JP7471934B2 - Reciprocating electric shaver - Google Patents

Description

The present invention relates to a reciprocating electric shaver.

In recent years, efforts have been made to increase the number of outer blades in the head of reciprocating electric razors in order to increase the contact area with the skin. The outer blades are used in combination with corresponding inner blades, and the inner blades are reciprocated by two oscillators. The outer blades are generally composed of a combination of a cutting blade and a trimmer blade.

Conventionally, a reciprocating electric shaver with five outer blades on the head is known (Patent Document 1: JP 2011-067420 A).

JP 2011-067420 A

In the configuration of Patent Document 1, depending on the combination of outer blades, the position of the arm part whose upper end is detachably attached to the inner blade when it is fixed upright on the movable base of one oscillator is farther away from the axis of the motor drive shaft than the position of the arm part whose upper end is detachably attached to the inner blade when it is fixed upright on the movable base of the other oscillator. This causes a problem in that the balance of the driving forces driving the two oscillators is lost, making it easier for abnormal vibrations to occur. If the number of outer blades is greater than in conventional products, the size of the head part becomes larger and it becomes even more easy to cause abnormal vibrations. For this reason, the reality is that a configuration with six or more outer blades on the head part has not been put to practical use.

The present invention was made in consideration of the above circumstances, and aims to provide a reciprocating electric shaver that is configured to allow smooth reciprocating motion of the oscillator even when the number of outer blades is increased while preventing the head from becoming larger in size.

In one embodiment, the above problem is solved by the solution disclosed below.

The reciprocating electric shaver according to the present invention comprises an outer blade, an inner blade that reciprocates left and right while sliding against the inner surface of the outer blade, an outer blade holding frame to which the outer blade is attached so as to follow the ascending and descending movement of the inner blade, a blade frame to which the outer blade holding frame is attached, a main body to which the blade frame is attached, a motor built into the main body, and an oscillator that reciprocates the inner blade by the driving force of the motor , the oscillator comprising a movable base that can reciprocate, and a blade that is fixed upright on the movable base and has an upper end that can be attached and detached to the inner blade. The arm portion has a first arm, a second arm, and a third arm arranged in this order from the front side of the main body, directly above the arm support portion at a predetermined interval, and an arm attachment portion arranged directly below the arm support portion, and the arm attachment portion is fixed upright to the movable base, the oscillator is composed of a first oscillator arranged closer to the front side of the main body and a second oscillator arranged closer to the back side of the main body, and the outer cutter is arranged on the upper surface side of the main body, and the outer cutter is The blade is made up of four first outer cutters and two second outer cutters having a different shape from the first outer cutters, the inner cutters are made up of a first inner cutter corresponding to the first outer cutters and a second inner cutter corresponding to the second outer cutters, the first outer cutters and the first inner cutters form a cutting blade, the second outer cutters and the second inner cutters form a trimmer blade, the trimmer blade is arranged adjacent to the cutting blade, one of the second inner cutters is attached on a first center line passing through the arm mounting portion, the arm support portion and the second arm of the first oscillator, the three inner cutters are arranged symmetrically in the front and rear with respect to the first center line, and one of the second inner cutters is attached on a second center line passing through the arm mounting portion, the arm support portion and the second arm of the second oscillator, the three inner cutters are arranged symmetrically in the front and rear with respect to the second center line that is parallel to the first center line .

With this configuration, the second inner blade, which is subject to a larger load when reciprocating in sliding contact with the first inner blade, is attached on or near the vertical center line of each oscillator, so that the driving forces driving the two oscillators can be balanced. In addition, by arranging the trimmer blade adjacent to the cutting blade and narrowing the gap between the outer blades, the size of the head can be prevented from increasing.

The present invention makes it possible to realize a reciprocating electric shaver that allows the oscillator to reciprocate smoothly even when the number of outer blades is increased while minimizing the increase in the size of the head.

FIG. 1 is a schematic perspective view showing an example of a reciprocating electric shaver according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along line II-II of FIG. FIG. 3 is a schematic exploded view of the structure of FIG. FIG. 4 is a schematic cross-sectional view showing an example of the arrangement of the outer cutter and the inner cutter in the first embodiment. FIG. 5A is a schematic side view showing an example of an arm portion in a first oscillator, and FIG. 5B is a schematic side view showing an example of an arm portion in a second oscillator. FIG. 6 is a schematic side view showing an example of an outer cutter holding frame to which an outer cutter is attached. FIG. 7 is a schematic perspective view showing an example of an outer cutter holding frame to which an outer cutter is attached. 8A to 8E are schematic perspective views each showing an example of the arrangement of a reinforcing portion in the first oscillator. FIG. 9 is a schematic exploded view showing a structure of an example of a reciprocating electric shaver according to the second embodiment of the present invention. FIG. 10 is a schematic cross-sectional view showing an example of the arrangement of the outer cutter and the inner cutter in the second embodiment. FIG. 11A is a schematic side view showing an example of a first oscillator, and FIG. 11B is a schematic side view showing an example of a second oscillator. FIG. 12A is a schematic side view showing an example of an arm portion in the first oscillator, and FIG. 11B is a schematic side view showing an example of an arm portion in the second oscillator. FIG. 13A is a schematic side view showing an example of a first oscillator, and FIG. 13B is a schematic side view showing an example of a second oscillator. FIG. 14A is a schematic side view showing an example of an arm portion in a first oscillator, and FIG. 14B is a schematic side view showing an example of an arm portion in a second oscillator.

