U.S. patent number 3,740,501 [Application Number 05/140,152] was granted by the patent office on 1973-06-19 for miniature oil-tight push button and selector switch assembly and improved contact unit therefor.
This patent grant is currently assigned to Square D Company. Invention is credited to Rudolf H. Kiessling, Richard C. Rothweiler.
United States Patent |
3,740,501 |
Kiessling , et al. |
June 19, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
MINIATURE OIL-TIGHT PUSH BUTTON AND SELECTOR SWITCH ASSEMBLY AND
IMPROVED CONTACT UNIT THEREFOR
Abstract
A plurality of modular contact units are adapted for attachment
to a housing containing an operating means which may be of either
the push-button or selector switch variety. Each contact unit
comprises a single pair of contacts and indicating means to display
the condition of the pair of contacts. Camming means may be
interchangeably attached to the operating means externally of the
switch units. Selector switch operation provides maintained
switching for up to eight positions, momentary switching, or
momentary-maintained switching. Selector switch cams may be double
stacked to provide a maximum number of switching programs with a
minimum number of parts. The operating means may be illuminated or
non-illuminated and is adaptable for use as a pilot light or a
push-to-test unit.
Inventors: |
Kiessling; Rudolf H. (Glendale,
WI), Rothweiler; Richard C. (Asheville, NC) |
Assignee: |
Square D Company (Park Ridge,
IL)
|
Family
ID: |
22489978 |
Appl.
No.: |
05/140,152 |
Filed: |
May 4, 1971 |
Current U.S.
Class: |
200/16R; 200/16B;
200/314; D13/171; 200/253.1 |
Current CPC
Class: |
H01H
13/02 (20130101); H01H 19/02 (20130101); H01H
11/0006 (20130101); H01H 13/023 (20130101); H01H
19/025 (20130101); H01H 11/0018 (20130101); H01H
13/06 (20130101); H01H 2011/0093 (20130101); H01H
19/62 (20130101); H01H 15/102 (20130101); H01H
11/0012 (20130101); H01H 2011/0043 (20130101) |
Current International
Class: |
H01H
19/00 (20060101); H01H 19/02 (20060101); H01H
13/02 (20060101); H01h 015/00 () |
Field of
Search: |
;200/14,16R,167A,159R,16B |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Gemco Electric Company, Catalog, July 1965, p. 14,.
|
Primary Examiner: Scott; J. R.
Claims
I claim:
1. A switch assembly comprising a switch housing having forward and
rear end portions, contact means secured to the rear end portion of
said switch housing, said contact means including a pair of
separable contacts and contact indicator means movable to one
indicating position as a result of opening of said contacts to
indicate an open condition of said contacts and movable to another
indicating position as a result of closing of said contacts to
indicate a closed condition of said contacts, switch operating
means in said switch housing, and camming means secured to said
switch operating means for controlling the condition of said
contacts and the position of said contact indicator means.
2. A switch assembly as in claim 1 wherein said contact means
includes a contact module containing said pair of contacts and said
contact indicator means.
3. A switch assembly as in claim 2 wherein said contact module
includes a contact operator means having a first position, wherein
said pair of contacts is closed, and a second position, wherein
said pair of contacts is open, and wherein said camming means is
operable to move said contact operator means selectively into said
first and second positions.
4. A switch assembly as in claim 3 wherein said contact operator
means has an end portion, and contact camming means is provided on
said contact operator means for changing the condition of said pair
of contacts, said contact camming means being located a first
distance from said end portion of said contact operator means, and
said contact means includes an additional contact module containing
an additional pair of said contacts, an additional contact operator
means having an end portion, and an additional contact camming
means on the additional contact operator means for changing the
condition of said additional pair of contacts, said additional
contact camming means being located a second distance from the end
portion of the additional contact operator means different from the
first distance.
5. A switch assembly as in claim 3 wherein said contact module
includes a housing having an opening therein and said contact
indicator means has one position to display, at said opening, an
indicia indicating a closed condition of said pair of contacts and
an other position to display, at said opening, an indicia
indicating an open condition of said contacts.
