JPH0782688B2 - Power transmission device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device that can be used in a front loading type cassette mounting device of a magnetic recording / reproducing apparatus.

2. Description of the Related Art Recently, in a cassette loading device of a front loading type video tape recorder, a device has been devised which moves a cassette holder to a predetermined position by using a slide member which linearly reciprocates by a motor.
Hereinafter, a conventional example which is not known and which is considered before embodying the present invention will be described with reference to FIG.

FIG. 4 shows a schematic configuration of a conventional cassette mounting device which is not publicly known.

In FIG. 4, 1 is a cassette holder for housing a cassette, 2 and 3 are side walls integrally formed on both sides of the cassette holder 1, 4 and 5 are guide pins provided on the side walls 2 and 3, and 6 and 7 are Side plates on both sides of the cassette holder 1, 8,
Reference numeral 9 is an L-shaped guide groove provided on the side plates 6 and 7, each of which is composed of two or three guide grooves.
Are engaged with each other. The guide pins 4 and 5 are guide grooves.
Of course, it is provided corresponding to the number of 8, 9. 1
Drive arms 0 and 11 are connected by a shaft 12 and are rotatably supported on the side plates 6 and 7. The drive arms are rotatably supported by the side plates 6 and 7 on the side wall members 2 and 3 of the cassette holder 1 described above. The main guide pins 4, 5 are respectively engaged. A gear 15 is integrally formed on one side 11 of the drive arm so as to be concentric with the shaft 12. Reference numeral 16 is a first slide member, and 17 is a second slide member integrally connected to the first slide member by a tension spring 18.
It is a slide member. Reference numerals 19 and 20 denote first and second elongated guide holes provided in the first slide member, respectively.
And 22 are the third members provided on the second slide member, respectively.
And fourth guide slots 23, 24 are provided in the side plate 7, and the first and third guide slots 19, 21 and the second and third guide slots 20, 22 are provided. They are guide members that are inserted respectively and guide the linear reciprocating movement of the first and second slide members 16 and 17.

Reference numeral 25 is a locking hole provided in the first slide member 16, and 26 is a locking projection provided in the second slide member 17 inserted so as to be locked. Reference numeral 27 is a first gear portion provided on the first slide member 16 and is driven by being connected to a drive gear 28 which is a drive source of the cassette mounting apparatus. Reference numeral 29 denotes a second gear portion provided on the second slide member, which is connected to the gear 15 integrally provided on the drive arm 11. Reference numeral 30 denotes a protrusion provided on the second slide member 17, which engages with an actuator 32 of a slide switch 31 fixed to the side plate 7. The structure in which the first and second slide members connected by the tension springs as shown in FIG. 4 are used as a power transmission device,
This is to improve the operability and operation feeling of the user and prevent the motor from locking.

With respect to the conventional cassette mounting device which is not publicly known and has the above-described structure, the operation of the power transmission device section will be described below with reference to FIGS. 4 and 6 to 7.

5, 6, and 7 show the details of the operation of the first and second slide members. FIG. 5 is a view when the cassette holder 1 is in the cassette take-out and insertion position, and at this time, in FIG. 4, the side wall 2 of the cassette holder 1,
The guide pins 5 and 6 provided on the 3 are in contact with the end faces 33 and 34 of the L-shaped guide grooves 8 and 9 provided on the side plates 6 and 7, respectively. When the guide pins 5 and 6 are in positions where they are in contact with the other end surfaces 35 and 36 of the L-shaped guide grooves 8 and 9, it is a cassette reproducing and recording position. When the cassette is inserted into the cassette holder 1 at the cassette take-out and insertion position shown in FIG. 5 and the cassette is further pushed, the cassette holder 1 is inserted into the L-shaped guide grooves 8 and 9 provided in the side plates 6 and 7. Move along. At this time, the movement is the cassette holder 1
Guide pins 5, 6 and drive arms 10, 1 provided on the side walls 2, 3 of the
It is transmitted to the second slide member 17 via the gears 15 integrally formed with the guide grooves 13 and 14 provided in 1 and the drive arms 10 and 11. At this time, the first slide member 16 is locked by the drive gear 28. When the power is turned on, when the second slide member 17 moves in the direction A to the position shown in FIG. 6, the slide switch 31 operates and the drive gear 28 starts to rotate, and
The slide member 16 is driven in the A direction.

