U.S. patent number 3,899,648 [Application Number 05/450,865] was granted by the patent office on 1975-08-12 for nodally operated push-button switch.
This patent grant is currently assigned to Alps Electric Co., Ltd.. Invention is credited to Taneo Murata.
United States Patent |
3,899,648 |
Murata |
August 12, 1975 |
Nodally operated push-button switch
Abstract
A snap-action operable push-button switch has a metal contact of
rectangular shape having a pair of rectangular holes at both sides
of a central stripe integrally formed therewith, the central stripe
being bent toward one side thereof and the metal contact also
having a pair of rectangular resilient contact pieces integrally
extended therefrom in a size smaller than the size of the
rectangular holes.
Inventors: |
Murata; Taneo (Tokyo,
JA) |
Assignee: |
Alps Electric Co., Ltd. (Tokyo,
JA)
|
Family
ID: |
12310532 |
Appl.
No.: |
05/450,865 |
Filed: |
March 13, 1974 |
Foreign Application Priority Data
|
|
|
|
|
Mar 16, 1973 [JA] |
|
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48-30685 |
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Current U.S.
Class: |
200/5R; 200/406;
200/5A |
Current CPC
Class: |
H01H
13/7006 (20130101); H01H 5/22 (20130101); H01H
2223/034 (20130101); H01H 2235/008 (20130101); H01H
2233/058 (20130101); H01H 2233/074 (20130101); H01H
2229/022 (20130101); H01H 2235/002 (20130101); H01H
2233/014 (20130101); H01H 2205/024 (20130101); H01H
2211/006 (20130101); H01H 2223/054 (20130101); H01H
2229/032 (20130101); H01H 13/703 (20130101) |
Current International
Class: |
H01H
13/70 (20060101); H01H 5/00 (20060101); H01H
5/22 (20060101); H01h 005/30 (); H01h 013/64 () |
Field of
Search: |
;200/67DB,159A,159B,5R,5A,67DA ;174/1P |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith, Jr.; David
Attorney, Agent or Firm: Shoup; Guy W.
Claims
What is claimed is:
1. A nodally operable push-button switch comprising a case, and a
flexible conducting metal plate, said plate having a normally
curved central stripe and a pair of rectangular holes at both sides
of said central stripe integrally formed therewith and also having
a pair of resilient contact pieces integrally extended therefrom
smaller than the size of the holes, and opposite side edges of said
metal plate being drawn so that they are shorter than the said
central stripe.
2. A nodally operable push-button switch as set forth in claim 1,
further comprising a lever mounted slidably into said case, and a
resilient means disposed between the said curved central stripe and
said lever.
3. A nodally operable push-button switch as set forth in claim 2,
further comprising a printed circuit substrate having stationary
contacts, and a frame, said case having legs with claws integrally
projected therefrom said claws being engaged with holes provided in
said printed circuit substrate, said lever being slidably inserted
into said case, and an insulating plate provided on said printed
circuit substrate and having a pair of rectangular holes formed
therethrough for contacting said stationary contacts.
4. A nodally operable push-button switch as set forth in claim 1,
further comprising a printed circuit substrate having a plurality
of stationary contacts, a frame having a plurality of holes aligned
in a manner crossing at right angles with each other, a plurality
of cases each having legs, each of said legs having claw portion
for engaging with said printed circuit substrate, a lever slidably
inserted into said case, a movable contacting plate disposed at the
bottom of said case, said contacting plate having a central strip
with a bent portion and having a pair of rectangular holes at both
sides of central stripe integrally formed therewith and also having
a pair of rectangular resilient contact pieces integrally extended
therefrom which are smaller than the size of the holes, and
opposite side edges of said metal plate being drawn to be shorter
than the central stripe of said metal plate, an insulating plate
having a pair of rectangular holes for contacting the stationary
contacts provided on said printed circuit substrate, said lever
having a spring hole, a resilient material inserted between the
spring holes of said lever and the bent portion of said movable
contacting plate to form an operating unit, a plurality of said
operating units mounted to said printed circuit substrate and said
frame, and a plurality of knobs with mounting shafts engaged with
the holes of said levers, said levers being slidably inserted into
the holes of said frame.