6. A switch assembly as in claim 5 wherein said contact module
includes spring means for biasing said contact indicator means into
said one position, and means on said contact operator means for
biasing said contact indicator means into said other position when
said contact operator means is in said second position.
7. A switch assembly as in claim 1 wherein said contact means
comprises a contact housing having forward and rear end portions
and inner and outer side walls, each of said side walls having an
aperture therethrough, the rear end portion of the contact housing
having a pair of openings therein, said pair of contacts being
disposed in said contact housing and normally biased into the
closed condition, a pair of terminals held respectively in said
pair of openings and connected respectively to said pair of
contacts, said contact indicator means being disposed in said
contact housing and visible through the aperture in said outer side
wall, a biasing spring disposed in said contact housing and biasing
said contact indicator means toward one of its indicating
positions, and a contact operator disposed in said contact housing
between said contacts and having a pair of opposite end portions, a
camming nose at one of said end portions extending through the
aperture in said inner side wall, contact camming surfaces
proximate to said contacts, and means at the other of said end
portions for moving said contact indicator means to the other of
its indicating positions.
8. A switch assembly as in claim 7 wherein interlocking tongue in
groove and threaded attachment means are provided on the forward
end portion of said contact housing and the back end portion of
said switch housing.
9. A switch assembly as in claim 1 wherein said switch operating
means comprises push button switch operating means.
10. A switch assembly as in claim 1 wherein said switch operating
means comprises selector switch operating means.
11. A switch assembly comprising a switch housing having forward
and rear end portions, contact means secured to the rear end
portion of said switch housing, a selector switch stem rotatably
mounted in said switch housing and rotatable selectively to a
plurality of positions and having a rear end portion extending
rearwardly of said switch housing, stop means in said switch
housing for determining the number of positions for said selector
switch stem, camming means removably secured to the rear end
portion of said selector switch stem for controlling the condition
of said contact means, and detent means for said selector switch
stem comprising a cam surface disposed on a portion of said
selector switch stem within said switch housing and defining
depressions, a pair of indexing pins reciprocably mounted in and
guided by said switch housing and selectively seating in said
depressions as said cam surface is moved during rotation of said
selector switch stem, and means in said switch housing for biasing
the indexing pins against said cam surface for defining positions
of said selector switch stem.
12. A switch assembly comprising a switch housing having forward
and rear end portions, contact means secured to the rear end
portion of said switch housing, a selector switch stem rotatably
mounted in said switch housing, having a cam surface thereon
defining a depression and a planar portion having an end portion,
having a rear end portion extending rearwardly of said switch
housing, and being rotatable selectively to a rest position and to
a maintained position and a momentary position respectively on
opposite sides of the rest position, camming means removably
secured to the rear end portion of said selector switch stem for
controlling the condition of said contact means, reciprocatable
indexing means seating in the depression of said cam surface in the
maintained position of said selector switch stem, seating at the
end portion of the planar portion of said cam surface in the rest
position of said selector switch stem, and sliding across the
planar portion of said cam surface when said selector switch stem
is moved between the rest position and the momentary position,
means for biasing the indexing means against said cam surface, a
return spring mounted for rotation with said selector switch stem
and having an end portion, holding means in said switch housing for
holding the end portion of the return spring upon rotation of said
selector switch stem from the rest position toward the momentary
position, and stop means for determining the number of positions
for the selector switch stem.
13. A switch assembly comprising a switch housing having forward
and rear end portions, a switch operating stem movably mounted in
said switch housing and having a rear end portion extending
rearwardly of said switch housing, a plurality of separate contact
modules each including a contact housing having a single pair of
separable contacts and a movable contact operator disposed therein,
means for mounting said contact modules on the rear end portion of
said switch housing in surrounding relationship to the rear end
portion of said switch operating stem, and camming means secured to
the rear end portion of said switch operating stem and movable
therewith to move the contact operators of said contact
modules.
14. A switch assembly as in claim 13 wherein there are four contact
modules in said plurality.