The following describes in detail an embodiment of the present invention with reference to the drawings. In this embodiment, a reciprocating electric shaver 1 has a motor 5, a power supply unit 22, and a control unit 23 built into the main body 2, and the inner blade 12 is reciprocated by the driving force of the motor 5. Known technologies can be applied to the motor 5, the power supply unit 22, and the control unit 23. In all the drawings used to explain the embodiment, members having the same functions are given the same reference numerals, and repeated explanations may be omitted.

First Embodiment
As shown in Figures 1 to 3, a reciprocating electric shaver 1, for example, has a main body 2 formed with a grip portion to be held by a user, a power switch 21 disposed on the front of the main body 2, and a blade frame 3 attached to a head portion 2a on the upper side of the main body 2. A plurality of outer blades 11 are disposed on the blade frame 3, and the outer blades 11 are used in combination with corresponding inner blades 12. In this example, six or more outer blades 11 are disposed on the upper surface side of the main body 2, and each inner blade 12 is configured to reciprocate in the longitudinal direction of the outer blade 11 while sliding against the inner surface of the outer blade 11. The outer blades 11 are attached to the outer blade holding frame 4 so as to be able to follow the ascending and descending movements of each inner blade 12, and the outer blade holding frame 4 is configured to be detachably attached to the blade frame 3.

The outer blade 11 is provided with a plurality of first outer blades 11a and a plurality of second outer blades 11b having a different shape from the first outer blades 11a. The inner blade 12 is provided with a first inner blade 12a that corresponds one-to-one with the first outer blade 11a and a second inner blade 12b that corresponds one-to-one with the second outer blade 11b. The first outer blade 11a and the first inner blade 12a form a wide-angle cutting blade 10a, and the second outer blade 11b and the second inner blade 12b form a trimmer blade 10b, with the trimmer blade 10b being arranged adjacent to the cutting blade 10a. By arranging the trimmer blade 10b adjacent to the cutting blade 10a, the spacing between the outer blades is narrowed, and the size of the head portion 2a can be suppressed from increasing. In order to make it easier to explain the relative positions of the various parts of the reciprocating electric shaver 1, the directions are indicated by arrows in the figures, and in this specification, the front of the main body 2 may be referred to as the "front" and the rear of the main body 2 may be referred to as the "rear."

In the example of Figs. 1 to 3, the head part 2a is configured to swing left and right or front and back with the main body 2 as a reference. The edge trimming blade 13 and slide switch 25 are also arranged on the rear side of the main body 2. The edge trimming blade 13 is configured such that a third outer blade made of a metal plate with one side processed into a comb shape is attached to a resin frame, and a third inner blade corresponding to the third outer blade reciprocates in the longitudinal direction of the third outer blade while sliding against the inner surface of the third outer blade. When the slide switch 25 is slid upward to raise the edge trimming blade 13, the fourth arm 18d of the arm part 8d in the second oscillator 8 is connected to enable the second oscillator 8 and the edge trimming blade 13 to be linked, and the inner blade of the edge trimming blade 13 is reciprocated by the driving force of the motor 5. In other words, when the slide switch 25 is slid upward to raise the edge trimming blade 13, the second oscillator 8 and the edge trimming blade 13 can be linked. Known technology can be applied to the edge trimming blade 13. Note that the configuration is not limited to the above, and for example, the main body 2 and the head portion 2a may be integrally formed, or the edge trimming blade 13 may be omitted.

As shown in FIG. 2, the main body 2 is equipped with a crank section 6 that converts the rotational motion of the drive shaft 5a of the motor 5 into linear motion, and a first oscillator 7 and a second oscillator 8 that reciprocate the inner blade 12 by the driving force of the motor 5 via the crank section 6, and a presser plate 24 is attached and fixed to the head section 2a. Here, the first oscillator 7 is disposed closer to the front of the main body 2, and the second oscillator 8 is disposed closer to the back of the main body 2. The drive shaft 5a is connected to the elongated hole 7e formed in the movable base 7a of the first oscillator 7 and the elongated hole 8e formed in the movable base 8a of the second oscillator 8 by the crank section 6. For the crank section 6, a known technology such as that described in JP 2018-187045 can be applied, as an example.

Figure 4 is a schematic diagram showing an example of the arrangement of the outer cutter 11 and inner cutter 12 in Figure 1, and is a schematic cross-sectional view showing the arrangement of the outer cutter 11, inner cutter 12, outer cutter holding frame 4, and cutter frame 3. As an example, the outer cutter 11 has four first outer cutters 11a arranged symmetrically in the front-rear direction, and two second outer cutters 11b of a different shape from the first outer cutters 11a arranged symmetrically in the front-rear direction, and the first outer cutters 11a and second outer cutters 11b arranged adjacent to each other are connected so that they can be raised and lowered.

