Patent Description:
Hand gestures are frequently used in interpersonal communications to help accentuate the ideas being communicated. This explains why a person's hands are often the focus of attention in addition to the person's face, and why a woman's hands are also referred to as her second face. With the development of technology, the market has been supplied with a great variety of nail beautifying devices such that meticulously beautified nails have gradually become a manifestation of modern women's fashion and an important feature of a woman's overall appearance.

During a nail beautifying process, nail files or emery boards are typically used to wear down the residues of gel nails or dip powder nails after such artificial nails are removed, or to shape acrylic nails by trimming the edges of or shortening such artificial nails. The conventional nail files or emery boards, however, are subject to limitations imposed by their shapes and sizes and therefore have problem doing their work in relatively small areas. Furthermore, the relatively large movements of nail filing tend to cause dispersion of the resulting nail filings, or nail dust, which ends up suspended in the air and is likely to harm an inhaler's health.

<CIT> describes a nail filing machine, an ultraviolet (UV) light sterilization container, and a nail filing system including the nail filing machine. The nail filing machine of the present invention comprises a pen-shaped nail filing device, a master device and a rotation speed-adjustable motor. The nail filing machine of the present invention is convenient for a user (i.e., a manicurist) to use for a long time, is easy to carry in use, has a UV light sterilization function, and can record the working mode of the user, thereby effectively improving the operability of the nail filing machine.

Accordingly, it is the object of the present invention to provide a nail grinding pen which is more versatile in use, is effectively enhanced in its nail grinding effect and operability, and can reduce the dispersion of nail dust in the air. This object is achieved by a nail grinding pen according to claim <NUM>. Advantageous embodiments are the subject of the dependent claims. The scope of the invention is limited by the appended claims.

As is conventionally done, the features and elements shown in the accompanying drawings are not drawn to scale but are drawn to best illustrate specific features and elements that are related to the present invention. In addition, identical or similar reference numerals are used throughout the drawings to indicate similar elements or parts.

The embodiments described below are not intended to impose excessive limitations on the present invention. A person of ordinary skill in the art may modify or change the embodiments discussed herein as long as it falls within the scope of the claims.

As used herein, terms such as "comprise," "include," "have," and "contain" are inclusive or open-ended unless otherwise stated and therefore do not exclude elements or steps that are not specified. The terms "a" and "said" may be construed as referring to a single referent or plural referents. The term "one or a plurality of" means "at least one" and therefore may be used to identify a single feature or a mixture/combination of features. Moreover, unless otherwise stated, the term "provided on an article" as used in this specification and the appended claims may be construed as being directly or indirectly attached to a surface of the article or as contacting the surface of the article in other ways, wherein the definition of the surface should be determined according to the context and common knowledge in the art.

Each "equipment," "device," "apparatus," or "module" used in the present invention, or its function, may be implemented by a single chip or by a plurality of chips that work together; the invention has no limitation on the number of such chips. The aforesaid chips may be, but are not limited to, processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or a combination of the above; the invention has no limitation in this regard.

One embodiment of the present invention is described below with reference to <FIG>, <FIG>, and <FIG>, which are a perspective view of a nail grinding pen according to the invention and two exploded views of the structure of the nail grinding pen. This embodiment discloses a nail grinding pen <NUM> that includes a nail grinding pen barrel <NUM>, a motor <NUM>, and an inner body <NUM>. The nail grinding pen barrel <NUM> has a receiving space SP therein. One end of the nail grinding pen barrel <NUM> has an opening OP in communication with the receiving space SP. The motor <NUM> is provided in the receiving space SP and has a rotating shaft <NUM> to be driven to rotate by electricity. The inner body <NUM> is connected to the rotating shaft <NUM> of the motor <NUM>. The rotating shaft <NUM> protrudes from the motor housing <NUM> by a length less than <NUM>, such as but not limited to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>; the invention has no limitation in this regard. The end of the inner body <NUM> that faces the opening OP is provided with a gripper <NUM>. The gripper <NUM> is configured to secure a grinding head GH so that by rotating the gripper <NUM>, the motor <NUM> can drive the grinding head GH into rotation.

The gripper <NUM> can be opened and closed by operating each of the following two types of switches. Please refer to <FIG>, which show how the gripper of a nail grinding pen according to the present invention is opened and closed by operating a push switch. In the embodiment shown in the drawings, the nail grinding pen barrel <NUM> is provided with a push switch 11A coupled to the gripper <NUM>. The push switch 11A can be pushed forward and pulled rearward to switch the gripper <NUM> between an opened state and a closed state. In <FIG> for example, the push switch 11A is pushed forward (or leftward as shown in the drawing) and thereby moved slightly forward such that the gripper <NUM> is expanded by an internal linkage mechanism and thus releases the grinding head GH. In <FIG>, the push switch 11A is pulled rearward (or rightward as shown in the drawing) and thereby moved back to its position in <FIG> such that the gripper <NUM> is radially constricted by the internal linkage mechanism and thus grips the grinding head GH. The linkage mechanism of the push switch 11A can be implemented in many ways and can be any suitable mechanism, and the techniques by which to implement the linkage mechanism of the push switch 11A are conventional. As the design of the linkage mechanism of the push switch 11A is not a feature for which patent protection is sought by the applicant, the working principle of the linkage mechanism will not be detailed herein.