15. A switch assembly as in claim 13 wherein said switch operating
stem is reciprocably mounted in said switch housing.
16. A switch assembly as in claim 13 wherein said switch operating
stem is rotatably mounted in said switch housing.
17. A switch assembly as in claim 39 wherein each of said contact
modules also includes a contact indicator means indicating whether
the respective pair of contacts are open or closed.
18. A switch assembly comprising a switch housing having forward
and rear end portions, a switch operating stem movably mounted in
said switch housing and having a rear end portion extending
rearwardly of said switch housing, four separate contact modules
each including a contact housing having a pair of separable
contacts and a movable contact operator disposed therein, means for
mounting said contact modules on the rear end portion of said
switch housing in surrounding relationship to the rear end portion
of said switch operating stem, and camming means secured to the
rear end portion of said switch operating stem and movable
therewith to move the contact operators of said contact
modules.
19. A switch assembly as in claim 18 wherein said switch operating
stem is reciprocably mounted in said switch housing.
20. A switch assembly as in claim 18 wherein said switch operating
stem is rotatably mounted in said switch housing.
21. A switch assembly as in claim 18 wherein each of said contact
modules also includes a contact indicator means indicating whether
the respective pair of contacts are open or closed.
Description
This invention relates to switches, and particularly to a switch
characterized by having a number of interchangeable parts for
selective attachment to certain common parts for adapting the
switch, with a minimum total inventory of parts, to perform a large
variety of switching arrangements.
More specifically the switch is adaptable to function with a push
button operator and stem or with a selector switch operator and
stem. Up to four contact modules can be independently controlled in
sequences which can be chosen by selectively connecting various
cams to the stem. Selector switch operation provides both momentary
and maintained operation for two or three position switching while
maintained action alone can be provided for up to eight
positions.
Both the push button and selector switch operators may be
illuminated and the push button switch assembly is adaptable for
use as a pilot light or push-to-test unit.
These and other advantages will become apparent from the following
description in which reference is made to the drawings wherein:
FIG. 1 is a side elevational view of a push button switch assembly
made in accordance with the present invention and mounted on a
panel;
FIG. 2 is a rear elevational view of the push button switch
assembly of FIG. 1 with contact modules and a push button cam
removed;
FIG. 3 is an enlarged cross-sectional view of the push button
switch assembly of FIG. 1 taken along the line 3--3 of FIG. 2;
FIG. 4 is an exploded perspective view of the push button switch
assembly of FIG. 1 with contact modules and panel mounting parts
removed;
FIG. 5 is a rear view of a push button stem for use in the push
button switch assembly of FIG. 1;
FIG. 6 is an end view of a push button cam for use in the push
button switch assembly of FIG. 1;
FIG. 7 is a side elevational view of the push button cam of FIG.
6;
FIG. 8 is a cross sectional view taken along the line 8--8 of FIG.
6;
FIG. 9 is a cross sectional view taken along the line 9--9 of FIG.
6;
FIG. 10 is a rear elevational view of a contact module for use in
the push button switch assembly of FIG. 1;
FIG. 11 is a front elevational view of the contact module of FIG.