As an example, the first outer blade 11a is configured by attaching a metal plate with fine holes formed therein to a resin frame with an inverted U-shaped cross section. As an example, the second outer blade 11b is configured by attaching a pair of metal plates with one side processed into a comb shape to a resin frame. The inner blades 12 are arranged in a one-to-one correspondence with the outer blades 11, and are configured to consist of a first inner blade 12a with an inverted U-shaped cross section corresponding to the first outer blade 11a, and a second inner blade 12b with an inverted L-shaped cross section corresponding to the second outer blade 11b, which are arranged symmetrically in the front and rear. As an example, the first inner blade 12a is biased by a coil spring 12j and reciprocates in the longitudinal direction of the first outer blade 11a while sliding against the inner surface of the first outer blade 11a. The second inner blade 12b is attached to the inside of the second outer blade 11b and reciprocates in the longitudinal direction of the second outer blade 11b while sliding against the inner surface of the second outer blade 11b. The first outer blade 11a and the first inner blade 12a form a wide-angle cutting blade 10a, which has a so-called arch shape in cross section. The second outer blade 11b and the second inner blade 12b form a trimmer blade 10b, which has a so-called T shape in cross section. The composition ratio of the cutting blade 10a and the trimmer blade 10b in the outer blade 11 is arbitrary. The outer blade 11 and the inner blade 12 can be made using known technology.

As shown in FIG. 1, the outer blades 11 of this embodiment are arranged in six or more than six pieces. This configuration allows for a larger contact area with the skin than conventional products, while more reliably shaving areas with large contours such as the chin. In addition, since the multiple outer blades 11 are arranged symmetrically front to back, the same shaving quality can be obtained whether the main body 2 is held from the front or back, regardless of how the main body 2 is held. This also makes it possible to arrange a large number of outer blades 11 while suppressing an increase in the size of the head portion 2a.

As shown in FIG. 4, the first outer blade 11a, the second outer blade 11b, the first outer blade 11a, the first outer blade 11a, the second outer blade 11b, and the first outer blade 11a are arranged symmetrically in the order of front to back. This allows the first inner blade 12a, the second inner blade 12b, and the first inner blade 12a reciprocated by the first oscillator 7 to be combined with the first inner blade 12a, the second inner blade 12b, and the first inner blade 12a reciprocated by the second oscillator 8. This makes it easy to maintain the balance of the driving forces that drive the first oscillator 7 and the second oscillator 8. Furthermore, the T-shaped trimmer blade 10b is arranged to fill the gap between the arch-shaped cutting blade 10a, so that the size of the head portion 2a can be minimized.

As an example, in a configuration in which six outer blades 11 are arranged on the top surface side of the main body 2, the number of inner blades 12 allocated to the first oscillator 7 will be two, three, or four.

The examples shown in Figures 3, 5A, and 5B are configured to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8 when the number of inner blades 12 allocated to the first oscillator 7 is three and the number of inner blades 12 allocated to the second oscillator 8 is three.

Figure 5A is a schematic side view showing an example of arm portion 7d in the first oscillator 7, and Figure 5B is a schematic side view showing an example of arm portion 8d in the second oscillator 8. Arm portion 7d is formed integrally with first arm 17a, second arm 17b, third arm 17c, arm support portion 17e, and arm attachment portion 17f. Arm portion 8d is formed integrally with first arm 18a, second arm 18b, third arm 18c, fourth arm 18d, arm support portion 18e, and arm attachment portion 18f.

The first arm 17a, the second arm 17b, and the third arm 17c of the arm section 7d are erected at equal intervals and point upward, and the arm attachment section 17f is attached and fixed to the arm receiving section of the first oscillator 7. The first arm 18a, the second arm 18b, and the third arm 18c of the arm section 8d are erected at equal intervals and point upward, and the fourth arm 18d is attached and point downward, and the arm attachment section 18f is attached and fixed to the arm receiving section of the second oscillator 8.

The arm portion 7d of the first oscillator 7 has one of the inner blades 12 attached on the first center line P1 in the vertical direction. Here, the first inner blade 12a is attached to the first arm 17a, the second inner blade 12b is attached to the second arm 17b, and the first inner blade 12a is attached to the third arm 17c. The arm attachment portion 17f is disposed directly below the second arm 17b via the arm support portion 17e. With this configuration, the first oscillator 7 has three inner blades 12 symmetrically arranged front to back with respect to the first center line P1, so that the load balance of the first oscillator 7 can be maintained.

The arm portion 8d of the second oscillator 8 has one of the inner blades 12 attached to the second center line P2 parallel to the first center line P1. Here, the first inner blade 12a is attached to the first arm 18a, the second inner blade 12b is attached to the second arm 18b, and the first inner blade 12a is attached to the third arm 18c. As a result, the three inner blades 12 of the second oscillator 8 are arranged symmetrically in the front and rear with respect to the second center line P2 in the vertical direction. Meanwhile, the arm attachment portion 18f is disposed in a position forward of the position directly below the second arm 17b via the arm support portion 17e. This allows the load balance of the second oscillator 8 to be maintained.