Another embodiment of the switch for opening and closing the gripper <NUM> is illustrated in <FIG>, which show how the gripper of a nail grinding pen according to the present invention is opened and closed by operating a rotary switch. In the embodiment shown in the drawings, the nail grinding pen barrel <NUM> is provided with a rotary switch 11B coupled to the gripper <NUM>. The rotary switch 11B can be rotated to switch the gripper <NUM> between an opened state and a closed state. In <FIG> for example, the rotary switch 11B is rotated clockwise (as indicated by the arrow A1 in the drawing) such that the gripper <NUM> is expanded by an internal linkage mechanism and thus releases the grinding head GH. In <FIG>, the rotary switch 11B is rotated counterclockwise (as indicated by the arrow A2 in the drawing) such that the gripper <NUM> is radially constricted by the internal linkage mechanism and thus grips the grinding head GH.

Please refer to <FIG> for a sectional view of the nail grinding pen in <FIG>. As shown in <FIG>, the inner body <NUM> in the embodiment of the present invention essentially includes a pushing post <NUM>; the gripper <NUM>, which is provided at the front end of the pushing post <NUM>; a position-limiting barrel <NUM> surrounding the gripper <NUM>; and a shaft sleeve <NUM> provided at the rear end of the pushing post <NUM> and attached to the rotating shaft <NUM> so that the motor <NUM> can drive the pushing post <NUM>, the gripper <NUM>, and the position-limiting barrel <NUM> into rotation. In one embodiment, the shaft sleeve <NUM> is made of plastic or metal. In a preferred embodiment, the material of the shaft sleeve <NUM> is plastic to enhance self-lubrication of the rotation mechanism; the present invention, however, has no limitation on the material of the shaft sleeve <NUM>. In one embodiment, bearings 35A and 35B are respectively provided between the two ends of the position-limiting barrel <NUM> and the wall of the receiving space SP. The bearings 35A and 35B are provided to prevent friction between the position-limiting barrel <NUM> and the inner wall of the nail grinding pen barrel <NUM> when the position-limiting barrel <NUM> is rotated by the motor <NUM> along with the pushing post <NUM> and the gripper <NUM>. The bearings 35A and 35B also define the concentricity of the position-limiting barrel <NUM>. In another embodiment, the connecting elements (e.g., fixing plates and washers) connected to the bearings 35A and 35B are made of copper or gold, or any metal coated with polytetrafluoroethylene (PTFE), hard chrome-plated, nickel-plated, or lubricated, or they can be thrust bearings; the invention, however, has no limitation on the material of those connecting elements.

For the design of the rotating shaft of the motor, please refer to <FIG>, which shows various rotating shaft designs for the motor in the present invention. In the embodiments shown in <FIG>, the rotating shafts are respectively designed as a shaft 21A with a circular cross section (see <FIG>), a shaft 21B with a cross-shaped cross section (see <FIG>), a shaft 21C with a D-shaped cross section (see <FIG>), and shafts 21D and 21E with a polygonal cross section (see <FIG> for a quadrilateral cross section and <FIG> for a pentagonal cross section). In fact, the rotating shaft of the motor may have any other cross-sectional shape without limitation. In another embodiment, an additional sleeve <NUM> is attached to and mounted around the rotating shaft <NUM> of the motor in the invention (see <FIG>), and the shaft sleeve <NUM> is fixed to the rotating shaft <NUM> via the additional sleeve <NUM>. The invention has no limitation on the shape of the additional sleeve <NUM>.

Please refer to <FIG> for a partial sectional view of the nail grinding pen in <FIG>. As shown in <FIG>, the gripper <NUM> includes a sleeve <NUM> connected to the pushing post <NUM>, an accommodating groove <NUM> provided at one end of the sleeve <NUM> and facing the opening OP, and a plurality of claw units <NUM> provided along the periphery of the accommodating groove <NUM>. The accommodating groove <NUM> is configured to accommodate the grinding head GH. A gap SG is formed between each two adjacent claw units <NUM> so that the claw units <NUM> can constrict radially to grip the grinding head GH or can expand radially to release the grinding head GH.

In one embodiment, the gripper <NUM> includes three claw units <NUM>. In other embodiments, the number of the claw units <NUM> may be four, five, six, or a greater number. Changes in the number of the claw units <NUM> shall be viewed as falling within the scope of the present invention. To provide an appropriate gripping force and prevent the grinding head GH from separating from the gripper <NUM>, one embodiment is so designed that when the claw units <NUM> are closed, the gap between each two adjacent claw units <NUM> is smaller than <NUM>, such as but not limited to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>; the invention has no limitation in this regard. In one embodiment, the depth of the accommodating groove <NUM> is between <NUM> and <NUM>, such as but not limited to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>; the invention has no limitation in this regard either.