Description
BACKGROUND OF THE INVENTION
This invention relates to a snap-action (nodally) operable
push-button switch used for terminal equipment of electronic
device.
It is an objective of the present invention to provide a
snap-action operable push-button switch having improved electric
characteristics; improved contacting sensitivity, and permitting
rapid assembly for high productivity of the siwtch.
It is another objective of the present invention to provide a
snap-action operable push-button switch which makes point contact
with stationary contacts on a printed circuit substrate and may
also positively separate therefrom.
It is a further objective of the present invention to provide a
snap-action operable push-button switch which may make contact
softly and may also provide sufficient play for knob (push-button)
movement.
It is still another objective of the present invention to provide a
snap-action operable push-button switch which may simplify the
assembling process, reduce the number of wiring parts, and to
simplify the wiring process so as to economically assemble small
electronic computers such as desk or hand electronic
calculators.
It is still another objective of the present invention to provide
an operable push-button switch which is advantageous for producing
the push-buttons in relatively small numbers and with various types
of buttons.
SUMMARY OF THE INVENTION
According to the present invention, the operable push-button
switch, as one aspect, comprises a plurality of operating units
mounted in a frame. Each unit has a sliding lever (not a pivoting
lever), a flexible conductive contacting plate with resilient
contact pieces, an insulating plate, a coil spring, and a case for
enclosing the aforesaid parts to form a multi-key push-button
assembly. The contacting plate includes a bent potion (a center
strip) formed at the center and bent reversely upon depression and
also including resilient contact pieces formed integrally with the
bent portion thereby providing a snap action or toggle like (nodal)
operation.
These and other objects, features, and advantages of the
push-button switch according to the present invention will become
more fully apparent from the following description taken in
conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top plane view of the assembly of the snap-action
push-button switch of the invention;
FIG. 1B is an enlarged sectional view of the switch taken along the
line IB--IB in FIG. 1A.
FIG. 2 is a perspective exploded view of the essential parts of the
switch of the invention;
FIG. 3A is a perspective view, partly broken away, of the back of
the frame;
FIG. 3B is a perspective view of the back of the case of the
switch, partly cut out;
FIG. 3C is a perspective view of the back of the lever, partly cut
out of the switch;
FIG. 4 is a side sectional view of the operating unit of the switch
of the present invention;
FIG. 5 is an enlarged side sectional view, in the engaged state, of
the knob and the lever of the switch of the present invention;
FIGS. 6A and 6B are enlarged perspective views of the flexible
contacting plate, in two steps of its manufacture;
FIGS. 7A to 7C are explanatory views of the operation of the
flexible contacting plate which deforms at the central stripe
thereof upon depression. Wherein FIG. 7A shows the state of the
contacting plate before it has been deformed, FIG. 7B shows the
state of the contacting plate deforming upon the switch is closed,
and FIG. 7C shows the state of the contacting plate mostly
deformed; and
FIG. 8 is a side sectional view of the essential part of another
embodiment of the switch using a rubber resilient spring instead of
the coil spring of the prior embodiment.
Referring now to the drawings, numeral 1 indicates knobs
(push-buttons), 2 a frame and 3 an operating unit. The operating
unit 3 includes a case 4, a sliding lever 5, a coil spring 6, a
flexible conductive contacting plate 7, and an insulating plate 8.
Numeral 9 is a printed circuit substrate, and 10 are screws for
mounting the printed circuit substrate 9 to the frame 2.
The snap-action nodally operable push-button of the present
invention comprises one frame 2, one printed circuit substrate, and
plurality of operating units 3 (composed as above) and a plurality
of knobs to form a multi-key push-button assembly.
The knobs (push-buttons) 1 are made of synthetic plastic resin,
and, as shown in FIG. 5, have an integral cylindrical mounting
shaft 11 engaged into a hole 24 of the lever 5 at the lower center
thereof. Each shaft 11 has integral projections 12, 12 which
oppositely project from both sides of the end of the shaft 11 so
that the knob 1 and the lever 5 are held together. The root portion
13 of the shaft 11 is tapered.
