Electric rotary shaver

An electric rotary shaver, in which the cutter head that includes outer and inner cutters is washable while the inner cutter(s) is being rotationally driven, including agitating vanes that agitate the liquid in which the cutter head is immersed and discharge shaving debris out of the cutter head by generating a flow of the liquid. The agitating vanes are provided on a drive shaft(s) that engages with and rotates the inner cutter(s) and rotationally drives the inner cutter(s).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electric rotary shaver and more particularly to an electric rotary shaver that has a washable cutter head.

2. Prior Art

In one type of electric shaver, a cutter head, which includes an outer cutter and an inner cutter, and a shaving debris accommodating section, which is inside the cutter head, are provided so that the cutter head and the shaving debris accommodating section can be cleaned or washed using a water rinse or cleaning liquid.

Such washable electric shaver is disclosed in, for instance, Japanese Patent Application Laid-Open (Kokai) Nos. 7-124347, 9-122363 and 2001-198367.

There are substantially two methods for washing electric shavers. In one method, the cutter head is removed from the main body of the electric shaver, and washing is performed with its power turned off. In another method, washing is performed with the cutter head mounted on the main body of the shaver and the power is turned on.

When washing is performed with the cutter head removed from the main body of the electric shaver, shaving debris is rinsed away using flowing water or the like. However, when washing is performed with the cutter head mounted on the main body of the electric shaver, it is necessary to perform washing in a state in which the discharge of shaving debris to the outside of the cutter head can be done easily.

FIG. 5shows one example of an electric rotary shaver that has three rotary cutters.

In this shaver, a cutter cradle12is provided inside upper portion of the main body10of the shaver, and a cutter head20is detachably mounted on the cutter cradle12.

The cutter cradle12is in a recessed shape so as to accommodate shaving debris. Three drive shafts14that drive or rotate three inner cutters are disposed so that these drive shafts protrude from the inside bottom surface of the cutter cradle12. The cutter head12includes three outer cutters22and three inner cutters (not shown) that respectively make sliding contact with the outer cutters. The drive shafts14that protrude from the bottom of the cutter cradle12respectively engage with the inner cutters when the cutter head20is mounted on the main body10, and these drive shafts14rotationally drive the inner cutters when the power of the electric shaver is turned on.

Accordingly, when washing is performed with the cutter head20removed from the main body10, shaving debris that has accumulated in the cutter cradle12can easily be discharged and washed away by removing the cutter head20from the main body10of the electric shaver as shown inFIG. 5.

FIG. 6shows the manner of washing the electric shaver with the cutter head on and while the power is on.

The reference numeral50is a cleaning vessel filled with a cleaning liquid52. The cutter head20is set to face down and is immersed in the cleaning liquid in the cleaning vessel50; then, the shaver is switched on and cleaning is performed while the electric shaver is being driven.

The space between the inside bottom of the cutter cradle12and the cutter head20constitutes a space that accommodates shaving debris. As a result of the action of the flow of cleaning liquid that is generated by the rotation of the inner cutters23and drive shafts14, the shaving debris that has been in this space is discharged into the cleaning vessel50via slit-form openings (or hair introducing apertures) formed in the outer cutters22.

However, as seen fromFIG. 6, when the washing is performed by rotating the inner cutters23in the cleaning liquid52in the cleaning vessel50, though the inner cutters23and the areas near the inner cutters23can be washed by agitating the cleaning liquid52in the vicinity of the inner cutters23, shaving debris cannot be effectively discharged to the outside of the space in which such shaving debris accommodates. Accordingly, after the cutter head20has been cleaned in the cleaning vessel50, it is further necessary to remove the cutter head20from the main body10and clean the cutter cradle12and other parts using a brush or the like.

SUMMARY OF THE INVENTION

The present invention is to solve the problems described above.

The object of the present invention is to provide an electric rotary shaver that efficiently discharges shaving debris by means of a cleaning operation that uses a water rinse or cleaning liquid in a state in which the electric shaver is being driven with the cutter head mounted on the main body of the electric shaver, thus making it possible to perform an easy cleaning operation and maintain the electric shaver clean.

The above object is accomplished by a unique structure of the present invention for an electric rotary shaver in which a cutter head is disposed so that washing thereof can be done while the inner cutter(s) in the cutter head is being rotationally driven; and in the present invention, agitating vanes are formed on the shaver's drive shaft(s) that engages with and rotationally drives the inner cutter(s), so that the agitating vanes agitate the liquid in which the cutter head is immersed and discharge the shaving debris out of the cutter head.

In this structure, the agitating vanes are disposed in an orientation that causes the liquid in which the cutter head is immersed to flow from the inside of the cutter head to the outside of the cutter head.

