JPH0611335Y2 - Latch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a latch device that locks a reciprocating moving member near its moving end, such as a door locking device of an audio device, and in particular, an audio device. Without pulling the door of
The present invention relates to a latch device that can be opened and closed only by pressing force.

[Background Art] As a latch device for locking the closed state of a door of an audio device or the like, a fixed member and a moving member that move relative to each other are provided, and a cam pivotally supported by the moving member rotates when reciprocating. A latch device for limiting the movement of the moving member near one end of the reciprocating movement has been proposed (Japanese Utility Model Application No. 57-446).
No. 31, No. Shokai 60-11977).

In these latch devices, a cam axially supported by the moving member is in contact with a corresponding portion provided on the fixed member near the reciprocating end of the moving member, and when the lid of the audio device or the like is pressed in the closing direction. , The striker provided on this door pushes the moving member into the fixed member, rotates the cam around the shaft by a slight amount, and when the moving member is pushed out from the fixed member by the spring force, the cam ends. The groove formed in the portion abuts on the corresponding portion of the fixed member to limit the movement of the moving member, whereby the lid of the audio equipment or the like is maintained in the closed state.

However, in the latch device, the cam provided on the moving member does not correspond to the corresponding portion of the fixed member at the intermediate portion of the reciprocating movement, and a freely rotatable state occurs. If unexpected vibration, load, or the like acts on the latch device from the outside in this state, the cam may rotate in the direction opposite to the desired rotation direction, which may cause a state in which the fixing member cannot be locked.

For this reason, grease or the like is applied to the shaft support portion of the cam to prevent inadvertent rotation of the cam, or the size of the shaft support portion is strictly maintained to limit the rotation of the cam. It may be possible to provide it. However, these increase the number of steps of the product inspection process and increase the cost.

SUMMARY OF THE INVENTION In consideration of the above facts, an object of the present invention is to provide a latch device that can reliably prevent reverse rotation of a rotary cam with a simple structure and can secure a latch operation.

[Summary and Action of the Invention] A latch device according to the present invention includes a case attached to a main body, a rod accommodated in the case so as to be capable of reciprocating movement, and a rod accommodated in the case in an extracting direction. Urging means, a cam rotatably supported by the rod, an inclined guide surface formed on the outer peripheral portion of the cam, and the inclination by the pushing operation of the rod that is provided so as to project from the inside of the case. A first projection having a projection surface on which a guide surface is slid to rotate the cam in a predetermined direction; and a recess formed on the cam and engageable with a corner of the first projection,
A rib extending radially from the shaft of the cam and protruding from the recess in a direction parallel to the axis of the cam, the inclined guide surface and the projecting surface of the first projection, and the recess and the first projection. A second protrusion that does not rotate the cam in the direction opposite to the predetermined direction by contacting the rib when the corner portion of the protrusion is in the non-contact state.

In the latch device according to the present invention, the cam is rotatably supported by the rod accommodated in the case so as to be reciprocally movable. When the rod is pushed into the case, the inclined guide surface formed on the outer peripheral portion of the cam slides on the protruding surface of the first protrusion,
The cam rotates in the specified direction.

When the pushing operation is completed, the concave portion formed on the cam becomes the first
Corresponding to each part of the projection, the rod is pushed in the pulling-out direction by the biasing force of the biasing means, and the recess and the corner are engaged. This prevents the rod from slipping out of the case.

Next, when the rod is pushed again, the engagement between the concave portion and the corner portion is released, and the biasing means pushes the rod in the pulling-out direction.
As a result, the cam rotates in a predetermined direction, and the rod is pulled out from the case while the inclined guide surface slides on the projecting surface.

Immediately before the concave portion and the corner portion of the cam engage with each other, the inclined guide surface and the projecting surface of the first protrusion and the corner portion of the first protrusion of the concave portion are not in contact with each other. The rib extending in the radial direction from the shaft portion abuts the second protrusion to prevent rotation of the cam in the direction opposite to the predetermined direction, and securely engages the concave portion and the corner portion.

[Embodiment of the Invention] As shown in FIGS. 2 to 4, the latch device 10 according to this embodiment accommodates a rod 14 shown in FIG. 7 which is a movable member in a case 12 which is a fixed member. Can be reciprocated in the pushing direction (arrow A direction) and the withdrawing direction (arrow B direction). The case 12 is an audio device M between a rectangular frame 12A and a claw 12B formed at the rod entrance.
Is fixed to.