10;
FIG. 12 is an enlarged cross sectional view taken along the line
12--12 of FIG. 11 with a contact operator partially cut-away;
FIG. 13 is an enlarged cross sectional view taken along the line
13--13 of FIG. 11;
FIG. 14 is an exploded perspective view of the contact module of
FIGS. 10-13;
FIG. 15 is a front elevational view labeled A and a pair of
fragmentary views labeled B and C showing embodiments of the
contact operator for the contact module of FIGS. 10-13;
FIG. 16 is a side elevational view, similar to FIG. 1, of an
illuminated push button switch assembly with a light module and a
single contact module attached;
FIG. 17 is a rear elevational view of the illuminated push button
switch assembly of FIG. 16;
FIG. 18 is an enlarged cross sectional view taken generally along
the line 18--18 of FIG. 17, but partially in elevation;
FIG. 19 is an exploded perspective view of a light assembly for use
in the illuminated push button switch of FIGS. 16-18;
FIG. 20 is a side elevational view of a selector switch assembly
made in accordance with the present invention and mounted on a
panel;
FIG. 21 is a partially cut-away rear elevational view of the
selector switch assembly of FIG. 20 with contact modules and a
selector switch cam removed;
FIG. 22 is an enlarged cross-sectional view of the selector switch
assembly of FIG. 20 taken along the line 22--22 of FIG. 21;
FIG. 23 is an exploded perspective view of the selector switch
assembly of FIG. 20 with contact modules and panel mounting parts
removed and a selector switch knob locking ring partially cut
away;
FIG. 24 is a rear end view of a selector switch stem for use in the
selector switch assembly of FIG. 20;
FIG. 25 is a rear end view of an alternate embodiment of the
selector switch stem of FIG. 24 with a selector switch cam assembly
attached;
FIG. 26 is a partially sectioned rear elevational view of the
selector switch assembly, similar to FIG. 21, with a retainer, stop
ring and index pin spring thereof removed;
FIG. 27 is a rear elevational view of a cam portion for use in the
selector switch assembly of FIG. 20;
FIG. 28 is a rear elevational view of another cam portion for use
in the selector switch assembly of FIG. 20;
FIG. 29 is a diagrammatic representation illustrating camming
operation of the selector switch assembly of FIG. 20;
FIG. 30 is another diagrammatic representation illustrating camming
operation of the selector switch assembly of FIG. 20;
FIG. 31 is a side elevational view of the selector switch assembly
of FIG. 20 provided with a double stacked cam assembly;
FIG. 32 is a cross-sectional view of a momentary selector switch
assembly, made in accordance with the present invention, taken
generally along the line 32--32 of FIG. 33;
FIG. 33 is a cross-sectional view of the momentary selector switch
assembly taken generally along the line 33--33 in FIG. 32;
FIG. 34 is a rear elevational view of a return spring for use in
the momentary selector switch assembly of FIG. 32;
FIG. 35 is a rear elevational view of a return spring holder for
use in the momentary selector switch assembly of FIG. 32;
FIG. 36 is a side elevational view of the return spring holder of
FIG. 35;
FIG. 37 is a partially cut-away side elevational view of a
momentary-maintained switch made in accordance with the present
invention and with contact modules removed; and,
FIG. 38 is a cross-sectional view of an illuminated selector switch
assembly similar to FIG. 22.
An embodiment of the switch assembly of the present invention is
illustrated in FIGS. 1-4. FIG. 1 shows a push button switch
assembly 11 which is mounted on a panel 12 with a push button
operator 14 extending forwardly of the panel 12.
An external oil seal, preferably in the form of a ring shaped
rubber oil sealing gasket 15, is fitted around a body 16 of the
push button switch assembly 11 and positioned to abut the rear
surface of the panel 12. To accommodate differences in panel
thickness, an appropriate number of metal spacers 17 may be placed
behind, and in abutting relation with, the oil sealing gasket 15. A
lock ring 19 holds the push button switch assembly on the panel 12
by threadably engaging external threads 20 (see FIG. 3) located at
the forward end of the body 16. A metallic locating ring 21 may be
interposed between the lock ring 19 and the panel 12, in a manner
well known in the art, to prevent rotation of the push button
switch assembly 11 with respect to the panel 12. If desired, the
locating ring 21 may be provided with an enlarged portion and thus
also function as a legend plate.
One or more contact modules 22 may be attached to the body 16 at
any or all of the locations which are provided and identified by
the Roman numerals I, II, III, IV on the body 16, as can be seen in
FIG. 2. The construction, functional details and mode of attachment
of the contact module 22 will be subsequently disclosed in
detail.
The push button switch assembly 11 is best described with reference
to FIGS. 3 and 4 and comprises the push button 14, the body 16, an
internal oil seal 24, an actuator means such as a push button stem
25, a return spring 26, which is preferably in the form of a
helical compression spring, a retainer 27, and a push button cam
29.
The push button 14 may be molded of any suitable material, such as
polycarbonate resin, and may have any suitable desired shape, size
or appearance.
