JPH062070Y2 - Driving force transmission device having double rack mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to an improvement of a driving force transmission device having a double rack mechanism suitable for application to, for example, a pickup feeding mechanism of a compact disc player.

"Prior Art" FIG. 2 shows an example in which a driving force transmission device having a double rack mechanism is used for a pickup feeding mechanism of a compact disc player.

In the figure, reference numeral 100 denotes the entire pickup feed mechanism, 101 denotes the pickup mechanism, and this pickup mechanism 101 lasers a digital audio signal recorded on a compact disc (CD) placed on a turntable 102. It is for reading with a beam.

A guide rod 102 serves as a guide for moving the pickup mechanism 101 from the inner peripheral surface of the compact disc toward the outer peripheral surface or from the outer peripheral surface toward the inner peripheral surface.

The above-described movement of the pickup mechanism 101 is performed by a double rack mechanism 103 including a driving rack integrally provided with the pickup mechanism 101 and a driven rack that is elastically coupled to the driving rack and is driven by the driving rack. This is made possible by transmitting the rotation of the motor M in the clockwise or counterclockwise direction via the.

FIG. 3 and FIG. 4 are views showing a main part and a cross section of the main part of the double rack mechanism 103, respectively.
a is provided integrally with the pickup mechanism 101, and the driven rack 103b is elastically coupled to the driving rack 103a by a resilient spring 105 and is arranged in a state of being displaced by a half pitch.

Further, as shown in FIG. 5A for explaining the operation of the double rack, the teeth of the rotary gear 104 have the double rack mechanism 103.
A1 of the driving rack 103a and the driven rack 10 constituting the
When it is arranged between the teeth b2 of 3b, the pitch between the driving rack 103a and the driven rack 103b shifts by more than half a pitch. 103a, 103
It is elastically clamped between the respective teeth of b. Since the backlash can be reduced by this elastic pinching, when the double rack mechanism is used, an inexpensive and highly reliable driving force transmission device can be configured. for that reason,
This transmission device is often used in a pickup feed mechanism of a compact disc player.

[Problems to be Solved by the Invention] In the above-described conventional apparatus, as shown in FIGS. 5B to 5E for explaining the operation of the double rack, the double rack mechanism 103 moves the rotary gear 104 in the counterclockwise direction. When moving to the left end by rotation, the drive rack 103a
When the tooth a1 of is disengaged from the position where it meshes with the teeth of the rotary gear,
Since the driving rack 103a contacts the stopper 106,
Although it cannot move any further, the driven rack 103b moves against the elastic force of the elastic spring 105 (FIG. 5B).

Further, the driven rack 103b moves to move the driven rack 10b.
3a and the same phase (FIG. 5C), the rotary gear 104
Since the meshed state between the double rack mechanism 103 and the double rack mechanism 103 is released for a moment, the driven rack 103a holds its position, but the driven rack 103b holds the elastic spring 105.
By the action of, the gear rack 103a returns to a position displaced by a half pitch, that is, the tooth b1 of the driven rack 103b meshes with the tooth of the rotary gear 104 (FIG. 5D).

While the rotary gear 104 maintains the counterclockwise rotation in this state, the B → C → D states of FIG. 5 are repeated.

Next, when the rotating direction of the motor M changes from this state and the rotating gear 104 rotates clockwise, the rotating gear 104 tries to enter between the tooth a1 of the driving rack 103a and the tooth b1 of the driven rack 103b this time. , Drive rack 103a
Since the tooth a1 and the tooth b1 of the driven rack 103b are displaced by only a half pitch, each tooth rides up and damages the tip of the tooth.

In view of this, the present invention proposes a driving force transmission device having a double rack mechanism in which the problems of the conventional device are simply solved.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, a rotary gear, a driving rack arranged to be horizontally movable, and a driving rack elastically coupled to the driving rack and driven by the driving rack. And a driven rack that horizontally moves, the teeth of the rotating gear are elastically sandwiched between the teeth of the driving rack and the teeth of the driven rack, and the rotation of the rotating gear causes the driving rack and the driven rack to move horizontally. In the drive force transmission device having the double rack mechanism described above, when the driving rack moves to the terminal end, the driving rack is forcibly moved so that the teeth at the final end of the driving rack move to the position where they mesh with the teeth of the rotary gear. It is characterized in that elastic means for urging is provided.

