US20040134675A1

US20040134675A1 - Electric screwdriver

Info

Publication number: US20040134675A1
Application number: US10/339,561
Authority: US
Inventors: Pei-Chang Sun
Original assignee: Modern Pioneer Ltd
Current assignee: Modern Pioneer Ltd
Priority date: 2003-01-10
Filing date: 2003-01-10
Publication date: 2004-07-15

Abstract

An electric screwdriver is disclosed to include a main body, a socket, an actuator, a switch, and a wrenching portion. The actuator is installed inside the main body, which has a front end and a rear end. The socket is rotatably positioned at the front end of the main body and is connected with the actuator. The switch is mounted on the main body. The wrenching portion is positioned at a position in proximity to the front end of the main body.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electric hand-held tools, and more particularly to an improved electric screwdriver.

2. Description of the Related Art

As shown in FIG. 1, a conventional

electric screwdriver

1 is composed of a main body 2, a switch 3, a socket 4, a bit 5, and an actuator (not shown). A screw 6 is driven to screw into a workpiece 7 by a front end of the bit 5 so as to be threadedly mounted or interconnected with the workpiece 7. In the above screwing process, since torsion, which is generated by the bit 5, against the screw 6 is quite powerful enough to drive the screw 6 to move toward inside of the workpiece 7, while the head 6 a of the screw 6 is stopped moving forward by contacting against the surface of the workpiece 7, the socket 4 will be automatically jammed so as to synchronically stop the bit 5 to rotate. In the meantime, the electric screwdriver 1 is electrically driven with the greatest output of the torsion. However, when the screw 6 is stopped moving forward, the screw 6 is usually screwed further by a user's screwing force so as to be tightly screwed with the workpiece 7 by the greatest screwing force. When the screw 6 is reversely screwed out of the workpiece 7, the user has to exert a reverse screwing force on the main body 2 to drive the screw 6 to move reversely.

Learned from the above operation, the

screw

6 is further tightly screwed into or reversely out of the workpiece 7 by the user's hand directly exerting on the main body 2 of the electric screwdriver 1, and accordingly, the electric screwdriver 1 works like a conventional hand-held screwdriver, which is not driven by electricity. In other words, the screw 6 is driven to rotate quickly and then to screw toward the workpiece 7 by the electric screwdriver 1 at first, but the screw 6 has to be further tightly screwed into or reversely out of the workpiece 7 by the user's force such that the conventional electric screwdriver 1 fails to be laborsaving. Especially for longer screws, it will take more efforts to screw the longer screws further tightly into the workpiece 7. Although some of conventional electric screwdrivers are respectively formed to be curved at a rear section of the main body 2 thereof, a force driving the screw 6 to be further tightly screwed into the workpiece 7 is not directly exerted on the bit 5 but is exerted by a component of the force. Accordingly, the front end of the bit 5 of the electric screwdriver 1 may slip off the screw.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide an improved electric screwdriver, which is provided with a laborsaving effect while a driven member, like screw, is further tightly screwed into or reversely out of a workpiece.

The secondary objective of the present invention is to provide an improved electric screwdriver, which is disposed with a wrenching portion for inserting a tool to drive the electric screwdriver to rotate so as to have a laborsaving effect.

The foregoing objectives of the present invention are attained by the improved electric screwdriver, which is composed of a main body having a front end and a rear end, a socket, an actuator, a switch, and a wrenching portion. The actuator is installed inside the main body. The socket is rotatably positioned at the front end of the main body and is connected with the actuator. The switch is mounted on the main body. The wrenching portion is mounted at a position in proximity of the front end of the main body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a conventional electric screwdriver at work; [0009]
FIG. 2 is a perspective view of a first preferred embodiment of the present invention; [0010]
FIG. 3 is a partial sectional view of the first preferred embodiment of the present invention; [0011]
FIG. 4 is a schematic view of the first preferred embodiment of the present invention to be connected with a tool; [0012]
FIG. 5 is a schematic view of the first preferred embodiment of the present invention driven to rotate by the tool; and [0013]
FIG. 6 is a perspective view of a second preferred embodiment of the present invention.[0014]

