JPS5858771B2 - Multi-contact push button switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-contact bush button switch with snap action.

The switch according to the invention is particularly suitable for telephones and other types of electrical and electronic equipment.

It is a constant requirement to make the switch more compact in order to minimize the space it occupies within the device.

At the same time, the switch must be easy and reliable.

In telephones and other devices, the button is operated by a user who can operate the button with a wide range of characteristics that affect the nature of the signal produced by the switch operation. .

Therefore, the unique characteristics of a pushbutton, such as feedback, actuation force, and button movement, are important.

The present invention provides a pushbutton switch that has a snap action that allows the switch to be reliably brought into contact, and that provides a reliable feel when operating the switch.

This button switch has a prestressed dome-shaped spring contact plate.

This contact plate performs a snap action when a predetermined force is applied by the bush button, and snaps back when the force is released.

In one particular form of the invention, the bushing button has a plurality of contacts spaced about a central point.

Detailed construction and advantages relating to the unique features of the invention will be clearly understood from the following description of specific examples illustrated in the accompanying drawings.

As shown in FIGS. 1 to 8, the spring contact plate 10 is, for example, in the form of a stainless steel stamping.

Around the contact area consisting of four contacts 12, 13, 14, 15 there is a flat sheet part 11.

The four contacts are connected to a radially extending connecting web 17.
a central part 1 connected to a flat sheet part 11 by
It extends radially from 6.

Contacts X2, 13° 14.15, central portion 16 and web 17 are formed from sheet portion 11 and further form a prestressed dome-shaped portion as shown in FIGS. ing.

The outer ends of the contacts 12-15 form downwardly extending rib-shaped portions 12a-15a, respectively, and these rib portions form the actual contact areas.

As seen in FIGS. 2 and 3, when downward pressure is applied to the central portion 16, the central portion lowers and the web 17 flexes.

Although the central portion 16 snaps down at a certain position, it has a residual stress tendency that returns the central portion 16 to the normal position shown in FIG.

Each of the webs 11 is deflected radially inwardly at a position 20 from the junction 21 with the flat sheet portion 11;
That is, it is curved.

1 As shown in FIG. 4, these joints 21 are bent upward at the starting point, and the web 17
You can see that it curves towards the inside of 1.

In FIG. 4, the contact board is indicated simply at 25;
A spacer is shown at 27.

The snap action and restoring force of contact plate 10 may vary depending on the particular design.

Therefore, by making the dome-shaped plate have a bistable state, e.g. stable in both the inactive state and the fully anteverted state shown in FIGS. 2 and 3 respectively, the dome shape plates can be placed.

Such a plate has no restoring force to return it to its undeflected state.

In such an arrangement, the contact board 25 is positioned relative to the contact plate 10 by the spacers 27 so that the central portion 16 can pivot downwardly enough to reach its other stable state.

In such an arrangement, the central portion 16 is indicated by arrow A in FIG.
It always snaps back when the operating force illustrated in is released.

When the contacts 12a-15a contact a corresponding contact area on the contact board 25, a wiping action is created by the contact in the radial direction on that contact area.

This is an important feature as it provides good electrical contact.

In addition, the central part is in one stable state, that is, as shown in FIGS. 2 and 3.
It is also possible to design the contact plate to have only the undeflected state shown in the figure.

The contact plate 10 shown in FIGS. 1 to 4 is of this type for convenience, and the particular shape of the upwardly curved joint portion 21 creates a single stable state.

This provides a positive restoring force on the center portion at all times, even if the center portion 16 snaps down under pressure applied to the center.

Other shapes may be provided to ensure constant restoring force.

Another effect regarding snap action and restoring force is provided by clamping the flat part 11 surrounding the dome-shaped part.

The clamping pressure, indicated by arrow B in FIG. 4, affects the restoring force and can convert a bistable contact plate to monostable when the contact plate is clamped.

FIG. 5 shows one form of a bush button switch incorporating the spring contact plate shown in FIGS. 1-4.

The switch has a rigid base member 25.

