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Description  |
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FIELD OF THE INVENTION
The present invention relates to push button electrical switches and in
particular to a switch having an expanding helical rachet which exhibits a
quiet, smooth, "tease free" operating characteristic.
BACKGROUND OF THE INVENTION
Push button switches are well known in the art and numerous examples
thereof may be found in commerce. Typically, a push button switch is
adapted to sequentially open and close an electrical circuit or to
sequentially switch a common lead between two or more alternate circuits
upon depression and release of its plunger.
A perceived problem with many types of push button switches is an
instability caused when the plunger is partially actuated. If in the
closed state, a less than full depression of the plunger may cause the
switch to momentarily open. Upon release of the plunger, the switch
returns to its original closed state. This problem is often found in
automotive applications, where push button switches are mounted in
cosmetic housings having an actuating button. During assembly, tolerance
stacking of the mounting components may cause the housing button to hold
the switch plunger in a partially actuated position. External vibration
may then cause the switch to intermittently open when it is in the closed
state. This problem has been overcome by ratchet tease free push button
switches, such as taught by U.S. Pat. No. 5,226,529.
Another perceived problem with many push button switches, including ratchet
tease free switches, is the snapping action of the switch as it changes
from one state to another. This results in a popping sound, which may be
amplified when the switch is mounted in an enclosed housing. In many
applications a quiet, smooth actuation is preferred. Heart and bail push
button switches provide the desired quiet and smooth actuation but, but
are not known to be tease free.
There is, therefore, a need for a quiet, smooth acting, tease free push
button switch.
SUMMARY OF THE INVENTION
According to the present switch invention, the foregoing and other desired
characteristics and advantages are achieved. In its presently preferred
embodiment, the switch includes a body having a barrel portion and a
cover. The cover has an axial post extending away from the cover into the
barrel. Two terminals are mounted in the cover, connectable to an external
electrical circuit. A contact cup is rotatibly mounted on the axial post,
its open end having one or more tabs extending radially outward from its
circumference. The tabs interruptably communicate with both the terminals,
alternately completing and interrupting a circuit between them. A ratchet,
actuator, plunger and spring are also mounted within the housing. The
rachet is engaged with the contact cup and includes a plurality of
radially expanding helical camming surfaces. The actuator may be a pawl,
bail or a resilient portion of the plunger. The actuator has at least one
hook for engaging a camming surface of the ratchet and rotating the rachet
and the cup. A portion of the plunger projects through the barrel portion
and is used to drive the actuator. The spring applies a biasing force
which urges the plunger outward from the housing and the contact cup tabs
into communication with the terminals.
Other features and advantages of the present invention will become readily
apparent to those skilled in this art from the following detailed
description; wherein this and other presently preferred embodiments of the
invention are shown and described simply by way of illustration of the
best mode contemplated of carrying out the invention. As will be realized,
the invention is capable of other and different embodiments, and its
several details are capable of modifications in various obvious respects,
all without departing from the invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature and not as
restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of this invention are more fully set forth in
the following description of the presently preferred embodiments. The
description is presented with reference to the accompanying drawings in
which:
FIG. 1 is a perspective view of a presently preferred embodiment of the
invention;
FIG. 2 is an exploded, perspective view of the switch of FIG. 1;
FIG. 3 is a perspective view of a body portion of the switch shown in FIGS.
1 and 2;
FIG. 4 is a perspective view of a plunger adapted for movement within the
body portion of the switch shown in FIGS. 2 and 3;
FIGS. 5-7 are bottom, perspective and top views, respectively, of a rachet
adapted for insertion within the plunger shown in FIGS. 2 and 4;
FIGS. 8 and 9 are side and top views of a contact cup adapted for insertion
into the rachet shown in FIGS. 2 and 6;
FIG. 10 is a top plan view of the cover portion of the switch shown in
FIGS. 1 and 2;
FIG. 11 is a sectional view of the switch shown in FIG. 1 taken along line
11--11, with the plunger shown fully depressed;
FIG. 12 is the sectional view of the switch shown in FIG. 11, with the
plunger in the fully extended position;
FIG. 13 is a top plan view of the cover portion of another embodiment of
the present invention;
FIG. 14 is a sectional view of another embodiment of the present invention
taken along line 11--11 of FIG. 1, with the plunger shown fully depressed;
FIG. 15 is a sectional view of the switch shown in FIG. 14, with the
plunger in the fully extended position;
FIGS. 16 and 17 are a perspective and bottom view of an actuator plunger
adapted for use with the switch of FIG. 1;
FIG. 18 is a top plan view of the cover portion of another embodiment of
the present invention; and
FIG. 19 is a sectional view of another embodiment of the present invention
taken along line 11--11 of FIG. 1, with the plunger shown in the fully
extended position.
