrusions 22A and 22B protruding from its left and right side walls, respectively.

As is clear from Figures 3 and 4,
Both protrusions 22A, 22B are provided to protrude from positions shifted from each other in the up and down direction, which is the urging direction of the push-up spring 3, and these two protrusions 22A, 22
Between B and the other side wall that they face,
A narrow passage is formed between the protrusion 22A located on the opening side and the other side wall. However, although this passage section is narrow, the biasing direction and the push-up spring 3
The width L ₁ in the direction perpendicular to the longitudinal direction of
The width L ₃ of the push-up spring 3 is larger than the width L ₃ of the push-up spring 3; It is said to be smaller than the width _L3 . Further, both side walls of the vertical groove 21 on the opening side of the protrusion 22A are tapered so that the width is wider on the opening side, and the protrusion 22A,
One side wall of the vertical groove 21 between the vertical grooves 22B and 22B also
It has a tapered shape with the opening side being wider.

However, in the inner cutter 2B of the lever, since the width L ₁ of the passage portion is larger than the width L 3 of the push spring ₃ , when assembling the inner cutter 2B to the inner cutter base 5, the push spring 3 is In order to reach the upper end of the vertical groove 21 from the lower opening of the vertical groove 21 through the narrow passage part, the push-up spring 3 will not be greatly bent and plastically deformed, and the vertical groove Since the side wall of 21 is tapered as described above, the push-up spring 3
The vertical groove 21 can be smoothly moved from its opening to the upper end without being caught by the groove 2B. The push-up spring 3 once contacts the upper end of the vertical groove 21.
Since the inner cutter 2B overlaps with the upper protrusion 22B by the minute dimension _L5 , the inner cutter 2B will not come off, and the push-up spring 3 will not come off due to the external force received when cleaning the beard debris, vibrations during shaving, etc.
moves in a direction perpendicular to its biasing direction and longitudinal direction, and as a result of this movement, even if the overlap amount _L5 with the projection 22B located above disappears, the overlap with the projection 22A located below it disappears. On the contrary, the overlap amount L ₆ increases, so
This prevents the inner cutter 2B from coming off.

FIG. 5 shows another embodiment. Here, vertical groove 2
Two protrusions 22 vertically shifted from one side wall of 1
A and 22C are provided to protrude with approximately the same amount of protrusion, and both protrusions 22C are provided in the vertical direction from the other side wall.
A protrusion 22B is provided between A and 22C. Note that two narrow passages are formed here, but their widths L ₁ and L ₄ are the same,
It is larger than the width _L3 of the push-up spring 3. With the three protrusions 22A, 22B, and 22C, the effect of preventing detachment is enhanced compared to the above embodiment.

〔Effect of the invention〕

As described above, in the present invention, the push-up spring is engaged with the upper end of the vertical groove that opens downward, and the push-up spring can be moved along the vertical groove to the upper end of the vertical groove during assembly. There is no fear that the push-up spring will be greatly bent and plastically deformed, and moreover, the push-up spring will not shift due to external force or vibration due to the plurality of vertically offset protrusions that protrude from both side walls of the vertical groove. Also, the inner cutter does not come off from the push-up spring.

[Brief explanation of the drawing]

Fig. 1 is a cutaway front view of an embodiment of the present invention, Fig. 2 is a bottom view of the inner cutter base of the above, Fig. 3 is a front view of the inner cutter on the outer peripheral side of the above, and Fig. 4 is an enlarged front view of the same as the above. 5 is an enlarged front view of another embodiment, FIG. 6 is a cutaway front view of the conventional example, FIG. 7 is a front view of the inner cutter of the above, FIG. 8 is an enlarged front view of the same, and FIG. The figure is a front view of another conventional example, and FIG. 10 is a longitudinal sectional view of the same.
2 is an outer cutter, 2 is an inner cutter, 3 is a push-up spring, 20 is an edge, 21 is a vertical groove, and 22A, 22B, and 22C are protrusions.

Claims (1)

[Claims] 1. The upper edge is provided with an edge that comes into sliding contact with the inner surface of the outer blade, and the lower part is provided with a vertical groove that opens downward. A plurality of protrusions protrude toward the other side wall at positions shifted in a certain vertical direction, and a passage is formed between the protrusions and the other side wall facing the tips of the protrusions, and the biasing direction is The width of the passage in the direction orthogonal to the longitudinal direction of the push-up spring is made larger than the width of the push-up spring that contacts the upper end of the vertical groove, and the width of the passage section is made larger than the width of the push-up spring that contacts the upper end of the vertical groove, and An inner blade of an electric shaver, characterized in that the interval in the orthogonal direction is smaller than the width of the push-up spring. 2. The inner blade of the electric shaver according to claim 1, wherein the side wall of the vertical groove between the protrusion located on the opening side and the opening has a tapered shape with the opening side being wider. . 3. The inner blade of an electric shaver according to claim 1, wherein the vertical groove side wall between the vertically shifted projections has a tapered shape with the opening side being wider.