In order for the gripper <NUM> to be switchable between an opened state and a closed state, one embodiment is so designed that the gripper <NUM> is restricted between a front position and a rear position, can be moved forward in order to be switched to the opened state, and can be moved rearward in order to be switched to the closed state. Please refer to <FIG> for another partial sectional view of the nail grinding pen in <FIG>. As shown in <FIG>, the rotary switch 11B includes a rotating ring 111B, a position-limiting track 112B disposed on the nail grinding pen barrel <NUM> and surrounded by the rotating ring 111B, a connecting ring 113B provided on the inner side of the position-limiting track 112B, and a rolling ball 114B provided on the connecting ring 113B and confined in the position-limiting track 112B. The outer periphery of the connecting ring 113B is provided with an annular track AT for interfering with the rolling ball 114B. By rotating the rotating ring 111B, the rolling ball 114B can be moved in and along the position-limiting track 112B between a first axial position and a second axial position such that the connecting ring 113B is moved in the axial direction due to interference and limitation by the position-limiting track 112B and thereby pushes the gripper <NUM> forward or rearward. In one embodiment, the rolling ball 114B can be locked at a first end P1 or a second end P2 of the position-limiting track 112B, wherein the first end P1 is the end of the position-limiting track 112B that faces the first axial position while the second end P2 is the end of the position-limiting track 112B that faces the second axial position. As to the locking method, one embodiment is so designed that a spring 115B is provided on one side of the connecting ring 113B to apply an elastic force to the connecting ring 113B in the axial direction, thereby applying an auxiliary force to the connecting ring 113B to secure the rolling ball 114B either in the first position-limiting groove P11 at the first end P1 of the position-limiting track 112B or in the second position-limiting groove P21 at the second end P2 of the position-limiting track 112B In order for the rolling ball 114B to be able to roll along with the rotating ring 111B and move in the axial direction, the inner side of the rotating ring 111B is provided with a confining track LT that extends in the axial direction, and the rolling ball 114B is located in the confining track LT.

The "first axial position" in the present invention is a position in the nail grinding pen <NUM> that is relatively close to the rear end (or a rear cover <NUM>, as defined further below) of the nail grinding pen <NUM> in the axial direction (i.e., relatively close to the right side of <FIG>), whereas the "second axial position" is a position in the nail grinding pen <NUM> that is relatively close to the front end (or the opening OP) of the nail grinding pen <NUM> in the axial direction (i.e., relatively close to the left side of <FIG>).

Please refer to <FIG> for still another partial sectional view of the nail grinding pen in <FIG>. As shown in <FIG>, the gripper <NUM> includes a constricting unit <NUM>. The constricting unit <NUM> is provided inside the position-limiting barrel <NUM>, is mounted around the sleeve <NUM>, and constricts the claw units <NUM> in normal circumstances. The inner side of the position-limiting barrel <NUM> is provided with an inner wall <NUM> facing one end of the constricting unit <NUM>, and the pushing post <NUM> is provided with a front wall <NUM> facing the other end of the constricting unit <NUM>. When the connecting ring 113B pushes the gripper 31via the pushing post <NUM>, the constricting unit <NUM> is compressed in two opposing directions and therefore expands radially to reduce the constricting force of the claw units <NUM>, thereby allowing the grinding head GH to be replaced. In one embodiment, the constricting unit <NUM> is, for example but not limited to, a spring or a leaf spring; the invention has no limitation in this regard.

Please refer to <FIG>, which shows how the rolling ball in the present invention moves when the rotating ring is rotated. As shown in the drawing, the foregoing structural configurations are such that the moving path of the rolling ball 114B is essentially limited by interference of the position-limiting track 112B on the nail grinding pen barrel <NUM>, by interference of the annular track AT on the outer periphery of the connecting ring 113B, and by interference of the confining track LT on the inner side of the rotating ring 111B. Referring to <FIG>, when the rotating ring 111B is rotated (e.g., clockwise), the rolling ball 114B is moved from the first end P1 toward the second end P2 of the position-limiting track 112B by the rotating ring 111B, as indicated by the arrow A3 in <FIG>. With the rolling ball 114B moving from the first end P1 to the second end P2, the connecting ring 113B, which is located on the inner side of the rolling ball 114B, is pushed by the rolling ball 114B and thus moved from the first axial position toward the second axial direction, as indicated by the arrow A4 in <FIG>. The connecting ring 113B, in turn, pushes and moves the pushing post <NUM> and the gripper <NUM> such that the constricting unit <NUM> is compressed from both ends by the front wall <NUM> of the pushing post <NUM> and the inner wall <NUM> on the inner side of the position-limiting barrel <NUM>. As a result, the constricting unit <NUM> is radially expanded (see <FIG>), and the inclined walls <NUM> at the distal ends of the claw units <NUM> are moved away from the bell-shaped opening of the position-limiting barrel <NUM> to allow removal of the grinding head GH. To mount the grinding head GH, referring to <FIG>, the rotating ring 111B is rotated in the opposite direction (e.g., counterclockwise), thereby moving the rolling ball 114B from the second end P2 toward the first end P1 of the position-limiting track 112B, as indicated by the arrow A5 in <FIG>. With the rolling ball 114B moving from the second end P2 to the first end P1, the connecting ring 113B, which is located on the inner side of the rolling ball 114B, is pushed by the rolling ball 114B and thus moved from the second axial position toward the first axial direction, as indicated by the arrow A6 in <FIG>. Once the connecting ring 113B is moved, the forces applied respectively to the two ends of the constricting unit <NUM> are removed such that the constricting unit <NUM> constricts radially and restores its original position (see <FIG>) as the distance between the front wall <NUM> of the pushing post <NUM> and the inner wall <NUM> on the inner side of the position-limiting barrel <NUM> is increased. Consequently, the inclined walls <NUM> at the distal ends of the claw units <NUM> are brought back into the bell-shaped opening of the position-limiting barrel <NUM> to secure the grinding head GH.

The motor <NUM> may be a brushless motor or a brushed motor; the present invention has no limitation in this regard. In one embodiment, the motor <NUM> has a rotation speed lower than <NUM> RPM. More specifically, the rotation speed of the motor <NUM> may be, but is not limited to, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, <NUM> RPM, or <NUM> RPM; the invention has no limitation in this regard. In one embodiment, the drive voltage for driving the motor <NUM> to rotate at the highest speed is higher than <NUM> V. More specifically, the drive voltage of the motor <NUM> may be, but is not limited to, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, <NUM> V, or <NUM> V; the invention has no limitation in this regard.