The first slide member 16 is moved to the position shown in FIG. 7 in which the locking projection 25 provided on the second slide member 17 contacts the left end of the locking hole 25 provided on the first slide member 16. After the movement, the second slide member 17 is driven in the A direction by the engagement of the locking hole 25 and the locking projection 26, and the driving force is applied to the cassette holder 1 via the driving arms 10 and 11. Then, the cassette holder 1 is driven from the cassette take-out / insertion position to the cassette reproduction / recording position. If the user does not insert the cassette to the position shown in FIG. 6, the tension spring 18 causes the second slide member 17 to move.
Is returned to the position shown in FIG. 5, and the cassette holder 1 is returned to the cassette taking-out and inserting position. When the power is off, when the cassette is inserted into the cassette holder 1 and pushed further, the second slide member 17 moves from the position shown in FIG. 6 to the position shown in FIG. 8, that is, the locking hole of the first slide member 16. twenty five
It moves to the position where the locking projection 26 of the second slide member 17 comes into contact with the right end of the second slide member 17 because the first slide member 16 is locked by the drive gear 28.
Cannot move any further, and the user receives resistance as a reaction force. Of course, if you release your hand, the tension spring
The force of 18 returns the cassette holder 1 to the cassette take-out and insertion position shown in FIG. In the discharge mode, the first slide member 16 is driven in the B direction by the drive gear 28 in FIG. A guide pin 5, which is provided on the side wall of the cassette holder 1, from the cassette reproducing and recording position to the cassette ejecting and inserting position.
When the second slide member 17 is driven by the second slide member 17 via the guide grooves 13 and 14 provided in the drive gear 6 and the drive arms 10 and 11 and the gear 15 integrally formed with the drive arms 10 and 11, The tension spring force is set so that the coupling force of the tension spring 18 between the first and second slide members 16 and 17 is larger than the load force acting on the. By doing so, the first slide member 16 drives the second slide member 17 to drive
The driving force is transmitted to the cassette holder 1, and the cassette holder 1 is driven to the cassette take-out and insertion position while the first and second slide members 16 and 17 maintain the positional relationship shown in FIG. When the cassette holder 1 is driven to the position near the cassette take-out and insertion position, the slide switch 31 operates and the motor stops. The guide pins 4 and 5 provided on the side walls 2 and 3 of the cassette holder 1 at the predetermined cassette take-out and insertion positions are the guide pins 4 and 5 of the side plates 6 and 7 and the end faces 33 and 33 of the L-shaped guide grooves 8 and 9, respectively. In order to drive to the position touching 34,
After the second slide member 17 has driven the cassette holder 1 to the predetermined cassette take-out and insertion position, as shown in FIG. 5, the locking hole 25 provided in the first slide member 16 and the second Locking projections provided on the slide member 17 of
1st slide member to the place where 26 leaves with a gap
16 is driven and then stopped.

Problems to be Solved by the Invention However, in the above configuration, the cassette holder 1 shown in FIG. 7 is driven from the cassette take-out / insertion position to the cassette reproduction / recording position, and vice versa. In the relationship between the second slide members 16 and 17, as shown in FIG. 9, a tension spring 18 causes a locking hole 25 of the first slide member 16 and a locking projection 26 of the second slide member 17. The rotation moment in the D direction is generated in the second slide member 17 in the C direction on the first slide member 16 around the engagement point 37 of the guide member provided on the side plate 7.
First of the first and second slide members 16 and 17 with respect to 23 and 24
The third and third guide slots 19 and 21 and the second and fourth guide slots 20 and 22 are formed in such a manner that they are inserted into each other, and a lateral pressure is applied from the vertical direction, so that the first and second slide members 16 and 16 are formed. , 17
There is a problem that a large sliding loss occurs during the movement of the. In order to prevent the occurrence of the rotational moments in the C and D directions, the first tension is applied to the first and second slide members 16 and 17 by the tension spring 18 on the vector line of the tension force.
Locking hole 25 of the slide member 16 and the second slide member 17
It suffices to arrange an engagement point 37 with the locking projection 26 of the first spring member 1 and the first and second slide members 1.
Due to the structure of the spring hook portions 6, 17, the locking holes 25, the locking projections 26, etc., it is extremely difficult and impossible to achieve.

In view of the above problems, the present invention provides a first slide member and a second slide member around a joint point between a locking hole and a locking projection formed in the first and second slide members by a tension spring. At least one of the first and second slide members that is provided with a rotational moment that is generated is provided with first and second restricting portions for restricting movement of the slide member, and a part of the slide member that can face the restricting portion is provided. Eliminates by providing first and second convex portions that respectively come into contact with the restriction portion,
The present invention provides a power transmission device in which the sliding resistance generated between the first and second slide members and the guide means for guiding the linear reciprocating movement thereof is extremely small.