[Operation] An elastic means for forcibly urging the driving rack 107a so that the tooth a1 at the final end of the driving rack 107a moves to a position where it meshes with the teeth of the rotary gear 104 when the driving rack 107a moves to the end. Since 108 is provided, as shown in FIGS. 1A to 1E for explaining the operation of the double rack mechanism, even if the rotation direction of the rotary gear 104 changes, the teeth of the rotary gear must be driven by the teeth a1 of the driving rack 107a and the driven gears. Since it is elastically sandwiched between the tooth b2 of the rack 107b (generally, the tooth an of the driving rack 107a and the tooth bn + 1 of the driven rack 107b), tooth tip chipping occurs. Never.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1A to 1E for explaining the operation of the double rack mechanism according to the present invention. The same reference numerals are used for the same parts as in the conventional device.

This invention has the same construction as the conventional device except that a stopper 108 made of an elastic member that comes into contact with only the driving rack 107a is provided on the moving end portion side of the driving rack 107a. The repulsive force of the stopper 108 is stronger than the biasing force of the elastic spring 105.

By the way, in the process in which the double rack mechanism 107 moves to the left end by the rotation of the rotary gear 104 in the counterclockwise direction, the driving rack 107a includes the stopper 1 made of an elastic body.
08 is compressed and moved to the left, and the driven rack 107b
Also moves to the left against the elasticity of the elastic spring 105 (FIG. 1B).

Further, after the driven rack 107b moves to the left and becomes in phase with the driving rack 107a (FIG. 1C), both the driving rack 107a and the driven rack 107b are rotated by the rotary gear 10.
The meshed state with 4 is released. As a result, the driving rack 107a is forcibly moved to the right by the elastic force of the stopper 108, and the driven rack 107b is moved by the elastic spring 105, so that both the driving rack 107a and the driven rack 107b move to the gear teeth of the rotary gear. It will be moved to a meshable range (Fig. 1D).

In this state, while the rotary gear 104 maintains the counterclockwise rotation, the B → C → D state of FIG. 1 is repeated.

Next, even if the rotation direction of the motor M changes from this state and the rotation gear 104 rotates clockwise, the teeth of the rotation gear are
Be sure to use the teeth a1 of the driving rack 107a and the driven rack 107b.
It will be inserted between the tooth b2 and the tooth (Fig. 1E).

Therefore, the teeth of the other ride on each other, and it is possible to avoid tooth loss.

In the above description, as one embodiment of the present invention, the case where the driving force transmission device having the double rack mechanism of the present invention is applied to the pickup feeding mechanism of the compact disc player has been described, but various embodiments are possible without departing from the gist of the present invention. Can be applied.

[Advantages of the Invention] As described above, according to the driving force transmission device having the double rack mechanism of the present invention, the rotary gear, the driving rack arranged to be horizontally movable, and the driving rack elastically coupled to the driving rack. A driven rack that horizontally moves following the rack, wherein the teeth of the rotary gear are elastically sandwiched between the teeth of the driving rack and the teeth of the driven rack, and the rotation of the rotating gear causes the driving rack and In a driving force transmission device having a double rack mechanism configured to horizontally move a driven rack, when the driving rack moves to the end, the last end teeth of the driving rack are moved to a position where they mesh with the teeth of the rotary gear. It is possible to propose a stable driving force transmission device capable of avoiding tooth breakage by a simple configuration in which elastic means for forcibly biasing the driving rack is provided.

[Brief description of drawings]

1A to 1E are views for explaining the operation of the double rack mechanism of the present invention, FIG. 2 is a perspective view of a main part of a pickup feed mechanism of a compact disc player, and FIGS. 3 and 4 are double views of a conventional device. FIG. 5 is a perspective view showing a main part of the rack mechanism and a cross-sectional view of the main part, and FIGS. 100 ... Pickup feed mechanism 101 ... Pickup mechanism 103 ... Double rack mechanism 104 ... Rotating gear 105 ... Repulsion spring 106 ... Stopper 107 ... Double rack mechanism 108 ... Stopper

Claims (1)

[Scope of utility model registration request] 1. A rotary gear, a main drive rack arranged to be horizontally movable, and a driven rack that is elastically coupled to the main drive rack and moves horizontally following the main drive rack, and the teeth of the rotary gear are the main drive. In a driving force transmission device having a double rack mechanism, which is elastically sandwiched between the teeth of the rack and the teeth of the driven rack, and is configured to horizontally move the driving rack and the driven rack by the rotation of the rotary gear, A double rack mechanism provided with elastic means for forcibly urging the driving rack so that the teeth at the final end of the driving rack are moved to the position where they mesh with the teeth of the rotary gear when moved to the terminal end. Driving force transmission device having.