The body 16 (FIGS. 2-4) is preferably die cast of a zinc alloy, or
a similarly suitable material. An internal wall portion 30 defines
a substantially cylindrical opening therethrough and a narrow
forward portion of the opening defines a rearwardly directed
shoulder 30a. A plurality of keyways 31 are formed in the wall
portion 30 and are axially aligned with the opening. The keyways 31
terminate in a widened portion toward the rear end portion of the
body 16 to expose surfaces 32 for use when the body 16 is
incorporated in a selector switch, as will be described in detail,
and surfaces 33 for supporting the retainer 27.
A plurality of arcuate grooves 34 (FIG. 2) are formed in a rear
surface 35 of the body 16 and are spaced circumferentially of the
cylindrical opening. A plurality of internally threaded openings
36, preferably one more than the number of arcuate grooves 34, are
drilled in the rear surface 36 of the body 16. In the preferred
embodiment, each of four threaded openings 36 is paired with a
corresponding arcuate groove 34 to accommodate attachment of one of
the contact modules 22. A fifth threaded opening, indicated as 36a,
is provided to accommodate attachment of a light module in a manner
to be later described with reference to FIG. 17.
The front end portion of the internal wall portion 30 has a
circumferential groove 37 formed therein (FIG. 4). The
circumferential groove 37 is adapted to house the internal oil seal
24 and hold it against axial motion during switch operation. The
internal oil seal 24 is formed of a resilient material and
preferably has a substantially Y-shaped cross section, as is best
illustrated in FIG. 3.
The push button stem 25 is molded of a suitable material such as
polyphenylene oxide and is molded or machined to provide an
external thread on a forward end portion 38 for attachment of the
push button 14 by engagement with a corresponding internal thread
39 therein (see FIG. 3). A circumferentially enlarged portion 40 of
the push button stem 25 interacts with the shoulder 30a of the body
16 to serve as a forward stop for the push button stem 25 and has
an outwardly facing circumferential surface which serves as a
forward bearing surface 41 to interact with the internal wall
portion 30 of the body 16 during switch operation. A plurality of
keys 42 are formed on the forward bearing surface 41. The keys 42
are preferably equal in number to and aligned with the keyways 31
in the body 16 and are held therein to prevent rotational motion of
the push button stem 25 during its longitudinal motion within the
body 16. The rear of the portion 40 forms a forward spring seat 44
(see FIG. 3).
The central portion of the push button stem 25 is preferably of
circular cross section and has a widened forward portion defining a
rearwardly directed shoulder 45 adjacent a rear bearing surface 46
on the central portion of the push button stem 25. The push button
stem 25 preferably tapers inwardly toward a rear end portion which
functions as a cam carrier portion 47 and is best illustrated in
FIG. 5. The cam carrier portion 47 has a cross section which is
substantially in the form of a square having foreshortened corners.
In the preferred embodiment, two opposite corners, indicated at 49,
are foreshortened equally. A third corner 50 is shortened by an
amount greater than the corners 49 and a fourth corner 51 has a
forward portion 51a which is shortened by substantially the same
amount as the corners 49 and a rear portion 51b which is shortened
by substantially the same amount as the corner 50. A rearwardly
directed shoulder 51c is thus formed in the corner 51.
The retainer 27 is die cast, preferably from a material similar to
that of the body 16, in the form of a ring with an outer dimension
enabling it to cover the rear end portion of the cylindrical
opening through the body 16. A tab 52 on the retainer 27 is adapted
to fit within a complementary recess 54 formed in the rear surface
35 of the body 16 (see FIG. 2). The inner portion of the retainer
27 is preferably elongated in a direction corresponding to the
longitudinal axis of the body 16 to provide an annular bearing
surface 55 for interacting with the rear bearing surface 46 on the
push button stem 25. A circumferential groove may be provided in
the forwardly facing surface of the retainer 27 to serve as a rear
spring seat 56.
