Note: Descriptions are shown in the official language in which they were submitted.
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ELECTRICAL ROCKER SWITCH
BACKGROUND OF THE INVENTION
Field of the Invention
The invention is directed to electrical toggle rocker-type switches and more
particularly to a simple switch which employs a unitary operating assembly to
establish
the two rest positions of the rocker, to insure intimate contact between the
assembly and
the rocker and to bear and position one or more movable contacts with respect
to one or
more fixed contacts.
Description of the Prior Art
In general, toggle action switches require a number of discrete components
in order to function. They generally have the toggle, either lever or rocker,
a spring to
hold the toggle in each of its two rest positions, one or more fixed contacts
supported in
the housing of the switch, and a device responsive to the movement of the
toggle for
moving the moving contacts into contact with the fixed contacts. Each of these
separate
elements must be properly positioned and moved to make and break the related
electrical
circuits.
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The patent to Hafemeister, U.S. Patent No. 1,782,780 issued November 19,
1924 shows a toggle switch employing a finger piece 15 in which are embedded
two
straps 16. A coiled compression spring 31 is placed on a guide rod 32 anchored
at one
end by a collar 19 and at its other by notch 25 in body portion 21. Movable
arms with
movable contacts are made to bridge fixed contacts 42 to close a circuit as in
Fig. 1 or
moved to open the circuit as shown by Fig. 2. Ears 13 are the stops for body
portion 21.
Russell et al, U.S. Patent No. 2,570,281 issued October 9, 1951 uses a
molded handle with a depending post to compress a helical spring 22 carried by
a yoke
15. Fixed contacts 32, 34 are bridged by a movable contact in the form of a
rod carried
by yoke 15. The final position of handle 20 depends upon the fixed stops 24,
25.
In U.S. Patent No. 2, 899,513 issued August 11, 1959 to Schmidt, an
operating lever 34 is held in positioned by a compressed coil spring 47 held
between cap
46 and a tongue 33a on a separate contact plate 33. Contacts are carried by
the lever 34
and enclosure (contacts 26, 28, 56; 58) and circuits are completed between
these contacts
under control of lever 34 and contact plate 33.
Lamaudiere, U.S. Patent No. 2,939,926 issued June 7, 1960 employs a
control knob 13, in which is mounted a compression spring 15, which controls
the
position of a rocker 21 which carries movable contact piece 24 to contact
fixed contacts
25, 26. All of the elements are discrete.
Schleicher, U.S. Patent No. 3,172,972, issued March 9, 1965 shows a
switch with a lever 20 which has a spring-operating finger 26 which compresses
a coiled
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compression spring 28 seated on spring-holding stud 29 molded to the bottom of
base 10.
Movable contact operating cams 24 operate movable contact arm 17 to move
contact 17C
away from fixed contact 18C or allow contact with it.
In U.S. Patent No. 3,300,605 issued January 24, 1967 to Ramsing et al,
lever 18 is pivoted to the housing and carries a projection 21 having a lever
recess 33.
Movable contacts 35, 36 are carried on movable conductive arm 34 to engage
fixed
contacts 37 or 38. The blade 31 and spring 25, 30 are required to operate arm
34 and fix
the position of lever 18 as well as control the circuits connected.
Schleicher, U.S. Patent No. 3,354,275 issued November 21, 1967 shows a
lever operated switch employing a leaf spring 59 and roller 61 to control the
position of
operating lever member 11. Caroming lugs 84 and 85 are provided to separate
movable
contact 28 from fixed contact 27 against the spring action of the movable
contact while
movable contact 44 remains in contact with fixed contact 48 in one position
and vice-
versa in the other. Thus contacts 28 and 44 have to provide their own springs
in addition
to spring 59 for lever 11.
U.S. Patent No. 3,532,846 issued October 6, 1970 to Schumacher shows a
lever operated switch with a coil spring 112 to control the position of
trigger 110. A
spring arm 82 supports movable contact 84 and attempts to move such contact
into
contact with fixed contact 62 depending upon the position of trigger cams 114
on trigger
110.
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Poliak, U.S. Patent No. 3,770,920 shows a switch with a rocker 24
employing a coil spring 65 to urge the trunnions 56 into pivotal engagement
with notches
57 on cover 25 and to urge the trunnions 51 of the movable contact ann 40 into
the
notches 50 on common contact 41. Spring 65 also urges rocker 24 towards it
rest
positions so that split cams 66 can urge the lower end of the movable arm 40
into
engagement with fixed contacts 3 8.