Means for Solving the Problems In order to solve the above problems, a power transmission device of the present invention has first and second elongated guide holes, and a locking hole is partially formed therein. A first slide member, a second slide member having third and fourth elongated guide holes, and a locking projection formed in part, and the first and second slide members. The first and second members are inserted into the respective guide long holes of the member.
Means for guiding the linear reciprocating movement of the slide member and the tension spring stretched between the first and second slide members so as to apply tension forces in directions opposite to each other with respect to their moving directions. And the first
The second slide member includes the first guide long hole and the third guide long hole, the second guide long hole and the fourth guide long hole, and the locking member. First protrusions and second protrusions that overlap with a portion of the locking hole so as to be lockably inserted, and restrict movement of the slide member on at least one of the first and second slide members. And a first convex portion and a second convex portion that are in contact with the regulating portion, respectively, are provided on a part of the sliding member that can face the regulating portion, and one of the first and second sliding members is provided. Is connected to the driving source, and the other is connected to the driven body.

Action The present invention has the above-described structure, and is generated in the first and second slide members by the tension spring centering on the joint point between the locking hole and the locking projection formed in the first and second slide members. The rotation moment is provided with at least one of the first and second slide members provided with first and second restricting portions for restricting the movement of the slide member, and the restricting portions are partly opposed to each other. Are canceled by each other by providing first and second convex portions that come into contact with the restriction portion, and are generated between the first and second slide members and the guide means for guiding the linear reciprocating movement thereof. The present invention provides a power transmission device capable of extremely reducing manual resistance.

Embodiment Hereinafter, a power transmission device according to an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show an embodiment of the present invention in which the present invention is introduced and embodied in the power transmission device portion of the above-described conventional non-known cassette mounting device. In FIGS. 1 and 2, 16 is a first slide member,
Is a long hole for the first and second guides provided in the first slide member 16, 25 is a locking hole provided in the first slide member 16, 17 is a second slide member, 21 , 22 is the second
Third and fourth elongated guide holes provided in the slide member 17, reference numeral 26 is a locking projection provided in the second slide member 17, and 23 and 24 are the first and second slides. Element
The guide members are inserted into the guide elongated holes 19, 21 and 20, 22 respectively and guide the linear reciprocating movement of the first and second slide members 16, 17. Reference numeral 18 is a tension spring stretched between the first and second slide members 16 and 17 so as to apply tension forces in directions opposite to each other with respect to their moving directions. 38 and 39 are first and second restricting portions that restrict the movement of the first and second slide members 16 and 17 provided on the first slide member 16, and 40 and 41 are the second slide members 17. The first and second restricting portions 38, 3 provided in the
9 are the first and second convex portions that respectively abut.

Other configurations and components of the present embodiment are exactly the same as those of the conventional unillustrated cassette mounting device described in FIGS. 3 and 4 to 8 above, and therefore the description thereof is omitted here. Note that FIG. 1 shows the first and second slide members 16,1.
The state in which the locking hole 25 and the locking projection 26 of 7 are joined,
That is, the first and second slide members 16 and 17 show that the cassette holder 1 is taken out of the cassette, and is being driven from the insertion position to the cassette reproducing and recording position and vice versa, and FIG. Also, a state in which the locking holes 25 and the locking projections 26 of the second slide members 16 and 17 are not joined is shown.

Next, FIG. 1 (A) and the first and second in FIG. 1 (A)
The operation of this embodiment will be described with reference to FIG. 1 (B) showing the relationship between the force and moment acting on the slide members 16 and 17. In FIG. 1 (B), F ₁ and F ₂ are spring springs 4 of the first and second slide members 16 and 17 by the tension springs 18.
It is the tensile force acting on 2,43 respectively. F ₄ and F ₅ are attached to the first and second restricting portions 38 and 39 of the first slide member 16 and to the second
The force received from the first and second convex portions 40 and 41 of the slide member 17 of FIG. F ₃ and F ₆ are forces received by the first and second convex portions 40 and 41 of the second slide member 17 from the first and second restricting portions 38 and 39 of the first slide member 16, respectively. l ₁ is a locking projection 25 of the first slide member 16, a locking projection 26 of the second slide member 17, a joint point 37, and the spring hook portion.
It is the distance between 42 and 43. 44 and 45 are contact points between the first and second restricting portions 38 and 39 of the first slide member 16 and the first and second convex portions 40 and 41 of the second slide member 17, respectively, and the acting force is It is the point of action of F ₄ , F ₅ and F ₃ , F ₆ . l ₂ and l ₃ are the connection point 37 between the locking hole 25 and the locking projection 26, the first and second restricting portions 38 and 39, and the first and second convex portions 40 and 41. Contact 4
It is the distance to each of 4,45. First, considering the rotational moment M ₁ acting on the first slide member 16 about the contact 37, M ₁ = F ₁ l ₁ −F ₄ l ₂ −F ₅ l ₃ (1) holds. . Similarly, the contact portion 37 is formed on the second slide member 17.
Considering the rotational moment M ₂ acting around, M ₂ = −F ₂ l ₁ + F ₃ l ₂ + F ₆ l ₃ (2) holds. However, here, the rotational moment in the C direction in FIG. 1 (B) is defined as positive. Here, the forces F ₄ , F ₅ exerted on the first slide member 16 by the second slide member 17
Is the force applied to the second slide member 17 by the tension spring 18.
Since it is due to F ₂ , the following equation holds.

