U.S. patent number 3,858,012 [Application Number 05/446,260] was granted by the patent office on 1974-12-31 for operating means for hermetically sealed double-throw double-pole switch.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Joseph LaRue Lockard.
United States Patent |
3,858,012 |
Lockard |
December 31, 1974 |
OPERATING MEANS FOR HERMETICALLY SEALED DOUBLE-THROW DOUBLE-POLE
SWITCH
Abstract
The present invention relates to a double-throw double-pole
switch the design of which requires but a minimum number of parts
and a minimum requirement for fasteners, adhesives and the like
thereby facilitating ease in manufacture. The switch is
additionally well adapted for miniaturization in the form of a
microelectronic component known as dual-in-line package (DIP). The
poles of the switch are in the form of electrical contacts aligned
to provide the well-known opposed pairs of electrical leads for the
DIP. A lever or cam for actuating the switch is assembled without
the need for conventional fasteners, such as screws or adhesives
and the like, thereby permitting rapid manufacture of the switch
without the time consumption and skill otherwise required for
assembly using such conventional fasteners.
Inventors: |
Lockard; Joseph LaRue
(Harrisburg, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
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Family
ID: |
27002640 |
Appl.
No.: |
05/446,260 |
Filed: |
February 27, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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364779 |
May 29, 1973 |
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325480 |
Jan 22, 1973 |
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Current U.S.
Class: |
200/16D; 200/17R;
200/302.3; 200/329; 200/339; 200/16R; 200/291; 200/303; 200/336;
200/561 |
Current CPC
Class: |
H01H
9/04 (20130101); H01H 15/10 (20130101); H01H
15/005 (20130101); H01H 23/164 (20130101) |
Current International
Class: |
H01H
15/00 (20060101); H01H 9/04 (20060101); H01H
23/16 (20060101); H01H 23/00 (20060101); H01H
15/10 (20060101); H01h 015/06 (); H01h
003/32 () |
Field of
Search: |
;200/16R,16C,16D,16F,17R,18,153P,158,302,303,324,330,332,335-337,339,291 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; James R.
Attorney, Agent or Firm: Kita; Gerald K.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of Ser. No.
364,779, filed May 29, 1973, and now abandoned, which is a
continuation-in-part of application Ser. No. 325,480, filed Jan.
22, 1973, and now abandoned.
Claims
What is claimed is:
1. A switch comprising: a base of dielectric material, a cover of
dielectric material overlying said base, said base and said cover
together comprising a housing, at least two adjacent electrically
conducting springs on each opposed side of said base, said springs
having first portions projecting in depending relationship from
said base to provide electrical terminals protruding externally of
said base for making electrical connections externally of said
housing, said springs having second portions in opposed spaced
relationship in said housing, a carriage slidably received for
sliding displacement in said housing, said carriage being received
between each opposed pair of second portions of said springs and
having a first and a second conductor strip on opposed sides of
said carriage, said carriage being displaceable to a first position
and having a first conductor strip electrically engaging two
adjacent springs to complete a first electrical circuit
therebetween, said carriage being displaceable to said first
position and having said second conductor strip electrically
engaging two adjacent springs to complete a second electrical
circuit therebetween, said carriage being displaceable in said
housing to a second position to disengage said first conductor
strip from one of said springs and thereby interrupt said first
electrical circuit, and to disengage said second conductor strip
from another of said springs and thereby interrupt said second
circuit, and a lever on said carriage protruding externally of said
housing for receiving applied forces thereto for pivoting said
lever and for displacing said carriage to either of said first or
said second positions.
2. The structure as recited in claim 1, wherein said lever includes
a pivotal connection to said carriage, said housing having an
aperture receiving said lever therethrough, and said housing having
at least a portion adjacent said aperture to provide a fulcrum over
which said lever is pivoted, said lever being pivotally
displaceable in one direction to slidably displace said carriage to
said first position, said lever being pivotally displaceable in a
second direction to slidably displace the carriage to said second
position.
3. The structure as recited in claim 2, wherein said pivotal
connection comprises projecting dowel portions on said lever, said
carriage having a pair of inverted grooves respectively receiving
said dowel portions, and further including: an opening in said
carriage freely receiving said lever therethrough.
4. The structure as recited in claim 2, wherein said base includes
a projection thereon, said lever having an end slidably engageable
over said projection upon pivotal displacement of said lever in
either of said first direction or said second direction, said
projection providing a latch to prevent pivotal motion of said
lever in the absence of forces applied to said lever.
5. The structure as recited in claim 2, wherein each of said
springs interfits with a groove on said base, said cover overlies
said base, and said cover retains said springs between said base
and said cover.
6. A sealed switch, comprising:
a housing,
a plurality of electrical contacts having first portions protruding
from said base providing electrical terminals externally of said
base,
said electrical contacts having second portions internally of said
housing in spaced relationship,
a carriage having an electrical conductor element and being
displaceable in said housing for engagement of said conductor
element sequentially with selected contact second portions,
a cylindrical cam element protruding from an aperture provided in
said housing,
a sealing ring encircling said cam element and in sealing
compression between said cam element and said housing to seal said
housing aperture from leakage of contaminants into said
housing,
said cam element being rotatable about fixed axis of rotation,
and
means connecting said cam element and said carriage for
transmitting rotation of said cam element into linear displacement
of said carriage, whereby rotation of said cam element causes
translation of said carriage to engage said conductor element
against selected contact second portions.
7. A structure as recited in claim 6, wherein said means
includes:
a cylindrical projection depending from said cam element and being
offset from the axis of rotation of said cam element, whereby
rotation of said cam element causes a curvalinear displacement of
said projection about the cam element axis of rotation,
an elongated slot in said carriage extending transversely of the
direction of linear displacement of said carriage; and
said slot receiving the projection therein, said projection upon
curvilinear displacement thereof causing linear translation of said
carriage and simultaneous translation of said projection along said
slot.