As shown in FIG. 2, the frame 2 is made of synthetic plastic resin,
and has plural rectangular holes 14 aligned in a manner crossing at
right angles for slidably engaging the levers 5. The frame 2 also
has corresponding rectangular holes 15 (see FIG. 3A) formed
stepwise to the holes 14 on the back of the frame 2 for engaging
the rectangular cases 4. Each of the cases 4 (see FIG. 4) includes
a small-sized rectangular portion 18 and large-sized rectangular
portion 19. The frame 2 has a plurality of thread holes 17 to
receive the screws 10 for mounting the printed circuit to the frame
2, at its peripheral edge and intermediate portion.
The cases 4 of the operating units 3 are made of synthetic plastic
resin. Each case 4 has a small-sized hollow rectangular portion 18
and large-sized hollow rectangular portion 19 integrally formed
therewith, and step 16 formed between the rectangular portions 18
and 19. As shown in FIG. 4, the lever 5 is slidably engaged with
the inner wall of the small-sized hollow rectangular portion 18.
The outer walls of the small-sized and large-sized hollow
rectangular portions 18 and 19 are engaged with the holes 15 of the
frame 2, respectively.
As shown in FIG. 3B a seat 20 is formed at the lower edge of the
large-sized hollow rectangular portion 19 for mounting the movable
contacting plate 7 to the insulating plate 8. Projections 21 are
provided at the respective corners of the seat 20 for fixing the
movable contacting plate 7 and the insulating plate 8. Legs 22 are
projected at the opposite surfaces of the large-sized hollow
rectangular portions 19 for securing the case 4 to the printed
circuit substrate 9, and claws 23 are integrally projected from the
end of the legs 22, respectively outwardly. The legs 22 are
resilient, and when the legs 22 are inserted into the rectangular
holes 36 formed at the printed circuit substrate 9 under pressure,
the claws 23 of the legs 22 are engaged with the edges of the
rectangular holes 36 so that the cases 4 are secured to the printed
circuit substrate 9.
As shown in FIG. 3C, the sliding lever 5 is made of synthetic
plastic resin and has a hole 24 formed at its upper central portion
thereof for engaging the shaft 11 of the knob 1 and the projections
12. Lever 5 has a hole 25 for holding coil spring 6, the hole 25
being of a larger diameter than the hole 24 at the lower portion
thereof, and a step 26 being formed between the hole 24 and 25.
Stoppers 27 are formed at the lower portion of the lever 5 for
preventing the lever 5, after having been inserted into the case 4,
from being discharged out. The stoppers 27 are in contact with the
step 16 of the case 4. The coil spring 6 is inserted into the hole
25 of the lever 5 in a manner that one end thereof is engaged with
the step 26 and the other end thereof is contacted with the center
of the movable contacting plate 7 to urge the movable contacting
plate 7 and also to return the lever 5. The lever 5 slides within
an opening and is not a pivoting lever.
The flexible conductive contacting plate 7 is, for example, made of
phosphorus bronze thin metal plate having electroconductivity and
resiliency. The plate 7 is punched, in the shape as shown in FIG.
6A, in such a manner that a pair of rectangular holes are formed at
both sides of central stripe 28. The stripe 28 is integrally formed
with the plate and a pair of rectangular resilient contact pieces
30 are integrally extended from the vicinity of the center of the
stripe 28 in a size, and a shape, smaller than the size of the
holes. Both side edges 29 of the plate 7 are parallel with the
central stripe 28 and are drawn (or formed with any alternative
process) into a bump so as to shorten the side edges compared to
the central stripe 28 as shown in FIG. 6B. The central stripe 28 is
bent with the result that the resilient contact pieces 30 extend
from the central stripe 28. The contact pieces change direction
relative to the curve of the central stripe 28, i.e. they are
tangential to the curve. The contact points 31, provided at the
ends of the resilient contact pieces 30 are bent to the other side,
(downwardly as seen in FIG. 6B). When the center of the bent
portion of central stripe 28 is depressed, the bent portion is
reversely bent (see FIG. 7B) and when the depression is released,
the bent portion returns to the original bent state by the
resiliency of the center stripe 28. There are provided holes 32 at
the respective four corners of the movable contacting plate 7 for
engaging (fitting upon) with the projections 21 of the case 4.