The member 25 has a printed circuit 26 thereon in this embodiment.
It is a printed circuit board with a

An insulating spacer 27 is arranged on the base member 25.

As shown in FIGS. 10 and 11, spacer 27 is made from a flat material having a circular hole 28 therein.

The axis of the hole 28 is aligned with that of the contact plate 10.

A contact plate 10 is placed on the space 2,
An elastic diaphragm 29 is mounted on the contact plate 10.
is located.

This diaphragm is illustrated in FIGS. 8 and 9 and is made of a flat sheet of elastic material having a circular recess 30 in its underside.

Recess 30 is positioned above the dome-shaped portion of contact plate 10 .

A bushing button 31 is positioned on the top surface of the diaphragm 29.

In the embodiment of FIG. 5, the button is pivoted or hinged and is illustrated in more detail in FIGS. 6 and 7.

The bushing button is formed as part of a flat member 33, most of its periphery being separated from the member 33 and joined at a portion 34.

This button consists of a flat section with a thin section 35 acting as a hinge.

Additionally, there is a thickened portion 36 forming a button that passes through the cover or key frame 37.

Generally, a plurality of pushbuttons are always provided, for example as a pushbutton dial on a telephone, a keyboard on a computer input terminal, or some other form of device.

In such an example, the contact plate consists of a flat sheet with a plurality of contact locations formed therein for each switch.

Similarly, spacer 27 and diaphragm 29 each consist of a flat sheet provided with a plurality of corresponding holes 28 and recesses 30.

The bushing buttons can also be formed from a common flat member 33, as shown in FIGS. 6 and 7.

When assembled, the bushing button contacts the top surface of the diaphragm 29 and the recess of the diaphragm 29 contacts the central portion 16 and web 17 of the contact plate.

Applying pressure to button 36 causes the bushing button to pivot on 35 and push the diaphragm and center portion 16 down.

After a short movement of the central portion 16, a snapping action occurs and the rib-shaped portions 122-15a of the contact move rapidly to securely contact the printed circuit 26.

The button then follows under the pressure of the user's finger.

This creates a unique feedback to the user, who perceives the snap action and sudden movement.

When the pressure on the button is released, the center part will
The stress at the deflection point 20 and the joint portion 21 causes it to snap back to its original position.

The button shown in FIG. 5 has a short operating distance.

On the other hand, FIG. 12 shows a switch having a longer travel distance.

The base member 25, printed circuit 26, spacer 27 and spring contact plate 10 are the same as in FIG.

In the embodiment of FIG. 12, a cover plate or cover member 40 fits over the contact plate 10 and spacer 27 and has a cylindrical hole 41. In the embodiment of FIG.

A lower button member 42 is located within the hole 41 and rests on the central portion 16 of the contact plate 10.

An upper button member 43 is also located within the hole 41 .

The button member 43 has an outwardly extending flange 44 and an inwardly extending flange 45 on the cover plate 40 restrains the upper button member within the hole 41.

A light compression spring 46 extends between the lower button member 42 and the upper button member 43 and engages each contact portion of both button members.

The axis of the lower button member 42 is aligned with the axially extending four portions 47 in the upper button member 43.

When pressure is applied on the upper button member 43, the spring 4
6 is compressed and the upper button member 43 slides downwardly around the lower button member 42.

Spring 46 presses down on lower button member 42, which presses down on central portion 16 of contact plate 10.

Then, after a slight displacement of the central portion 16, a snap action occurs and the lower button member follows the downward movement of the contact plate under the pressure of the spring 46.

When the force applied to the upper button member 43 is released,
The spring pressure on the lower button member is removed and the spring contact plate pushes the lower button member 42 back to its normal position shown in FIG.

When used in a telephone or other device, a plurality of button switches are mounted on a common base member 2, as described above.
It is installed on top of 5.

FIG. 13 shows a plurality of printed circuits or conductors 5 on it.
One form of the base member 25 having 0 is shown.

The positions of the individual switches are indicated by dashed circles 51. In the example of this figure, each switch connects four pairs of contacts, or forms two signals simultaneously on four closing occasions.