8. The structure as recited in claim 6, and further including:
said housing being provided with a plurality of detents,
a resilient projection depending from said carriage for
registration in said detents, said projection being resiliently
deflected by said housing and resiliently deflecting into
registration with each detent in turn to position and locate said
carriage in desired positions within said housing.
9. The structure as recited in claim 8, wherein said projection
means comprises a pair of resilient fingers integral with said
carriage, said detent means comprises a slot having relatively wide
and relatively narrow width portions,
said fingers being forcibly resiliently deflected toward each other
upon passage of said fingers along said relatively narrow portions
of said slot, and said fingers being permitted to resiliently
deflect away from each other for registration within said
relatively wide portions of said slot and thereby detent said
carriage in desired positions, with said fingers being in
registration in said slot between relatively narrow portions of
said slot to provide a resilient latch against displacement of said
carriage from said desired positions.
10. The structure as recited in claim 6, wherein, said carriage
slidably abuts said base portion and said cover portion, and said
cam element slidably abuts said carriage.
11. The structure as recited in claim 6, wherein said base portion
and said cover portion overlap each other to provide relatively
large surface areas abutting to resist flow of contaminants.
12. The structure as recited in claim 6, and further including:
said housing being provided with a plurality of detents,
a resilient portion on said cam element for registration in turn
within each of said detents, said projection being resiliently
deflected into and out of registration within said detents to
position and locate said carriage in desired positions within said
housing.
13. The structure as recited in claim 12, wherein said cam element
is provided with a substantially hollow portion defining a
resilient flap portion to which said projection is mounted, said
housing having said detents spaced opposite the periphery of said
cam element, and said projection adapted for registration in turn
with each of said detents as said cam element is rotated.
14. The structure as recited in claim 6, wherein the housing
includes a bottom wall provided with a track, said carriage being
provided with a pair projecting feet slidably received in said
track.
15. The structure as recited in claim 14, wherein said feet project
outwardly in outrigger relationship from said carriage to assist
said carriage in slidable displacement within said housing.
Description
The present invention relates to a double-throw double-pole switch
the design of which requires but a minimum number of parts and a
minimum requirement for fasteners, adhesives and the like thereby
facilitating ease in manufacture. The switch is additionally well
adapted for miniaturization in the form of a microelectronic
component known as a dual-in-line package (DIP). The poles of the
switch are in the form of electrical contacts aligned to provide
the well-known opposed pairs of electrical leads for the DIP. A
lever or cam for actuating the switch is assembled without the need
for conventional fasteners, such as screws or adhesives and the
like, thereby permitting rapid manufacture of the switch without
the time consumption and skill otherwise required for assembly
using such conventional fasteners.
As a further feature of the present invention, the switch includes
a carriage which is slidably displaceable internally of the switch.
The carriage includes electrical contacts for bridging between
selected contacts to complete corresponding electrical circuits in
the familiar double-throw double-pole switch operation. The housing
for the carriage and contacts which is in the form of a DIP package
receives the switch actuating lever of one embodiment through an
aperture provided in the housing. The housing portion which
encircles the lever is utilized as a fulcrum against which the
lever is pivoted in order to actuate the switch carriage and
thereby either complete or interrupt the aforementioned electrical
circuits. A rubber grommet is applied over the lever portion which
protrudes through the housing to provide a dust cover for covering
the aperture which receives the lever therethrough. In addition the
housing is provided with a projection internally thereof over which
the lever is forced to engage and slidably traverse. Accordingly
such a projection provides some frictional resistance to pivotal
motion of the lever as the lever is traversed thereover. Once the
lever is pivoted to either of two fully pivoted positions which
cause either completion or interruption of the double-pole
double-throw circuits through the switch, the lever will become
disengaged from the projection, with the projection serving
therefore to latch the lever in such fully pivoted positions and
prevent unwanted movement of the lever in the absence of forces
applied thereto, which forces are required to operate the
lever.
According to another preferred embodiment of the present invention
the lever is replaced by a stepped cylindrical cam element which is
rotatable about its cylindrical axis. The stepped cam element
advantageously receives a sealing ring thereover to seal the
interior of the switch. A short dowel or shaft depends from the cam
element and is offset from the axis of rotation such that as the
cam element is rotated the dowel or shaft is pivoted through a
circular arc. The dowel or shaft is received in a transverse slot
of the carriage, whereby the carriage is slidably displaced as the
dowel is rotated through its arc of displacement. The cam element
is capable of 360.degree. rotation and can never be overstressed or
broken during actuation thereof.
In either of the embodiments, the base and cover latch together
with large surface areas of abutting surfaces to provide seals
preventing the flow of contaminants into the switch.
Accordingly, it is an object of the present invention to provide a
double-throw double-pole switch capable of miniaturization into a
DIP package, with the electrical poles of the switch arranged to
provide depending electrical leads for the DIP.
Another object of the present invention is to provide a
double-throw double-pole switch in the form of a DIP package with
the electrical poles of the switch providing depending electrical
leads for the DIP package, the switch further including a carriage
which is slidably displaceable internally of the switch and a lever
pivotally connected to the carriage and protruding from the
housing, which lever is pivoted to first and second positions for
either interrupting or completing the electrical circuits through
the poles of the switch, and wherein the housing is provided with a
projection over which the lever is slidably traversed in order to
latch the lever in its first and second positions in the absence of
forces applied to the lever.
Another object of the present invention is to provide a
double-throw double-pole switch wherein the electrical poles of the
switch provide externally protruding electrical leads for the
switch, and wherein the electrical circuits through the poles are
either interrupted or completed by pivoting a lever to either of
two positions, thereby causing a carriage containing electrical
bridging contacts to be slidably displaced internally of the
switch, with the electrical contacts thereof either bridging
between selected poles to complete the electrical circuits through
the switch, the lever being pivotally connected to the carriage
without the need for conventional fasteners or adhesives.
