U.S. patent number 3,858,019 [Application Number 05/355,888] was granted by the patent office on 1974-12-31 for flex spring contact switch for push buttons.
Invention is credited to Richard C. LaBorde, Robert A. Muri.
United States Patent |
3,858,019 |
Muri , et al. |
December 31, 1974 |
FLEX SPRING CONTACT SWITCH FOR PUSH BUTTONS
Abstract
An insulation panel having a printed circuit on one surface and
is provided with button actuated switch blades on its opposite
surface. Each blade is connected through the panel with a portion
of the printed circuit, and is opposed to a stationary contact also
connected through the panel to a portion of the printed circuit.
The switches are preferably actuated by buttons slidably supported
above said blades and operable to engage said blades with said
stationary contacts with a wiping action.
Inventors: |
Muri; Robert A. (Chisholm,
MN), LaBorde; Richard C. (Hibbing, MN) |
Family
ID: |
23399220 |
Appl.
No.: |
05/355,888 |
Filed: |
April 30, 1973 |
Current U.S.
Class: |
200/535; 200/5A;
200/275; 200/241 |
Current CPC
Class: |
H01H
13/7006 (20130101); H01H 13/12 (20130101) |
Current International
Class: |
H01H
13/70 (20060101); H01H 13/12 (20060101); H01h
003/12 () |
Field of
Search: |
;200/5A,159R,159A,166BH,166J,166PC,241,27S,340 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Tolin; Gerald P.
Claims
We claim:
1. A switch for use in combination with a panel of insulating
material including:
a spring blade having an anchoring end portion in face contact with
the insulating panel,
a curved blade portion connected to said anchoring end portion at
an acute angle to said panel,
said curved blade portion curving gradually toward parallel
relation to the surface of said panel and then toward the surface
of the panel,
an actuating end connected to the end of said curved blade portion
along a reversely curved area of short radius providing a convex
wiping surface directed toward said panel and in spaced relation
thereto,
means securing said anchoring end portion in face contact with said
panel,
a stationary contact on one surface of said panel having a rounded
surface in spaced opposed relation to said spring blade,
said actuating end of said blade extending from said convex wiping
surface in a direction away from said panel and having a reversely
curved extremity to provide a convex actuating surface directed
away from said panel, said convex wiping surface being between said
convex actuating surface and said anchoring end portion,
a top panel in spaced parallel relation to said panel of insulating
material having an aperture in opposed relation to said actuating
end of said blade, and
a button slideably supported in said aperture removably bearing
against said convex actuating surface and operable, when actuated
to flex said curved blade portion to cause engagement between said
convex wiping surface of said blade against said stationary
contact, further movement of said button acting to flex said convex
wiping surface of said blade toward said anchoring end portion to
create a wiping action of said convex wiping surface of said blade
relative to said stationary contact.
Description
This invention relates to an improvement in Flex Spring Contact
Switch and deals particularly with a type of switch which can be
mounted on a printed circuit panel or the like.
BACKGROUND OF THE INVENTION
During recent years the production of electronic computers has
tremendously increased. These computers are electronically capable
of adding, subtracting, multiplying or dividing by merely
depressing actuating buttoms on the surface of the computer body.
These computers have become smaller and smaller in size, and are
now becoming available in a size which can be readily carried in a
pocket if desired.
One of the problems which has been experienced with any device of
this type lies in the fact that after a period of time, the
contacts which are push buttom actuated become coated or partially
covered with a film which at times will prevent the contacts from
closing the circuit. If any of the push buttom contacts does not
function properly, the entire computation is is thrown off, and the
result received is erroneous. This can cause serious problems and
considerable embarrasment when the computer is being depended upon
for supplying accurate results.
SUMMARY OF THE INVENTION
We have found that an extremely effective and reliable switch may
result if the switch blade is so shaped as to engage the stationary
contact upon depression of an actuating button, and if the
contacting portion of the spring blade will wipe over the
stationary contact upon slight further depression of the button.
This slight wiping action maintains the contacts clean and
eliminates the chance of the spring switch blade from continuously
contacting one area only of the stationary contact as is usual
practice.
An added feature of the present invention resides in the provision
of flex spring contact switches which may be mounted directly upon
one side of an insulation panel and which may be electrically
connected by electrically conductive rivets or similar means to
portions of a printed circuit on the opposite side of the panel.
With this arrangement, the spring contacts and stationary contacts
are directly connected through the panel to the printed circuit,
minimizing the chance of incurring broken connections between the
switches and the remainder of the circuit.
A further feature of the present invention resides in the provision
of a flex spring contact switch including a blade which is anchored
to the circuit board panel, and is curved to present a convex
wiping surface to the stationary contact. The switch blade is
extended to provide an actuating end which is curved to provide
reversely curve to provide a convex furface in contact with an
actuating button. When this actuating button is depressed toward
the circuit board, the convex wiping surface engages the stationary
contact on the circuit board. Further depression cuases the convex
wiping surface to slide along the surface of the stationary
contact, keeping the interengaging surfaces clean.
