Screwdriver

A screwdriver includes a first section, a second section where a positioning groove is annularly formed, a sleeve member detachably disposed on the second section, and an engagement member disposed in the sleeve member. The sleeve member has a body with a through hole, a magnetic unit disposed in the through hole, and an accommodation groove adapted to accommodate the engagement member. When the second section and the sleeve member engage in position, the accommodation groove and the positioning groove meet to engage the engagement member with the positioning groove. The engagement between the second section and the sleeve member allows a gap to be formed between a screw head and the sleeve member while inserting the second section into a socket of the screw head, so the magnetic attraction exists without the contact between the sleeve member and the screw head for a firm engagement therebetween.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a driving tool and relates particularly to a screwdriver.

2. Description of the Related Art

Referring toFIG.1andFIG.2, a magnetic screwdriver1is disclosed in a China Patent No. CN205043687U, the conventional magnetic screwdriver1comprises a tool unit11, an extending unit12formed on the tool unit11, a sleeve unit13sleevedly disposed on the tool unit11, a magnetic unit14disposed on an end of the sleeve unit13, and an engagement unit15disposed on another end of the sleeve unit13. The tool unit11has a first section111, a second section112opposite to the first section111, and a third section113connected between the first section111and the second section112. The extending unit12is integrated with the tool unit11and located between the second section112and the third section113. The sleeve unit13has a body130, a through hole131located in the middle of the body130and penetrating through the body130, a bottom groove132formed on an end of the body130, and a top groove133formed on another end of the body130. A diameter131A of the through hole131is larger than a maximum diameter12A of the extending unit12. The magnetic unit14is disposed in the bottom groove132of the sleeve unit13. The engagement unit15is disposed in the top groove133of the sleeve unit13. When the sleeve unit13sleeves on the tool unit11, the sleeve unit13is restricted by the engagement unit15and the extending unit12to move within the third section113. The extending unit12helps prevent the sleeve unit13from moving to the second section112. When the second section112of the tool unit11is inserted into a socket21of a screw head2, a distance B1defined between the magnetic unit14and the screw head2is smaller than a distance B2defined between the magnetic unit14and the extending unit12. The magnetic unit14then attracts the screw head2through the magnetic force to cause the sleeve unit13to move toward the second section112along the third section113but being restricted by the extending unit12whereby the magnetic unit14contacts the screw head2and drives the screw head2to execute a screwing operation. When the screw head2is removed from the second section112of the tool unit11, the sleeve unit13then moves toward the first section111along the third section113.

However, the conventional magnetic screwdriver1still has deficiencies as follows:

1. The magnetic unit14is in contact with the screw head2directly when the second section112is positioned in the socket21of the screw head2. Thus, metal chips or powders of the screw head2caused during the screwing operation will adhere to the magnetic unit14easily, and that will reduce the magnetic force of the magnetic unit14. Although most of the metal chips or powders can be cleaned by other tools, it is difficult to remove all metal chips or powders. Accordingly, the magnetic attraction between the magnetic unit14and the screw head2is affected and the magnetic unit14cannot guide the screw head2effectively. The screwing operation then cannot be executed smoothly.

2. The sleeve unit13cannot be detached from the tool unit11. The sleeve unit13can only slide within the third section113but cannot be separated from the tool portion11. When the magnetic unit14attracts and releases the screw head2to allow the sleeve unit13to slide along the third section113, the metal chips or powders will enter and accumulate between the through hole131and the third section113, and that causes the metal chips or powders to be cleaned away difficultly since the sleeve unit13cannot be separated from the tool unit11. Further, accumulated metal chips or powders will hinder the sleeve unit13from sliding. Accordingly, the magnetic unit14cannot attract and guide the screw head2and the screwing operation is affected.

3. Only if a type of the second section112is corresponding to a type of the socket21of the screw head2can the second section112be introduced into the socket2to further drive the screw head2. However, the sleeve unit13cannot be removed from the tool unit11. Several magnetic screwdrivers1should be prepared in order to execute a screwing operation of screw heads2with different sockets21, and that will burden the user to bring many heavy magnetic screwdrivers1. If once the second section112of the tool unit11is damaged after a long-term use or the magnetic force of the magnetic unit14is reduced, the magnetic screwdriver1can only be abandoned. Thus, the cost is increased, and that requires to be improved.

SUMMARY OF THE INVENTION

The object of this invention is to provide a screwdriver capable of supporting a screw head stably and facilitating a screwing operation of the screw head to be smooth, speedy, and steady.