Another object of the present invention is to provide a
double-throw double-pole switch containing a housing, a plurality
of contacts in the housing providing the switch poles, a slidable
carriage having electrical contacts bridging between selected
electrical poles to complete electrical circuits through the
switch, a lever pivotally connected to the carriage and pivotally
displaceable to either of two positions for interrupting or
completing the electrical circuits, and with the lever protruding
through a housing containing the switch with a portion of the
housing encircling the lever to provide a fulcrum over which the
lever is pivoted to slidably displace the carriage.
Another object of the present invention is to provide a switch of
miniature size adapted for mounting on a printed circuit board
wherein the component parts of the switch are assembled to provide
overlapping seams having relatively long barrier paths sealing the
interior of the switch from solder flow and other types of
contaminate flow.
Another object of the present invention is to provide a miniature
switch for mounting on a printed circuit board, wherein the
interior of the switch is substantially sealed to permit immersion
of the switch together with the printed circuit board in cleaning
solutions and to prevent all additional types of contaminants from
entering the switch.
Another object of the present invention is to provide a
double-throw double-pole switch containing a housing, a plurality
of contacts in the housing providing the switch pole, a slidable
carriage having electrical contacts bridging between selected
electrical poles to complete electrical circuits to the switch, a
stepped cylindrical cam element which is advantageously sealed to
the cover of the housing, an offset dowel or shaft on the cam
element which is displaceable through an arc upon rotation of the
cam element, and the carriage being provided with a transverse slot
receiving the dowel therein, such that the carriage is displaceable
along a linear axis upon displacement of the dowel about a
curvilinear path when the cam element is rotated about 360.degree.
of arcuate displacement.
Another object of the present invention is to provide a switch
having a displaceable carriage actuated by a cam element which is
capable of 360.degree. rotation without breakage, which cam element
causes back and forth displacement of the carriage during such
360.degree. rotation.
Other objects and many attendant advantages of the present
invention will become apparent upon perusal of the following
detailed description taken in conjunction with the accompanying
drawings wherein:
FIG. 1 is an enlarged fragmentary perspective of a preferred
embodiment of the present invention illustrating a plurality of
double-throw double-pole switches according to the present
invention arranged in a DIP package mounted on a circuit board;
FIG. 2 is an enlarged fragmentary section taken along the line 2--2
of FIG. 1;
FIG. 3 is an enlarged fragmentary perspective of the switch
illustrated in FIG. 1 with certain of the component parts thereof
illustrated in exploded configuration to illustrate the details
thereof;
FIG. 4 is an enlarged fragmentary section taken along the line 4--4
of FIG. 2;
FIG. 5 is an enlarged fragmentary section taken along the line 5--5
of FIG. 2;
FIG. 6 is an enlarged fragmentary perspective of another preferred
embodiment according to the present invention;
FIG. 7 is a fragmentary enlarged section taken along the line 7--7
of FIG. 8;
FIG. 8 is an enlarged section of the switch taken along the lines
8--8 of FIG. 6;
FIG. 9 is a fragmentary enlarged perspective of the preferred
embodiment illustrated in FIG. 8 with the component parts thereof
in exploded configuration to illustrate the details thereof;
FIG. 10 is a fragmentary enlarged section taken along the lines
10--10 of FIG. 8;
FIG. 11 is an enlarged plan of a carriage component part of the
preferred embodiment illustrated in FIG. 9; and
FIG. 12 is an enlarged section taken along the lines 12--12 of FIG.
10.
FIG. 13 is an enlarged fragmentary perspective with parts broken
away and with parts in section to illustrate the details thereof of
a preferred embodiment according to the present invention;
FIG. 14 is an enlarged fragmentary section of an assembled switch
embodiment disclosed in FIG. 13;
FIG. 15 is an enlarged section taken along the line 15--15 of FIG.
14; and
FIG. 16 is an enlarged fragmentary section taken along line 16--16
of FIG. 14.
With more particular reference to the drawings there is illustrated
in FIG. 1 generally at 1 a switch according to the present
invention. As shown in FIGS. 1, 2, and 5 the switch is provided
with a base 2 of dielectric material having integral projecting
sidewall portions 4 and 6 giving the base a generally channel
shaped configuration extending in an elongated direction. The base
further includes a plurality of spaced partitions generally
bridging between the sidewall portions 4 and 6, with two of the
partitions being illustrated at 8 and 10 in FIGS. 4 and 5.
Accordingly the sidewalls and each pair of partitions of the base
cooperate to provide an interior compartment, an exemplary one of
which is illustrated at 12. Each of the compartments contains
therein a double-throw double-pole switch according to the present
invention, it being understood that either one or a plurality of
switches may be fabricated according to the present invention with
a corresponding one or a plurality of compartments being fabricated
on the base to correspond with the number of switches desired.
As more particularly shown in FIGS. 2 and 3, the outer surfaces of
sidewalls 4 and 6 are provided with a plurality of spaced generally
parallel grooves, one of which is shown at 14 in FIG. 3. Each of
the grooves receives therein a corresponding resilient metal spring
16, 16' or 16". Each of the springs 16, 16' or 16" is generally of
elongated metal strip form received internally of a corresponding
groove 14, as shown more particularly in FIG. 3. The grooves
accordingly space the springs 16, 16' and 16" in aligned spaced
relationship along the sidewalls 4 and 6 of the base. Each of the
springs has an end portion 18 protruding from the base 2 to form
depending electrically conducting leads or terminals for external
connection to a printed circuit board 20. The aligned springs 16,
16' and 16" thereby form electrical contacts with depending
terminals or electrical leads 18 which are also aligned along the
sidewalls 4 and 6 of the base. The spacings between the aligned
leads correspond with the spacings between apertures 22 of the
printed circuit board 20 into which the leads 18 are inserted. In
the usual manner, well-known in the prior art, the apertures 22 of
the printed circuit board 20 are lined with plating, with solder
filled into the plating lined apertures to form solder joints
between the plating lined apertures and the electrical leads 18.