In other words, the arm 7d of the first oscillator 7 has one of the second inner blades 12b attached on the first center line P1 in the vertical direction of the first oscillator 7 or closer to the first center line P1 in the vertical direction, and the arm 8d of the second oscillator 8 has one of the second inner blades 12b attached on the second center line P2 in the vertical direction of the second oscillator 8 or closer to the second center line P2 in the vertical direction. According to this configuration, one of the second inner blades 12b, which is subject to a larger load when reciprocating in sliding contact compared to the first inner blade 12a, is attached on the first center line P1 or closer to the first center line P1 in the vertical direction, and one of the second inner blades 12b is attached on the second center line P2 or closer to the second center line P2 in the vertical direction, so that it is easy to maintain a balance in the driving forces that drive the first oscillator 7 and the second oscillator 8.

As shown in Figures 3 and 5A, the arm portion 7d of the first oscillator 7 has a first arm 17a, a second arm 17b, and a third arm 17c arranged at equal intervals directly above the arm support portion 17e, and an arm attachment portion 17f arranged directly below the arm support portion 17e, and the arm attachment portion 17f is fixed upright to the movable base 7a, and the arm attachment portion 17f of the first oscillator 7 and the second arm 17b to which the second inner blade 12b is attached are arranged in a position that overlaps in a plan view. 3 and 5B, the arm portion 8d of the second oscillator 8 has the first arm 18a, the second arm 18b, and the third arm 18c arranged at equal intervals directly above the arm support portion 18e, the arm attachment portion 18f arranged directly below the arm support portion 18e, and the arm attachment portion 18f is fixed upright to the movable base 8a, and the arm attachment portion 18f of the second oscillator 8 and the second arm 18b to which the second inner blade 12b is attached are arranged in a position that overlaps in a plan view. This makes it easy to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8.

As shown in FIG. 2, the axis P3 of the drive shaft 5a of the motor 5 is located rearward within a range that does not reach the first arm 18a, with the exact midpoint between the third arm 17c and the first arm 18a as the reference. As an example, the axis P3 of the drive shaft 5a is located rearward within a range of 0.5 mm or more and 1.5 mm or less, with the exact midpoint between the third arm 17c and the first arm 18a as the reference. This makes it easy to maintain the load balance of the first oscillator 7 and the second oscillator 8. Note that in the case of a configuration that does not have the trimming blade 13, the second oscillator 8 is arranged in the same configuration as the first oscillator 7, so the axis P3 of the drive shaft 5a is located rearward within a range that does not reach the first arm 18a, with the exact midpoint between the third arm 17c and the first arm 18a.

Figure 6 is a schematic side view showing an example of an outer cutter holding frame 4 to which the first outer cutter 11a and the second outer cutter 11b are attached. The outer cutter holding frame 4 has a first window 14a, a second window 14b, a third window 14c, a fourth window 14d, a fifth window 14e, and a sixth window 14f formed on both sides at a predetermined interval from the front to the rear. The first outer cutter 11a and the second outer cutter 11b have protrusions 11d formed on both sides thereof attached to each window, and the first outer cutter 11a and the second outer cutter 11b are each configured to be able to move up and down within the range in which each protrusion can slide up and down in each window.

The first outer blade 11a and the second outer blade 11b are configured to be able to move up and down independently. Here, the first outer blade 11a is configured so that the amount of lift at the position closer to the front of the main body 2 and the amount of lift at the position closer to the back of the main body 2 are both greater than the amount of lift at the position closer to the center of the main body 2. As a result, when shaving a beard in an area with large undulations such as the chin, the first outer blade 11a closer to the front of the main body 2 or the first outer blade 11a closer to the back of the main body 2, which is likely to hit the area with large undulations first, can have a larger stroke than the first outer blade 11a closer to the center of the main body 2, so that the beard can be more reliably captured and shaved. Here, the second outer blade 11b is configured so that the amount of lift at the position closer to the front of the main body 2 and the amount of lift at the position closer to the back of the main body 2 are the same as the amount of lift at the position closer to the front of the main body 2 and the amount of lift at the position closer to the back of the main body 2 of the first outer blade 11a. In addition, the above configuration is not limited to the above, and the first outer blade 11a and the second outer blade 11b may be configured so that the amount of lift gradually decreases from the front to the center of the main body 2, and also from the back to the center of the main body 2.