In addition, the agitating vanes are disposed in close proximity to the bottom of an accommodating section of the shaver that accommodates shaving debris, so that the shaving debris adhering to the bottom and side wall surfaces of the accommodating section is scraped off and removed by means of the flow of the cleaning liquid, so that the shaving debris accumulated inside the cutter head is efficiently discharged.

In the structure of the electric rotary shaver of the present invention:the cutter head includes an outer cutter frame, a cutter retaining plate detachably attached to the outer cutter frame, an inner cutters) provided on the cutter retaining plate, and an outer cutter(s) supported in the outer cutter frame via the inner cutter(s);a cutter cradle is provided in the top portion of the main body of the electric shaver in such a manner that the cutter head is detachable with respect to the cutter cradle; andthe drive shaft(s) is disposed so as to protrude from the bottom of the cutter cradle in a water-tight manner with respect to the main body of the electric shaver.

Furthermore, in the present invention, the drive shaft(s) is comprised of an engagement shaft and a paddle body; and the engagement shaft engages with the inner cutter when the cutter head is mounted on the cutter cradle, thus letting the inner cutter rotate, and the paddle body has the agitating vanes on its outer surface and is rotated as a unit with the engagement shaft.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the electric rotary shaver of the present invention will be described in detail below.

The characterizing structure of the electric rotary shaver of the present invention lies in the drive shafts14which are disposed to protrude from the bottom12aof the cutter cradle12.

As seen fromFIG. 1, the cutter cradle12is in substantially a triangular shape with its corners rounded, and three drive shafts14are respectively disposed in positions that correspond to the vertices of the equilateral triangle.

The drive shafts14are connected to a motor (not shown) installed inside the main body10of the electric shaver. When the motor is switched on by the operation of a switch, the drive shafts14are rotationally driven about their axes.

FIG. 2Ashows the elements of one of the drive shafts14, all having the same structure; andFIG. 2Bshows the drive shaft14assembled. In the shown embodiment, as seen fromFIG. 2A, each drive shaft14comprises a paddle body15, an engagement shaft16, a cutter push-up spring17and a drive shaft bearing18.

The paddle body15is cylindrical in shape, and an engaging portion15ais disposed on the upper portion of the paddle body15. The engaging portion15aengages with the engagement shaft16and allows the paddle body15to rotate as a unit with the engagement shaft16about its axis. The engaging portion15aprotrudes inward in the form of an eave. The reason for this shape of the engaging portion15ais to allow the engagement shaft16to be movable in the axial direction and to prevent the engagement shaft16from slipping out of the paddle body15. The paddle body15is further formed with three cut-outs15a′ in the engaging portion15aat equal intervals in the circumferential direction. These cut-outs15a′ are provided so as to allow the engagement shaft16to engage with the cut-outs and rotate the paddle body15as a unit with the engagement shaft16about their axes. The engagement shaft16is movable in the axial direction relative to the paddle body15; and when the engagement shaft16is moved to protrude (or moved to a position that protrudes from the paddle body15) the engagement shaft16engages with the engaging portion15aof paddle body15, so that the engagement shaft16and paddle body15can be rotated as a unit about their axes.

The paddle body15is formed with three agitating vanes15bat circumferentially equal intervals on its cylindrical outer surface. The agitating vanes15b, when the electric shaver is cleaned using water or a cleaning liquid, generate a positive flow of liquid from the internal space in which shaving debris is accommodated toward the outside of the cutter head20by the rotation of each corresponding drive shaft14. The agitating vanes15bare shaped so that they can generate such an outward-oriented flow of liquid when the drive shaft(s)14is rotated.

In the shown embodiment, the agitating vanes15bare formed near the base (lower) portion (i.e., the side closer to the bottom of the cutter cradle12) of the paddle body15. This arrangement is made in order to generate a flow of liquid from the area closer to the bottom of the cutter cradle12, so that even shaving debris adhering to the bottom surface of the cutter cradle12is easily removed.

Though in the shown embodiment three agitating vanes15bare disposed at equal intervals on the outer circumferential surface of the cylindrical paddle body15, the number of agitating vanes15bthat are disposed can be different. They can be two or more than three.

The engagement shaft16is substantially a slender shaft, and it has at its tip end portion an engaging portion160that engages with a corresponding inner cutter that is in the cutter head20, and engaging portions16athat engage with the engaging portion15aof the paddle body15are formed near the base (lower) portion of this shaft16. As shown inFIG. 2B, the engagement shaft16is inserted in the paddle body15from beneath the paddle body15.

A cutter push-up spring17is provided so as to contact the undersurface of the engagement shaft16when the drive shaft14is connected to and assembled in the main body of the electric shaver. The cutter push-up spring17supports the engagement shaft16so that the engagement shaft16is constantly urged in the protruding direction (upward inFIG. 2A). The inner cutter and outer cutter are supported in a manner that they can “float” (to make axial motions) by the engagement shaft16via this cutter push-up spring17.