The plating lined apertures then mechanically and electrically
support the leads or terminals 18. Customarily the printed circuit
board is provided with a plurality of circuit paths thereon, some
of which are illustrated at 24, which are joined electrically to
the solder joints to thereby connect the electrical leads or
terminals 18 with corresponding conductor paths on the printed
circuit board. As shown, each of the depending electrical leads or
terminals 18 may be formed with a flute 26 which performs the
functions of stiffening the leads 18, to resist bending and
misalignment, and providing a channel shaped groove on one side of
the lead, which allows solder to flow therealong and to be wicked
therealong in the well-known wicking behavior of molten solder, and
on the other side of the lead providing an outwardly bulged
configuration, to render an apparent increase in thickness of the
lead which substantially fills the clearance between the aperture
22 and the lead which is relatively thin in thickness except for
the outwardly bulged flute portion 26 thereof.
Again with reference to FIGS. 2 and 3, taken in conjunction with
FIGS. 4 and 5, the other end 28 of each spring or contact 16, 16'
and 16" is generally of inverted U-shape to provide a reversely
curved portion to overlie the corresponding sidewall 4 or 6 and to
project generally into the corresponding internal cavity 12 defined
between the sidewalls 4 and 6. Adjacent one of the terminal ends of
each spring or contact is provided a protruding arcuate button or
projection 30 to provide an arcuate electrical contact surface as
will be explained hereinafter. As shown in FIG. 2, the end portions
28 of the springs generally project into the cavity 12 and in
diagonal diverging relationship with the corresponding sidewalls 4
and 6. This permits the spring portions 28 to be resiliently
deflected in resilient spring fashion and in cantilever motion from
its diverging relationship toward the corresponding sidewalls 4 and
6 as will be explained hereinafter.
With more particular reference to FIGS. 2 - 5, there is illustrated
a carriage generally at 32. The carriage 32 is of dielectric
material and is generally of rectangular block configuration. Each
side of the block has a corresponding recess 34 or 36 on the
external surface thereof. Each side further is provided thereon
with a electrical conductor strip of resilient spring metal 38 or
40. The two conductor strips form spring contacts which are
provided at the ends thereof with corresponding generally laterally
formed U-shaped portions 38' and 40'. Each of the spring contacts
38 and 40 is assembled to a corresponding side of the block with
the ends 38' and 40' partially encircling the ends of the block as
shown in FIGS. 3 and 4. The U-shaped portions 38' and 40' thereby
resiliently grip onto the periphery of the carriage 32 by resilient
spring action. Since the contacts 38 and 40 are of resilient spring
material, no additional fasteners are required, the resilient
nature of the contacts thereby resiliently gripping on the outer
periphery of the carriage 32 without the need for additional
fasteners. As a further feature of the present invention, the
carriage 32 is provided with a generally central aperture 42
generally of rectangular configuration. Two of the opposed inner
sides of the carriage which define the aperture 42 are provided
with generally inverted grooves 44 and 46 each of which terminates
into a rounded arcuate end portion as more particularly shown in
FIGS. 2 - 4. The aperture 42 receives therethrough an elongated
lever generally illustrated at 48 fabricated of dielectric material
and having an enlarged central portion 50 which is generally
rectangular in cross section, with one end of the portion 50 being
generally rounded at 52. Adjacent to the rounded end 52 are
provided a pair of outwardly projecting arcuate dowel portions 54.
For example, the dowel portions 54 may be molded integrally with
the portion 50 of the lever, or, in the alternative, a single hole
may be drilled through the lever and provided with a single dowel
which projects on either side of the lever 50 to provide the
protruding dowel portions 54. The other end of the lever 48 is
provided with a generally cylindrical knob 56 having a groove 58 in
the circular or cylindrical periphery thereof.
As shown in the figures, the lever 48 is received freely through
the aperture 42 of the carriage 32, with the dowel portions 54 in
registration within corresponding rounded ends of the grooves 44
and 46. The lever 50 is thereby pivotally mounted to the carriage
32 without the need for additional fasteners or adhesives. The
dowel portions 54 are aligned with respect to each other and are
captured for rotation in the rounded ends of the grooves 44 and 46
to provide a pivotal connection between the carriage and lever. So
long as the dowel portions 54 remain in the corresponding grooves
44 and 46, the lever will be properly assembled to the
carriage.
As more particularly shown in FIGS. 2 and 4, the carriage together
with the lever assembled thereto as described is placed into a
corresponding cavity 12. As shown, each desired cavity 12 is
provided therein with three aligned contacts 16, 16' and 16" along
each of the sidewalls 4 and 6. In the position shown in FIG. 4 the
carriage 32 is disposed so that its conductor strip or contact 38
bridges between two selected contacts 16 and 16' on the wall 6, and
the conductor strip or contact 40 bridges between two selected
contacts 16 and 16' on the sidewall 4. As shown in FIG. 2, the
carriage 32 is wedged between the contacts 16 and 16', on the
sidewall 6, and the contacts 16 and 16', on the sidewall 4, thereby
resiliently deflecting the spring end portions 28 of the contacts
by cantilever deflection generally toward the corresponding
uprights 4 and 6. Such resilient deflection assures a pressure
engagement of the button portions 30 of the contacts against a
corresponding terminal strip or conductor strip 38 or 40 of the
carriage. To complete the assembly, a generally inverted box-like
cover generally illustrated at 60 is received over the base 2. The
cover has sidewalls 62 and 64 which are received over the
corresponding sidewalls 4 and 6 with the springs or contacts 16
being received between the cover and base thereby to retain the
contacts in place. The cover is generally made from a dielectric
material which has some inherent spring resiliency so that the
cover may be force-fitted over the base. The base and cover may
therefore be attached without the need for separate fasteners or
adhesives or the like. As shown, the lever 48 is received through
an aperture 66 provided in the cover. As shown more particularly in
FIGS. 2 and 5, the lever 48 is generally freely received through
the aperture 66. As shown in FIG. 2 the aperture 66 has a pair of
opposed sidewalls 68 and 70 which are outwardly flared at each of
their open ends in a slight hourglass configuration forming opposed
projecting portions 72 and 74 defining a slightly narrowed neck
receiving the portion 50 of the lever therethrough. By providing
the reduced necked portion, the possibility of frictional abrasion
of the lever against the sidewalls 68 and 70 is reduced to abrasion
only in the narrowed necked portion 72 and 74. As shown in FIG. 5,
the aperture 66 has a pair of opposed sidewalls 76 and 78 which are
outwardly flared at both the open ends of the aperture 66 to
provide a generally hourglass shape to the aperture. With the
carriage 32 in the position shown in FIGS. 4 and 5, the lever 48
projects through the aperture 66 at an incline. For example, the
sidewall 78, being outwardly flared at its ends, defines a
projecting corner edge 80 at the narrow neck intersection of the
flared ends. The edge 80 provides a cover portion serving as a
fulcrum against and over which the lever 48 is pivoted to slidably
displace the carriage 32 to a first position as shown in FIGS. 4
and 5. In such a position the lever 48 will be disposed at an angle
projecting through the aperture 66 as shown in FIGS. 4 and 5. The
carriage 32 will have its contact or conductor strip 38 engaged
electrically on corresponding buttons 30 of a selected two of the
contacts 16 and 16' which are adjacent to the sidewall 6.