Please refer to <FIG> for various electrical connection port designs for the motor in the present invention. In one embodiment, the electrical connection ports of the motor <NUM> are in the form of a plurality of electrical sockets 23A, as shown in <FIG>. When the electrical connection ports are designed as the electrical sockets 23A, the power cord to be connected to the electrical connection ports may have a plug corresponding to the electrical sockets 23A so that electrical connection can be established by connecting the plug of the power cord to the electrical sockets 23A of the motor <NUM>. In another embodiment, the electrical connection ports of the motor <NUM> are in the form of terminals 23B, as shown in <FIG>, and when the electrical connection ports are designed as the terminals 23B, the power cord to be connected to the electrical connection ports may have a socket corresponding to the terminals 23B so that electrical connection can be established by inserting the terminals 23B of the motor <NUM> into the socket of the power cord. In yet another embodiment, the electrical connection ports of the motor <NUM> are in the form of soldered wires 23C, as shown in <FIG>, and when the electrical connection ports are designed as the soldered wires 23C, the power cord to be connected to the electrical connection ports may have wires or solder pads corresponding to the soldered wires 23C so that electrical connection can be established by soldering the soldered wires 23C of the motor <NUM> to the wires or solder pads of the power cord. Changes in design of the electrical connection ports of the motor <NUM> shall be viewed as falling within the scope of the invention.

Please refer to <FIG> for partial sectional views of two nail grinding pens according to the present invention. As shown in the drawing, the nail grinding pen barrel <NUM> in the invention is provided with a rear cover <NUM> at the rear end, and the rear cover <NUM> is configured to close the receiving space SP from the rear side. In the embodiment shown in <FIG>, the rear side of the rear cover <NUM> is provided with an electrical wire having a protective sleeve <NUM> through which a power cord can pass, and which can protect the power cord from damage by being bent. When the electrical connection ports of the motor <NUM> are designed as soldered wires, the inner side of the rear cover <NUM> will be provided with a pliable wire-surrounding member <NUM> for enclosing the soldered wires, and once the rear cover <NUM> is locked to the nail grinding pen barrel <NUM>, the rear cover <NUM> and the motor <NUM> press tightly on the pliable wire-surrounding member <NUM> from two opposite sides thereof to secure and seal the pliable wire-surrounding member <NUM>. In one embodiment, the pliable wire-surrounding member <NUM> is made of flexible polyvinyl chloride (PVC), rubber, or silicone rubber; the invention, however, has no limitation on the material of the pliable wire-surrounding member <NUM>. In the embodiment shown in <FIG>, the electrical connection ports of the motor <NUM> are designed as a plurality of electrical sockets or a plurality of terminals, a power cord is inserted into the rear cover <NUM> from the outer side thereof and then soldered to the electrical ports inside a pliable terminal-surrounding member <NUM>, and the electrical ports and the electrical sockets or terminals are electrically connected through the pliable terminal-surrounding member <NUM>. Once the rear cover <NUM> is locked to the nail grinding pen barrel <NUM>, the rear cover <NUM> and the motor <NUM> press tightly on the pliable terminal-surrounding member <NUM> from two opposite sides thereof to secure and seal the pliable terminal-surrounding member <NUM>.

In another embodiment as shown in <FIG>, which shows a partial sectional view of a nail grinding pen according to the present invention, the rear cover <NUM> is dispensed with. As shown in the drawing, the rear end of the nail grinding pen barrel <NUM> has a rear opening <NUM>, and the rear opening <NUM> is provided with a position-limiting portion <NUM>. The position-limiting portion <NUM> is located on the outer side of a pliable wire-surrounding member <NUM> with respect to the rear opening <NUM> so as to prevent the pliable wire-surrounding member <NUM> from leaving the rear opening <NUM> from inside the receiving space SP, wherein the pliable wire-surrounding member <NUM> closes the receiving space SP by closing the rear opening <NUM>. In one embodiment, the position-limiting portion <NUM> is, for example, a protruding ring provided on the inner periphery of the rear opening <NUM> to prevent the pliable wire-surrounding member <NUM> from separating from the rear opening <NUM>. In another embodiment, the position-limiting portion <NUM> is formed by gradually reducing the receiving space SP toward the rear opening <NUM> such that the inner diameter of the tapered end of the receiving space SP is smaller than the outer diameter of the pliable wire-surrounding member <NUM>, causing interference between the rear opening <NUM> and the pliable wire-surrounding member <NUM> and thereby preventing the pliable wire-surrounding member <NUM> from separating from the rear opening <NUM>.

In one embodiment, the material of the pliable wire-surrounding member is, for example but not limited to, flexible PVC, rubber, or silicone rubber; the present invention has no limitation in this regard.