Figure 7 is a schematic perspective view showing an example of an outer cutter holding frame 4 to which the first outer cutter 11a and the second outer cutter 11b are attached. The outer cutter holding frame 4 has an axial member 9 that guides the first outer cutter 11a and the second outer cutter 11b to move up and down while regulating the range in which the first outer cutter 11a and the second outer cutter 11b can move up and down. The axial member 9 is disposed at a predetermined position in the longitudinal direction of the outer cutter holding frame 4, and the axis of the axial member 9 is oriented in the short direction of the outer cutter holding frame 4. Here, the first outer cutter 11a and the second outer cutter 11b disposed adjacent to each other are connected so that they can move up and down. According to this configuration, by disposing the axial member 9, it is possible to prevent the outer cutter 11 from moving up and down in a staggered manner. In other words, the shaft-shaped member 9 guides the outer cutters 11 to move up and down smoothly and regulates the range in which they can move up and down, so even if the number of outer cutters 11 in the head portion 2a is increased, they can move up and down smoothly. In addition, the guide plate separating the first outer cutter 1 and the second outer cutter 11b, as in conventional products, is eliminated, resulting in a configuration that further reduces the size of the head portion 2a. In other words, by providing the shaft-shaped member 9, the range in which the first outer cutter 11a and the second outer cutter 11b can move up and down is regulated within a range appropriate for shaving, resulting in a configuration that allows for smooth movement up and down. Furthermore, the reciprocating electric shaver 1 is equipped with a small, easy-to-use head portion 2a.

The shaft-shaped member 9 is made of resin, metal, ceramics, or a composite material of these. The shaft portion of the shaft-shaped member 9 has a guide function, and is, for example, pin-shaped or rod-shaped. The cross-sectional shape of the shaft portion of the shaft-shaped member 9 is circular, elliptical, square, rectangular, triangular, or polygonal.

The shaft-shaped member 9 has an axis in the short direction of the outer cutter holding frame 4, is arranged at a predetermined position in the longitudinal direction of the outer cutter holding frame 4, and regulates the range in which the first outer cutter 11a and the second outer cutter 11b can be raised and lowered. With this configuration, smooth raising and lowering is possible even if the number of outer cutters 11 is increased compared to conventional products. As an example, the shaft-shaped member 9 is arranged at a position toward the left or right in the longitudinal direction of the outer cutter holding frame 4. This results in a configuration with a high degree of freedom in the raising and lowering of each of the outer cutters 11. As an example, the sharpened parts formed on both ends of the shaft-shaped member 9 are fitted into the through holes 14g formed on both sides of the outer cutter holding frame 4. It is not limited to the above configuration, and it is also possible to attach flanges to both ends of the shaft-shaped member 9 and attach the flanges of the shaft-shaped member 9 to guide grooves formed on the inner walls on both sides of the outer cutter holding frame 4.

The first outer cutter 11a has a slit 11c formed in the upward direction from the bottom surface. The shaft-shaped member 9 passes through the slit 11c, and the slit 11c is configured to slide on the shaft-shaped member 9. Here, the shaft-shaped member 9 is fitted into the slit 11c. This allows the first outer cutter 11a and the second outer cutter 11b to be tilted left and right, and to be raised and lowered up and down, resulting in a configuration with a high degree of freedom of movement for the outer cutter 11 and the inner cutter 12. Furthermore, assembly is facilitated when attaching the first outer cutter 11a, the second outer cutter 11b, and the shaft-shaped member 9 to the outer cutter holding frame 4, and maintenance is also facilitated.

3, the first oscillator 7 is disposed closer to the front of the main body 2, and the second oscillator 8 is disposed closer to the back of the main body 2. The first oscillator 7 has a movable base 7a that can move back and forth, support parts 7b that are disposed at both ends of the movable base 7a and suspend the movable base 7a, mounting parts 7c that are disposed at both ends of the support parts 7b and attached to the inside of the main body 2 by fixing means such as screws, and an arm part 7d that is fixed upright to the movable base 7a and has an upper end that is detachably attached to the inner blade 12. The second oscillator 8 has a movable base 8a that can move back and forth, support parts 8b that are disposed at both ends of the movable base 8a and suspend the movable base 8a, mounting parts 8c that are disposed at both ends of the support parts 8b and attached to the inside of the main body 2 by fixing means such as screws, and an arm part 8d that is fixed upright to the movable base 8a and has an upper end that is detachably attached to the inner blade 12. Support portion 7b and support portion 8b are U-shaped (including approximately U-shaped) when viewed from the front. Movable base 7a and movable base 8a reciprocate left and right by crank portion 6 connected to long hole 7e and long hole 8e, respectively.

As an example, a conventional product has a configuration in which five outer blades are provided on the head section, and the position of the arm section, which is fixed upright on the movable base of one oscillator and has its upper end detachably attached to the inner blade, is located farther from the axis of the motor drive shaft than the position of the arm section, which is fixed upright on the movable base of the other oscillator and has its upper end detachably attached to the inner blade. This causes the arm section to easily wobble sideways, and when this occurs, there is a problem that the oscillator vibrates abnormally. If an attempt is made to increase the number of outer blades even further than in the past, the situation becomes even more susceptible to abnormal vibration. For this reason, the upper limit of the number of outer blades provided on the head section was five.

In this embodiment, as shown in FIG. 2, the distance between the axis P3 of the drive shaft 5a and the first center line P1 of the arm portion 7d is made larger than the distance between the axis P3 of the drive shaft 5a and the second center line P2 of the arm portion 8d, allowing for a greater number of outer blades 11 than in conventional products.