The insulating plate 8 is made of synthetic plastic resin film, and
is sized to meet the size of the seat 20 of the case 4. There are
provided holes 33 at the respective corners of the rectangular
insulating plate 8 for engaging with the projections 21 of the case
4. There are also formed rectangular holes 34 in the insulating
plate 8 for inserting the free ends of the resilient contact pieces
30, respectively. The rectangular holes 34 also enable the contact
points 31 (at the ends of the resilient contact pieces 30) to make
contact with the stationary contacts 35 of the printed circuit
substrate 9. The insulating plate 8 insulates (other than its holes
34) the movable contacting plate 7 from the printed circuit
substrate 9.
The desired circuit is formed on the printed circuit substrate 9.
The plural stationary contacts 35 are to be contacted with the
contact points 31 of the resilient contact pieces 30. The printed
circuit substrate 9 also has plural pairs of rectangular holes 36
formed therethrough for inserting the legs 22, which mount the
cases 4. Since the oblique surfaces of the claws 23 are contacted
with the edges of the rectangular holes 36, when the legs 22 of the
cases 4 are inserted into the rectangular holes 36 and the cases 4
strongly depressed, the legs 22 are bent inside so that the ends of
the claws 23 pass through the rectangular holes 36. Simultaneously
the bent portions of the legs 22 are returned to their original
states by their resiliency with the result that the claws 23 are
engaged with the edges of the rectangular holes 36 so that the
cases 4 are secured to the printed circuit substrate 9. There are
also provided plural holes 37 at the printed circuit substrate 9
for inserting the screws 10. The mounting of the printed circuit
substrate 9 to the frame 2 may be made by alternative means instead
of the screws 10.
Assemblying of the snap-action nodally operable push-button switch
of the present invention will now be described.
The sliding lever 5 is inserted into the small-sized hollow
rectangular portion 18 of the case 4, the coil spring 6 is then
inserted into the hole 25 of the lever 5, the bent portion of the
movable contacting plate 7 is placed at the side of the coil spring
6 so that the holes 32 of the four corners are engaged with the
projections 21 of the four corners of the case 4, the movable
contacting plate 7 is mounted to the case 4, the holes 33 of the
four corners of the insulating plate 8 are engaged with the
projections 21 of the four corners of the case 4 in the state that
the rectangular holes 34 of the insulating plate 8 coincide with
the stationary contacts 35 of the printed circuit substrate 9, and
the insulating plate 8 is mounted to the case, then the projections
21 of the case 4 are punched, and then the movable contacting plate
7 and the insulating plate 8 are fixed to the case 4, and thus the
operating unit 3 is assembled.
As shown in FIG. 4, the assembled operating unit 3 is so
constructed that the central stripe of the movable contacting plate
7 is bent upwardly as shown in the drawing, so as to push upwardly
the coil spring 6. The coil spring 6 urges upwardly the lever 5
with the result that the stoppers 27 of the lever 5 are contacted
with the step 16 of the case 4 so as to prevent the lever 5 from
being discharged out. The desired number of the operating units 3
are previously assembled, and then the legs 22 of the case 4 of the
operating unit 3 are press-fitted within a pair of rectangular
holes 35 of the printed circuit substrate 9, and then the claws 23
of the legs 22 are engaged with the edges of the pair of
rectangular holes 36 so that the operating units 3 are secured to
the printed circuit substrate. Thus, a desired number of operating
units 3 are mounted to the printed circuit substrate 9.
Then, the cases 4 of the respective operating units 3 are engaged
with the holes 15 of the frame 2, i.e., the frame 2 is located on
plural operating units 3, and then screws 10 are inserted into
plural holes 37 of the printed circuit substrate and are screwed
with the thread holes 17 of the frame 2 and are then tightened so
as to secure the printed circuit substrate 9 to the frame 2, and
the operating units 3 are fixed between the printed circuit
substrate 9 and the frame 2. Then, the mounting shafts 11 of the
respective knobs 1 are engaged so as to press-fit the projections
12 to the holes 24 of the levers 5 presented at the holes 14 of the
frame 2 thereon, and then the knobs 1 are turned at 90.degree. so
as not to be discharged out from the lever 5 to complete the
assembling.
Then, the operation of the nodally operable push-button switch of
the present invention will now be described.