The screwdriver comprises a first section, a second section connected to the first section, a sleeve member detachably disposed on an outer periphery of the second section, and an engagement member disposed in the sleeve member. A positioning groove is annularly formed on the outer periphery of the second section. The sleeve member has a body defining a top end and a bottom end, a through hole formed through the body for defining an inner peripheral wall between the top end and the bottom end, a magnetic unit disposed in the through hole and located opposite to the top end, and an accommodation groove recessed into the inner peripheral wall and formed opposite to the bottom end. The engagement member is disposed in the accommodation groove. When the sleeve member is properly positioned on the second section by passing the second section through the through hole, the accommodation groove and the positioning groove meet each other so as to engage the engagement member with the positioning groove and achieve a firm engagement between the sleeve member and the second section. A gap is formed between a top surface of a screw head and the bottom end of the sleeve member when the second section is positioned properly in a socket of the screwhead. Thus, the magnetic unit can attract the screw head though the magnetic force without contacting the screw head to thereby position and guide the screw head stably, help stabilize the screw head, and accelerate a screwing operation of the screw head. Meanwhile, the sleeve member can be separated from the second section and engaged with another second section provided with different types to thereby increase the convenience of use and practicality. Further, metal chips or powders generated during the screwing operation can be cleaned easily and quickly by removing the sleeve member from the second section and cleaning the metal chips or powders thereafter whereby the magnetic effect of the sleeve member is improved and the service life of the sleeve member is prolonged.

Preferably, a cover unit extends outwards from the bottom end of the sleeve member. The cover unit defines a room communicating with the through hole.

Preferably, the cover unit includes a lower end and an upper end. The upper end is connected to the bottom end of the sleeve member. An inner diameter of the lower end is larger than an inner diameter of the upper end.

Preferably, the room of the cover unit defines a maximum diameter larger than a diameter of the through hole of the sleeve member.

Preferably, the gap ranges from 2 mm to 3 mm.

Preferably, the second section is formed into a cruciform type, a square type, or a hexalobular type.

Preferably, the sleeve member is positioned in the middle of the second section when the accommodation groove and the positioning groove meet each other.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG.3, a first preferred embodiment of a screwdriver4is disclosed. The screwdriver4is driven by a driving tool (not shown) and adapted to engage with a socket51of a screw head5in order to drive the screw head5to execute a screwing operation. The screwdriver4in this preferred embodiment comprises a first section41adapted to engage with the driving tool, a second section42connected to the first section41and adapted to engage with the socket51of the screw head5, a sleeve member43sleevedly disposed on an outer periphery of the second section42and capable of being separated from the second section42, and an engagement member44disposed in the sleeve member43and adapted to fix the sleeve member43to the second section42. A positioning groove421is annularly recessed into the outer periphery of the second section42. A type of the second section42is corresponding to a type of the socket51of the screw head5. The type of the second section42is formed into a cruciform type, a square type, a hexalobular type or other polygonal types. Here takes an example that the second section42is a hexalobular type which is commonly known as a Torx type.

Referring toFIG.3andFIG.4, the sleeve member43has a body431defining a top end431A and a bottom end431B, a through hole432penetrating through the body431for defining an inner peripheral wall431C between the top end431A and the bottom end431B, a magnetic unit433disposed in the through hole432and located opposite to the top end431A, and an accommodation groove434recessed into the inner peripheral wall431C and formed opposite to the bottom end431B. The engagement member44is disposed in the accommodation groove434.

When the second section42passes through the through hole432of the sleeve member43to position the sleeve member43properly on the second section42, the accommodation groove434and the positioning groove421are located in correspondence and aligned with each other to thereby restrict the engagement member44between the accommodation groove434and the positioning groove421and position the sleeve member43in the middle of the second section42. Thus, a firm engagement between the sleeve member43and the second section42is achieved. When the second section42is engaged with the socket51of the screw head5, the bottom end431B of the body431is adjacent to but not in contact with a top surface52of the screw head5to thereby form a gap D between the top surface51and the bottom end431B. The gap D ranges from 2 mm to 3 mm.

Referring toFIG.4andFIG.5, an installation of the screwdriver4is executed by inserting the second section42through the through hole432of the sleeve member43until the accommodation groove434and the positioning groove421face each other to thereby engage the engagement member44with the positioning groove421. Thus, the sleeve member43is positioned in the middle of the second section42. After that, the second section42is inserted into the socket51of the screw head5to form the gap D between the bottom end431B of the sleeve member43and the top surface52of the screw head5, so the magnetic unit433attracts the screw head5though the magnetic force without being in contact with the screw head5whereby the screw head5is positioned stably and properly. Further, the magnetic attraction between the magnetic unit433and the screw head5can help guide and straighten the screw head5. After the screw head5is straightened by the screwdriver4, a rotational force is applied on the screwdriver4to further rotate the screw head5into an object6quickly and stably until the screw head5enters into the object6entirely to achieve a tight engagement between the screw head5and the object6. Finally, the second section42of the screwdriver4is removed from the socket51of the screw head5whereby the screwing operation of the screw head5is completed.

