JPH035056Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a push button switch used in a data input device such as a keyboard.

(b) Technical background The present invention relates to an improvement of a push button switch for a keyboard installed on the operation panel of a data input device, and is intended to ensure contact reliability of the switch especially in a dusty atmosphere.

(c) Problems with the Prior Art FIG. 1 is a perspective view showing the structure of a conventional push button switch, and FIG. 2 is a sectional view taken along the line AA in FIG. 1.

In the perspective view of Fig. 1, 1 is an insulating casing forming a switch assembly base with a circular recess in which a plurality of fixed contacts are buried, and 2 is a rod-shaped insulating casing with one end fixed to the insulating casing 1 that operates the switch contacts. A spring plate, 3 is a caulking rivet for fixing the rod-shaped spring plate 2 to the housing 1, 4 is an adhesive sheet for dustproof sealing of the contact portion, which is applied to the entire surface of the housing 1, and 5 is a plate that can be turned upside down. type movable contact spring (this spring is also called a dome spring due to its shape), and 6 and 7 are inner (center) and outer (periphery) fixed contacts located at the bottom of the housing recess. 7 forms a switch contact portion of the main push button switch, facing the dish-shaped movable contact spring 5 which is placed over the main push button switch.

Further, reference numeral 8 in the same figure denotes a through hole through which the outside air flows through the recessed space 12 where the switch contact portion is formed, and this makes the reversal operation (snap operation) of the movable contact spring 5 smooth. Further, 9 is an external terminal of the push button switch.

Next, the snapping operation of the disc spring 5 will be explained with reference to the sectional view in FIG.

The operating states of the disc-shaped movable contact spring 5 are shown in Fig. A during switch operation and in Fig. B during switch recovery.

In Figure A, the other end 1 of the rod-shaped spring plate 2 is fixed at one end.
0 is pressed down, the apex of the movable contact spring 5 connected at the operating point 11 is depressed, and the movable contact spring 5 is reversely displaced. During reversal displacement, an inherent buckling action (non-linear action) occurs and the outside and inside of the switch and the fixed contacts 7 and 6 are closed. In this case, the air in the housing recess where the contact portion is formed is momentarily discharged from the through hole 8.

On the other hand, Figure B shows a state in which the push-down input to the armature spring plate 2 is released, and the movable contact spring 5 recovers with its own restoring force to open the outer contact 6 and inner contact 7. . In this case, air in the housing recess forming the contact portion is sucked in through the through hole 8.

The snapping action of the movable contact spring 5 is an essential function that improves the key input operability of the main push button switch, but each time the switch is restored to operation, outside air (air) enters the contact space through the through hole 8. It is taken in and exhausted. This causes a problem in that external dust is sucked into the contact portion, leading to poor contact of the switch contact.

(d) Purpose of the invention The purpose of the invention is to solve the above problems.

The present invention provides the through hole with a valve action function that protects the contact forming space from dust without interfering with the snapping function of the movable contact spring.

(e) Structure of the invention The object is to have an insulating casing, an elastic spring, a movable contact spring, and an air intake/exhaust hole, and the insulating casing has a plurality of fixed contacts planted in the center thereof. and a dish-shaped movable contact spring that fits into the recessed space and reverses its vertical motion and connects and disconnects the fixed contact, and the rod-shaped spring plate has both sides of one end The movable contact spring is fixed to an insulating casing, and when the other end is pressed down, the apex of the movable contact spring is pushed down, and has an elastic deformation part in the middle of one end, and the intake/exhaust hole is connected to the movable contact spring. It is located in the middle of the spring, and is bent in a hook shape from the inner wall of the recessed space to open on the surface of the insulating casing, and the opening is always closed by a hook-shaped spring plate. and the intake/exhaust hole is achieved by a push button switch configured such that the opening is unblocked when the other end of the armature spring plate is pressed down and the elastic deformation portion is expanded. .

(f) Example of the invention Figure 3 is a perspective view of the push button switch according to the invention.
Fig. 4 is a sectional view taken along line A-A showing the functional operation of Fig. 3, in which A corresponds to when the switch is operating, B corresponds to when the switch is restored, and Fig. 5 corresponds to Fig. 4. FIG.

Among the numbers in the figure, elements indicating functions equivalent to those of the conventional device are numbered the same as in FIG. 1, and 13 is an intake/exhaust hole, and 14 is an elastic deformation portion.