The drive shaft bearing18receives the engagement shaft16therein and is inserted into the paddle body15. The drive shaft bearing18and engagement shaft16are free to move in the axial direction and are axially rotatable as a unit. Since the engagement shaft16is supported in a floating state by the cutter push-up spring17, the engagement shaft16is connected to a shaver driving mechanism that rotates the inner cutter regardless of the position in its axial direction. The drive shaft bearing18and engagement shaft16rotate as a unit about their axes regardless of the position in the axial direction, and a connection with the driving mechanism is thus maintained.

The drive shaft14is, as seen fromFIG. 2B, obtained by assembling the above-described paddle body15, engagement shaft16, cutter push-up spring17and drive shaft bearing18into a single unit; and since the paddle body15is in the outermost position, the agitating vanes15bprotrude from the outer surface of the drive shaft14. Thus, each one of the three drive shafts14has the agitating vanes15b.

FIG. 3shows, in cross-section, the cutter head20that is mounted on the main body10of the electric shaver.

The reference numeral12bis a bottom plate of the cutter cradle12, and it partitions the cutter head20and the main body10of the electric shaver. Each one of the drive shafts14is connected to the driving mechanism of the shaver by fastening the drive shaft bearing18to the upper portion of each rotating shaft30that protrudes from a through-hole formed in the bottom plate12b. In this through-hole in the bottom plate12b, the space between the rotating shaft30and the bottom plate12bis sealed in a water-tight manner by a sealing member32on the undersurface side of the bottom plate12(i.e., on the bottom surface of the bottom plate12that faces the main body10).

The cutter push-up spring17of each drive shaft14is installed so that a resilient force thereof is applied between the tip end portion of the rotating shaft30and the inside surface of the engagement shaft16. The engagement shaft16is thus supported in a floating manner with respect to the rotating shaft30.

InFIG. 3, the reference numeral34is a motor which is installed in the main body10of the shaver. The motor34and each rotating shaft30are connected via a gear36afastened to the output shaft of the motor34, a common gear36b, and a gear36cwhich is connected to each rotating shaft30.

Furthermore, in the cutter head20, inner cutters23and outer cutters22that are supported via the inner cutters23are provided by a cutter retaining plate (not shown in the drawing) which is detachably attached to the outer cutter frame24so that these cutters can swing and move in the axial direction and do not drop out of the cutter head20.

The reference numeral42is an inner cutter base (only one inner cutter base shown) that is fastened to central portion of the inner cutter23. The inner cutter base42is formed from a resin, and engaging recess with which the engaging portion160formed on the tip end of the engagement shaft16engages is formed in the undersurface (lower portion) of the inner cutter base42.

When the cutter head20is mounted on the cutter cradle12, the engaging portion160of each one of the three engagement shafts16engages with the engaging recess of each one of the three inner cutter bases42so that the inner cutters23can be rotated as a unit with the engagement shafts16. The cutter surfaces of the inner cutters23constantly makes sliding contact with the inner surfaces of the corresponding outer cutters22via the engagement shafts16and inner cutter bases42by the resilient force of the cutter push-up springs17, and thus the outer cutters22and inner cutters23are supported and pushed in a direction in which these cutters are urged toward the outside of outer cutter frame24. Slit-form hair introduction openings (not shown) are formed in the outer cutters22, and hair (whiskers) that is introduced into the outer cutters22through the hair introduction holes are cut by the outer cutters22and the rotating inner cutters23.

As seen from the above, when the cutter head20, which is detachable from the cutter cradle12, is mounted on the cutter cradle12, the inner cutters23in the cutter head23and the drive shafts14protruding from the bottom of the cutter cradle12engage with each other.

As shown inFIG. 3, an internal space is formed between the cutter head20and the cutter cradle12when the cutter head20is mounted on the cutter cradle12, and this internal space forms an accommodating section that accommodates shaving debris.

In the above structure, the paddle bodies15of the drive shafts14are merely fitted over the drive shaft bearings18that rotate as a unit with the rotating shafts30, and these paddle bodies15are rotated as a unit with the engagement shafts16only when engaged with the engagement shafts16. In other words, the engagement shafts16are provided so as to be movable in the axial direction; and when the engagement shafts16are in the protruding positions, the engagement shafts16engage with the paddle bodies15.

FIG. 4shows the above-described electric rotary shaver being washed or washed using a cleaning liquid52in a cleaning vessel50.