Please refer to <FIG> for another partial sectional view of the nail grinding pen in <FIG>. As shown in <FIG>, the nail grinding pen barrel <NUM> is provided with a grip portion <NUM> to facilitate operation of the nail grinding pen <NUM>. The grip portion <NUM> has an ergonomic design in terms of its thickness so that the nail grinding pen <NUM> can be easily held by the grip portion <NUM>. In one embodiment, the greatest gripping comfort can be achieved by providing the nail grinding pen barrel <NUM> with a width less than <NUM>, such as but not limited to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>; the invention has no limitation in this regard. In one embodiment, the grip portion <NUM> is provided with a cool-feeling material, and the cool-feeling material may be, but is not limited to, a gel, silicone, or polyester fiber; the invention has no limitation in this regard. In one embodiment, the grip portion <NUM> is provided with a cushioning material corresponding to the inner side or the outer side of the nail grinding pen barrel <NUM>. When corresponding to the outer side of the nail grinding pen barrel <NUM>, the cushioning material may cover the grip portion <NUM> and an area extending from the grip portion <NUM>. When corresponding to the inner side of the nail grinding pen barrel <NUM>, the cushioning material may cover the contact surfaces between the position-limiting barrel <NUM> and the bearings 35A and 35B, or cover the contact surfaces between the bearings 35A and 35B and the nail grinding pen barrel <NUM>, or lie between the position-limiting barrel <NUM> and the nail grinding pen barrel <NUM>, in order to absorb the vibrations generated by the motor <NUM> rotating the inner body <NUM>. To protect the nail grinding pen barrel <NUM> from damage by solvents, the nail grinding pen barrel <NUM> in one embodiment is made of an acetone-resistant material or has a coating, the nail grinding pen barrel <NUM> in another embodiment has a surface with a polyurethane (PU) paint layer or a UV-resistant paint layer, the nail grinding pen barrel <NUM> in still another embodiment has a surface with a metal coating layer, and the nail grinding pen barrel <NUM> in yet another embodiment has a surface with a layer formed by water electroplating; the invention has no limitation on such a protective material or coating.

Please refer to <FIG> for still another partial sectional view of the nail grinding pen in <FIG>. In the embodiment shown in <FIG>, the nail grinding pen barrel <NUM> includes a dust cover <NUM> attached to the gap between the wall of the opening OP of the nail grinding pen barrel <NUM> and the position-limiting barrel <NUM> to prevent the nail dust generated by nail grinding from entering the interior of the nail grinding pen barrel <NUM> through the opening OP (or more particularly through the aforesaid gap) and hence from making the electromechanical devices inside the nail grinding pen barrel <NUM> malfunction.

Please refer to <FIG> for two nail grinding pens according to the present invention, each incorporating a fan. In the embodiments shown in the drawing, the nail grinding pen <NUM> is further provided with a fan to dissipate heat from the electromechanical parts (e.g., the motor <NUM>) inside the nail grinding pen barrel <NUM>. In the embodiment shown in <FIG>, a fan FF1 is provided inside the nail grinding pen barrel <NUM> by way of example and is supplied with electricity through internal wires inside the nail grinding pen barrel <NUM> (e.g., by way of the pliable wire-surrounding member <NUM>). In the embodiment shown in <FIG>, a fan FF2 is mounted directly around the nail grinding pen barrel <NUM> by way of example, is configured to dissipate the heat of the nail grinding pen barrel <NUM> from the outside and thereby dissipate heat from the electromechanical parts inside the nail grinding pen barrel <NUM>, and is driven by electricity supplied either through external wires or by an independent power source. Changes in the mounting method and power supply circuitry of the fan shall be viewed as falling within the scope of the invention.

Please refer to <FIG> for a partial perspective view of a nail grinding pen according to the present invention. As shown in the drawing, a front end portion of the nail grinding pen barrel <NUM> is peripherally provided with heat dissipation slots <NUM> to enhance heat dissipation efficiency. The term "front end portion" refers to a peripheral wall portion of the nail grinding pen barrel <NUM> that is adjacent to the opening OP. The slots <NUM> allow the heat generated by operation of, or friction between, the electromechanical parts inside the nail grinding pen barrel <NUM> to be dissipated effectively. To satisfy practical nail grinding needs, the grinding head GH in one embodiment has a diameter preferably ranging from <NUM> to <NUM>, such as but not limited to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>; the invention has no limitation in this regard.

Please refer to <FIG>, which shows two nail grinding pens according to the present invention, each incorporating an auxiliary light. In order to provide proper lighting during the nail grinding process and thereby allow the operator to better see the nail grinding effects and details, the nail grinding pen barrel <NUM> in each embodiment in <FIG> is provided with an auxiliary light. In one embodiment, the auxiliary light may be, for example but not limited to, a LED, an annular light, a homogeneous light, or an optical fiber; the invention has no limitation in this regard. In the embodiment shown in <FIG>, an auxiliary light 17A is incorporated into the nail grinding pen barrel <NUM> and obtains electricity through internal wires inside the nail grinding pen barrel <NUM> (e.g., is electrically connected to the pliable wire-surrounding member <NUM> through internal wires). In the embodiment shown in <FIG>, an auxiliary light 17B is mounted on the outer side of the nail grinding pen barrel <NUM> and is driven by electricity supplied either through external wires outside the nail grinding pen barrel <NUM> or by an independent power source. Changes in the mounting method and power supply circuitry of the auxiliary light shall be viewed as falling within the scope of the invention.

The present invention further provides a nail grinding host machine <NUM> for use with the nail grinding pen <NUM>, as described below with reference to the embodiment illustrated in <FIG>, <FIG>, and <FIG>, which show the exterior, the internal devices, and a block diagram of a nail grinding host machine according to the invention, respectively. The nail grinding host machine <NUM> according to the embodiment shown in the drawings is connected to the foregoing nail grinding pen <NUM> in order to control the operating mode of the motor <NUM> in the nail grinding pen <NUM>.