As shown in Figures 8A to 8E, in the first oscillator 7 of this embodiment, a reinforcing portion 7f that reinforces the connection between the movable base 7a and the support portion 7b is extended from the support portion 7b toward the long hole 7e. The reinforcing portion 7f is the portion surrounded by a dashed line in the figure. With this configuration, the reinforcing portion 7f can prevent the arm portion 7d from shaking sideways, so that abnormal vibration of the first oscillator 7 can be prevented. As a result, the position of the arm portion 7d in the first oscillator 7 can be located farther from the drive shaft 5a of the motor 5 than the position of the arm portion 8d in the second oscillator 8. This increases the degree of freedom in the combination of the outer cutters 11, and even if the number of outer cutters 11 is increased compared to the conventional product, the first oscillator 7 and the second oscillator 8 can smoothly reciprocate. The second oscillator 8 can also be configured in the same way as the first oscillator 7.

The first oscillator 7 is provided with a rectangular, plate-like first beam 7h that directly connects one side of the support 7b to the other side of the support 7b, and a triangular, plate-like first connecting portion 7g that extends from the other side of the support 7b to the other side of the support 7b, primarily for the purpose of increasing rigidity and improving durability when reciprocating back and forth at high speed between the movable base 7a and the support 7b. The second oscillator 8 can be configured in the same way as the first oscillator 7.

If the number of outer blades 11 is increased compared to the conventional product, the position of the long hole 7e of the first oscillator 7 will be away from the position of the mounting portion 7d1 to which the arm portion 7d is attached, and the peripheral portion of the long hole 7e will be away from the support portion 7b and the first connecting portion 7g. As a result, the arm portion 7d is prone to lateral vibration, and when lateral vibration occurs, there is a problem that the oscillator will vibrate abnormally. As shown in Figures 8A to 8E, when the long hole 7e is located at a position protruding from the first connecting portion 7g, lateral vibration will occur in the arm portion 7d. On the other hand, if the width of the support portion 7b is increased, the load increases and it becomes difficult to reciprocate at high speed. Therefore, in this embodiment, the reinforcing portion 7f that reinforces the connection between the movable base 7a and the support portion 7b is extended from the support portion 7b toward the long hole 7e to prevent twisting of the long hole 7e, and the structure is such that lateral vibration of the arm portion 7d can be prevented. The second oscillator 8 can also be configured in the same manner as the first oscillator 7.

The reinforcing portion 7f has an overhanging structure. This reduces the weight load while preventing twisting of the long hole 7e. A pair of reinforcing portions 7f are provided on the left and right. As an example, the reinforcing portion 7f has a rib structure. As an example, the overhanging structure is formed by using vertical ribs, horizontal ribs, or a combination of vertical ribs and horizontal ribs.

In the example of FIG. 8A, the reinforcing portion 7f is composed of a triangular plate-shaped second connecting portion and a plate-shaped second beam portion that is directly connected to the first connecting portion 7g on the side. This allows the driving force from the crank portion 6 connected to the long hole 7e to be efficiently converted into reciprocating motion. In the example of FIG. 8B, the reinforcing portion 7f is composed of a triangular plate-shaped second connecting portion, a plate-shaped second beam portion that is directly connected to the first connecting portion 7g on the side, and a plate-shaped third beam portion that is directly connected to the first connecting portion 7g on the top. This allows the driving force from the crank portion 6 connected to the long hole 7e to be efficiently converted into reciprocating motion. In the example of FIG. 8C, the reinforcing portion 7f is composed of a trapezoidal plate-shaped second connecting portion. This allows the weight load to be reduced while preventing twisting of the long hole 7e.

In the example of Figure 8D, the reinforcing portion 7f is configured with a rectangular, plate-shaped second connecting portion. This reduces the weight load while preventing twisting of the long hole 7e. In the example of Figure 8E, the reinforcing portion 7f is configured with the movable base 7a extended toward the long hole 7e. This minimizes the weight load while preventing twisting of the long hole 7e.

As an example, the first oscillator 7 is made of a relatively lightweight engineering plastic such as polyacetal. The configurations of Figures 8A to 8C are particularly preferred because they reduce the weight load. As an example, the first oscillator 7 is made of a material such as a higher density engineering plastic such as a liquid crystal polymer or a highly elastic metal. The configurations of Figures 8D to 8E are particularly preferred because they increase the rigidity. The second oscillator 8 can also be configured in the same way as the first oscillator 7. In addition, in a configuration in which the shaft-shaped member 9 is arranged, a guide plate is provided to separate the first outer cutter 11a and the first outer cutter 11a arranged adjacent to each other, and the first outer cutter 11a and the first outer cutter 11a are separated by the guide plate and are connected by a sliding structure so that they can be raised and lowered. As an example, in a configuration in which six outer cutters 11 are arranged on the upper surface side of the main body 2, the number of inner cutters 12 allocated to the first oscillator 7 is two, three, or four. In addition, if six outer blades 11 are arranged on the top surface of the main body 2, the number of inner blades 12 allocated to the second oscillator 8 will be four, three, or two.