FIG. 20 is a sectional view of another embodiment of the present invention
taken along line 11--11 of FIG. 1, with the plunger shown in the fully
extended position.
DETAILED DESCRIPTION
The present invention provides a push button switch in which a ratchet and
actuating mechanism is utilized to change the state of the switch. In
operation the actuator, such as a pawl, engages a camming surface of the
ratchet thereby translating a linear motion of the pawl to a rotary motion
of the ratchet; the linear motion of the pawl being provided by the
operator of the switch and the rotary motion of the ratchet being utilized
to make and break electrical connections between terminals within the
switch.
Referring to FIGS. 1 and 2, there are shown perspective and exploded views
of a preferred embodiment of the present invention. This embodiment
includes separable housing portions comprising a cover 2 and a body 4.
Within the body 4, a plunger 6, a pawl 8, a helical spring 10, a rachet 12
comprised of one moving element and a contact 14 are disposed. The cover
2, body 4, plunger 6 and pawl 8 may be made of any of several plastic
materials with nylon or acetal being presently preferred. The spring 10
may be made of stainless steel or carbon steel with a corrosion resistant
coating such as zinc or tin.
Referring to FIGS. 2 and 3, the body 4 has a planar portion 16 and a barrel
portion 18. The barrel 18 is generally cylindrical in shape, open at both
ends and may optionally have threads 20 on its exterior surface. A
plurality of ribs 22 are disposed longitudinally on the interior surface
of the barrel 18. Four equally spaced ribs 22 are preferred in this
embodiment, but more or less may be utilized.
The planar portion 16 is provided with a mating surface 24. A plurality of
spaced pin members 26 extend perpendicularly away from the mating surface
24, with eight pin members 26 being presently preferred. The pin members
26 are generally disposed over the mating surface 24 and are engagable
with recesses 28 correspondingly located in a conforming surface 30 of the
cover 2, as described below.
Referring to FIG. 4, the plunger 6 is generally cylindrical in form and has
two portions; a relatively smaller diameter closed ended portion 32 and a
relatively larger diameter open ended portion 34. A shoulder 36 is formed
by the junction of the closed ended and open ended portions 32 and 34,
respectively. The plunger 6 is adapted for axial sliding movement within
the barrel 18.
The exterior surface of the closed ended portion 32 has a plurality of
grooves 38 disposed longitudinally along a portion of its exterior surface
adapted in number and form for engagement with the ribs 22. The engagement
of the ribs 22 and grooves 38 prevents rotational movement of the plunger
6 within the barrel 18 and limits the extension of the closed end portion
32 out of the barrel 18. When plunger 6 is fully inserted into the barrel
18, the closed ended portion 32 projects sufficiently out of the barrel 18
to provide an actuating button for operation of the switch.
The open ended portion 34 contains a longitudinal wall slot 40 extending
through its sidewall from adjacent to the shoulder 36 to its open end.
Wall slot 40 prevents the pawl 8 from rotating during operation of the
switch, as described below.
Referring to FIGS. 5-7, the ratchet 12 has a generally frustum shaped body
with its exterior formed into a plurality of surfaces and its interior
formed into two nonconnecting cylindrical surfaces. The first cylindrical
interior surface 42 extends axially from near the center of the ratchet 12
through a relatively smaller diameter end portion 44. The second
cylindrical interior surface 46 extends axially from near the interior end
of the first cylindrical interior surface 42 through a relatively larger
diameter end portion 48. The end portions 44 and 48 are approximately
coplaner and perpendicular to a central axis 62 of the ratchet 12. A
plurality of triangular ribs 50 are disposed longitudinally on the first
interior surface 42, with three equally spaced ribs 50 being presently
preferred.
The exterior of the ratchet 12 is formed into a plurality of terminating
faces 52, radially expanding helical camming surfaces 54, stops 56,
openings 58 and optional recesses 60. Six of each, spaced equally around
the exterior of the ratchet 12 is preferred in this embodiment, but the
number utilized may be more or less, depending upon the degrees of
rotation desired from each actuation of the switch.