The push button cam 29 is illustrated in FIGS. 6-9 and is molded of
a suitable material, such as fluorocarbon filled acetal resin, and
has an appropriate external shape for performance of the desired
switching program. It should be understood that a plurality of
different externally shaped cams 29 may be provided.
In the preferred embodiment, each cam 29 must be able to perform
two switching programs and must accordingly have two, and only two,
distinct mounting positions. Therefore, the internal form of the
cam 29 is made to cooperate with the cam carrier portion 47 of the
push button stem 25 to provide the two required distinct mounting
orientations. The cam 29 has an opening 57 extending longitudinally
therethrough and formed substantially in the shape of the cam
carrier portion 47 of the push button stem 25. Two opposite corners
59 of the cam 29 have a size and shape which allows them to be
fitted over the respective corners 49 on the cam carrier portion
47. The other two corners 60 have substantially the same dimensions
as the corners 59 over most of their lengths but terminate at
opposite end portions in inwardly projecting ledges 61 which
foreshorten the corners 60 by an amount corresponding to the
foreshortening of the third corner 50 and of the rear portion 51b
on the fourth corner 51 on the cam carrier portion 47 of the push
button stem 25.
With this construction, the cam 29 can be seated on the cam carrier
portion 47 with either end face 62 in a forward direction. However,
in each of these orientations, the push button cam 29 can be seated
on the cam carrier portion 47 in only one position. In either
orientation of the cam 29, one of the ledges 61 will be located at
the forward end face and the other ledge 61 will be at the rear. To
seat the cam 29, the ledges 61 must be fitted over the more greatly
foreshortened corners 50 and 51 of the cam carrier portion 47. If
the corner 60 having the forward facing ledge 61 is placed over the
cam carrier corner 51, the passage of the ledge 61 will be blocked
by the shoulder 51c so that the cam cannot be seated. Therefore,
the corner 60 having the forward facing ledge 61 must be positioned
over the cam carrier corner 50. This enables the cam 29 to be fully
and properly seated since the foreshortened rear portion 51b of the
fourth corner 51 of the cam carrier portion 47 will accommodate the
rear facing ledge 61.
If the cam 29 is removed and rotated 180.degree. around an axis
through the corners 59 in FIG. 6, the positions of the ledges 61
are reversed so that the push button cam 29 can be seated, in the
same manner as hereinbefore described, in its second orientation.
Thus two and only two camming programs may be provided with one cam
29.
Cooperating detent means may be provided in the form of bosses 63a
on the cam carrier portion 47 of the push button stem 25 adapted to
interfere with corresponding shoulders 63b on the push button cam
29. This interference fit holds the cam 29 in place during
operation of the push button switch assembly 11 and provides
snap-action mounting and removal for the cam.
Assembly of the push button switch assembly 11 is best described
with reference to FIGS. 3 and 4. The internal oil seal 24 must
first be fitted into the circumferential groove 37 provided for
that purpose in the body 16. The push button stem 25 can then be
inserted into the rear of the cylindrical opening in the body 16 so
that the keys 42 on the forward bearing surface 41 of the push
button stem 25 ride within the keyways 31 on the internal wall
portion 30 of the body 16.
The correspondence of the keys 42 and keyways 31 allows the push
button stem 25 to be inserted in any of a number of different
orientations. However, to provide reproduceability for the
switching programs which can be performed by each cam, it is
necessary that the push button stem 25 be inserted in a single
predetermined orientation. For this purpose, an indexing mark 64
(FIGS. 2 and 5) which may be in a form such as the arrow shown, is
preferably provided on the push button stem 25. In the preferred
embodiment, proper orientation of the push button stem 25 is
achieved by positioning the indexing mark 64 halfway between Roman
numerals I and II (see FIG. 2) on the rear surface 35 of the body
16.
The return spring 26 is then placed within the body 16 and around
the push button stem 25 so that its forward end portion is seated
within the forward spring seat 44. The return spring 26, in its
uncompressed state, extends a short distance beyond the rear of the
body portion 16.