Second Embodiment
Fig. 9 is a schematic exploded view showing an example of a reciprocating electric shaver 1 according to the second embodiment, and Fig. 10 is a schematic cross-sectional view showing an example of the arrangement of the outer blade 11 and the inner blade 12. The second embodiment will be described focusing on the differences from the first embodiment.

As shown in Figures 9 and 10, the outer cutter holding frame 4 has a guide plate 19 that restricts the range in which the first outer cutter 11a can be raised and lowered. In the second embodiment, the shaft-shaped member 9 is not provided. Here, the first outer cutter 11a and the second outer cutter 11b arranged adjacent to each other are connected so that they can be raised and lowered, and the first outer cutter 11a and the first outer cutter 11a arranged adjacent to each other are separated by the guide plate 19 and are connected by a sliding structure so that they can be raised and lowered. Therefore, the range in which the second outer cutter 11b can be raised and lowered is restricted by the guide plate 19 to within a range appropriate for shaving.

The examples shown in Figures 11A, 11B, 12A, and 12B are configured to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8 when the number of inner blades 12 allocated to the first oscillator 7 is four and the number of inner blades 12 allocated to the second oscillator 8 is two.

In other words, the arm 7d of the first oscillator 7 has one of the second inner blades 12b attached on the first center line P1 in the vertical direction of the first oscillator 7 or close to the first center line P1 in the vertical direction, and the arm 8d of the second oscillator 8 has one of the second inner blades 12b attached on the second center line P2 in the vertical direction of the second oscillator 8 or close to the second center line P2 in the vertical direction. With this configuration, one of the second inner blades 12b, which is subject to a larger load when reciprocating in sliding contact compared to the first inner blade 12a, is attached on the first center line P1 or close to the first center line P1 in the vertical direction, and one of the second inner blades 12b is attached on the second center line P2 or close to the second center line P2 in the vertical direction, so that it is easy to maintain a balance in the driving forces that drive the first oscillator 7 and the second oscillator 8.

11A and 12A, the arm portion 7d of the first oscillator 7 is configured such that the first arm 17a, the second arm 17b, and the third arm 17c are arranged directly above the arm support portion 17e at equal intervals, and the fourth arm 17d is arranged directly above the arm support portion 17e at a distance greater than the distance between the second arm 17b and the third arm 17c or the same as the distance between the second arm 17b and the third arm 17c, the arm attachment portion 17f is arranged directly below the arm support portion 17e, and the arm attachment portion 17f is fixed upright to the movable base 7a, and the arm attachment portion 17f of the first oscillator 7 and the second arm 17b to which the second inner blade 12b is attached are arranged in positions that overlap in a plan view. 11B and 12B, the arm 8d of the second oscillator 8 is configured such that the second arm 18b and the third arm 18c are disposed directly above the arm support 18e at the same distance as the distance between the second arm 17b and the third arm 17c, the arm attachment 18f is disposed directly below the arm support 18e, and the arm attachment 18f is fixed upright to the movable base 8a, and the arm attachment 18f of the second oscillator 8 and the second arm 18b to which the second inner blade 12b is attached are disposed in a position that overlaps in a plan view. This makes it easy to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8.

The examples shown in Figures 13A, 13B, 14A, and 14B are configured to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8 when the number of inner blades 12 allocated to the first oscillator 7 is set to 2 and the number of inner blades 12 allocated to the second oscillator 8 is set to 4.

In other words, the arm 7d of the first oscillator 7 has one of the second inner blades 12b attached on the first center line P1 in the vertical direction of the first oscillator 7 or close to the first center line P1 in the vertical direction, and the arm 8d of the second oscillator 8 has one of the second inner blades 12b attached on the second center line P2 in the vertical direction of the second oscillator 8 or close to the second center line P2 in the vertical direction. With this configuration, one of the second inner blades 12b, which is subject to a larger load when reciprocating in sliding contact compared to the first inner blade 12a, is attached on the first center line P1 or close to the first center line P1 in the vertical direction, and one of the second inner blades 12b is attached on the second center line P2 or close to the second center line P2 in the vertical direction, so that it is easy to maintain a balance in the driving forces that drive the first oscillator 7 and the second oscillator 8.

13B and 14B, the arm portion 8d of the second oscillator 8 has the first arm 18a, the second arm 18b, and the third arm 18c arranged directly above the arm support portion 18e at equal intervals, and the fifth arm 18g arranged directly above the arm support portion 18e at a distance greater than the distance between the first arm 18a and the second arm 18b or the same distance as the distance between the first arm 18a and the second arm 18b, the arm attachment portion 18f is arranged directly below the arm support portion 17e, and the arm attachment portion 18f is fixed upright to the movable base 8a, and the arm attachment portion 18f of the second oscillator 8 and the second arm 18b to which the second inner blade 12b is attached are arranged in positions that overlap in a plan view. 13A and 14A, the arm 7d of the first oscillator 7 is configured such that the first arm 17a and the second arm 17b are disposed directly above the arm support 17e at the same distance as the distance between the second arm 18b and the third arm 18c, the arm attachment 17f is disposed directly below the arm support 18e, and the arm attachment 18f is fixed upright to the movable base 8a, and the arm attachment 17f of the first oscillator 7 and the second arm 17b to which the second inner blade 12b is attached are disposed in a position that overlaps in a plan view. This makes it easy to maintain a balance between the driving forces that drive the first oscillator 7 and the second oscillator 8.