The case 12 and the rod 14 are each formed of synthetic resin, and the case 12 has a box shape in which the right end of the drawing into which the rod 14 is inserted is open.

The rod 14 inserted into the case 12 is the case 12
A compression coil spring 16 is interposed between the bottom portion (the left end portion in the drawing) and receives a biasing force in a direction projecting from the case 12. A recess 18 is formed in the rod 14 to accommodate a part of the compression coil spring 16. Further, a projection 20 projects from the surface of the rod 14 opposite to the recess 18 and is inserted into a guide slot 22 formed in the case 12. Therefore, in the rod 14, the projection 20 has the guide long hole 2
By reciprocating with respect to the case 12 by moving inside 2, the protrusion 20 abuts against one end of the elongated guide hole 22 as shown in FIG. It has become so.

The protrusion 20 and the rod 14 arranged in the case 12
As shown in FIG. 7, a circular hole 26 is formed between the end of the rod and the end of the rod and has an axial center in a direction perpendicular to the moving direction of the rod 14. A rotary cam 28 shown in FIG. 1 is pivotally supported in the circular hole 26. That is, one end of the columnar portion 28A of the rotary cam 28 is inserted into the circular hole 26 so that the rotary cam 28 can rotate around the axis of the columnar portion within the circular hole 26. Further, the other end of the columnar portion 28A corresponds to the inner peripheral surface of the case 12 so that the rotary cam 28 cannot be pulled out from the rod 14.

The rotary cam 28 has a pair of plate-shaped portions 28B protruding in opposite directions when viewed from the axial direction of the columnar portion 28A. At the tips of these plate-like portions 28B, there are formed recesses 28C which are recessed in a substantially V shape in the axial direction. One of the bifurcated tip portions of the plate-like portion 28B formed by the recessed portion 28C has a surface on the opposite side of the recessed portion 28C as an inclined guide surface 28D that gradually reduces the width dimension of the bifurcated tip portion toward the tip portion.

On the other hand, as shown in FIG. 8, inside the case 12 corresponding to the rotary cam 28, a pair of corresponding portions, that is, a first projection 32 and a projection 34, project into the movement locus of the rotary cam 28. The first projection 32 has a protruding surface 32A for restricting the clockwise rotation of the rotary cam 28 in the vicinity of the maximum extraction state of the rod 14 from the case 12, and the rod 14 as shown in FIGS. 4 (C) and (D). Corner portion 32B for preventing the rod 14 from being pulled out by entering the concave portion 28C of the rotary cam 28 when is moved from the maximum pushed state by a slight amount in the pulling direction.
Is provided. As shown in FIG. 4 (A), the projecting surface 32A extends along the pushing-out direction of the rod 14 so as to slide with the side surface of the plate-shaped portion of the rotary cam 28 when the rod 14 is pushed in by a slight amount.

Further, the protrusion 34 is provided on the rod 14 as shown in FIG.
28C corresponding to the first protrusion 32 in the maximum pushed state of
It corresponds to the concave portion 28C on the opposite side. The projection 34 is arranged at a position slightly downwardly displaced from the concave portion 28C of the rotary cam 28 which is pushed in in the state of FIG. 4 (A). Therefore, as shown in FIG. 4 (C). When the rod 14 is pushed in by the maximum amount, the concave portion 28C guided by the protrusion 34 rotates the rotary cam 28 counterclockwise by a slight amount, and the concave portion 28C on the opposite side is moved to the first protrusion 3a.
It corresponds to the second corner 32B. Therefore, when the rod 14 is moved in the pulling-out direction by the urging force of the compression coil spring 16 from the maximum pushed state of FIG. 4 (C), the concave portion 28C on the side opposite to the protrusion 34 has a corner portion as shown in FIG. It comes in contact with 32B.