The retainer 27 is placed over the cylindrical opening at the rear
surface 35 of the body 16 with the rear spring seat 56 oriented in
a forward direction and the tab 52 aligned with and received in the
recess 54. The rear spring seat engages the rear end of the return
spring 26 urging it forward into a partially compressed
configuration. The retainer 27 is then staked in position or
affixed to the body 16 by other suitable means.
A desired one of the push button cams 29 is then placed on the cam
carrier portion 47 of the push button stem 25 and the push button
14 is connected to the push button stem 25 by engaging the internal
threads 39 in the push button 14 with the threads on the forward
end portion 38 of the stem. It should be noted, however, that, if
the push button 14 is large in size, it may be necessary to connect
the push button 14 after installation of the push button switch
assembly 11 on the panel 12.
In the preferred embodiment, an identification mark 65 (FIG. 6) is
formed on the ledge 61 at the end face 62 of the push button cam
29, indicating the switching program performed by the cam when
seated with that end face 62 facing rearwardly of the push button
assembly 11. Since the indexing mark 64 on the push button stem 25
is positioned at the fourth corner 51, alignment of the
identification mark 65 on the push button cam 29 with the indexing
mark 64 on the push button stem properly orients the parts to
facilitate rapid and easy cam seating.
When the push button assembly 11 is held in place, as by affixing
it to a panel 12 in the manner shown in FIG. 1, and the push button
14 is biased, as by finger pressure, in a direction along the
longitudinal axis of the push button stem 25, the combination of
push button 14, push button stem 25 and push button cam 29 is moved
toward the rear of the push button switch assembly 11. The
interaction of the forward bearing surface 41 and the rear bearing
surface 46 of the push button stem 25 with the internal wall
portion 30 of the body 16 and the bearing surface 55 of the
retainer 27, respectively, permits substantially wobble-free
longitudinal motion of the push button stem 25 while interaction of
the keys 42 within the keyways 31 prevents rotation. The shoulder
45 serves as a stop for the push button stem 25 by interfering with
the forward face of the retainer 27 to limit rearward travel of the
push button stem 25.
Rearward motion of the push button stem 25 causes the forward
spring seat 44 to move toward the rear spring seat 56 thereby
further compressing the return spring 26 so that, upon release of
the push button 14, the push button stem 25 and the attached cam 29
and push button 14 are biased toward the forward end of the push
button assembly 11.
Referring now to FIGS. 10-15, a preferred contact module 22 is
illustrated having a base 66 and a cover 67 molded of suitable
materials such as polycarbonate resin. The forward end portion 69
of the base 66 has an arcuate projecting tongue 70 molded thereon.
The tongue 70 is formed to fit within one of the arcuate grooves 34
on the rear surface 35 of the body 16. An extended edge 71 of the
forward end portion 69 is molded or drilled to provide an opening
72 therethrough which is adapted for holding a threaded fastener
such as a screw 74. If desired, an internal peripheral lip 75 (FIG.
13) may be formed at the rear end portion of the opening 72 and
threaded to allow passage of the screw 74 which is provided with an
unthreaded shank portion 76 of reduced diameter. This allows the
screw 74 to be threaded through the lip 75 so that the shank
portion 76 is within the lip 75 and free to move longitudinally
within the opening 72 without being removable. In this manner, the
screw 74 becomes a "captive screw".
The opening 72 is located on the extended edge 71 in a position
which will permit alignment and threaded attachment of the screw 74
in the corresponding opening 36 in the body portion 16 when the
tongue 70 is in the groove 34. The combination of tongue in groove
and threaded attachment locks the contact module 22 onto the body
16 and keeps it aligned for proper switch operation.
The base 66 and cover 67 have a plurality of internal chambers
formed therein. The base 66 (see FIG. 12) has a contact chamber 77
and a torsion spring chamber 79. The cover 67 (FIG. 14) has an
indicator chamber 80 and two terminal holding chambers 81 opening
to the rear of the cover 67 (see FIG. 13). The base 66 and cover 67
may be attached to each other by cementing or ultrasonic welding or
any other desired method. Upstanding ridges 82 may be provided on
the cover 67 to cooperate with corresponding recesses 84 in the
base 66 to aid in alignment and attachment of the cover 67 to the
base 66.