Additionally the conductor strip or contact 40 of the carriage will
likewise electrically engage corresponding buttons 30 of a selected
two of the contacts 16 and 16' which are adjacent to the sidewall
4. Accordingly, the contacts 38 and 40 electrically bridge across
selected pairs of adjacent contacts 16 and 16' to complete a
corresponding electrical circuit therebetween. Thus with the
carriage 32 in the position shown in FIGS. 4 and 5, such a position
can be considered a "throw" of the switch and since two electrical
circuits are completed between selected pairs of contacts the
switch is considered the "double-throw" variety, with the contacts
16 and 16' serving as the electrical "poles" of the switch. The
carriage is also compressed between the opposed contacts 16 and
also the opposed contacts 16'. Although not shown, the lever 48 may
also be pivoted to a second position. More specifically, with
reference to FIG. 5, the lever 48, shown in its first position in
FIG. 5, may be pivoted against and over a projecting corner edge 81
at the intersection of the flared ends of the aperture sidewall 76
in the cover 60 so as to pivot the lever fully to a second position
wherein its elongate centerline lies along the axis indicated at
82. The edge 81 of the sidewall 76 thereby provides a cover portion
acting as a fulcrum over which the lever is pivoted to its second
position. With the lever in its second position, the carriage 32 is
slidably displaced from left to right in FIG. 5. The carriage 32 is
thereby displaced internally of the corresponding cavity 12 such
that it is interposed between the opposed contacts 16 and also
between the opposed contacts 16", at the same time being disengaged
from the opposed contacts 16'. Accordingly the respective
electrical circuits formed by bridging the conductor strips 38 and
40 between the respective adjacent electrical poles 16 and 16'
become interrupted, while at the same time the conductor strips 38
and 40 bridge between the corresponding adjacent pairs of
electrical contacts 16 and 16" to complete additional electrical
circuits between the bridged contacts 16 and 16". Thus the carriage
is in its second position has its contact or conductor strip 38
bridging between the poles 16 or 16" on the sidewall 6 to complete
a first electrical circuit, with the electrical conductor strip 40
bridging between the adjacent contacts 16 and 16" on the sidewall 4
to complete a second electrical circuit. Accordingly, the carriage
in its second position serves as the second "throw" for the switch
according to the present invention. Since two electrical circuits
are completed by the switch, the switch according to the present
invention operates as a double-throw double-pole variety, with the
contacts 16' serving as the electrical poles of the switch. It
should be noted that the conductor strips 38 and 40 engage
electrically on the arcuate buttons or projections 30 of the
contacts 16, 16' and 16". The buttons or projections are arcuate so
as to reduce the sliding friction of the conductor strips 38 and 40
thereover. Since sliding contact is made between the projections 30
and the conductor strips 38 and 40, such sliding action produces a
wiping action which scrub and clean the surfaces of the conductor
strips 38 and 40 and the projections 30 to improve the electrical
contact therebetween. Since the conductor strips 38 and 40 are
continuously maintained in compression between opposed pairs of the
contacts or poles 16, 16' and 16" a pressure contact between each
of the projections 30 and the corresponding conductor strips 38 and
40 is always assured. Additionally the conductor strip 38 and 40
are maintained in compression against the periphery of the carriage
32, further obviating the need for fasteners or adhesives
therefor.
According to a further feature of the present invention reference
will be made particularly to FIG. 5. As shown in the figure, the
rounded end portion 52 of the lever 48 is pivotally displaced
through an arc generally indicated at 84. The base 2 has an
interior bottomwall 86 over which the end portion 52 is pivotally
displaced. The bottomwall 86 has a projecting ridge 87 which
accordingly is provided with an arcuate recess 88 to provide a
clearance for the rounded end 52 as it is slidably displaced over
the bottomwall 86 of the base. The recess 88 further is provided
with an arcuate projection 90 generally centrally thereof. The
ridge 87 and projection 90 as shown is molded integral with the
bottomwall 86 of the base. The ridge 87 is received in an inverted
rectangular recess 89 of the carriage 32, enabling the carriage to
straddle the ridge 87 which serves as a sliding bearing surface to
guide the carriage along the ridge in slidable traverse within the
housing.