The surfaces of terminating faces 52 and stops 56 are formed in approximate
radial and axial alignment with the axis 62. As viewed in FIG. 6, the
terminating faces 52 extend upward from the smaller end portion 44 and the
stops 56 extend downward from the larger end portion 48, each being of
sufficient length to prevent rotation of the ratchet past the pawl 8, as
described below.
Camming surfaces 54, are formed between an outer sidewall 57 and an inner
sidewall 59. The camming surfaces 54 form a radially expanding helix from
the terminating faces 52 towards the larger end portion 48, with
terminations 49 located a distance from the stops 56 to form the openings
58. The openings 58 must be of a sufficient size to allow the pawl 8 to
fit therein. In the presently preferred embodiment each termination 49 is
axially in line with a portion of the adjacent camming surface 54,
resulting in each camming surface 54 rotationally overlapping a portion of
both of its adjacent camming surfaces 54. The camming surfaces 54 are
preferably formed to have a surface angle 64 of greater than 0 degrees to
the end portion 48. Angles of between 3 and 15 degrees are presently
preferred, but they may be larger or smaller. Recesses 60 are optional
providing, together with stops 56, a guiding track for the pawl 8 during
switch operation. When recesses 60 or other means are present to provide a
guiding track for the pawl 8, the camming surfaces 54 need not overlap.
Referring to FIGS. 2, 8 and 9, the contact 14 is made of a conductive
material such as 70/30 cartridge brass or the like and is adapted for
rotation to make and break electrical connections between a common 68 and
a left 70 or a right 72 terminal, as described more fully below. The
contact 14 is generally triangular in form with a cup shaped center
bearing portion 66. The open end of the bearing portion 66 has several
tabs 74, extending radially outward from the circumference thereof. In the
presently preferred embodiment, three radial tabs 74 are evenly spaced
around the circumference. During switch operation, the tabs 74 engage in
wiping contact with a portion of the center 68, left 70 and right 72
terminals. The tabs 74 are provided with radiused edges 76 to prevent
galling the terminals when making wiping contact with them.
The bearing portion 66 is provided with a plurality of elongated axial
V-shaped grooves 78 on its external surface and is adapted to be inserted
into the first interior surface 42 of the ratchet 12. The grooves 78 are
of the same number and are adapted to mate with the triangular ribs 50
within the first interior surface 42. The mating of the ribs 50 and
grooves 78 causes the rachet 12 and contact 14 to rotate as a single unit.
As depicted in FIG. 10, the tabs 74, ribs 50 and grooves 78 are aligned
such that after each full actuation of the switch, one of the tabs 74 is
at rest in communication with the center terminal 68, while one of the
other tabs 74 is at rest in communication with either the left 70 or right
72 terminal.
Referring now to FIGS. 2 and 10, the cover 2 is provided with a plurality
of recesses 28 in conforming surface 30. As described above, the recesses
28 are configured and adapted to mate with pin members 26 located in the
mating surface 24 of the switch body 4. The cover 2 and the body 4 are
held together by means of an interference fit between the pin members 26
and the recesses 28.
An approximately circular recess 80 extends into the conforming surface 30,
its center aligned with the ratchet axis 62. An optional central post 83
extends perpendicularly away from the center of the recess 80. Three
terminal recesses, a center 84, a left 86 and a right 88 open into the
circular recess 80. The left 86 and right 88 terminal recesses are located
approximately 67.5 degrees on either side of the center recess 84. Within
the center 84, left 86 and right 88 terminal recesses are mounted the
common 68, left 70 and right 72 terminals.
The left 70 and right 72 terminals each include, respectively, mounting
portions 89 and 90, planar contact portions 92 and 94, crimped end
portions 96 and 98, and locating holes 100 and 102. The terminals are held
in place between the mating surface 24 and conforming surface 30, the
conforming surface 30 being recessed as necessary to conform to the shape
of the terminals. The terminals 70 and 72 are further secured in position
by locating posts 101 and 103 on the conforming surface 30, which pass
through the locating holes 100 and 102, respectively in the mating surface
24. The terminals 70 and 72 are additionally secured in position by a
portion of the mounting portions 89 and 90 which descend into and seat in
the terminal recesses 86 and 88, respectively. The contact portions 92 and
94 are located in a plane on and are coplanar with the bottom of the
circular recess 80, the bottom of the circular recess 80 being recessed as
necessary to conform to the shape of the contact portions 92 and 94.
The common terminal 68 has a mounting portion 104, a contact portion 106,
and a crimped end portion 108. In the presently preferred embodiment the
contact portion 106 is coplaner with and has a relatively larger surface
area along the arc described by the tabs 74 than the contact portions 92
and 94 of the left 70 and right 72 terminals, respectively.
