JPH04171182A - electric screwdriver - Google Patents

Abstract

PURPOSE:To provide a motor operated screwdriver easier to handle in various conditions and applications by employing a mechanism for selecting the start up methods between push and lever types. CONSTITUTION:To select the push start, an MS lever is raised to the top and fixed there by means of a lock lever 14. As a result, a limit switch 13 is kept both mechanically and electrically in the condition turned on. To select the lever start, the lock lever 14 is lowered to the bottom and fixed there. Here, because a T lever 10 is brought in a specified position by a trigger spring 12, the limit switch 13 is also brought and kept in the position turned off. Under this condition, operation is made with a series of push start mechanism in operation, namely in a condition of the limit switch 8 being turned on both mechanically and electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric screwdriver employing a mechanical clutch.

Conventional Technology In recent years, screw tightening work has changed from air screwdrivers to electric screwdrivers, and electric screwdrivers that can be used flexibly in a variety of ways are now in demand.

An example of the conventional electric screwdriver mentioned above will be described below with reference to the drawings.

FIG. 5 shows an overall view of a conventional push-start type electric screwdriver.

In FIG. 5, 20 is a motor, 21 is a planetary gear reducer, and 22 is a clutch, which are covered and fixed with a cover 23. A bit 24 is held in the clutch 22 via a steel ball. Reference numeral 25 denotes a switch rod, which is set so that the clutch 22, the planetary gear reducer 21, and the inside of the motor 20 can be operated in the thrust direction. 2
Reference numeral 6 denotes a lever bin, which has a structure capable of moving in the thrust direction, and is fixed to the cover 23. 27 is a limit switch for starting the electric screwdriver.

The operation of the electric screwdriver configured as above will be explained below.

When a screw applying work is pressed against the tip of the bit 24, the bit 24 is moved in the direction of the arrow by the thrust mechanism of the clutch 22, and the switch slot 25 and the lever bin 26 are moved.
push up. The movement of the lever bin 26 is transmitted to the limit switch 27, which turns on mechanically and electrically to start the electric screwdriver.

Problems to be Solved by the Invention However, with the structure configured as described above, the electric screwdriver starts up just by placing a screw on the tip of the bit and pressing it against a workpiece, making it very difficult to make minor adjustments during work.

For example, when a worker corrects the misalignment between the lower and upper holes of a workpiece, he or she uses a screw like a regulating pin and presses it down while turning it to align the holes, which causes the electric screwdriver to start immediately. The difficulty of use, such as not being able to match the holes, caused discomfort to workers.

Means for Solving the Problems In order to solve the above problems, the electric screwdriver of the present invention has the following features:
By adding a lever start method to the conventional push start method, there are two types of starting methods, and the structure allows for easy selection.

Operation The present invention has the above-described configuration, and the screw is placed on the tip of the bit and pressed against the workpiece to activate the bush start mechanism.
When the limit switch is kept mechanically ON and the limit switch is mechanically and electrically turned ON by the lever start mechanism, the limit switch that was mechanically ON also turns ON electrically and the electric screwdriver is turned ON. It will start.

EXAMPLE Hereinafter, an electric screwdriver according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an overall view of an electric screwdriver according to an embodiment of the present invention.

In the figure, 1 is a motor, 2 is a planetary gear reducer, and 3 is a clutch, which are covered and fixed with a cover 4. Reference numeral 5 denotes a bit, which is held in the clutch 3 via a steel ball.

Reference numeral 6 denotes a switch rod, which is set so that the insides of the clutch 3, planetary gear reducer 2, and motor 1 can be moved in the thrust direction. Reference numeral 7 denotes a lever pin, which has a structure capable of sliding in the thrust direction, and is fixed to the cover 4. 8 is a first limit switch, and the lever pin 7
It is installed so that the point of action is at the center of the 9 is a lever, and 10 is a T lever which is fastened to the lever 9 with a screw. The lever 9 is fixed to the cover 4 with a pin so that it can rotate.

Reference numeral 11 denotes an MS lever, which is fixed to the cover 4 with a pin so as to be rotatable. A trigger spring 12 is set between the MS lever 11 and the cover 4. Reference numeral 13 denotes a second limit switch, which is fastened with a screw so that its point of action is located at the tip of the MS lever 11. A lock lever 14 is attached to the cover 4 by turning the pin.

The operation of the electric screwdriver configured as described above will be described below with reference to FIGS. 1 to 4.

FIG. 2 is a detailed view of section A when the bush start method is selected. Since the MS lever 11 is pushed up to the upper limit and fixed by the lock lever 14, the limit switch 1
3 is kept mechanically and electrically turned on. From this state, when a screw is applied to the tip of the bit 5 shown in FIG. 1 and pressed against the workpiece, the bit 5 moves in the direction of the arrow B. This operation is transmitted to the switch rod 6 and lever pin 7, and further transmitted to the limit switch 8, which is turned on mechanically and electrically, thereby turning on the two limit switches and starting the electric screwdriver.

FIG. 3 shows the details of section A when the lever start method is selected. The lock lever 14 is pushed to its lower limit and fixed. The T lever 10 has a trigger spring 1
2, so the limit switch 2.13
is also mechanically and electrically turned off.

In this state, the following operation will be performed with the series of bush start mechanisms operating, that is, with the limit switch 8 mechanically and electrically turned on.

When the lever 9 shown in FIG. 4 is pushed, the T-lever 10, which is fastened with a screw, also moves in the direction C centering on the pin fixing the lever 9. In conjunction with this movement, the trigger spring 12 MS lever 11 was waiting in the fixed position.
is pushed up to the upper limit, and in synchronization with this, the limit switch 13 is turned on mechanically and electrically. This results in 2
The two limit switches are turned ON and the electric screwdriver is activated.

Effects of the Invention As described above, the present invention provides the market with an electric screwdriver that is easier to handle under all usage conditions and methods by allowing easy selection of two types of starting methods, a push start method and a lever start method. It is.

[Brief explanation of the drawing]

FIG. 1 is an overall view of an electric screwdriver according to an embodiment of the present invention, FIGS. 2 to 4 are detailed views of section A of the lever start mechanism, and FIG. 5 is an overall view of a conventional electric screwdriver. 1... Motor, 2... Planetary gear reducer, 3... Clutch, 4... Cover, 5
...Bit, 6...Switch lot,
7...Lever pin, 8...Limit switch, 9...Lever, 10...T lever, 11...MS lever, 12...・・・・・・
Tricar spring, 13...Limit switch, 1
4...Lock lever-0 Name of agent: Patent attorney Haruaki Koebi and 2 others If...-
Mu high - 2nd day 1.3 /Z -= ) 9 to Ishi - Iris 3 @ /4 13 纂 4 Figure

Claims (1)

[Claims] When tightening a screw, the electric screwdriver mechanically and electrically stops the rotation of the bit when the tightening torque reaches the set torque.You can easily select between two types of starting methods: push start or lever start. An electric screwdriver characterized by being equipped with a mechanism.