In addition, the cover 60 has a projecting inverted wall 91 which
is impressed over the carriage to provide a sliding bearing surface
against which the carriage slidably impinges when displaced
internally of the housing. The rounded end 52 is forced to engage
and slidably traverse over the arcuate projection 90 as the lever
48 is pivoted either to its first position shown in FIG. 5 or to
its second position whereby it lies along the centerline 82. In
order to pivot the lever 48 to either of its two positions as
described, an operator must apply a pivoting force to the knob 56
of the lever, thereby forcing the lever to pivot in the manner
described and to additionally forcibly traverse the rounded end 52
over the projection 90. Some resistance to pivotal motion will be
felt by the operator, which will be an indication that the switch
is operating properly. When the lever 48 is fully pivoted to either
of its two positions, the rounded end 52 thereof will become
disengaged from the projection 90, thereby giving an indication of
feel to the operator that the lever has clicked or suddenly sprung
free from its resistance, thereby indicating the lever is fully
pivoted to a corresponding one of its two positions. When the lever
is fully pivoted to either of its two positions the projection 90
thereby remains in the arcuate path of the rounded end 52 of the
lever, thereby resisting pivotal motion of the lever in the absence
of pivoting forces applied thereto. The projection 90 accordingly
serves as a latch to prevent unwarrented pivotal motion in the
absence of the applied pivoting forces, thereby further preventing
the carriage 32 to slidably displace and undesirably interrupt the
circuit paths in the absence of applied pivoting forces to the
lever 48.
As an additional feature of the present invention the lever is
provided thereover with a generally cup-shaped grommet or washer 92
having a central aperture 94 therethrough. The washer or grommet 92
registers within the groove 56 of the knob and engages continuously
on a generally arcuate projection 96 on the housing 60, thereby
covering the aperture 66 which receives the lever 48 therethrough,
so as to prevent contaminants from entering the corresponding
internal cavity 12. The switch assembly as described may be
duplicated to provide an array of switches of any desired number
within a single housing or DIP package.
The cover may be sealed to the base, for example, by applying a
band of adhesive on the outer periphery of the base, including the
sidewalls 4 and 6 and the endmost partitions, such as 8. Then when
the cover 60 is assembled over the base, the band of adhesive forms
a seal to prevent entry of contaminants into the housing.
The cover 60 is assembled over the sidewalls and partitions 8 of
the base such that the overlapping margins of the cover and base
provide a substantial surface area of contact therebetween. The
adjacent margins of the cover and base thereby form a relatively
long sealing path to prevent the flow of contaminants and liquid
solder into the switch interior, particularly when an adhesive is
applied between the margins and there is pressure between the
assembled cover and base margins.
With more particular reference to FIGS. 6 - 12, another preferred
embodiment according to the present invention will be described in
detail.
As shown in FIG. 6, there is illustrated at 98 another preferred
embodiment of the switch according to the present invention. Such
switch comprises an array of individual switches, the details of an
individual switch being further described hereafter as a preferred
embodiment.
The switch array 98 is mounted to a printed circuit board
illustrated at 100, with individual conductor paths 102 provided on
the printed circuit board in the usual fashion.
With reference to FIGS. 8 through 12, a preferred embodiment of an
individual switch will be described in detail. More particularly in
FIG. 9 there is illustrated a dielectric housing 104 generally of
channel shape having a pair of opposing elongated sidewalls 106 and
108 which are integral with end walls, one of which is shown at
110. The base 104 additionally is provided with a bottomwall 112
from which the walls 106, 108 and 110 project. The sidewalla 106
and 108 are provided with a series of channels or grooves 114
similar to the grooves 14 of the preferred embodiment described in
conjunction with FIGS. 1 - 5. Accordingly the grooves 114 are
parallel in nature and extend over the exterior surfaces of the
sidewalls 106 and 108 and receive therein corresponding resilient
metal springs 116, 116' or 116". Each of the springs has an end
portion 118 protruding from the base bottomwall 112 to form
depending electrically conducting leads or terminals for pluggable
external connection to a printed circuit board 100. The end
portions 118 thus provide electrical leads which are aligned along
the sidewalls 106 and 108. The spacings between the aligned leads
correspond with the spacings between apertures provided in the
printed circuit board 100 into which the leads 118 are inserted.
Such apertures are usually lined with plating to allow constructed
solder joints between the plating lined apertures and the leads
thereby mechanically and electrically supporting leads within the
apertures. Thus such solder joints may connect the leads
electrically to selected circuit paths 102 provided on the printed
circuit board 100. As in the prior embodiment the contact ends 118
may be provided thereon with longitudinal flutes 120 for the
purpose similar to the flutes 26 described in conjunction with the
prior disclosed embodiment. It is to be understood however that
such flutes are optional and may be eliminated in either of the
embodiments if desired.
The other end 122 of each spring or contact 116, 116' and 116" is
generally of inverted U-shape to provide a curved portion to
overlie the corresponding sidewall 106 or 108 and to project
generally into the corresponding internal cavity defined between
the sidewalls and the end walls 110. Each of the contact ends 122
are arcuate about an axis longitudinally of the contacts to provide
an arcuate electrical contact surface for a purpose to be explained
hereinafter. The end portions 122 of the springs generally project
into the internal cavity of the base 110 and in diagonal diverging
relationship with the corresponding sidewalls 106 and 108. This
permits the spring portions 122 to be resiliently deflected in
resilient cantilever spring motion from its diverging relationship
toward the corresponding sidewall for a purpose to be explained
hereinafter.
As shown more particularly in FIGS. 9 and 11, there is illustrated
a carriage generally at 124 fabricated from dielectric material and
generally of rectangular block configuration. Each side of the
block has a corresponding recess 126 or 128 on the external
surfaces thereof. Each side is further provided thereon with an
electrical conductor strip of resilient spring metal 130 or 132.