The nail grinding host machine <NUM> includes a host machine body <NUM> and a main board <NUM>. The host machine body <NUM> is provided with at least one man-machine interface <NUM>. The main board <NUM> is provided in the host machine body <NUM>, is connected to the man-machine interface <NUM>, and is configured to receive instructions from and send instructions to the man-machine interface <NUM>. The main board <NUM> includes a power module <NUM>, at least one driver <NUM>, and a microcontroller C1 connected or coupled to the man-machine interface <NUM> and the driver <NUM>. The main board <NUM> is connected through wires, or is coupled, to the motor <NUM> of the nail grinding pen <NUM> in order to transmit control instructions and driving power to the motor <NUM> and thereby control the operation of the motor <NUM>. In one embodiment, the microcontroller C1 and the driver <NUM> may be co-constructed as a single chip or implemented as different chips; the present invention has no limitation in this regard.

The main board <NUM> is not necessarily a single circuit board. More specifically, the main board <NUM> may be composed of a plurality of circuit boards to meet the requirements in function, circuit design, or mechanism layout. For example, the main board <NUM> may be composed of a plurality of sub-functional circuit boards due to the fact that, in practice, the product corresponding to each function of the main board <NUM> may be provided with an independent circuit board by its manufacturer. Changes in the number of such circuit boards shall be viewed as falling within the scope of the present invention.

When the motor <NUM> is a brushless motor, the driver <NUM> in this embodiment may be, for example but not limited to, a three-phase inverter, a buck converter, a boost converter, a pulse-amplitude modulator (PAM), a pulse-width modulator (PWM), a pulse-position modulator (PPM), a variable-frequency drive (VFD), or other similar devices that can drive a brushless motor with a square wave, a six-step square wave, or a sine wave, or by field-oriented control (FOC). When the motor <NUM> is a brushed motor instead, the driver <NUM> may, apart from being any of the aforesaid drivers, include a converter, switch, metal-oxide-semiconductor (MOS) device, voltage stabilizer, or relay that can provide a voltage to and thereby drive a brushed motor. In one embodiment, the MOS device <NUM> of the brushless or brushed motor driver <NUM> may be externally connected to a chip including the driver <NUM> or be a built-in element of the chip; the present invention has no limitation in this regard. In an embodiment where the motor <NUM> is a brushed motor, forward and reverse rotation of the motor <NUM> is switched by a switching device; the invention, however, has no limitation in this regard. In one embodiment, the switching device may be, but is not limited to, an H-bridge, a MOS device, or a relay; the invention has no limitation in this regard either.

In one embodiment, the man-machine interface <NUM> may be, for example but not limited to, a rotating knob, a pushbutton, a liquid crystal display screen, a touchpad, a touch-controlled button, a touch screen, LED, LED display, slide switch, rocker switch, or a combination of the above; the present invention has no limitation in this regard. In one embodiment, the man-machine interface <NUM> includes a motor speed regulator <NUM>, and the motor speed regulator <NUM> includes a varistor or an encoder. The motor speed regulator <NUM> comprises a varistor or an encoder, which is used by the driver <NUM> to control the rotation speed of the motor <NUM> accordingly, wherein the driver <NUM> is driven by either the voltage level or a PWM signal.

Please refer to <FIG> for block diagrams of some alternative nail grinding host machines according to the present invention. In the embodiment shown in <FIG>, the main board <NUM> includes a rotation speed detector <NUM> connected or coupled to the driver <NUM> and the motor <NUM>. The rotation speed detector <NUM> is configured to detect the rotation speed of the motor <NUM> and provide feedback to the driver <NUM> in order to modify the output of the driver <NUM>. In another embodiment, the rotation speed detector <NUM> detects the rotation speed of the motor <NUM> by detecting the induced voltage generated by rotation of the motor <NUM>, with the term "induced voltage" referring to the voltage generated in a rotating magnetic field. In the embodiment shown in <FIG>, the motor <NUM> includes a built-in Hall sensor H1, and the rotation speed detector <NUM> detects the rotation speed of the motor <NUM> via the built-in Hall sensor H1 of the motor <NUM>. In the embodiment shown in <FIG>, the rotation speed detector <NUM> detects the rotation speed of the motor <NUM> via a Hall sensor H2 that is externally connected to the motor <NUM>, and such a change in the connection method of the Hall sensor shall be viewed as falling within the scope of the invention. In the embodiment shown in <FIG>, and by way of example only, the rotation speed detector <NUM> detects the rotation speed of the motor <NUM> via a direct-current tachometer H3 that is externally connected to the motor <NUM>. In the embodiment shown in <FIG>, and by way of example only, the rotation speed detector <NUM> detects the rotation speed of the motor <NUM> via a rotary transformer H4 that is externally connected to the motor <NUM>.