SUMMARY OF THE INVENTION
The instant invention overcomes the complex manufacturing and assembly
of many small parts to provide a simple, easily manufactured and assembled
rocker type
switch which can be used as a single pole, single throw or single pole, double
throw
switch. A single, unitary operating assembly provides all of the necessary
switch
operating functions previously provided by a number of separate assemblies.
The unitary
operating assembly provides a spring function to seat the fulcrum of the
rocker member
against the housing pivot point and provide over center rest positions for the
rocker
member. The unitary operating assembly carries the movable switch contacts and
is
directly connected to one line of the circuit to be closed. It is an object of
the instant
invention to provide a simple, easily manufactured and assembled switch.
It is an object of the instant invention to provide a simple, easily
manufactured and assembled switch which employs a unitary operating assembly.
It is another object of the invention to provide a unitary operating assembly
which includes the mounting of the rocker member, the establishment of rocker
rest
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positions, mechanical and electrical contact between movable and fixed
contacts and
direct electrical contact with the movable contacts.
Other objects and features of the invention will be pointed out in the
following description and claims and illustrated in the accompanying drawings,
which
disclose, by way of example, the principles of the invention, and the best
mode which is
presently contemplated for carrying them out.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings in which similar elements are given similar reference
characters:
FIG. 1 is a side elevational view of a switch and environmental enclosure
constructed in accordance with the concepts of the invention.
FIG. 2 is a side elevational view, partly in section, of the switch of FIG. 1
taken along the lines 2-2 with conductors added.
FIG. 3 is an exploded front, right perspective view of the switch of FIG. 2
with the outer environmental shell removed to better display the switch
components.
FIG. 3A is an enlarged, exploded, fragmentary view of a terminal pocket
and a terminal support plate of the switch of FIG. 3.
FIG. 4 is an enlarged front, left perspective view of the unitary operating
assembly of FIG. 3.
FIG. 5 is right, front perspective view of the rocker of FIG. 1.
FIG. 6 is a right, rear perspective view of the rocker of FIG. 1.
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FIG. 7 is a fragmentary, side elevational view, of the switch of FIG. 2
arranged as a single pole, double throw switch.
FIG. 8 is an exploded front, right perspective view of a modification of the
switch of FIG. 3.
FIG. 9 is an enlarged front, left perspective view of the unitary operating
assembly of FIG. 8.
FIG. 10 is a side elevational view, partly in section, of the assembled
switch of FIG. 8, arranged as a single pole, single throw switch.
FIG. 11 is a side elevational view, partly in section, of the assembled
switch of FIG. 8, arranged as a single pole, double throw switch.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIGS. 1 to 6 there is shown a rocker switch 30 of which
only a portion of the rocker 32 is shown above an environmental enclosure 10
in which
rocker switch 30 may be placed. A moisture and foreign matter seal 12 allows
electrical
conductors 14, 18 and 22 to enter and exit the enclosure 10 without permitting
foreign
matter or moisture to enter.
Rocker switch 30 is made up of two mirror image housing portions or side
walls 34, 36 (see FIG. 3). For ease in describing the housing, the description
will
generally be directed to housing portion or side wall 34. A pin 40 of a
generally diamond
shape projects from a circular boss 38. A socket 44, having a circular cross-
section of a
diameter slightly less than the width of pin 40 across its face between two
opposite
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apexes is placed in a second boss 42. To assemble housing portions 34, 36, the
pin 40 of
portion 34 is inserted in socket 44 of portion 36. In a similar fashion, pin
40 of portion
36 is inserted into socket 44 of portion 34 and the portions 34, 36 are
pressed towards
one another so that the apexes bite into the material of bosses 42 and hold
portions 34, 36
in assembly. Serrations can be added at the apexes or along the faces of pins
40 to
improve its grip. The portions 34, 36 can be pried apart if necessary.
A triangular opening 46 having an upwardly facing pivot point 48 and a flat
base 50 is placed in each of the side walls 34, 36. Placed in each of the
triangular
openings 46 is one of the triangular trunnions 52 of rocker 32. Each of the
triangular
tru.nnions 52 has knife edge 54 which engages the pivot point 48 of opening 46
to permit
the rocker 32 to rotate about knife edge 54. The base 56 of each of the
trunnions 52 is
arcuate and the trunnion has an altitude less than that of the opening 46 so
that the
tmnnions 52 can pivot about pivot point 48 without base 56 engaging aperture
base 50.
Trunnion side surfaces 58, 60 have clearances with respect to triangular
opening 46 side
surfaces 62, 64, respectively. The rotation of the tiunnions 52 with respect
to side walls
34, 36 is limited by engagement of fixed contact 78 and movable contact 170 or
rocker
notch 500 against bosses 38 and 42 in the case of a single pole switch.