When the cutter head20is immersed in the cleaning liquid52and the switch of the electric shaver is turned on, the inner cutters23are rotated, and the paddle bodies15are rotated together with the rotation of the inner cutters23. As a result of the rotation of the paddle bodies15, the cleaning liquid is agitated inside the cutter head20, and shaving debris that has accumulated inside the cutter head20is moved by the cleaning liquid and is discharged out of the cutter head20into the cleaning vessel50via the slit-form openings formed in the outer cutters22.

The action of the agitating vanes15bon the paddle bodies15is first of all an action that forcibly moves shaving debris by agitating the cleaning liquid inside the cutter head20. As a result, the shaving debris can easily be discharged from the interior of the cutter head20, and shaving debris adhering to the wall surfaces of the shaving debris accommodating section can easily be discharged.

In the shown embodiment, when the agitating vanes15brotate, the cleaning liquid that has entered into the cutter head20through the slit-form openings formed in the outer cutters22, etc. flows from the inside to the outside of the cutter head20; and with this flow of the cleaning liquid, shaving debris is discharged through the slit-form openings into the cleaning vessel50. Thus, since the agitating vanes15bare provided so as to cause the cleaning liquid to flow from the inside to the outside of the cutter head20, shaving debris can be effectively discharged, accomplishing cleaning of the electric shaver.

As seen from the above, the electric rotary shaver of the present invention is cleaned by way of discharging the shaving debris that has accumulated inside the cutter head20out of the cutter head while the shaver is being driven; and in this electric rotary shaver, since the drive shafts14that rotationally drive the inner cutters23has the paddle bodies15that are formed with the agitating vanes15b, the cleaning liquid is forcibly agitated by the rotating agitating vanes15bthat are rotated together with the drive shafts14, and a flow of cleaning liquid is created inside the cutter head20, and shaving debris is discharged out of the cutter head with the cleaning liquid.

In the shown embodiment, the paddle bodies15are provided on the drive shafts14, and agitating vanes15bare formed on the paddle bodies15. However, as long as the cleaning liquid is agitated by the rotation of the drive shafts14so as to generate a flow of the cleaning liquid, the construction in which the agitating vanes are on the drive shafts14is not limited to the structure in which the vanes are formed on the paddle bodies15.

Furthermore, the electric rotary shaver of the above-described embodiment has three sets of outer and inner cutters. However, as long as the shaver involved is an electric rotary shaver, there are no particular restrictions on the number of outer and inner cutters. The present invention is applicable to electric rotary shavers that include not only a single set of outer and inner cutters but also a plurality of sets of outer and inner cutters.

Furthermore, in the above-described embodiment, cleaning is performed by immersing the cutter head in a cleaning liquid. The electric shaver of the present invention can be cleaned, instead, by immersing the cutter head in flowing water in exactly the same manner as in the case where the shaver is cleaned using flowing water.

Furthermore, it is also possible to attach an ultrasonic apparatus to the cleaning vessel50, so that the ultrasonic apparatus is operated when cleaning is performed by immersing the cutter head20in the cleaning liquid52so that shaving debris is stripped form the inside wall surfaces of the accommodating section by the action of ultrasound, thus discharging the shaving debris out of the cutter head20together with the cleaning liquid52.

FIG. 5shows the electric shaver of the present invention in which hair-debris releasing holes40are formed in the cutter head20.

More specifically, in this shaver ofFIG. 5, holes40for releasing hair debris during cleaning of the cutter head20are opened in the upper portion of the cutter head20that is attached to the cutter cradle12. The hair-debris releasing holes40are respectively provided so as to be between two outer cutters22(or outer cutter holes that receive the outer cutters22) in the cutter head20; and each of them is a through hole that is opened to penetrate the outer cutter frame24and has a diameter of, for instance, 2 mm as seen fromFIG. 6.

When cleaning of the cutter head20is performed, long hair debris that is difficult to be washed out through the slit-form openings in the outer cutters can easily flow out of the hair-debris releasing holes40to the outside of the cutter head20. Since water or cleaning liquid flows into and out of the cutter head20not only through the slit-form openings but also through the hair-debris releasing holes40during cleaning, water or liquid circulation inside the cutter head20is smoother than in the case in which water flows into and out of the cutter head20only through the slit-form openings, and thus cleaning is done further efficiently.

As seen from the above, in the electric rotary shaver of the present invention, agitating vanes are provided on a drive shaft(s) that rotationally drives the inner cutter(s), and cleaning liquid is agitated by the agitating vanes so as to generate a liquid flow. As a result, cleaning of the shaver (or the cutter head that includes outer and inner cutters) is performed by way of discharging shaving debris to the outside of the cutter head together with the liquid in which the cutter head is immersed. Consequently, an electric rotary shaver in which cleaning using water rinse or cleaning liquid is efficiently performed can be provided.