The projection 34 is further connected to the rod 14 from the state of FIG.
When is pushed, a sloped surface 34A is formed continuously corresponding to the sloped guide surface 28D to further rotate the rotary cam 28 to the state shown in FIG. 4 (E). Therefore, in the state of FIG. 4 (E), the engagement of the rotary cam 28 with the corner portion 32B is released, and when the pushing force is released in this state, the rod 14 is extracted by the urging force of the compression coil spring 16,
As shown in FIG. (F), the side surface of the rotary cam 28 has a corner 32.
When the rotary cam 28 is in contact with B, the longitudinal direction of the rotary cam 28 is
In parallel with the push-in / pull-out direction of (1), it is moved to the maximum withdrawal state as shown in FIG. 4 (G).

A pair of arms 36 and 38 are attached near the tip of the compression coil spring 16 protruding from the case 12 in a diameter-expanded state in which the tips are separated from each other as shown in FIG.
As shown in FIG. 4 (A), a striker 40 of the opening / closing lid L pivotally supported by the audio equipment main body M corresponds between the arms 36 and 38, and the opening / closing lid L is indicated by an arrow A in FIG. When the operation part is closed by moving it in the direction, striker 4
The tip enlarged diameter portion 40A of 0 is the rod 1 between the arms 36 and 38.
Corresponding to No. 4, the rod 14 is pushed into the case 12. The opening / closing lid L receives a biasing force in a clockwise direction (opening direction) about a lower end portion (not shown) of FIG. 4 as a rotation center.

The arms 36 and 38 have a side surface opposite to the tip enlarged diameter portion 40A corresponding to the facing surface of the rectangular frame 12A formed at the inlet of the case 12, and as the rod 14 is pushed into the case 12, the arms 36 and 38 are moved. , 38 collide with the rectangular frame 12A and receive a rotational force, and as shown in FIG. 4 (A), the enlarged tip end diameter portion 40A can be held. Therefore, the arms 36 and 38 generate a biasing force so as to separate them from each other in the free state, as shown in FIG.

Here, in this embodiment, as shown in FIG.
A pair of ribs 28E extending from the columnar portion 28A to the upper side of B are integrally formed. These ribs 28E are plate-like parts 28
B is an arrangement that is offset in the axial direction of the columnar portion 28A. However, the columnar portion 28A forms the same surface as the concave portion 28C of the plate-shaped portion 28B near the tip thereof.

Corresponding to these ribs 28E, the 8th and 9th parts are provided in the case 12.
A second protrusion 44 shown in the figure is formed. As shown in FIG. 8, when viewed in the axial direction of the rotary cam 28, the second protrusion 44 is formed with an inclined surface 44A forming an extension surface of the inclined surface 34A of the protrusion 34. However, the notch 44B is formed in the second protrusion 44, so that the second protrusion 44 does not correspond to the plate portion 28B but corresponds only to the rib 28E. Further, as shown in FIG. 4 (B), the inclined surface 44A is in the middle of the pushing operation of the rod 14, and more specifically, the columnar portion 2 is in the middle of the pushing operation.
8A is disengaged from the projecting surface 32A of the first protrusion 32, and as shown in FIG. 4 (B), the rotating cam 28 can come into contact with the recess 28C in a state in which it is carelessly rotated clockwise. For this reason, the rotation of the rotary cam 28 in the clockwise direction is blocked so that only the normal rotation of the rotary cam 28 in one direction (counterclockwise in FIG. 4) is ensured.

Next, the operation of this embodiment will be described.

FIG. 4 (G) shows a state in which the opening / closing lid L receives a rotational force by a manual operation in the direction of arrow A in order to close the operation portion of the audio equipment main body M.

When the opening / closing lid L is further rotated from this state in the direction of the arrow A, the tip expander 40A of the striker 40 has the rod 1 with the enlarged diameter.
Push 4 into case 12.

As shown in FIG. 4 (A), the arms 36 and 38 come into contact with each other inside the rectangular frame 12A so as to approach each other, and the tip expanded portion 40 is formed.
A will be gripped. Further, the rotating cam 28 is the columnar portion 2
When 8A passes through the protruding surface 32A and is further pushed in, the concave portion 28C of the rotary cam 28 on the tip side of the rod 14 is moved to the fourth position.
As shown in FIG. 3C, the protrusion 34 is rotated counterclockwise by a slight amount.