After the sleeve member43is properly engaged with the second section42, the sleeve member43is positioned in the middle of the second section42stably. Hence, the bottom end431B of the sleeve member43is spaced apart from the top surface52of the screw head5to form the gap D after the second section42is inserted into the socket51of the screw head5. Thus, the gap D helps prevent metal chips or powders caused during the screwing operation from adhering to the magnetic unit433while the magnetic attraction is still maintained. Meanwhile, the gap D also prevents the top surface52of the screw head5from being rubbed unduly by the sleeve member43. If the metal chips or powders enter into the through hole432, the metal chips or powders can be cleaned easily by detaching the sleeve member43from the second section42as shown inFIG.5. After the metal chips or powders in the through hole432are removed, the second section42is inserted into the sleeve member43through the through hole432until the engagement member44is engaged with the positioning groove421whereby the sleeve member43is properly engaged with the second section42and the screwdriver4can be used again.

Referring toFIG.6shows the object6is provided with a pre-drilled opening61. After the second section42is positioned in the socket51of the screw head5, the screwdriver4can drive the screw head5to screw into the opening61of the object6without being hindered by the sleeve member43. Because the sleeve member43is not in contact with the top surface52of the screw head5to form the gap D when the second section42is inserted into the socket51of the screw head5, the sleeve member43will not contact and press the object6to further allow the second section42to screw the screw head5deeply into the opening61. Meanwhile, the screwing operation of the screw head5can be completed in one time and no additional tool is required. Further, the opening61will not be damaged by the screwdriver4. The screwing operation of the screw head5can be executed smoothly to thereby attain the speedy and steady screwing effect. In order to drive the screw head5provided with different types of sockets51, the sleeve member43can be separated from the second section42and detachably disposed on another second section42having the type in correspondence with the socket51of the screw head5. Hence, the user's burden is lightened by bringing only one sleeve member43and different second sections42. Further, when the sleeve member43is worn or damaged, the second section42can be still kept to be used with other sleeve member43. Alternatively, when the second section42is worn or damaged, the sleeve member43can be kept to be used with other second section42to thereby reduce the cost and increase the convenience of use.

Referring toFIG.7andFIG.8show a second preferred embodiment of the screwdriver4of this invention. The correlated elements and the concatenation of elements, the operation and objectives of the second preferred embodiment are the same as those of the first preferred embodiment. This embodiment is characterized in that a cover unit435extends outwards from the bottom end431B of the sleeve member43and defines a room435C communicating with the through hole432. The cover unit435has a lower end435A and an upper end435B. The upper end435B is connected to the bottom end431B of the sleeve member43. An inner diameter R1of the lower end435A is larger than an inner diameter R2of the upper end435B. The inner diameter R1of the lower end435A is also larger than a diameter R3of the through hole432of the sleeve member43. In this preferred embodiment, the inner diameter R1, as for instance shown inFIG.7, can be deemed to be a maximum diameter of the room435C of the cover unit435. The lower end435A of the cover unit435and an end surface422of the second section42are aligned horizontally when the sleeve member43is positioned properly on the second section42. In other words, the lower end435A of the cover unit435and the end surface422of the second section42are located at the same horizontal line L when the sleeve member43is properly engaged with the second section42. Thus, when the second section42is placed in the socket51of the screw head5, the lower end435A will not contact the top surface52of the screw head5but surround the screw head5to thereby retain the metal chips or powders within the room435C of the cover unit435and prevent the metal chips or powders from spurting or hurting the user during the screwing operation. Simultaneously, the magnetic unit433can still attract the screw head5without contacting the screw head5. After the screwing operation of the screw head5is completed, the metal chips or powders remained in the through hole432and the room435C of the cover unit435can be cleaned easily by removing the sleeve member43from the second section42and cleaning the through hole432and the room435C thereafter as shown inFIG.9to thereby improve the magnetic effect of the sleeve member43and improve the smoothness and the screwing effect of the screwing operation effectively.

To sum up, the screwdriver of this invention takes advantages that the engagement member is engaged with the positioning groove of the second section to position the sleeve member on the second section properly. When the second section is inserted into the socket of the screw, the bottom end of the sleeve member is spaced apart from the top surface of the screw head to form the gap whereby the magnetic unit can attract the screw head without being in contact with the screw head. Thus, the sleeve member can position and guide the screw head through the magnetic attraction to thereby accelerate the screwing operation of the screw head and attain the stable screwing effect. Further, the metal chips or powders caused during the screwing operation can be cleaned easily by detaching the sleeve member from the second section and cleaning the through hole thereafter to thereby improve the magnetic effect of the sleeve member and extend the service life of the sleeve member.

While the embodiments of this invention are shown and described, it is understood that further variations and modifications may be made without departing from the scope of this invention.