The two conductor strips form spring contacts or conducting contact
elements which are provided at the ends thereof with corresponding
laterally formed U-shaped portions 134 and 136. Each of the spring
contacts is assembled to the corresponding side of the block with
the ends 134 and 136 partially encircling the block as shown in
FIGS. 7, 9 and 10. Tabs 138 and 140 are provided respectively on
the contact portions 134 and 136. The tabs register in a pair of
recesses 142 provided in the block, thereby permitting the contacts
130 and 132 to partially encircle the block. In addition, each of
the contacts 130 and 132 are mounted upon laterally projecting
flanges 144 and 146 integral on the block and adjacent to the
bottom surface 148 of the block. As shown in FIGS. 8 and 12, the
carriage block 124 is mounted within the internal cavity of the
base 104 with the bottomwall 148 of the block in slidable
registration on the surface of the bottomwall 112 of the base. As
shown more particularly in FIGS. 7 - 12, the base bottomwall 112 is
provided thereon with an integral projecting ridge or rail 150
elongated in a direction generally extending between the end walls
110 of the base 104. As shown in FIG. 7, the projection 150 is
provided with an elongated recess 152. As shown the recess 152 is
also generally elongated along the length of the projection 150.
The recess is provided with generally arcuate end walls 154 with
opposed generally parallel sidewalls 156 connecting the end walls
154. The sidewalls 156 are provided with undulated surfaces created
by spaced arcuate projections 158 which project into the recess
152. The carriage or block 124 is provided with generally inverted
rectangular recess defined by planar bottomwall 160 and opposed
sidewalls 162. The opposed sidewalls 162 straddle the base
projection 150 to provide a sliding bearing surface for the
carriage 124 along the projection 150. In addition the bottomwall
160 of the block 124 slidably engages against the surface of the
block 150 also to provide a sliding bearing surface for slidable
actuation of the carriage along the projection 150. Centrally of
the block 124 is provided a resilient expansion element which is
bifurcated to form a pair of depending fingers 162 which project
into the recess 162 of the block. The fingers 162 are
advantageously molded integrally with the block 124 and are
provided with arcuate surfaces illustrated in FIG. 7 for
registration against the sidewalls 156 provided in the projection
150. The fingers 162 are resiliently deflectable toward and away
from each other, such that they are partially deflected toward each
other when in registration against the sidewalls 156. Upon slidable
displacement of the carriage 124 along the projection 150, the
resilient fingers 162 will resiliently spread apart and register in
the relatively wide spaces between the projections 158 so as to
latch or detent the carriage 124 in place at a desired position.
When it is desired to displace the carriage to another position,
the carriage is displaced along the projection 150 with the spring
fingers 162 being forced to resiliently deflect toward each other
as they are forcibly traversed and squeezed between opposed
projections 158 of the sidewalls 156. The arcuate surfaces of the
projections 158 and of the fingers 162 permit relative ease in
slidably displacing the fingers over the surfaces of the
projections without excessive friction or binding.
The block 124 is provided with a planar top surface 166 which
provides a sliding bearing surface for a purpose to be described.
The transverse slot 168 is provided in the surface 166 for a
purpose to be described hereinafter.
As shown with reference to FIGS. 8, 9 and 12, the switch further
includes a cam element in the form of a stepped cylindrical shaft
illustrated generally at 170. The cam element includes a central
enlarged cylindrical portion 172 coaxial with a reduced cylindrical
portion 174 with a stepped shoulder 176 provided at the
intersection of the coaxial cylindrical portions 172 and 174. The
cylindrical portion 174 is domed and provided with a transverse
groove 178. a resilient sealing ring 180 is received over the
cylindrical portion 174 in registration against the shoulder 176. A
short cylindrical stem or shaft 182 depends from a substantially
planar inverted bottom surface 184 of the cylindrical portion 172.
The bottom surface is rotatable over the top surface 166 of the
block 124, the surfaces 166 and 124 thus being bearing surfaces for
low frictional resistance to rotation of the cam element and
translation of the block 124. The shaft 182 is substantially offset
from the common cylindrical axis of the coaxial cylindrical
portions 172 and 174. The cam element 170 is assembled over the
block 124 with the shaft 182 being received internally of the
transverse groove 168. In addition the surface 184 of the cam
element is a bearing surface in registration on the planar surface
166 of the carriage 124, also a bearing surface, such that the cam
element may be slidably displaced over the surface 166 in a manner
to be described.
To complete the switch, a cover portion 186 of dielectric material
is in the form of an inverted container having sidewalls 188 and
endwalls 190 which are received over the base member 104. More
particularly, the sidewalls 188 are received overlapped against the
corresponding sidewalls 106 and 108 of the base 104. Each of the
end walls 190 of the cover are received overlapped against at least
one of the endwalls 110 of the base 104. As shown in FIG. 8, the
contacts 116, 116' and 116" are received in compression between the
sidewalls 188 of the cover and the corresponding sidewalls 106 and
108, thereby rigidly retaining the contacts in desired parallel
alignment. In addition, the cover 186 has a bottomwall 192 which
impinges against the top surfaces of the sidewalls 106 and 108, the
top surfaces of the end walls 110 and against the inverted U-shaped
portions of the contacts 116, 116' and 116". Accordingly, the cover
and base with their abutting margins overlap over relatively large
surface areas which, when tightly compressed together prevent the
passage of contaminants and flow of molten solder into the interior
of the base 104. If desired an adhesive may be coated between the
abutting surfaces of the cover and base further serving to seal the
margins thereof against the flow of contaminants. In addition, the
relatively large surface areas of contact between the base and
cover serve also to prevent the flow of adhesive into the interior
of the switch merely by limiting the application of adhesives to
but a small area portion of the abutting surfaces.
As shown in FIGS. 8 and 12, the cover is provided with a thickened
portion 194 which projects from the surface 192. The thickened
portion 194 is provided with a stepped interior bore 196 which
provides cylindrical bearing surfaces rotatably receiving the cam
element 170. The seal 180 is retained in compression between the
cam element and the cover 186 to prevent contaminants from entering
the switch through the stepped bore 196. The housing further is
provided with a domed lip 198 which overlaps and encircles the
periphery of the reduced cylindrical portion 174 to enclose the
surfaces of the cam element 170 further, and thus provide a
relatively long path further sealing the flow of contaminants into
the switch. The thickened portion 194 has an inverted planar
bearing surface 200 which slidably abuts against the bearing
surface 166 of the carriage.
