JPS604790Y2 - rechargeable electric pencil sharpener - Google Patents

Description

[Detailed description of the invention] This invention relates to a rechargeable electric pencil type with a built-in rechargeable battery, and in particular, displays an indication when the battery is being charged and indicates when the pencil tip has been sharpened. The circuit is such that a single light emitting diode (LED) or lamp can be used for both display and display.

Hereinafter, one embodiment of the present invention will be described. A box-shaped main body case 1 includes a rechargeable battery 2, a motor 3, a step-down transformer 4 for charging, and a charging plug blade 5. Furthermore, a gear group 6 for decelerating and transmitting the rotational power of the motor 3, a cutter holder 7, a waste receiving box 8, etc., which rotate by receiving power from the gear group 6, are provided.

A decorative plate 9 that can be slid freely in the direction of the arrow is attached to the top surface of the main body case 1, and a hole 10 formed in this plate matches the pencil insertion slot 11 when the pencil is pulled out, and the pencil is inserted into the cutter holder 7. It is possible.

Reference numeral 12 denotes an operator of a drive switch 13 that moves to the left when a pencil is inserted and energizes the motor 3.

14 is a detection rod 14 that moves downward when the tip of the core is cut by the flat blade attached to the cutter holder 7 and is pushed by the tip of the core.
A movable piece 17 having tapered surfaces 16 and 16 on both sides is supported by a leaf spring 18 at the lower end and is normally biased upward.

19 is the tapered surface 16 when the movable piece 17 is pressed down.
This is an actuator that moves in the lateral direction and brings the movable contact piece 20 into contact with the fixed contact piece 21.

Therefore, the switch section 2 detects when cutting of the core tip is completed.
2 is composed of a movable contact piece 20 and a fixed contact piece 21.

A light emitting element such as a light emitting diode 25 or a zero bulb 26 faces the elongated hole 24 of the decorative plate 9, and is turned on when cutting of the core tip is completed or when the battery 2 is charged.

Next, a lighting circuit for the light emitting elements 25 and 26 will be explained.

First, a light emitting diode (LED) is used as the first example circuit.
To explain with reference to FIG. 5 using 25, the positive electrode of the storage battery 2 is connected to the motor 3 via the drive switch 13,
The other end of the motor 3 is connected to the negative electrode of the storage battery 2, forming a motor drive circuit.

In the charging circuit, a charging diode 27 is connected to the secondary coil 4' of the step-down transformer 4 to which the charging plug blade 5 and the primary coil are connected, and the output side of this diode 27 is connected to the storage battery 2.

Furthermore, a light emitting diode 25 is cascaded between the secondary coil 4' in parallel with the storage battery 2 via a backflow prevention diode 28, and further connected to a resistor 29.

The positive electrode side of the light emitting diode 25 is connected to a switch 22 for detecting the completion of tip cutting, and the other end of the detection switch 22 is connected to the storage battery 2 via the drive switch 13.

With such a circuit, when cutting a pencil, when the pencil is inserted into the pencil insertion slot 11, the drive switch 13 is closed, the motor 3 rotates, and cutting begins.

Eventually, the tip of the lead is shaved off, the detection rod 14 slides downward, and when the cutting is completed, the detection switch 22 is closed.

Then, current from the storage battery 2 flows through the drive switch 13 and the detection switch 22 to the light emitting diode 25, and the diode 25 emits light to notify that cutting of the tip has been completed.

Next, when charging, push the charging plug blade 5 downward,
When plugged into an outlet, the secondary output of the step-down transformer 4 is rectified by the charging diode 27, and the storage battery 2 is charged.

Simultaneously with this charging, the output current on the secondary side flows through the backflow prevention diode 28 to the light emitting diode 25 and the resistor 29, causing the light emitting diode 25 to light up.

Therefore, this light emitting diode 25 now serves as an indicator indicating that charging is in progress.

In this way, one light emitting diode 25 can be used both to indicate that the tip of the pencil lead has been cut and to indicate that the pencil is being charged.

FIG. 6 shows a display circuit of a second embodiment using a zero ball 26,
To explain this, the motor 3 is driven by the drive switch 13
The 0 bulb 26 is connected to both ends of the storage battery 2 via the drive switch 13, the detection switch 22 which closes when cutting the tip of the core is completed, and further forms a discharge circuit separate from the motor drive circuit via a resistor 30. .

Moreover, this 0 ball 26 is inserted in series with the charging circuit,
The secondary coil 4' of the step-down transformer 4, the charging diode 27.0 bulb 26, and the storage battery 2 are connected in cascade.

The action is as follows: when a pencil is inserted, the drive switch 13 closes, the motor 2 rotates, the cutting progresses, the tip becomes thinner and the detection switch 22 closes, and the zero ball 26 → resistance 30 → detection switch 22 → drive switch 13 A storage battery current flows, and the 0 bulb 26 lights up, indicating that cutting has been completed.

Therefore, in this case as well, one 0 ball 26 can serve both as a cutting completion display and a charging display.

As described above, the present invention has a circuit configuration in which a light emitting element that lights up when a storage battery is being charged is connected to the storage battery via a detection switch that closes when cutting the tip of a pencil lead is completed. Can be used for both display and cutting completion display.

It is economical because it reduces the number of parts, and the circuit configuration is simple, so it can achieve the above-mentioned effects and is very practical.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view of the overall external appearance of the pencil mold, Fig. 2 is a cross-sectional view, and Fig. 3 is a cross-sectional view of main parts mainly showing the switch mechanism for detecting completion of tip cutting. , 4th
The figure shows the structure of the switch contact part, Figure 5 shows the configuration of the display circuit of the present invention using light emitting diodes (LEDs), and Figure 6 shows another embodiment of the display circuit using 0 bulbs. FIG. 2...Storage battery, 25, 26...Light emitting element, 22...Detection switch.

Claims (1)

[Scope of utility model registration request] A rechargeable electric pencil device comprising a light-emitting element that lights up when the storage battery is charged and is connected to the storage battery via a detection switch that closes when cutting the tip of the lead is completed.