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2 and 3, an [0015] electric screwdriver 100 of the present invention is composed of a main body 10, a socket 20, an actuator 30, a switch 40, and an auxiliary member 50. The main body 10 is an elongated cylindrical shaft and has a front end 11 and a rear end 12. The socket 20 is rotatably mounted with the front end 11 of the main body 10 and is coupled with a bit 60, as shown in FIG. 4. The actuator 30, which is composed of a plurality of actuating elements, is installed inside the main body 10 and is connected with the socket 20. Because the actuator 30 is a prior art, it will not be described in detail thereafter. The switch 40 is laterally mounted on the main body 10 for easily pressing by a finger to control the actuator 30 to drive the socket 20 and then to drive the bit 60 to rotate quickly. The improvement of the present invention is described as follows.
The [0016] main body 10 is interconnected with two half shells 13, which correspond to each other both in shape and structure. Each of the two half shells 13 is provided with a semicircular convexity 14 at a position in proximity of the front end 11 of the main body 10. The convexity 14 is provided with a chamber 15 inside and a first through hole 16, which communicates with the chamber 15 and outside, and a matching recess 17 positioned at an inner periphery of the chamber 15. While the two half shells 13 are correspondingly interconnected with each other, the two convexities 14 are formed to be an arched convex ear, at which bilateral sides the two first through holes 16 are correspondingly positioned to form a main through hole. A longitudinal axle of the main through hole is normal with a longitudinal axle of the main body 10. The above convex ear and the main through hole together form a wrenching portion of the main body.
The [0017] auxiliary member 50 is installed inside the main body 10 of the electric screwdriver 100 and includes an annular frame 51, a convex portion 52, and a second through hole 53 running through the convex portion 52. The annular frame 51 is externally fit to the actuator 30 without interfering operation of the actuator 30. The convex portion 52 protrudes outwardly from a side of the annular frame 51 and has a matching portion 521 at a lateral fringe thereof. The convex portion 52 is received in the chambers 15 of the convexities 14 and the matching portion 521 is embedded into the matching recess 17 such that the auxiliary member 50 will not move irregularly. The second through hole 53 and the main through hole, which are coaxially positioned and are identical in diameter, communicate with one another.
Referring FIG. 4, while a driven member, embodied as a [0018] screw 70, fails to be screwed further tightly into a workpiece (not shown) by the electric screwdriver 100, the socket 20 will be automatically jammed. In the meantime, a user inserts a tool 200 through the main through hole, i.e. through the first through hole 16 of the half shell 13, the second through hole 53 of the auxiliary member 50, and the then the other first through hole 16 of the other half shell 13, such that the tool 200 vertically crosses the electric screwdriver 100. And then, as shown in FIG. 5, the user simply pushes the tool 200 to drive the electric screwdriver 100 to rotate in a direction in which the screw 70 is screwed into the workpiece (not shown) such that the screw 70 will be further tightly screwed into the workpiece with more powerful torsion output generated by the user's force as well as the electric screwdriver 100. Accordingly, the present invention improves a disadvantage, which is resulted from that it takes more efforts to make the screw 70 screwed further tightly by directly exerting on the main body 10, of a conventional electric screwdriver by pushing the tool 200 to drive the electric screwdriver 100. Especially for a longer screw, it takes fewer efforts to screw the longer screw further tightly by the present invention. While the longer screw is reversely screwed out, it's laborsaving likewise by the present invention.
Referring to FIG. 6, the difference between a second preferred embodiment and the first preferred embodiment of the present invention lies in that the [0019] electric screwdriver 300, which is provided with an opening 303 at the front end of the main body 301 and close to the socket 302, and the auxiliary member, which is provided with a convex portion 304 and a through hole 305. The convex portion 304 protrudes outwardly from the opening 303. The through hole 305 runs through the convex portion 304 for the aforementioned tool 200 inserting through and works identically like the main through hole in the first preferred embodiment of the present invention.

Claims

What is claimed is:

1. An electric screwdriver comprising:

a main body having a front end and a rear end;

an actuator installed inside the said main body;

a socket rotatably mounted to said front end of said main body and connected with said actuator;

a switch mounted on said main body; and

a wrenching portion positioned in proximity to the front end of said main body.

2. The electric screwdriver as defined in claim 1, wherein said wrenching portion is in the shape of a convex ear and is provided with a main through hole, said main through hole having a longitudinal axle perpendicular to a longitudinal axle of said main body.

3. The electric screwdriver as defined in claim 2, wherein said main body includes two half shells, each said half shell having a convexity positioned in proximity to a front end thereof and a first through hole running through said convexity, said two convexities forming said convex ear, said two first through holes forming said main through hole.

4. The electric screwdriver as defined in claim 3, wherein said two convexities further respectively have a chamber inside, said chamber communicating with said first through hole.

5. The electric screwdriver as defined in claim 4 further comprising an auxiliary member installed inside said main body, said auxiliary member having an annular frame, a convex portion, and a second through hole running through said convex portion, said annular frame being fit to said actuator, said convex portion being received in said chambers, said second through hole coaxially communicating with said first through holes.

6. The electric screwdriver as defined in claim 5, wherein said chamber is further provided with a matching recess at an inner periphery thereof; wherein said convex portion further has a matching portion to be embedded into said matching recess.

7. The electric screwdriver as defined in claim 1, wherein said main body is provided with an opening in proximity to said front end thereof and an auxiliary member installed therein, said auxiliary member having a convex portion and a through hole, said convex portion protruding outwardly from said opening of said main body, said through hole running through said convex portion.