When contacting the surface of a nail, the grinding head GH of the nail grinding pen <NUM> may be subjected to different levels of resistance such that the rotation speed of the motor <NUM> (equivalent to the force applied to the nail by the nail grinding pen <NUM>) is changed and becomes inconsistent. In order to maintain the rotation speed of the grinding head GH (or the motor <NUM>), the microcontroller C1 detects the rotation speed of the motor <NUM> via the rotation speed detector <NUM> and, when the rotation speed of the motor <NUM> is reduced, increases the output of the motor <NUM> to compensate for the reduced rotation speed. More specifically, the microcontroller C1 may set a rotation speed threshold according to the current rotation speed and, when the rotation speed threshold has yet to reached, increase the rotation speed of the motor <NUM> either at once or gradually until the rotation speed threshold is reached. In another embodiment, the rotation speed threshold includes a lower limit Threshold <NUM> and an upper limit Threshold <NUM> higher than the lower limit Threshold <NUM>. When the rotation speed value fed back to the microcontroller C1 is lower than the lower limit Threshold <NUM>, the microcontroller C1 increases the rotation speed of the motor <NUM> until it is higher than the lower limit Threshold <NUM>. When the rotation speed value fed back to the microcontroller C1 is higher than the upper limit Threshold <NUM>, the microcontroller C1 reduces the rotation speed of the motor <NUM> until it is lower than the upper limit Threshold <NUM>. The foregoing design helps prevent the motor <NUM> from rotating too fast when the grinding head GH leaves the surface of a nail. In an embodiment where the microcontroller C1 is dispensed with, the driver <NUM> detects the rotation speed of the motor <NUM> via the rotation speed detector <NUM> and, when the rotation speed of the motor <NUM> is reduced, increases the output of the motor <NUM> to compensate for the reduced rotation speed. In another embodiment, the microcontroller C1 or the driver <NUM> may increase the switching speed of a MOS device, adjust a duty ratio or voltage, or perform self-adaptive I×R compensation in order to control the output of the driver <NUM> and thereby carry out rotation speed compensation.

Please refer to <FIG> for block diagrams of some more alternative nail grinding host machines according to the present invention. In the embodiment shown in <FIG>, the driver <NUM> includes a comparator <NUM> for detecting whether or not a feedback voltage V1 (or current) has reached a setting value TH. If the setting value is reached, the output power to the motor <NUM> will be maintained; otherwise, compensation for the output will continue until the feedback voltage or current reaches the setting value. In the embodiment shown in <FIG>, the microcontroller C1 carries out self-adaptive regulation by receiving a feedback parameter V2 of the motor <NUM>, calculating the corresponding compensation value from the feedback parameter, and controlling the output of a MOS device or the driver <NUM> according to the compensation value. In the embodiment shown in <FIG>, the microcontroller C1 performs self-adaptive regulation by receiving a feedback parameter of the motor <NUM>, finding the corresponding compensation value in a lookup table, and controlling the output of a MOS device or a voltage stabilizer according to the compensation value.

Please refer to <FIG> for the receiving mechanisms of different nail grinding host machines according to the present invention. In one embodiment, the host machine body <NUM> is provided with a receiving mechanism for receiving the grinding head GH. In the embodiments shown in <FIG>, the receiving mechanisms include a receiving box 42A for receiving the grinding head GH (see <FIG>); a plurality of receiving blocks 42B so that the grinding head GH can be engaged in any of the gaps 421B between the receiving blocks 42B (see <FIG>); and a receiving groove 42C sunken into the host machine body <NUM> so that the grinding head GH can be engaged and received in the engaging groove 42C (see <FIG>). In another embodiment, the receiving mechanism <NUM> is provided with one or a plurality of magnetic units <NUM> for magnetically attracting and thereby retaining the grinding head GH (see <FIG>). In yet another embodiment, the receiving mechanism <NUM> is provided with one or a plurality of engaging units <NUM> so that the grinding head GH can be engaged and secured in the one or plurality of engaging units <NUM> (see <FIG>).

In one embodiment, the nail grinding host machine <NUM> includes a replaceable or rechargeable battery connected to the power module <NUM>. In embodiments that use a rechargeable battery, the power module <NUM> may include, for example, a recharging module, and the recharging module may or may not support a rapid-charging function for increasing the efficiency with which a rechargeable battery can be recharged. In one embodiment, the charging current ranges from <NUM>. 3c to 1c, the unit "c" refers to the charging rate in relation to the battery capacity. In one embodiment, the power module <NUM> includes an electrical socket located on the host machine body <NUM>, and the electrical socket may be exposed from the host machine body <NUM> or include a dust cover or dust shield that can cover the electrical socket to ward off dust and water or repel water. In one embodiment, this electrical socket may be, for example but not limited to, a USB Type-C socket. Changes in configuration of the electrical socket shall be viewed as falling within the scope of the present invention.

Please refer to <FIG> for a block diagram of another nail grinding host machine according to the present invention. As shown in the drawing, the main board <NUM> includes an over-current protection module M1, an over-voltage protection module M2, and an over-temperature protection module M3, each connected to the microcontroller C1. The over-current protection module M1 may include, for example but not limited to, a current detector. The over-current protection module M1 produces decision information upon detecting that the input current on the secondary side (corresponding to the input into the motor <NUM>) exceeds a safe value. The over-voltage protection module M2 may include, for example but not limited to, a voltage detector. The over-voltage protection module M2 produces decision information upon detecting that the voltage exceeds a safe value. In one embodiment, the over-voltage protection module M2 is provided on the driver <NUM> and is configured to track the input of the motor <NUM>. In other embodiments, the over-voltage protection module M2 may be provided anywhere in the circuit on the secondary side of the power module <NUM> in order to detect the voltage across an arbitrary node. The invention has no limitation on the location of the over-voltage protection module. The over-temperature protection module M3 may include, for example but not limited to, a temperature sensor or a thermistor. The over-temperature protection module M3 produces decision information upon detecting that the temperature of the motor <NUM> exceeds a safe value. In one embodiment, the decision information may be, but is not limited to, a power-off instruction, circuit-breaking instruction, or warning instruction to the microcontroller C1; the invention has no limitation in this regard. In another embodiment, the decision information may be sent directly to the power module <NUM>. The invention has no limitation on whether the decision information is sent to the power module <NUM> directly or otherwise.