The top surface 80 of rocker 32 is generally concave with the low point in
the center above the knife edges 54 of the tru.nnions 52. One of the free
ends, 82, 84 of
rocker 32 will extend above the housing 10 depending upon the state of switch
30. The
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end 82, 84 extending above housing 10 will be depressed to change the state of
switch
30.
A raised, molded terminal pocket 70, 70a is formed to each side of the
vertical center line of the side walls 34, 36. The terminal pockets 70 and 70a
each have a
slot 72 into which is placed a terminal support plate 76 (see FIG. 3A)which
supports
fixed contact 78 thereon. Support plate 76 has a tab 81 of lesser width to act
as a welding
tab to permit the bared end 16, 24 of electrical conductors 14 and 22 to be
welded
thereto. A fixed contact 78 is mounted upon terminal support plate 76 by means
of an
aperture as shown in FIG. 2 or it may be welded, braised or otherwise attached
to plate
76. A slot 66 permits the conductors 14 and 22 to exit the rocker switch 30
and provides
strain-relief for such conductors.
The arrangement in FIG. 2 is for a single pole, single throw switch. A
single pole, double throw switch 131 can be realized as shown in FIG. 7 by
adding a
fiurther support plate 76 to the pocket 70a to the right of the vertical
center line, and by
adding a fixed contact to such plate 76 and welding the bared end of a
conductor to it.
As will be described below a second movable contact will also be required so
that a
circuit can be completed.
Returning to FIG. 3, a shelf 85 extends perpendicularly from the bottom
edge of side wall 34 in the same direction as bosses 38, 42. The shelf 85 is
slotted as at
86 at its mid-point. A projection 88 in the form of a half cylinder is
positioned on the top
surface 90 of shelf 85 midway between the shelf free end 92 and slot 86. A
projection 94
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extends over shelf 85 top surface 90 adjacent free end 92 and is separated
from shelf 85
top surface 90 by a slot 96. It should be appreciated that side wall 36 will
have a similar
structure on the left interior side opposite flat portion of shelf 85 between
slot 86 and free
end 98.
Above the shelf 85 is a support member 106 in the shape of a truncated
triangle with a slot 112 extending from the flat top 108 thereof towards but
short of the
base 110.
Extending below the rocker 32 from the inside surface 87 at the midpoint is
toggle element 100 which has a reinforcement rib 102 to each side (only one is
visible in
FIG. 6) and a vee notch 104 at its free end.
Referring now to FIGS. 2,3 and 4 the details of the three legged operating
assembly 120 can be appreciated. The entire operating assembly 120 is
fabricated from a
single blank of spring material such as a berylium-copper alloy or the like.
The central
body portion 122 has a generally T-shape with a cross-member 124 and an
extending
member 126. Spring arms 128, 130 are formed from the member 126 making the
remaining member 132 narrower than cross-member 124. Member 132 is bent at a
right
angle to central body portion 122 to provide a welding tab 134 to which the
bared end 20
of insulated conductor 18 may be welded as shown in FIG. 2. The width of cross-
member 124 is such that it bridges the space between housing portion 34, 36.
Edge 136
of cross-member 124 enters slot 112 of support member 106 on housing portion
34 and
edge 138 enters a similar slot 112 on the inside wall of housing portion 36
(not shown).
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Spring arms 128, 130 bend away from the plane of central body portion 122 at
an acute
angle of about 80 degrees. Spring arm 130 is positioned on shelf 85 of housing
portion
134 so that its free end 131 enters the slot 96 between top surface 90 of
shelf 85 and the
bottom surface of projection 94, and the main body of spring arm 130 rests
upon
projection 88. In a similar manner spring arm 128 is positioned on shelf 85
top surface
90 with its free end 129 in slot 96 and the main body portion resting upon
projection 88
of housing portion 36. The effect of the two spring arms 128, 130 is to resist
any
downward forces upon the operating assembly 120 applied by toggle element 100
and
apply an upward bias to such toggle element 100.
If it is desired to provide a higher spring force to the rocker 32, a modified
two legged operating assembly 120' as shown in FIGS. 8 to 11 may be employed.