In operation, a suitable tool such as a screw driver is inserted
into the groove 178 of the cam element 170 to rotate the stepped
cylindrical cam element either clockwise or counter-clockwise. The
offset shaft 182 will then be displaced through an arc illustrated
in FIG. 10 at 202. Since the shaft 182 is received in the slot 168,
the arcuate displacement of the shaft 182 will force the carriage
to translate back and forth by slidable displacement along the
elongated projection 150, with the bearing surfaces 184 and 166
allowing such displacement without undue frictional resistance. The
shaft 182 will freely translate back and forth in the slot 168,
whereas the carriage will be restricted from translation in a
direction transverse to the elongated projection 150, since the
carriage straddles the projection. An advantage resides in the cam
element being fully capable of 360.degree. rotation without
providing positive stops which might be broken or defeated by
excessive force actuating the switch cam. The cam element can never
be broken during actuation thereof. Accordingly, the slidable
traverse of the carriage as described will connect the conducting
elements 130 and 132 with desired contacts 116, 116' or 116" to
provide a double-throw, double-pole switch, with such contacts
operating as the poles of such a switch. When the carriage is
received between opposed contacts, the contacts will be resiliently
deflected toward the corresponding sidewalls 106 and 108 to insure
pressure applied between the contacts and the contact elements 130
and 132 provided on the carriage 124. The arcuate shape of the
contacts 116, 116', and 116" provide dome shapes over which the
corresponding contact elements 130 and 132 slidably impinge without
undue frictional resistance.
Thus the carriage is slidably traversed, yet retained in desired
position by the abutting bearing surfaces on the component parts of
the switch. By selecting the component parts from a dielectric
material having low surface friction properties, the component
parts may be assembled and retained with their surfaces in opposed
abutment with one another while their abutting surfaces provide
sliding bearing surfaces enabling the carriage to slidably traverse
over the abutting surfaces thereof without producing frictional
resistance. In addition, a need for separate fasteners or adhesives
is eliminated to assure ease in manufacture and assembly of the
component parts. The dielectric parts can be readily molded such
that all the appendages, bearing surfaces and recesses on the
various parts may be provided quickly in molding operations without
a need for separate machining or fabrication by assembly.
FIGS. 13-16 illustrate a modification of the preferred embodiment
illustrated in FIGS. 6-12. With reference to FIG. 13, the modified
embodiment includes a dielectric base or housing 104" similar to
the housing 104. The housing 104' includes side walls 106 and 108
and end walls 110. As shown in FIG. 14, grooves 114 are provided in
the end walls 106 and 108 to receive contact 116, 116' and 116" in
similar fashion as the previously disclosed embodiment.
As shown in FIGS. 13 and 15, the base or housing 104' includes a
bottom wall 112' similar to the previous housing 104. However, the
bottom wall 112' differs in that it includes a pair of elongated
projecting rails 201 which define therebetween a groove or track
203. For example the rails 201 may be molded integral with the
bottom wall 112. The modification further includes a carriage 124'
which is similar to the carriage 124 in that it includes the
elongated slot 168' similar to the slot 168 of the previous
embodiment. Certain portions of the carriage 124' are illustrated
in phantom outline for clarity. The carriage 124' includes a pair
of projecting and depending feet portions 204 which project
outwardly of the carriage 124 in an outrigger arrangement. As shown
more particularly in FIG. 15, the carriage 124' carries a pair of
contacts 132' and 130' which are similar to the contacts 130 and
132. The projecting feet 204 are in sliding registration within the
track 203. The rails 201 defining the track are received within an
inverted recess 162' of the carriage 124'. The carriage 124' is
thus slidably received along the track 203. The outrigger
configuration of the feet portions 204 and the relatively arcuate
peripheries thereof provide relative ease in sliding between the
rails.
As shown more particularly in FIGS. 13, 14, and 16, the modified
embodiment of FIGS. 13-16 further includes a cam element 170'
similar to the cam element 170. A central cylindrical enlarged
portion 172' of the cam element is similar to the central enlarged
portion 172 except that it is partially hollowed out at 206 to
provide the cylindrical periphery of the central enlarged portion
172' with a relatively thin web segment 208. As shown in the
figures the web portion 208 is defined between a pair of kerfs
which make the web portion resiliently deflectable in and out of
the cylindrical periphery. The web portion 208 is further provided
with an integral arcuate surfaced projection 210 for a purpose to
be described. The cam element further includes a depending offset
shaft 182' similar to the shaft 182 for registration within the
slot 168'. As in the embodiment before, when the cam element 170 is
turned, the shaft 182' is forcibly disposed through an arc which
creates the desired reciprocation of the carriage 124' along the
rails 201, switching the contact elements 130' and 132' between the
contacts 116, 116' and 116" which are mounted in the grooves 114'.
Rotation of the cam element is accomplished for example by
insertion of a coin or screwdriver into the transverse slot 178'
provided in the reduced cylindrical portion 174'. In addition, the
reduced cylindrical portion 174' is provided with a recess 212
which is pointer shaped to indicate the position of the offset
shaft 182'.
As shown more particularly in FIGS. 14 and 16, the cover portion
104' is provided with a relatively thickened portion 194' similar
to the corresponding thickened portion 194. The thickened portion
194' is provided with a cylindrical recess therein for receiving
the enlarged cylindrical portion 172' of the cam element. In
addition the thickened portion 194 is provided with a plurality of
recesses or detents 214 spaced about the cylindrical recessed
portion which receives the cam element. When the cam element is
rotated, the projecting portion 210 is rotated into registration in
turn within each of the detents 214. Since the flap 208 is
resilient, the projection 210 will provide a snap action when
brought into registration within a detent to provide a tactile feel
for indicating to an operator of the cam element the position of
the carriage during a switching function.
What has been described is a preferred embodiment of the present
invention. It is to be understood that other embodiments and
modifications of the present invention will become apparent to one
having ordinary skill in the art as defined within the spirit and
scope of the appended claims wherein:
* * * * *