JPS6023571Y2 - gear system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gear device that prevents tooth loss and damage.

As shown in FIG. 7, in a gear device in which a driving gear 20 and a driven gear 21 are meshed, the driving gear 20 is indicated by an arrow X1.
．． By rotating the driven gear 21 in the x2 direction, the driven gear 21 is rotated in the direction of the arrow Y1. In order to moderately rotate the gear in the Y2 direction within a predetermined rotation angle range, it is known that a regulating protrusion 22 is formed on the surface of the driven gear 21, and a stopper 23 is provided with which the regulating protrusion 22 comes into contact. .

However, in the gear device described above, when the driving gear 20 is rotated in the normal rotation direction (arrow X1) in FIG. 7 as shown in FIG.
Even though the drive gear 2 is in contact with
If a rotational force in the direction of the arrow x1 is applied to the gear 0, problems such as the teeth 20a and 21a of both gears 20 and 21 will come off or the stopper 23 will be destroyed will occur.

This also applies to the case of rotation in the reverse direction (arrow X2) in FIG.

This idea was developed in view of the above points, and even though the driven gear rotates moderately at a predetermined rotation angle and stops, even if the driving gear further rotates in the same rotational direction, both gears It is an object of the present invention to provide a gear device that does not cause damage to the teeth or break the stopper.

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

In FIG. 1, 1 is a driving gear, and 2 is a driven gear. The teeth 1a and 2a of these gears 1 and 2 mesh with each other so that they can rotate at the same time.
It forms b.

The driven gear 2 is made of elastically deformable synthetic resin, and has a regulating protrusion 3 protruding from its surface.

Reference numeral 4 denotes a stopper, and when the driving gear 1 is rotated and the driven gear 2 is rotated, the regulating protrusion 3 comes into contact with the stopper 4, and the driven gear 2 is rotated moderately within a predetermined rotation angle range. ing.

The driven gear 2 has teeth 2b that mesh with the teeth 1a of the drive gear 1 at the position where the regulating protrusion 3 abuts the stopper 4, and a substantially T-shaped piece extending in the circumferential direction from the center of the driven gear 2. It is formed at the outer peripheral end of an arcuate edge 6 that is distantly connected to both sides of the tip of the arm 5.

In the above configuration, from the state where the drive gear 1 and the driven gear 2 are meshed as shown in FIG.
and rotate it in the normal rotation (arrow A) direction, and the driven gear 2
Rotate in the reverse direction (arrow B).

Due to the above rotation, the regulating protrusion 3 comes into contact with the stopper 4, as shown in FIG. 3, and stops the driven gear 2.

Even though the regulating protrusion 3 of the driven gear 2 is in contact with the stopper 4 in this way, the drive gear 1 is further moved as shown by the arrow A.
When rotated in the direction, the driven gear 2 is formed of an elastically deformable synthetic resin material, and the teeth 2b are connected to the arm 5
Since it is formed on the outer peripheral end of the arcuate edge 6 that is connected to both sides of the tip of the drive gear 1, when a local force acts on the meshing portion C, the arcuate edge 6 is deformed as shown in the figure, and the drive gear 1 tooth 1
a rotates while slipping against the teeth 2b of the driven gear 2.

Therefore, damage to the teeth 1a, 2a, 2b of both gears 1, 2 and breakage of the stopper 5 can be prevented.

In the state shown in Fig. 3 above, drive gear 1 is rotated in reverse (arrow D
) direction and meshing the teeth 1a with the teeth 2a of the driven gear 2, the arcuate edge 6 returns to its original shape.

Further, when the drive gear 1 is rotated in the direction of the arrow,
The regulating protrusion 3 comes into contact with the stopper 4 as shown in FIG. 4 to stop the driven gear 2.

Even if the drive gear 1 is further rotated in the direction of the arrow from this state, the teeth 1a of the drive gear 1 rotate while slipping against the teeth 2b of the driven gear 2, as in the case of FIG.
To prevent loss of teeth 1a, 2a, 2b and damage to stopper 5.