The reciprocating electric shaver 1 of this embodiment described above allows the size of the head portion 2a to be reduced while increasing the degree of freedom in the combination of the outer blades 11, and allows for a configuration that allows smooth reciprocating motion of the first oscillator 7 and the second oscillator 8 even if the number of outer blades 11 is greater than in conventional products.

In the above embodiment, an example in which six outer blades 11 are arranged on the head portion 2a of the main body 2 has been described, but this is not limited to this example. The number of outer blades 11 can be seven or eight, and the number of outer blades 11 can be four or five to make the head portion smaller. The specifications of the reciprocating electric shaver 1 described above may be changed as appropriate to suit the specifications, etc.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention.

1 Reciprocating electric shaver 2 Main body, 2a Head portion 3 Blade frame 4 Outer blade holding frame 5 Motor, 5a Drive shaft 6 Crank portion 7 First oscillator (oscillator), 7a Movable base, 7b Support portion, 7c Mounting portion, 7d Arm portion, 7e Long hole, 7f Reinforcement portion 8 Second oscillator (oscillator), 8a Movable base, 8b Support portion, 8c Mounting portion, 8d Arm portion, 8e Long hole 9 Shaft-shaped member 10a Cutting blade, 10b Trimmer blade 11 Outer blade, 11a First outer blade, 11b Second outer blade, 11c Slit, 11d Convex portion 12 Inner blade, 12a First inner blade, 12b Second inner blade, 12j Coil spring 13 Edge trimming blade 14a First window portion, 14b Second window portion, 14c Third window portion, 14d Fourth window portion, 14e Fifth window portion, 14f Sixth window portion, 14g Through hole 17a First arm, 17b Second arm, 17c Third arm, 17e Arm support portion, 17f Arm attachment portion 18a First arm, 18b Second arm, 18c Third arm, 18d Fourth arm, 18e Arm support portion, 18f Arm attachment portion, 18g Fifth arm 19 Guide plate 21 Power switch 22 Power supply unit 23 Control unit 24 Presser plate 25 Slide switch P1 First center line P2 Second center line

Claims (3)

The cutting tool is provided with an outer cutter, an inner cutter that reciprocates left and right while sliding against the inner surface of the outer cutter, an outer cutter holding frame to which the outer cutter is attached so as to follow the ascending and descending movement of the inner cutter, a blade frame to which the outer cutter holding frame is attached, a main body to which the blade frame is attached, a motor built into the main body, and an oscillator that reciprocates the inner cutter by the driving force of the motor , the oscillator has a movable base that can reciprocate, and an arm portion that is fixed upright on the movable base and has an upper end that is detachably attached to the inner cutter, the arm portion has, in order from the front side of the main body, a first arm, a second arm, and a third arm that are arranged directly above the arm support portion at a predetermined interval, an arm attachment portion is arranged directly below the arm support portion, and the arm attachment portion is fixed upright on the movable base, the oscillator is composed of a first oscillator that is arranged near the front side of the main body and a second oscillator that is arranged near the back side of the main body, the outer cutter is arranged on the upper surface side of the main body, the outer cutter is a reciprocating electric shaver comprising four first outer cutters and two second outer cutters having a shape different from the first outer cutters, the inner cutters comprising a first inner cutter corresponding to the first outer cutters and a second inner cutter corresponding to the second outer cutters, the first outer cutters and the first inner cutters forming a cutting blade, the second outer cutters and the second inner cutters forming a trimmer blade, the trimmer blade being disposed adjacent to the cutting blade, one of the second inner cutters being attached on a first center line passing through the arm attachment portion, the arm support portion and the second arm of the first oscillator, the three inner cutters being disposed symmetrically in the front-rear direction with respect to the first center line, and one of the second inner cutters being attached on a second center line passing through the arm attachment portion, the arm support portion and the second arm of the second oscillator , the three inner cutters being disposed symmetrically in the front-rear direction with respect to the second center line which is parallel to the first center line . 2. The reciprocating electric shaver according to claim 1, wherein the first inner blade has an inverted U-shaped cross section corresponding to the first outer blade, the second inner blade has an inverted L-shaped cross section corresponding to the second outer blade and is arranged symmetrically front to back , and the trimmer blade is configured to undergo a greater load when reciprocating in sliding contact with the cutting blade . 3. The reciprocating electric shaver according to claim 1 or 2, characterized in that an edge trimming blade and a slide switch are arranged on the rear side of the main body, and when the slide switch is slid upward to raise the edge trimming blade, the second oscillator and the edge trimming blade can be linked , and an axis passing through the drive shaft of the motor is located at a rear position within a range that does not reach the first arm of the second oscillator, based on a midpoint between the third arm of the first oscillator and the first arm of the second oscillator .

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