A further feature of the present invention lies in the fact that
the flex spring contacts serve the dual purpose of closing circuits
of the circuit board, and also resiliently supporting the spring
acutating buttons in circuit breaking position.
These and other objects and novel features of the invention will be
more clearly and fully set forth in the following specification and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of an electronic computer showing the
general arrangement of parts therein.
FIG. 2 is a top plan view of the printed circuit board.
FIG. 3 is a fragmentary bottom of the under surface of the printed
circuit board.
FIG. 4 is a transverse sectional view through the computer, the
electronic components being omitted to simplify the
illustration.
FIG. 5 is an enlarged sectional view through one of the switches
and one of the actuating buttons.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawings illustrate a portable electronic computer of the type
which may be battery actuated, or may be plugged into a normal
electrical outlet. In view of the fact that details of the circuit
are unimportant to the structure being claimed, such details have
been omitted. As indicated in FIG. 1, the top panel 10 of the
computer A is provided with a flat top surface 11 having a series
of apertures 12 extending therethrough to slidably support the
necessary actuating buttons 13. An upwardly extending flange 14
forming the upper edges of the side walls and one end wall
encircles the panel surface 11 to act as a protection for the
buttons 13, the flange extending slightly above the level of the
buttons 13 in their normal position.
The top panel 10 is provided with a slightly inclined panel portion
15 which slopes downwardly to a window opening 16 in which is
supported a lens 17 through which the answer of the computation is
visible.
As indicated in FIG. 4 of the drawings, the portion of the top
panel 10 through which the button apertures 12 are provided is
thickened to provide bearing portions of suitable length to
maintain the buttons 13 for sliding movement. As indicated, the
buttons are preferably square in horizontal section and bear
suitable indicia 18 to identify the button. As indicated in FIGS. 4
and 5 of the drawings, each button is provided with a laterally
projecting peripheral flange at its lower extremity. This flange 20
limits the upward movement of each button through the panel 10.
Each button 13 also includes a downwardly extending projection 21
coaxial with the button, the projection engaging the flex spring
contact switch associated therewith as will be later described.
As is indicated in FIG. 4 of the drawings, the housing 22 of the
computer includes a bottom section 23 and a top section 24 of which
the top panel 10 forms a part. The bottom section 23 includes a
bottom panel 25 and rectangularly arranged side and end walls such
as 26 extending upwardly therefrom. The top panel 10 is supported
by downwardly and outwardly inclined side walls 27 and parallel end
walls which are not shown in the drawings. The lower periphery of
the upper section side walls and end walls may dovetail with the
upper edges of the lower section 23 as indicated at 29.
A printed circuit board panel 30 closes the lower end of the upper
section 24 and is secured thereto by screws 31 or other suitable
means extending into internally threaded bosses 32 in the upper
section 24. The under surface of the panel 30 bears a printed
circuit 33, a small fragment of which is shown in FIG. 3 of the
drawings merely for the purpose of illustration. A second partial
printed circuit board 34 may be mounted near the upper extremity of
the lower section 23, for connecting and suspending various
components of the circuit.
With reference now to FIG. 5 of the drawings, an enlarged section
of the printed circuit board is provided diagramatically showing
one of the flex spring contact switches, together with its
cooperable stationary contact and push button actuater. The spring
is indicated in general by the numeral 35 and includes a flat
anchoring end 36 in face contact with the panel 30 and secured
thereto by a fixed contact 37 which extends through the spring,
through the panel 30 and through a portion of the metal forming the
printed circuit 33. From the flat anchoring end, the blade 35
extends upwardly as indicated at 39 at an acute angle to the upper
surface of the panel 30. The blade 35 extends to form a curved
portion 40 which passes through an area which is parallel to the
surface of the panel 30 and curves back toward the panel 30. The
blade is then reversely curved as indicated at 41 to provide a
convex wiping surface, the reversely curved portion being of
relatively short radius. The blade 35 then extends upwardly and is
again reversely curved at 42 to terminate in a downturned end
directed toward the panel 30. This reversely curved portion 42 of
the actuater end of the switch blade forms a convex surface which
is directed away from the panel 30 and engages the downwardly
projecting actuater portion 21 of a corresponding push button
13.
A stationary contact 44 is preferably formed by a rivet or similar
means extending through the panel 30 and electrically connected to
a portion of the printed circuit 33. The upper surface of the
stationary contact 44 is preferably rounded to some extent.
The shape of the switch blade 35, and its position of engagement
with the push button 13 is such that the push button 13 is normally
held in its elevated position by the resiliency of the switch
blade. When each button such as 13 is depressed, the convex wiping
surface of the reversely curved portion 41 of the blade makes
contact with the stationary contact 44. Further slight depression
of the push button causes the convex wiping surface in the area 41
to slide over the stationary contact 44 in a direction toward the
anchored end 36 of the switch blade, creating a wiping action which
tends to maintain the contacting surfaces clean.
In accordance with the Patent Statutes, we have described the
principles of construction and operation of our improvement in Flex
Spring Contact Switch and while we have endeavored to set forth the
best embodiment thereof, we desire to have it understood that
changes may be made within the scope of the following claims
without departing from the spirit of our invention.
* * * * *