In order to provide enhanced operability and safety, the nail grinding host machine of the present invention can be paused according to a pause instruction triggered by a user instruction or by a predetermined operation state. In one embodiment, the microcontroller C1 stops the motor <NUM> upon detecting that the pause instruction is triggered via the man-machine interface <NUM>. In another embodiment, the microcontroller C1 stops the motor <NUM> when the pause instruction is triggered by the degree of inclination of the nail grinding pen <NUM> as is detected by the inclinometer of the nail grinding pen <NUM>. More specifically, the inclinometer of the nail grinding pen <NUM> is connected or coupled to the main board <NUM> or the microcontroller C1. When the inclinometer detects that the nail grinding pen <NUM> is placed horizontally, the microcontroller C1 determines that the user has stopped operating the nail grinding pen <NUM>, and in consequence, the microcontroller C1 triggers the pause instruction to pause the motor <NUM>. As the angle value detected by the inclinometer will vary with the inclination angle at which the inclinometer is mounted in/on the nail grinding pen <NUM>, the invention has no limitation on the angle detected by the inclinometer. Please refer to <FIG>, which shows an angle between a nail grinding pen according to the invention and a horizontal plane, or more particularly the angle θ1 between the pen body of the nail grinding pen <NUM> and a horizontal plane in the world coordinate system. The angle θ1 that will trigger the pause instruction preferably ranges from -<NUM>° to <NUM>° and may be, but is not limited to, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, -<NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>°; the invention has no limitation in this regard. In one embodiment, the microcontroller C1 stops the motor <NUM> when the pause instruction is triggered by the motion sensor of the nail grinding pen <NUM> detecting that the nail grinding pen <NUM> has been still for a predetermined amount of time. In another embodiment, the main board <NUM> or the microcontroller C1 includes a timer that will trigger a shut-down instruction when the nail grinding pen <NUM> has been still for a predetermined amount of time. The time-related pause in the last two embodiments can prevent unnecessary power consumption and eliminate safety concerns while the nail grinding pen <NUM> is not in operation. In one embodiment, the microcontroller C1 controls the power of the motor <NUM> at a stable wattage lower than <NUM> W when the motor <NUM> is idling; thus, by limiting the driving power of the motor <NUM>, safety issues associated with damage and/or too high a rotation speed of the motor <NUM> are prevented. The stable wattage may be set at, for example, <NUM> W, <NUM> W, <NUM> W, <NUM> W, <NUM> W, <NUM> W, <NUM> W, or <NUM> W; the invention has no limitation in this regard.

The present invention may dispense with the microcontroller and use only the driver to drive the motor. Please refer to <FIG> for a block diagram of yet another nail grinding host machine according to the invention. In the embodiment shown in the drawing, the nail grinding host machine <NUM> essentially includes a host machine body <NUM> and a main board <NUM>. The host machine body <NUM> is provided with at least one man-machine interface <NUM>. The main board <NUM> is provided in the host machine body <NUM>, is connected to the man-machine interface <NUM>, and is configured to receive instructions from and send instructions to the man-machine interface <NUM>. The main board <NUM> includes a power module <NUM>. The main board <NUM> is connected through wires, or is coupled, to the motor <NUM> of the nail grinding pen <NUM> in order to transmit control instructions and driving power to the motor <NUM>. The motor <NUM> is a brushed motor, and the man-machine interface <NUM> is connected to the driver <NUM> of the brushed motor. The driver <NUM> serves to provide a voltage output for the brushed motor.

In contrast to its brushless counterpart in the previous embodiments, the motor in this embodiment is a brushed motor and can be implemented without using the microcontroller C1. All that is needed to control the activation, deactivation, and rotation speed of the brushed motor is for the driver <NUM> to provide, or stop providing, stable direct-current power to the brushed motor. This embodiment is different from the previous ones only in the type of the motor and the lack of the microcontroller C1. The remaining parts of this embodiment are identical to their respective counterparts in the previous embodiments and therefore will not be described repeatedly.

Claim 1:
A nail grinding pen (<NUM>), comprising:
a nail grinding pen barrel (<NUM>), wherein the nail grinding pen barrel (<NUM>) has a receiving space (SP) therein, and the nail grinding pen barrel (<NUM>) has an end with an opening (OP) in communication with the receiving space (SP);
a motor (<NUM>) provided in the receiving space (SP) and having a rotating shaft (<NUM>) to be driven to rotate by electricity; and
an inner body (<NUM>) connected to the rotating shaft (<NUM>), wherein the inner body (<NUM>) has an end facing the opening (OP) and provided with a gripper (<NUM>), and the gripper (<NUM>) is configured to secure a grinding head (GH) so that the motor (<NUM>) is able to drive the grinding head (GH) into rotation by rotating the gripper (<NUM>); wherein
the nail grinding pen barrel (<NUM>) is provided with a rotary switch (11B) coupled to the gripper (<NUM>), and the rotary switch (11B) is configured to be rotated in order to switch the gripper (<NUM>) between an opened state and a closed state, and the inner body (<NUM>) comprises: a pushing post (<NUM>);
characterized in that the gripper (<NUM>), is provided at a front end of the pushing post (<NUM>); a position-limiting barrel (<NUM>) surrounding the gripper (<NUM>); and a shaft sleeve (<NUM>) provided at a rear end of the pushing post (<NUM>) and attached to the rotating shaft (<NUM>) so that the motor (<NUM>) is able to drive the pushing post (<NUM>) and the gripper (<NUM>) into rotation.