As shown in FIG. 2, the crimped end portions 108, 96 and 98 of the
terminals are attachable to conventional electrical conductors 110, 112
and 114, respectively, to connect the switch to, for example, a common
lead and two portions of an electrical circuit. Crimped end recesses 116,
118 and 120 are located in the conforming surface 30 to provide clearance
for the crimped ends 108, 96 and 98. Conductor recesses 122, 124 and 126
are located in the conforming surface 30 adjacent to the crimped end
recesses 116, 118 and 120 provide clearance for the electrical conductors
110, 112 and 114, respectively.
Referring additionally to FIGS. 11 and 12, the pawl 8 is a generally
L-shaped body having a relatively longer arm 128 and a relatively shorter
arm 132. The longer arm 128 has an inner and outer portion, with the outer
portion terminating in a hook 130. The outer portion, hook 130 and the
shorter arm 132 are aligned in the same plane, while the hook 130 and the
shorter arm 132 extend away from the longer arm 128 in the same direction.
The shorter arm 132 contains a pivot 133 extending laterally through both
of its vertical sides. The pivot 133 has upper pivot edges 134 and lower
pivot edges 136. The upper pivot edges 134 rest on plunger shelf 137. The
pawl 8 pivots on pivot edges 134 during operation of the switch. The lower
pivot edges 136 provide a sharply defined attack point for the force of
spring 10. The lateral displacement between pivot edges 134 and 136
transforms the axial force of spring 10 to a torque urging the hook 130
against the ratchet 12, as described below. The shorter arm 132 terminates
in a finger 138 which is captured in a plunger internal slot 139.
FIG. 11 shows the switch with the plunger 6 depressed, as indicated by the
arrow A, while FIG. 12 depicts the switch with the plunger 6 in the fully
extended position, as depicted by the arrow B. When assembled, the plunger
6 is positioned in the barrel 18 and the pawl 8 is inserted into the open
end portion 34 of the plunger 6, with the outer portion of the longer arm
128 inserted into the slot 40 of the plunger 6. The spring 10 is inserted
into the open end portion 34 of the plunger 6, with the end of the spring
10 resting against the lower pivot edges 136. The other end of the spring
10 is positioned in the second interior surface 46.of the ratchet 12. The
ratchet 12 is positioned in the open end portion 34 of the plunger 6 with
its relatively larger diameter end portion 48 upward as depicted in FIGS.
11 and 12. The bearing portion 66 of the contact 14 is inserted into the
first interior surface 42 of the ratchet 12 and over the optional central
post 83 if it is present.
The spring 10 provides a continual force against the ratchet 12, thereby
biasing the tabs 74 against the common 68 and one of the left 70 or right
72 terminals. The spring 10 additionally provides a continual force
against the pawl 8, biasing the plunger 6 to its furthest extension out of
the barrel 18. The spring 10 is preferably sized to provide a resistive
force of from 2 to 8 Newtons during the operation of the switch, but
stronger and weaker force springs may be used to adjust the "feel" of the
switch.
When the switch is operated, one of the tabs 74 is located on the common
terminal 68 and another tab 74 is, for example, located on the right 72
terminal completing a circuit through the switch between the center 110
and the right 114 conductors, as shown in FIG. 10. The spring 10 is
biasing the pawl 8 and the plunger 6, urging the plunger 6 out of the
barrel 18 to its fullest extent. The hook 130 is located in one of the
openings 58 of the ratchet 12, as shown in FIG. 12.
Referring to FIGS. 6 and 11, switch actuation begins with a downstroke of
the plunger 6. During the downstroke, the plunger 6 and the pawl 8 move
into the barrel 18 compressing the spring 10. The hook 130 moves towards
the smaller end portion 44 of the ratchet 12, traveling along a stop 56
and, if provided, a recess 60 until reaching a camming surface 54. At this
point, the force of the spring 10 on pivot edges 136 causes the pawl 8 to
rotate on pivot edges 134 moving the hook 130 radially across the camming
surface 54 towards the ratchet axis 62. The movement of the pawl is
stopped by the inner sidewall 59.