The
extending member 126' of central body portion 122' has a width slightly less
than the
width of cross-member 124 and is bisected to form two spring arms 128' and
130'. The
two spring arms 128' and 130' are bent away from the plane of central body
portion 122'
at an acute angle of about 80 degrees and are far longer than the spring azms
128 and
130. The spring arm 130' is positioned on shelf 85 of housing portion 34 so
that its free
end 131' enters the slot 96 between top surface 90 of shelf 85 and the bottom
surface of
projection 94, and the main body of spring arm 130' rests upon the edge 91 of
top surface
90. The projections 94 provide strain relief for the spring arms 130' and
128'. In a
similar manner spring arm 128' is positioned on shelf 85 top surface 90 with
its free end
129' in slot 96 and the main body portion resting upon the edge 91 of top
surface 90. The
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width of the spring arms 128', 130' are significantly greater than the width
of the
respective spring arms 128 and 130 and consequently provide greater spring
forces to
control the position of the rocker 32 and the movable contacts 160, 170. In
the absence
of the downwardly and longitudinal extending members, as 132; 134 in FIG. 4,
the bared
end 20 of the insulated conductor 18 can be attached to either the end 129' or
131',
respectively, of the spring arms 128' and 130'. If desired the spring arms
128' and 130'
can be made longer and the conductor end 20 attached to such extensions beyond
the
projections 94, and these extensions could also be made at some angle to each
of the
spring arms 128' and 130'.
With the member 134 eliminated the central slot 86 can be eliminated from
shelf 85 making for a stronger shelf 85 to support spring arms 128' and 130'
(see FIGS. 8,
and 11). Also, the projections 88 can be omitted because the length of spring
arms
128',130' as extended beyond the edges 91 of shelf 85 give greater spring
resilience.
Cross-member 124 has a slot 140 extending through much of its width but
short of edges 136, 138. Extending from edge 142 upwardly is the contact
portion of
operating assembly 120. A contact central portion 150 extends to a flat edge
152 which
will be positioned within vee notch 104 of toggle element 100 to transmit
forces to the
operating assembly 120 from the toggle element 100 and from the operating
assembly
120 to the toggle element 100.
Extending from one edge of contact central portion 150 is an arm 154 the
end of which is bent at approximately 35° to the plane of central
portion 150 to form
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contact support tab 156 in which is placed on aperture 158 to receive contact
160 which
may be of copper, a copper alloy or silver. Extending from the opposite edge
of contact
central portion 150 is a second arm 164, the end of which is bent at
approximately 35° to
the plane of central portion 150 to form a second contact support tab 166 in
which is
placed an aperture 168 to receive a second contact 170 as shown in FIG. 7. The
entire
contact central portion 150 pivots about pivot axis 172 through cross-member
124 above
slot 140 (see FIG. 4). In so doing the contact central portion 150 above pivot
axis 172
operates as an over center toggle spring. Thus as long as right end 84 of the
rocker 32
remains as shown in FIG. 2 or providing left end 82 is not pushed down to move
central
portion 150 beyond the central vertical axis of switch 30 the central portion
150 is stable
and will remain in or return to the position as shown. If, however, the left
side 82 of
rocker 32 is depressed to move the central portion 150 beyond the central
vertical axis,
the central portion 150 will continue to move to the right of FIG. 2 until it
reaches a
stable point where it will remain until the right side 84 of rocker 32 is
depressed to return
the central portion 150 to the position shown in FIG. 2.
Assuming rocker 32 is in the position shown in FIG. 2, movable contact
160 is in contact with fixed contact 78 and a circuit is completed from
conductor 14 to
conductor 18. Pushing on the left side 82 of rocker 32 causes rocker 32 to
pivot counter-
clockwise with respect to housing portions 34, 36. Knife edges 54 of the
intnnions 52
pivot about the pivot points 48 of the triangular openings 46. Contact between
knife
edges 54 and pivot points 48 are assured by the upward bias of operating
assembly 120.
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Unless stopped sooner, downward movement of left end 82 of rocker 32 will end
when
notch 502 engages 38, 42. Toggle element 100 will move central portion 150 of
operating assembly 120 beyond the central vertical axis to the right in FIG.
2. This will
cause central portion 150 to pivot about axis 172 separating movable contact
160 from
fixed contact 78. It will cause tab 166 to move close to pocket 70a but will
make no
electrical contact because no movable contact is located on tab 166 and no
fixed contact
with conductor attached is found in pocket 70a. The switch 30 is thus
considered a single
pole, single throw switch having an on and an off position. The position when
movable
contact 160 does not engage fixed contact 78 is considered the "ofP' position
while
contact between them is the "on" position.
FIG. 7 shows an arrangement similar to FIG. 2 but with a contact 83 on
support plate 76 in pocket 70a coupled to the bared end 24 of conductor 22. A
movable
contact 170 is attached to tab 166. By this arrangement circuits can be
completed
between conductor 18 and conductor 14 or conductor 22. This arrangement is
termed a
single pole, double throw switch and there is no off position.
While there have been shown and described and pointed out the
fundamental novel features of the invention as applied to the preferred
embodiment, it
will be understood that various omissions and substitutions and changes of the
form and
details of the device illustrated and in its operation may be made by those
skilled in the
art, without departing from the spirit of the invention.
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