The central stripe 28 of the movable contacting plate 7 of the
push-button switch, assembled but not yet operated, is bent
upwardly as in FIG. 7A. At the side of the lever 5, the free ends
of the resilient contact pieces 30 are also directed upwardly. The
contact points 31 (at the free ends of the resilient contact pieces
30) are separated from the stationary contacts 35 of the printed
circuit substrate 9, and the push-button switch is in its open
state. The bent portion of the central stripe 28 of the movable
contacting plate 7 pushes the lever 5 and the knobs 1 upwardly, and
the stoppers 27 of the lever 5 are contacted with the step 16 of
the case 4 to hold the lever 5 in the stopped state.
When the knob 1 is now depressed, the lever 5 compresses the coil
spring 6, which spring 6 urges the center of the central stripe 28
of the movable contacting plate 7. When the coil spring 6 is
compressed to a certain degree, the central stripe 28 is also
started to be in flexure, and when the coil spring 6 is further
compressed, the central stripe 28 cannot endure the depression so
that the central stripe 28 is abruptly deformed from the state
shown in FIG. 7A to that shown in FIG. 7B, with the result that the
center of the central stripe 28 is reversely bent and the inclined
direction of the resilient contact pieces 30 are also abruptly
changed so that the contact points 31 are abruptly moved
downwardly. The contact points 31 are then positively contacted
with the stationary contacts 35 of the printed circuit substrate 9,
and then the circuit is closed. The reversing speed of the central
stripe 28 of the movable contacting plate 7 when reversely bent is
faster than the moving speed of the knob 1 up to that time, (a type
of toggle action), and the depression to the knob 1 when reversely
bent is abruptly reduced, and accordingly the knob 1 is nodally
moved. When the knob 1 is further depressed even after the circuit
is closed, the coil spring 6 and the central stripe 28 of the
movable contacting plate 7 are further compressed so that the
central stripe 28 of the movable contacting plate 7 becomes as
shown in FIG. 7C so as to provide sufficient moving allowance of
the knob 1. When the depression is released, the central stripe 28
of the movable contacting plate 7 urges the coil spring 6, by its
own resiliency, and returns to its original bent state and the coil
spring 6 is also returned to its original state by its resiliency
thereof so as to simultaneously return the knob 1.
A resilient member such as spring 38, see FIG. 8, formed of rubber
of rubber resilient material as shown in FIG. 8 may be used instead
of the coil spring 6.
The following advantages and effects can be provided by the nodally
operable push-button switch of the invention:
It should be understood from the foregoing description that since
the nodally operable push-button switch of the present invention
comprises the movable contacting plate 7 which is shortened at the
edges 29 by drawing so that the opening and closing of the switch
is nodally conducted and the switch also comprises spherical
contact points 31 at the free end of the resilient contact pieces
30 so as to effect point-contact with the stationary contacts 35 on
the printed circuit substrate 9, positive separation of the point
contacts 35 can be attained so as to improve the electric
characteristics.
It should also be understood that since the coil spring 6, such as
resilient material made of rubber or rubber substance, is disposed
between the movable contacting plate 7 and the lever 5 in the
switch of the invention, the contacting sensitivity of the contacts
is soft and the play of the moving degree of the knob 1 may be
sufficiently provided so as to improve the contacting
sensitivity.
It should also be understood that since the nodally operable
push-button switch of the invention comprises wiring portion of
operational circuit, stationary contacts and circuit portion of
push-button switch formed on one printed circuit substrate and said
operational circuit mounted at the wiring portion of the
operational circuit, operating units mounted at the push-button
switch portion as one-touch operation type simply assembled
compared with the conventional desk type electronic computer which
as separate push-button portion and operational circuit portion and
lead wires for connection the former to the latter, the assembling
process, wiring parts and the number of wiring processes can be
reduced so as to assemble the desk type electronic computer less
expensively.
It should also be understood that since the knobs 1 and frame 2 and
operation units 3 are combined with the printed circuit substrate 9
in the switch of the present invention, so that when push-button
switches for different key numbers are produced, only the designs
of printed circuit substrate and the frame 2 may be changed and
when different design of the knob 1 is necessary, only the knob 1
of different design may be formed and may be mounted thereto, it is
advantageous for producing small numbers and various types of
push-button switches.
* * * * *