JPS6137155Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of the switch operation mechanism of small electric appliances such as electric toothbrushes.

Conventionally, as shown in FIG. 4, this type of switch operating mechanism has a knob setting recess 41 formed in a main body case 40, and is rotatably supported by an inner wall 42 of this recess 41. The drive shaft 4 protrudes into
A knob 45 for reciprocating the drive shaft 44 is fixed to one end 44a of the drive shaft 44, and an O-ring 46 fitted into the drive shaft 44 is clamped between the support wall 42 of the drive shaft 44 and the knob 45. By interposing a moderation elastic mechanism 47 between the lower surface of the knob and the bottom wall of the recess 41 to selectively position the knob 45 in the ON and OFF positions, the knob 45 can be pressed. There is a configuration in which the movable contact piece 49 of the switch 48 is moved toward and away from the fixed contact piece 50 via the other end 44b of the drive shaft 44 by turning ON and OFF.

However, in the above configuration, the elastic force F of the spring 51 constituting the elastic mechanism 47 is
The recess 41
The drive shaft 44 supported by the support wall 42 is constantly rotated under a twisting force, making the knob 45 unstable to operate and rattling due to repeated use. This is likely to occur, and in that case, contact failure of the switch 48 will result. Furthermore, due to the biasing force, the clamping pressure on the O-ring 46 is uneven, resulting in instability and an inability to exhibit an effective waterproofing effect.

Therefore, this invention improves the operability of the knob by setting the resilient force of the resilient mechanism in the direction along the clamping direction of the O-ring, and eliminates the risk of poor contact with the switch. Moreover, the waterproof effect is effectively maintained.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a main body case, in which a battery 2, a motor 4 held by a motor holding plate 3, etc. are housed. 5 is a driving gear fixed to the rotating shaft 6 of the motor 4, and 7 is a driven gear rotatably supported by the motor holding plate 3, which is meshed with the driving gear 6. Reference numeral 8 denotes a drive shaft body rotatably supported by a bearing member 9 fixed to the main body case 1, and a tip end 10 of this drive shaft body 8
protrudes outward from the tip of the main body case 1, a brush handle 12 having a brush portion 11 is removably attached to the tip 10, and a base end 13 of the drive shaft 9 has a brush handle 12 removably attached thereto. , a drive lever 15 fitted to an eccentric shaft 14 protruding from the driven gear 7;
is fixed. Reference numeral 16 denotes a power switch consisting of movable and fixed contact pieces 17 and 18. When the power switch 16 is turned on, the rotational force of the motor 4 is transmitted to the drive shaft body 8 as a reciprocating rotational movement via the drive lever 15. , the brush part 11 of the brush handle 12
has begun to perform a shaking motion. 19 is a packing member.

20 is a drive shaft for operating the movable contact piece 17, and one end 20a of this drive shaft 20 is connected to the opposing inner wall 22 of the knob setting recess 21 formed in the main body case 1, as clearly shown in FIG. , one of 23 2
It is rotatably supported by a support wall 22 constituted by a support wall 22, protrudes into the recess 21, and is connected to a knob 24 disposed within the recess 21. This knob 24 allows the drive shaft 20 to be rotated back and forth in the direction of arrow a in FIG. Reference numeral 25 denotes an O-ring interposed between the support wall 22 of the drive shaft 20 and the knob 24, which is inserted into the one end 20a of the drive shaft 20 and inserted into the insertion hole 26 of the drive shaft 20.
It is a seal. 27 is the support wall 22
This is a resilient mechanism that is interposed between the opposing wall 23 and the knob 24 that face each other via the knob 24, and this resilient mechanism 27 is fitted into a recess 28 formed in the knob 24, for example. It consists of a spring 29 that is attached to the switch lever 20 and generates a spring force along the axis of the one end 20a of the switch lever 20, and a steel ball 30 supported by the spring 29. Recesses 3 formed in the opposing wall 23 corresponding to the positions
1 and 32 (FIG. 3), and the above-mentioned knob 24 is appropriately positioned by the reaction force at the time of fitting.

In this way, the O-ring 25 is interposed between the support wall 22, which is one inner wall of the knob setting recess 21, and the knob 24, and the O-ring 25 is interposed between the opposing wall 23 and the knob 24.
Since the elastic mechanism 27 for moderation is interposed between the knob 24 and the one end 2 of the drive shaft 20,
The elastic force F along the axial direction of 0a becomes biased, and therefore the twisting force on the drive shaft 20 is suppressed, the operation of the knob 24 becomes stable, and there is a risk of poor contact of the switch 16. is resolved. Furthermore, since the resilient force F of the resilient mechanism 27 and the resilient force F' of the O-ring 25 are in the same direction, the
The resilient force F' of the O-ring 25 that acts on the knob 24 that is resiliently directed toward the ring 25 acts as a reaction force in the opposite direction toward the support wall 22, and this reaction force acts on the support wall 22 as described above. It always acts effectively on the support wall 22, thus improving the sealing effect of the O-ring.

In addition, in the above embodiment, the elasticity mechanism 27 for moderation is
Although the spring 29 and the steel ball 30 are used as the spring 29, the resilient mechanism 27 may be made of a plate spring or the like.

Further, although the above embodiment has been described as an example applied to an electric toothbrush, it goes without saying that it can also be applied to other small electric appliances such as an electric shaver.

As described above, this invention is designed to provide an O
By clamping the ring, interposing an elastic mechanism for knob moderation between the opposing wall and the knob, and setting the elastic force of this elastic mechanism in a direction along the clamping direction of the O-ring, It is possible to provide a switch operation mechanism for a small electrical device that can improve the operability and waterproof effect of the switch.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view showing an example of the switch operation mechanism of a small electric device according to this invention, Fig. 2 is an enlarged sectional view of the main part, Fig. 3 is an explanatory diagram of the moderation triggering mechanism, FIG. 4 is an explanatory diagram of a conventional example. 1... Main body case, 20... Drive shaft, 20a...
...One end, 22...Supporting wall, 23...Opposing wall, 2
4...knob, 25...O-ring, 27...bounce mechanism, F...bounce force.

Claims (1)

[Scope of utility model registration request] a drive shaft 20 rotatably supported by the main body case 1 and for driving the built-in power switch 16;
A knob 24 is fixed to one end 20a of the drive shaft 20 and rotates the drive shaft 20 back and forth; 24, and an O-ring 25 is interposed between the opposing wall 23 and the knob 24, which face the support wall 22 via the knob 24, and rotates the knob 24 in a predetermined manner. It has an elastic force F of the elastic mechanism 27 for moderation to hold it in position.
A switch operation mechanism for a small electric device, in which the switch is set in a direction along the clamping direction of the O-ring 25.