FIG. 5 shows an example in which the gear device according to this invention is applied to a range switching mechanism in a timer with multiple time ranges.

In the figure, by rotating a rotary switch 7, it is possible to switch between four time specifications, and a gear 2 according to this invention is fixed to a rotating shaft 7a of the rotary switch 7, and the gear 2 is a driving gear. 1 and character gear 8.

Therefore, when a rotation drive jig such as a screwdriver is fitted into the shaft hole 1b of the drive gear 1 and the drive gear 1 is rotated, the rotation shaft 7a of the rotary switch 7 is rotated, and the time specification of the timer is changed. At the same time, the character gear 8 also rotates.

The character gear 8 has a number sequence (0
,,1,,2,,3,,4,,5),(0,.

2. 4. ．． 6.8,1), (0,1,2,3,4゜5
), (0, 2, 4, 6, 8, 10).

Since it is displayed by printing, the switched number sequence can be visually seen from the scale number window 10 of the nameplate 9.

A notch 11 and a regulating protrusion 1 are provided on a part of the circumference of the character gear 8.
2 is formed, and when the driving gear 1 is rotated a predetermined number of times in the forward and reverse directions, the regulating protrusion 12 comes into contact with the stopper 13, and the character gear 8 is pressed.

When the character gear 8 is locked in this way, even if the drive gear 1 is further rotated, the driven gear 2 is elastically deformed as in the above embodiment, so the drive gear 1 slips and rotates. , 2.8, and the stopper 12 can be prevented from being damaged and damaged.

In the figure, 14 is a knob fixed to the tip of the volume shaft 15, and 16 is a timer IC.

As explained above, this invention uses a circular drive gear,
In a gear device that meshes with a circular driven gear and in which a regulating protrusion contacts a stopper when the driven gear rotates by a predetermined angle in a forward and reverse rotation direction, an arm extending in a radial direction from a center of the driven gear; , a substantially T-shaped piece consisting of an elastically deformable arcuate edge extending integrally in the circumferential direction at the tip of the arm is formed in the driven gear, and a tooth row is formed on the outer peripheral surface of the arcuate edge. At the same time, since a tooth row is formed on the outer circumferential surface of the driven gear that extends continuously from both ends of the tooth row of the arcuate edge through the notch in the forward and reverse rotation directions of the driven gear, the driven gear does not rotate in the normal direction. Alternatively, when the regulating protrusion contacts the stopper after rotating in the reverse direction, the driving gear meshes with one end of the tooth row on the arcuate edge of the driven gear and slips, causing the teeth of each gear to slip. This can prevent damage to the stopper and breakage of the stopper.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the gear device according to this invention, Figs. 2 to 4 are front views of the operating state, and Fig. 5 is an example of the gear device according to this invention applied to a time range switching mechanism of a timer. FIG. 6 is a front view of the character gear, FIG. 7 is a front view of a conventional example, and FIG. 8 is an explanatory diagram of the same operation. 1... Drive gear, 1a... Teeth, 2...
...Driven gear, 2b...Teeth, 3...
・Regulation protrusion, 4... Stopper, 5...
Arm, 6... arcuate edge.

Claims (1)

[Scope of utility model registration request] In a gear device in which a circular driving gear and a circular driven gear are engaged with each other, and a regulating protrusion contacts a stopper when the driven gear rotates by a predetermined angle in a forward/reverse rotation direction, radially from the center of the driven gear. A substantially T-shaped piece consisting of an extended arm and an elastically deformable arcuate edge extending integrally to both sides in the circumferential direction at the tip of the arm is cut out in the driven gear, and the outer periphery of the arcuate edge is A tooth row is formed on the surface, and a tooth row is formed on the outer peripheral surface of the driven gear that extends continuously from both ends of the tooth row of the arcuate edge through the notch in the forward and reverse rotation directions of the driven gear. , at a position where the driven gear rotates in the forward or reverse direction and the regulating protrusion abuts the stopper, the driving gear meshes with one end of the tooth row of the arcuate edge of the driven gear and slips. A gear device characterized by being configured as follows.