In FIG. 3, the intake/exhaust hole 13 is different from the conventional straight through hole 8 shown in FIG. It is bent into a hook shape from the inner wall of the insulating casing 1 to open in the direction of the arrow 15 on the surface of the insulating casing 1 .

The opening of this intake/exhaust hole 13 is designed so that it is not blocked by the adhesive sheet 4 that covers and seals the recessed space 12, and the rod-shaped spring plate 2 is designed so that the opening is almost always blocked. It is caulked with rivets 3. When the caulking of the rivets 3 is loosened appropriately, an elastic deformation portion 14 is formed in the intermediate portion between the two rivets 3 of the rod-like spring plate 2.

In FIG. 4A and FIG. 5A, when the other end 10 of the rod-shaped spring plate 2 is pressed down to operate the switch,
Deformation occurs so that the elastic deformation portion 14 swells. As a result, the opening of the intake/exhaust hole 13 that had been blocked by the rod-like spring plate 2 opens, and the air in the recessed space 12 is rapidly exhausted from the intake/exhaust hole 13 .

Next, in FIGS. 4B and 5B, when the other end 10 of the rod-like spring plate 2 is returned to its original position to restore the switch, the elastic deformation portion 14 stops deforming and returns to its original state. Therefore, the opening of the intake and exhaust hole 13 is
Since the recessed space 12 is closed again and there is only a small gap, air can only be sucked into the recessed space 12 gradually. As a result, the intrusion of dust can be suppressed as much as possible.

In other words, in the present invention, by applying the deformation of the rectangular spring plate 2, when the switch is operated, the intake/exhaust hole 1 is
3 deforms and the elastically deformable portion 14 swells, air is rapidly exhausted and the dust in the recessed space 12 is discharged to the outside.

On the other hand, when the switch is restored and air is sucked into the recessed space 12, the deformation of the rod-like spring plate 2 stops and the elastic deformation part 14 returns to its original state, opening the air intake and exhaust hole 13 to the extent that dust can be prevented from entering as much as possible. Since it is occluded, air intake only occurs gradually. Therefore, the extent to which dust is sucked in from the outside is also suppressed.

In this way, it is possible to realize a push button switch in which the armature spring plate 2 performs a valve action on the intake/exhaust hole 13 in conjunction with the operation and restoration of the switch.

(g) Effects of the invention As described above, according to the embodiment of the push button switch of the invention,
Due to the exhaust window with low resistance when the switch is activated,
In addition to providing sufficient snap functionality, dustproof functionality will be added upon restoration. In this way, a switch can be expected to have a crisp operation when operating the switch, and a switch with high contact reliability can be provided.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the configuration of a conventional push button switch, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a perspective view of the push button switch according to the present invention, and Fig. 4 is a
A-A sectional view showing the functional operation in the figure, Figure 5 is the 4th
FIG. 3 is a perspective view corresponding to each of the figures. In the figure, 1 is an insulating casing, 2 is a rod-shaped spring plate,
3 is a rivet, 5 is a movable contact spring, 6 and 7 are fixed contacts, 10 is the other end of the spring plate 2, 12 is a recessed space, 13 is an intake/exhaust hole, and 14 is an elastic deformation portion.

Claims (1)

[Claims for Utility Model Registration] It has an insulating casing 1, an elastic spring plate 2, a movable contact spring 5, and an intake/exhaust hole 13, and the insulating casing 1 has a plurality of fixed contacts in its center. It has a recessed space 12 in which the fixed contacts 6 and 7 are planted, and a plate-shaped movable contact spring 5 that is fitted into the recessed space 12 and reverses vertically and connects and disconnects the fixed contacts 6 and 7. Both sides of one end of the rod-like spring plate 2 are fixed to the insulating casing 1, and when the other end 10 is pressed down, the apex of the movable contact spring 5 is pushed down, and the one end The intake/exhaust hole 13 is located in the middle of one end of the movable contact spring 5, and is bent into a hook shape from the inner wall of the recessed space 12 to close the insulation. The opening is open on the surface of the casing 1, and the opening is always closed by the rod-like spring plate 2. The intake and exhaust hole 13 is located at the other end of the rod-like spring plate 2 1. A push-button switch characterized in that when 10 is pressed down and the elastically deformable portion 14 expands, the opening is unblocked.