Therefore, when the pushing force in the direction of arrow A is released in this state, the rod 14 moves in the direction of being extracted from the case 12 by the urging force of the compression coil spring 16, and the recess 28 of the rotary cam 28 is moved.
C engages the corner 32B. In this state, the rotary cam 28
Since the counterclockwise rotation of the rod is blocked, the rod 14 cannot move in the pull-out direction. Therefore, the arm 36,
38 holds the striker 40 to maintain the closed state of the opening / closing lid L.

In order to open the opening / closing lid L, it is sufficient to press the opening / closing lid L again in the direction of arrow A by a slight amount. As a result, as shown in FIG. 4 (E), the concave portion 28C corresponding to the corner portion 32B is formed.
The inclined guide surface 28D on the outer side of the concave portion 28C on the opposite side via the columnar portion 28A is guided by the inclined surface 34A and rotates counterclockwise by a slight amount. Therefore, even if the pushing force is released and the rod 14 is moved in the extraction direction by the urging force of the compression coil spring 16, the concave portion 28C, which has corresponded to the corner portion 32B until then, does not correspond to the corner portion 32B. , Recess 28C
Since the vicinity of the outer inclined guide surface 28D contacts the corner 32B, the rotary cam 28 is further rotated counterclockwise and the recess 18 is pulled out from the case 12 by the maximum amount as shown in FIG. 4 (G). As a result, the arms 36 and 38 release the grip of the striker 40, and the opening / closing lid L is opened.

Here, when the rod 14 is pushed into the case 12 and the columnar portion 28A passes through the projecting surface 32A as shown in FIG. 4 (A), the rotary cam 28 can rotate clockwise. Therefore, when an external force acts due to vibration or the like, the rotating cam 28 may inadvertently rotate clockwise as shown in FIG. 4 (B). However, in this embodiment, the rib 28E corresponds to the second protrusion 44, so that even if the rotary cam 28 rotates clockwise in this state, the second cam is rotated as shown in FIG.
Only a slight amount of rotation is possible until it comes into contact with the projection 44 of FIG.

Therefore, when the rod 14 is further pushed in, the rib 28E is guided by the inclined surface 44A and rotates counterclockwise, so that the rib 28E is securely engaged with the protrusion 34 as shown in FIG. 4 (C). Therefore, even if the rotary cam 28 is rotated counterclockwise due to inadvertent vibration between FIGS. 4 (A) and 4 (C), an appropriate latch operation cannot be prevented.

[Advantages of the Invention] With the configuration described above, the present invention ensures that the cam rotates in a predetermined direction even when an external force such as vibration is applied, so that the cam is locked in the case and the rod is inserted in the case. It is retained and the latch function can be secured.

[Brief description of drawings]

FIG. 1 is a perspective view of a rotary cam used in an embodiment of the present invention, FIG. 2 is a front view showing a latch device of this embodiment, FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. (A) to (G) are operation diagrams corresponding to the section taken along the line IV-IV in FIG. 3 of the present embodiment, FIG. 5 is a front view showing the rotary cam, and FIG. 6 is a line VI-VI in FIG. Sectional drawing, FIG. 7 is a front view showing the rod, FIG. 8 is a sectional view corresponding to a section taken along line VIII-VIII of FIG. 9 of the case, and FIG. 9 is a sectional view taken along line IX-IX of FIG. 10 ... Latch device, 12 ... Case, 14 ... Rod, 28 ... Rotating cam, 32 ... First projection, 34 ... Projection, 44 ... Second projection.

Claims (1)

[Scope of utility model registration request] 1. A case attached to a main body, a rod reciprocally accommodated in the case, an urging means accommodated in the case for urging the rod in a pull-out direction, and the rod. A cam that is rotatably supported, an inclined guide surface formed on the outer peripheral portion of the cam, and an inclined guide surface that protrudes from the inside of the case and slides the inclined guide surface by the pushing operation of the rod so that the cam is predetermined. A first projection having a projecting surface for rotating in the direction, a recess formed in the cam and engageable with a corner of the first projection, and a radial extension from the shaft of the cam The rib protruding in a direction parallel to the axis of the cam, the inclined guide surface and the projecting surface of the first protrusion, and the recess and the corner of the first protrusion are in non-contact with each other, the rib is provided. Contact with the cam to rotate the cam in the opposite direction. Latch unit and having no second protrusion, the.