-F ₄ l ₂ -F ₅ l ₃ = -F ₂ l ₁ (3) Also, F ₁ and F ₂ are spring forces generated by the tension spring 18, so F ₁ = F ₂ …… ( 4) Therefore, (1) (3), (4) by substituting the formula _{M 1 = F 1 l 1 +} (- F 4 l 2 -F 5 l 3) = F 1 l 1 -F 2 l 1 [Substituting equation (3)] = F ₁ l ₁ −F ₁ l ₁ [Substituting equation (4)] = 0 (5) Similarly, F ₃ l ₂ + F ₆ l ₃ = F ₁ l ₁ (6) F ₁ = F ₂ (4) From this, the formula (2) is M ₂ = -F ₂ l ₁ + (F ₃ l ₂ + F ₆ l ₃ ) = -F ₂ l ₁ + F ₁ l ₁ [substituting equation (6)] = − F ₂ l ₁ + F ₂ l ₁ [substituting equation (4)] = 0 (7) From the equations (5) and (7), the rotational moment generated by the tension spring 18 on the first and second slide members 16 and 17 becomes zero.

As described above, according to the present embodiment, it occurs in the first and second slide members around the joint point between the locking hole and the locking projection formed in the first and second slide members. A rotational moment is provided with at least one of the first and second slide members, first and second restriction portions for restricting movement of the slide member, and a part of the slide member that can face the restriction portion. By providing the first and second convex portions that come into contact with the restriction portion, the first and second convex portions are canceled each other, and the first and second convex portions are provided.
Further, the sliding resistance generated between the second slide member and the guide means for guiding the linear reciprocating movement thereof can be made extremely small.

According to the present embodiment, the first slide member 16 is provided with the first and second restricting portions 38 and 39, and the second slide member 17 is provided with the first restriction member 38, 39.
And the second convex portions 40, 41 are provided, but these are tension springs 18
This is for canceling the rotational moment generated in the first and second slide members 16, 17 by means of such a combination, and the first and second slide members 16, 17 are not necessarily combined in such a combination.
And the first and second restricting portions 38, 39, the first and second convex portions 40, 4
1 need not be provided.

Further, in this embodiment, the restricting portions 38 and 39 are the first slide member 1
I took the structure that is formed by bending 6
These are for canceling the rotational moment generated in the first and second slide members 16 and 17, and do not necessarily have to have such a shape, and for example, as shown in FIG. There may be two elongated holes 46 and 47 and convex portions 48 and 49 that engage with them, respectively.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to obtain an excellent effect that the sliding resistance generated between the first and second slide members and the guide means for guiding the linear reciprocating movement thereof is extremely reduced. Obtainable.

[Brief description of drawings]

1 (A) and 2 are side views of an embodiment of the present invention, FIG. 1 (B) is a side view showing the working relationship of force and rotational moment of FIG. 1 (A), and FIG. Is a perspective view of another embodiment of the present invention, FIG. 4 is a perspective view of a conventional cassette mounting device which is not known, and FIGS. 5 to 9 are for explaining the operation of the power transmission device portion of FIG. It is a side view. 16 ... First slide member, 17 ... Second slide member, 18 ... Tension spring, 19,20 ... First and second elongated guide holes, 21,22 ... Third and fourth Long holes for guides, 23,24
...... Guide member, 25 …… Locking hole, 26 …… Locking protrusion, 27
...... First gear portion, 28 ...... Drive gear, 29 ...... Second gear portion, 38,39 ...... First and second regulating portions, 40,41 ...... First and second convex portions .

Claims (1)

[Claims] 1. A first slide member having first and second elongated guide holes, and partly formed with locking holes, and third and fourth elongated guide holes. A second slide member having a locking projection formed in a part thereof, and the first and second slides inserted into the guide elongated holes of the first and second slide members. A guide means for guiding the linear reciprocal movement of the member, and a tension spring stretched between the first and second slide members so as to apply a tensile force in directions opposite to each other with respect to their moving directions. The first and second slide members are provided with the first guide long hole and the third guide long hole, and the second guide long hole and the fourth guide long hole. They are opposed to each other and overlap so that the locking protrusions can be inserted into a part of the locking holes in a lockable manner. At least one of the first and second slide members may be provided with first and second restricting portions for restricting displacement of the slide member due to a rotation moment generated by the tension spring, and may face the restricting portion. Part of the slide member is provided with first and second protrusions that respectively come into contact with the restriction portion, one of the first and second slide members is connected to a drive source, and the other is connected to a driven body. A power transmission device that is connected.