At the end of the downstroke, release of pressure on the plunger 6
initiates an upstroke. During the upstroke, the hook 130, engages the
camming surface 54, causing a rotational force to be generated. As a
counter rotational movement of the pawl 8 is prevented by the confines of
the wall slot 40 and the internal slot 139, the rotational force causes
the ratchet 12 and contact 14 to pivot within recess 80 about the central
post 83 if present. During the continuation of the upstroke, the hook 130
continues to engage the camming surface 54, resulting in continued
rotation of the ratchet 12 and contact 14. Rotation ceases when the hook
130 comes to rest in the opening 58 adjacent to that in which it was
located at the beginning of the downstroke.
Referring again to FIG. 10, the angular rotation of the rachet 12 and
contact 14 is about 60 degrees after each full operation of the plunger 6.
During this rotation a first of the three tabs 74, which was initially
located on the common terminal 68, is rotated to the left terminal 70;
while a second tab 74, initially located at a first position between the
left 70 and right 72 terminals, is rotated to a second position between
the left 70 and right 72 terminals; and the third tab 74, initially
located on the right terminal 72, is rotated to the common terminal 68,
completing a circuit through the switch between the center 110 and the
left 112 conductors.
Successive plunger strokes will result in one of the tabs 74 coming to rest
on the common terminal 68 while another of the tabs 74 comes to rest
alternatively on the left 70 or right 72 terminals, completing a circuit
through the switch between the common conductor 110 and alternatively the
left 112 and right 114 conductors.
The nonmovement of the tabs 74 during the downstroke provides the switch
with a tease free feature, as the state of the switch does not change
during a partial downstroke of the plunger. Downstroke movement
insufficient to move the hook 130 into engagement with the next successive
camming surface 54, will not cause the switch to change state upon removal
of such downstroke pressure.
While the preferred embodiment described above is directed to a single pole
double throw switch, the present invention is not limited to use on this
type of switch. In another preferred embodiment one of either the left 70
or right 72 terminals may be removed causing the switch to operate as a
single pole, single throw switch.
In another preferred embodiment, shown in FIG. 13, differently configured
left 140 and right 142 terminals are utilized, together with a contact 144
having two tabs 146. In this embodiment the switch operates as an on-left,
off and on-right switch. The left 140 and right 142 terminals each
include, respectively, mounting portions 148 and 150, planar contact
portions 152 and 154, crimped end portions 156 and 158, and locating holes
160 and 162. A center terminal contact portion 106 is configured to allow
contact tabs 146 to alternatively connect the left or right terminal
contact portions 152 and 154 with the center terminal contact portion 106.
The terminals are held in place between the mating surface 24 and
conforming surface 30 and are further secured in position by locating
posts 101 and 103 which pass through the locating holes 160 and 162. The
contact portions 152 and 154 are located within the arc described by the
tabs 146 and are coplanar with the bottom of the circular recess 80. Each
of the contact portions 152 and 154 have a surface area approximately
equal to one of the tabs 146. The crimped end portions 156 and 158 are
attachable to conventional electrical conductors 112 and 114 as described
above.
Another preferred embodiment of the invention utilizes an actuator in the
form of a bail rather than a pawl and is depicted in FIGS. 14 and 15. FIG.
14 shows the switch with the plunger 6 depressed, as indicated by the
arrow A, while FIG. 15 depicts the switch with the plunger 6 in the fully
extended position, as shown by the arrow B. The plunger 170 is adapted to
conform to the bail 168 by incorporating two slots 169 in its sidewall
located 180 degrees apart. The bail 168 is a generally U-shaped body with
each arm 172 stepping outward in three portions and terminating in a hook
174. The bail 168 may be made of stainless or zinc coated carbon steel
spring wire. The bail 168 is formed with an opening between the hooks 174
smaller than the diameter of the smaller end portion 44 of the ratchet 12.
This results in the hooks 174 being continually urged towards the ratchet
axis 62 by the spring tension of the bail 168. The operation of this
embodiment is similar to that of the embodiment described above, but with
two hooks 174 simultaneously engaging the ratchet 12 rather than just one.
Also, the impetus for moving the hooks 174 across the camming surfaces 54
to the inner sidewall 59 is provided by the spring tension of the bail
168, rather than by action of the spring 10.
Another preferred embodiment of the invention, shown in FIGS. 16 and 17,
eliminates the use of any separate actuating element and utilizes a
portion of the plunger instead. A plunger actuator 176 is adapted to have
an resilient member 178. A hook 180 is formed on the lower inner portion
of the resilient member 178. The hook 180 is sized to displace the
resilient member 178 a small amount when the hook 180 is located in an
opening 58 of the ratchet 12. In operation the hook 180 engages the
ratchet 12, as described above, with the impetus for moving the hook 180
across the camming surface 54 to the inner sidewall 59 being provided by
the resilient member 178 returning to its original shape.