The number of contacts and signals formed can be changed by changing the arrangement of the contacts and the shape and number of contacts 12-15.

Conductor 50 is also shown in FIG. Thus, although the number of contacts on the button can vary, the number of contacts that can be applied to each button is limited.

When used in telephones and the like, four contacts are usually sufficient.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a spring contact plate. FIG. 2 is a cross-sectional view taken along line 2--2 in FIG. FIG. 3 is a cross-sectional view taken along line 3--3 in FIG. FIG. 4 is a cross-sectional view of the contact plate taken along line 3--31 of FIG. 1, showing the contact plate in an operative condition. FIG. 5 is a sectional view showing an example of a bush button switch incorporating the contact plate of FIGS. 1 to 4. FIG. 6 is a perspective view of a pivot bushing button used in the switch of FIG. 5; FIG. FIG. 7 is a plan view of the button shown in FIG. 6. FIG. 8 is a perspective cross-sectional view of the elastic diaphragm used in the switch of FIG. 5. FIG. 9 is a plan view of the diaphragm of FIG. 8. FIG. 10 is a perspective view of a spacer used in the switch of FIG. 5. FIG. 11 is a sectional view of the spacer of FIG. 10. FIG. 12 is a sectional view showing another specific example of a bush button switch incorporating the contact plate of FIGS. 1 to 4. FIG. 13 is a plan view of a printed circuit board on which a plurality of pushbutton switches are installed. 10... Spring contact plate, 11...
...Flat sheet parts, 12, 13, 14, 15...
... Spring contact, 16 ... Center part,
17...Radial web, 21...Joint portion, 25...Circuit member, 26...
Contact areas 36, 42, 43...buttons.

Claims (1)

Claims: 1. A spring contact plate 10 with a switch position having a prestressed dome-shaped part and a flat seat part 11 surrounding the dome-shaped part, the dome-shaped part central portion 16 and central portion 1
a radial web 17 connecting the dome-shaped portion 6 to the corular sheet portion 11, and further prestressed so that the dome-shaped portion is in a stable position above a plane coincident with the corular sheet portion 11. radial webs 17 are added, each of said radial webs 17 having an upwardly curved portion 21 at the junction with the hollow sheet portion 11, and each further extending radially from said central portion 16 of said radial webs 17. a plurality of spring contacts 12, 13, 14 extending between pairs of
, 15;
a circuit member 25 spaced below the spring contact plate 10 and comprising a contact area 26 below the spring contacts 12, 13, 14, 15; applying a downward force to the dome-shaped portion; Buttons 36, 42, 48 located above the central portion 16 for the purpose of
and: when pressure is applied to the bushing buttons 36, 42, 43, the central portion 16 is pushed down from the stable position and the radial web 17 is deflected at the centered portion 21, The spring contact 1 snaps through the plane in which the central portion 16 coincides with the flat sheet portion 11.
2, 13, 14, 15 are in contact with the contact area 26, and the dome-shaped portion returns to the stable position when the bushing button 36, 42, 43 is released. Button switch. 2 the spring contact plate 10 comprises a plurality of switch positions, the circuit member 25 comprises a contact area 26 at each of the switch positions, and each of the plurality of bushing buttons 36, 43 comprises a contact area 26 at each of the switch positions; A button switch according to claim 1, characterized in that the button switch is equipped with a button switch. 3. A button according to claim 2, characterized in that the bushing button 36 is formed as a multiple bushing button member 33, each of the bushing buttons 36 being hinged to the member 33. button switch. 4. Each of the bushing buttons 42, 43 has a lower button member 42 acting on the central portion, an upper button member 43 whose axis substantially coincides with the axis of the lower button member 42; 3. The button switch according to claim 2, further comprising a spring 46 disposed between the upper button member and the lower button member. 5 a cover member 40 extending above the spring contact plate 10; and a cover member 40 provided within the cover member 40;
A hole 41 for the upper button member 43 and interengaging features on the upper button member 43 and the cover member 40 to hold the upper button member 43 in place. 5. The button switch according to claim 4, further comprising portions 44 and 45.