Nose hair cutter

A main body of an inner blade is inserted into an inner blade insertion hole of an inner blade frame such that the main body can extend and retreat, a tip end cutting edge is pushed by a spring such that it comes into contact with an inner peripheral surface of a slit outer blade, the main body of the inner blade projecting outward from the inner blade insertion hole is bent rearward in a rotational direction, and the cutting edge of the inner blade is located rearward of the main body in the inner blade insertion hole in the rotational direction. With this configuration, the cutting edge does not fall forward in the rotational direction, and no gap is generated between the cutting edge and the inner peripheral surface of the slit outer blade.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application P2005-216214 filed on Jul. 26, 2005; the entire contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates to a nose hair cutter for cutting nose hair.

As a conventional nose hair cutter, as disclosed in Japanese Patent No. 3536345 (Patent document 1, hereinafter) there is a known nose hair cutter including a slit outer blade and an inner blade that is rotated, in which nose hair that enters an inner peripheral surface of the slit outer blade is cut by the inner blade.

According to such a nose hair cutter, as shown inFIG. 1, a main body1aof an inner blade1is inserted into an inner blade insertion hole2aof an inner blade frame2such that the inner blade1can expand and retreat, a tip end cutting edge lbis pushed by a spring (not shown) (pushing direction is shown with arrow a) such that the cutting edge1bcomes into contact with an inner peripheral surface3aof a slit outer blade3.

Normally (likewise in the patent document 1), cutting edges1bof many inner blades1is easily formed to have acute angles (to have edges) collectively and thus, the main body1aof the inner blade1projecting outward from the inner blade insertion hole2ais forwardly bent in a rotational direction R. Therefore, the cutting edge1bof the inner blade1is located closer to a front side than the main body1ain the inner blade insertion hole2ain the rotational direction R.

SUMMARY OF THE INVENTION

If the cutting edge1bof the inner blade1is located closer to the front portion than the main body1ain the inner blade insertion hole2ain the rotational direction R, however, when the cutting edge1bcomes into contact with the inner peripheral surface3aof the slit outer blade3by the pushing force of the spring, the cutting edge1bfalls forward in the rotational direction by a component force b of the pushing force a, and a back portion1ccomes into contact with the inner peripheral surface3aof the slit outer blade3. With this configuration, a gap t is generated between the cutting edge1band the inner peripheral surface3aof the slit outer blade3. Thus, there is a problem that pieces of nose hair that enter the inner peripheral surface3afrom a slit groove3bof the slit outer blade3cannot be cut reliably, and cutting sharpness is deteriorated.

The present invention has been achieved to solve the above problem, and it is an object of the invention to provide a nose hair cutter that is devised such that no gap is generated between the cutting edge of the inner blade and the inner peripheral surface of the slit outer blade, thereby enhancing the cutting sharpness.

To solve the above problem, the present invention provides a nose hair cutter including a slit outer blade and an inner blade that is rotated and driven, wherein a main body of the inner blade is inserted into an inner blade insertion hole of an inner blade frame such that the main body can extend and retreat, a tip end cutting edge is pushed by a spring such that it comes into contact with an inner peripheral surface of the slit outer blade, the main body of the inner blade projecting outward from the inner blade insertion hole is bent rearward in a rotational direction, the cutting edge of the inner blade is located rearward of the main body in the inner blade insertion hole in the rotational direction.

According to the present invention, since the cutting edge of the inner blade is located rearward of the main body in the inner blade insertion hole in the rotational direction. With this configuration, when the cutting edge rotates while being in contact with the inner peripheral surface of the slit outer blade by the pushing force of the spring, the cutting edge does not fall forward in the rotational direction. Therefore, no gap is generated between the cutting edge and the inner peripheral surface of the slit outer blade and thus, pieces of nose hair entering into the inner peripheral surface from the slit groove of the slit outer blade can be cut reliably, and the cutting sharpness is enhanced.

To enhance the assembling properties, it is preferable that a detent piece is formed on the main body of the inner blade, a retaining recess is formed in the inner blade insertion hole of the inner blade frame, and the detent piece can be retained to the retaining recess when the main body of the inner blade is inserted.

It is preferable that the inner blade frame is formed with a joint insertion hole of an electric motor that rotates and drives the inner blade, the joint insertion hole passes through the inner blade insertion hole so that the inner blade insertion hole is less prone to be clogged with pieces of cut hair.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 2Ais a front view of a nose hair cutter10, andFIG. 2Bis a side sectional view of the nose hair cutter10. The nose hair cutter10includes a main body assembly (main body block)11, and a blade assembly (blade block)12detachably amounted on an upper portion of the main body assembly11.

An electric motor15and a dry battery accommodating chamber16in which a dry battery for driving the electric motor15are provided in a housing14of the main body assembly11. A joint member17is press fitted and fixed to an output shaft15aof the electric motor15. The front surface of said housing14is provided with a push button switch18for turning the electric motor15ON and OFF.

As shown inFIGS. 3toFIGS. 7A,7B, and7C, the blade assembly12includes an outer blade block12A and an inner blade block12B. The outer blade block12A includes an outer blade frame20and a slit outer blade21. The inner blade block12B includes an inner blade frame22, a pair of inner blades23and a coil spring24.

In the outer blade block12A, the outer blade frame20is formed into a shape of truncated cone pipe, and its top is formed with an opening20a. A bayonet (not shown) is formed on each of a lower portion of the outer blade frame20and an upper portion of the main body assembly11. The outer blade frame20is attached to and detached from the upper portion of the main body assembly11by twisting and rotating the outer blade frame20.