In another preferred embodiment, shown in FIG. 18, the switch operates as
an on-left, on-right switch, also having an off position. Tripartite left
182 and right 184 terminals are utilized, in conjunction with a contact
186 having one tab 188. The left 182 and right 184 terminals each include,
respectively, mounting portions 190 and 192, crimped end portions 194 and
196, and locating holes 198 and 200. The left terminal 182 additionally
includes a spaced apart three portion planar contact having areas 202, 204
and 206. Interspersed between the contact areas of the left terminal are
three spaced apart portions of the right terminal 184 comprising areas
208, 210 and 212. A center terminal 214 is employed having a crimped end
portion 216 and a planer portion 218; the planer portion 218 being in
continual communication with the contact 186. As with previously disclosed
embodiments, the terminals are held in place between the mating surface 24
and conforming surface 30 and are further secured in position by locating
posts 101 and 103 which pass through the locating holes 198 and 200. The
contact areas 202-212 are located within the arc described by the tab 188
and are coplanar with the bottom of the circular recess 80. The crimped
end portions 194, 196 and 216 are attachable to conventional electrical
conductors 112, 114 and 110 as described above. This preferred embodiment
is only one example of a switch of this type. By varying the shape and
location of the left 182 and right 184 terminals, those skilled in the art
may create other on-left, on-right and off switch operation sequences.
Another preferred embodiment is shown in FIG. 19. In this embodiment a
provision is made to allow adjustment of the noise generated during the
operation of the switch. A resilient stop 220, which terminates the
outward movement of plunger 6, is provided at the end 221 of the barrel
portion 18. The stop 220 is held in place by a threaded endcap 222, which
has a partially closed end portion 224. The resiliency of the stop 220
reduces the impact force and therefore the noise generated as the plunger
6 impacts, then comes to rest against the stop 220 at the termination of
the switch operation. The stop 220 is preferentially an open center disk
in shape and covers all or nearly all of the area between the side 223 of
the plunger 6 and the end portion 224. The stop 220 may be made of plastic
or metal with hard stainless steel or copper alloy having a thickness of
0.002 to 0.010 inch being presently preferred. The stop 220 should be
resistant to corrosion to insure long life. The stop 220 is retained on
most or all of its outer circumference by the end portion 224, while a
shoulder 225 of the plunger 6 contacts only an inner portion of the stop
220. A temporary elastic deformation of the stop 220 into a cone shape
during switch operation provides the desired resiliency. The sound level
made by the switch during operation may be adjusted by varying the
material and thickness of stop 220.
Another preferred embodiment is shown in FIG. 20. An elastic ring 226
provided in place of an open center disk to provide the resilient stop.
The ring 226 is preferentially made of an elastomer such as neoprene or
the like and has a diameter of 0.020 to 0.060 inch. The ring 226 is
circular in cross section, but may have a variety of other non-circular
cross-sectional shapes. The operation of the ring 22 is similar to that of
the stop 220 and provides a similar effect.
A resilient snap-fit endcap 228 is shown in FIG. 20 as retaining the ring
226. The endcap 228 has a partially open end portion 230 configured to
enclose approximately one half the diameter of the ring 226. The barrel
portion exterior 232 is configured to engage the endcap 228. A protrusion
234 of the external surface of the barrel portion surface 232 having
inclined upper and horizontal lower surfaces, as depicted in FIG. 20,
engages an oppositely configured protrusion 236 on the interior surface of
the endcap 228 to provide an interference fit. While this snap-fit endcap
228 and conforming barrel portion surface 232 configuration is presently
preferred, other snap-fit engagement configurations known in the art may
be used.
In view of the foregoing, it will be appreciated that a variety of changes,
modifications and variations may be made thereto without departing from
the spirit and scope of the inventive concept expressed herein. For
example, a differing number of camming surfaces 54 or a differing number
or differently shaped terminals or tabs may be utilized. Actuators
differently configured from the pawl 8, bail 172 or plunger actuator 176
may be utilized. The snap-fit endcap 228 and conforming barrel surface 232
may be used with any of the described embodiments. The cover 2 and body 3
may be held together by a bonding or welding process. Rotary and multiple
pole single or multiple throw switches may be made incorporating the
principles of the present invention. Accordingly, the above description
should not be used to limit the scope of the invention as defined in the
following claims.
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