The slit outer blade21is formed into a cylindrical shape. The slit outer blade21is formed with slit grooves21bat equal distances (40° in this embodiment) from one another on its circumference such as to extend from an upper portion to a side portion of the slit outer blade21.

The slit outer blade21is inserted into the opening20afrom below the outer blade frame20, and a base portion21cis fixed to the outer blade frame20in a state where the slit outer blade21projects upward from the opening20a.

In the inner blade block12B, the inner blade frame22is formed into a cannonball-like shape. The inner blade block12B is formed at its lower portion with knobs22aused at the time of cleaning operation. The inner blade block12B is formed at its intermediate portion with positioning projections22bfor determining the insertion position when the inner blade block12B is inserted into the slit outer blade21from below. The inner blade frame22is formed at its lower portion with a joint insertion hole22cthrough which the joint member17of the output shaft15aof the electric motor15is inserted so that the joint member17does not rotate. The inner blade frame22is rotated by the electric motor15through the joint member17. A later-described inner blade insertion hole22dof the inner blade frame22is inserted through the joint insertion hole22c.

The inner blade frame22is formed at its upper portion with a slit-like inner blade insertion hole22dextending in a direction perpendicular in its axial direction. A retaining recess22eand a spring insertion hole22fare formed in the inner blade insertion hole22d.

Each of the inner blades23is formed into a plate-like shape. A main body23ais formed at its tip upper end with a cutting edge23b, and at its tip lower end with an inclination-preventing portion23cthat comes into contact with an inner peripheral surface21aof the slit outer blade21so that the cutting edge23bdoes not incline. The main body23ais integrally formed with a detent piece23dthat is formed by cutting and rising a portion of the main body23a

In a state where the spring24is inserted into the spring insertion hole22fof the inner blade frame22, if the main body23aof each inner blade23is inserted into the inner blade insertion hole22dfrom outside against a biasing force of the spring24while bending the detent piece23d, the detent piece23drestores in the retaining recess22ein the inner blade insertion hole22d, and the detent piece23dcan be retained in the retaining recess22e(seeFIG. 7C). With this configuration, in a state where the inner blade23is biased outside by the spring24, the inner blade23is retained by the inner blade frame22at a constant projection position (position where the cutting edge23bslightly exceeds a position where the cutting edge23bcomes into contact with the inner peripheral surface21a of the slit outer blade21). The main body23aof each inner blade23is inserted into the inner blade insertion hole22dof the inner blade frame22such that the main body23acan extend and retreat, and the cutting edge23bat the tip end is pushed and comes into contact with the inner peripheral surface21aof the slit outer blade21by the spring24.

As shown inFIG. 3in detail, the inner blade23is set such that the main body23aprojecting outward from the inner blade insertion hole22dof the inner blade frame22is bent into a L-shape rearward of the rotational direction R as viewed from above, and the cutting edge23bis located rearward from the main body23ain the inner blade insertion hole22din the rotational direction R. The angle of the cutting edge23bis an acute angle with respect to the inner peripheral surface21aof the slit outer blade21. As shown inFIG. 6Bin detail, the inner blade23can also be set such that the main body23aprojecting outward from the inner blade insertion hole22dof the inner blade frame22is bent into a “<”-shape rearward of the rotational direction R as viewed from above, and the cutting edge23bis located rearward from the main body23ain the inner blade insertion hole22din the rotational direction R.

According to the nose hair cutter10, if the cutting edge23bof the inner blade23is located rearward of the main body23ain the inner blade insertion hole22din the rotational direction R, the cutting edge23bdoes not fall forward by a component force (component force in the direction opposite from the component force b of the conventional example shown inFIG. 1) c of the pushing force when the cutting edge23brotates while being in contact with the inner peripheral surface21aof the slit outer blade21by the pushing force a of the spring24. Thus, no gap (see a symbol t inFIG. 1) is generated between the cutting edge23band the inner peripheral surface21aof the slit outer blade21. Therefore, pieces of nose hair that enter the inner peripheral surface21afrom the slit grooves21bof the slit outer blade21can be cut reliably, and the cutting sharpness is enhanced.

If the main body23aof the inner blade23is inserted into the inner blade insertion hole22dof the inner blade frame22, the detent piece23dof the main body23ais retained to the retaining recess22ewith a single operation and thus, the assembling performance becomes favorable. Since no other parts is required for preventing the inner blade23from being pulled out, the number of parts can be reduced, the cost is reduced, and variation of assembling size can be reduced.

Since the joint insertion hole22cof the inner blade frame22is inserted through the inner blade insertion hole22d, pieces of cut hair entering into the inner blade insertion hole22dfall into the joint insertion hole22c. Therefore, the gap between the inner blade23and the inner blade insertion hole22dis less prone to be clogged with the pieces of cut hair, and extending and retreating motion of the inner blade23is not hindered. Thus, it is possible to prevent the cutting sharpness from being deteriorated. If the blade assembly12is removed from the main body assembly11at the time of cleaning, the joint member17on the side of the main body assembly11is pulled out from the joint insertion hole22con the side of the blade assembly12. Thus, the pieces of cut hair that fell into the joint insertion hole22ccan be discharged downward from the joint insertion hole22c.

While the embodiment of the present invention has been described above, the invention is not limited to the above embodiment and changes and modifications can be made within the scope of the gist of the present invention.