The contact module 22 (FIG. 14) includes a pair of contact
assemblies 85, an indicator 86, a contact operator 87 and a torsion
spring 89.
Each contact assembly 85 has a terminal portion 90 and a contact
spring portion 91 and, since the contact assemblies 85 are
identical, only one will be described. The terminal portion 90 is
preferably stamped from an electrically conductive material such as
brass with a rear end portion preferably formed in the shape of a
push-on type solderless terminal. Other desired terminal types may,
of course, be utilized in a manner well known in the art.
The contact spring portion 91 is preferably stamped from an
electrically conductive material, such as beryllium copper, and
formed, as best shown in FIG. 13, to have a substantially planar
rear end portion 92 with a pair of openings 94 therein (FIG. 14)
corresponding to a pair of alignment studs 95 (FIG. 13) provided on
the terminal portion 90. When the contact spring portion 91 is
positioned against the terminal portion 90 with the alignment studs
95 in the corresponding openings 94, the contact assembly is
properly aligned and may be permanently attached, preferably by
welding or brazing.
A central portion 96 of the contact spring portion 91 is offset in
a direction away from the terminal portion 90 and is aligned in a
plane substantially parallel to that of the rear end portion 92. A
boss 97, protruding away from the terminal portion 90, is formed in
the central portion 96 for interaction with the contact operator
87. The forward end portion of the contact spring portion 91 is
further offset away from the terminal portion 90 and bowed to
define a contact 99, which may be silvered and bifurcated to
improve its electrical characteristics and minimize contact
damage.
The contact operator 87, also shown in FIG. 15A, is preferably
molded of an insulating material, such as a thermoplastic resin,
and has a central portion 100 which widens toward one end portion
to terminate in projecting leg portions 101 which have parallel
guide surfaces 102 externally thereof. The guide surfaces 102
interact with corresponding surfaces 104 (FIG. 12) in the torsion
spring chamber 79 of the base 66 to maintain lateral alignment of
the contact operator 87 during operation of the contact module 22.
An indicator stop portion 105 in the form of a web is preferably
formed between the leg portions 101 for interaction with the
indicator 86.
The contact operator 87 widens from the central portion 100 toward
the other end portion thereby defining contact spring camming
surfaces 106 which interact with the respective bosses 97 on the
contact spring portions 91 of the contact assembly 85 to effect
movement of the contact spring portion 96 during operation of the
contact module 22 thereby to open and close the contacts 99. Early
or late opening and closing of the contacts 99 may be provided by
forming the contact operator 87 with the camming surfaces 106
shifted toward or away from the central portion 100. An early
opening, late closing contact operator 87a can be formed by
shifting the camming surfaces toward the central portion 100, as
shown by the camming surface 106a in FIG. 15B. A late opening,
early closing contact operator 87b can be formed by shifting the
camming surfaces away from the central portion 100, as shown by the
camming surface 106b in FIG. 15C. The time differential between
operation of an early or late opening contact module and a standard
contact module is dependent upon the distance between the relative
positions of the camming surfaces 106.
Each camming surface 106 terminates with a shoulder 107 which
interacts with an inner surface of the contact chamber 77 of the
base 66 to provide a stop for the contact operator 87. A projecting
nose portion 109 is formed at the end portion opposite the leg
portions 101 and is provided with a cam surface 110 thereon. The
shape of the cam surface 110 allows movement of the contact
operator 87 along a longitudinal axis thereof upon interaction with
a camming surface moving substantially perpendicular to the line of
motion of the contact operator 87.
The indicator 86 (see FIG. 14) is formed of a suitable material,
such as a fluorocarbon-fiber filled acetal, and has a projecting
nose 111 at one end portion. The other end portion 112 has suitable
indicia such as a contact condition indicating mark 114 hot stamped
or otherwise visibly displayed thereon.
For assembly of the contact module 22, each contact assembly 85 is
positioned with the terminal portion 90 held within a terminal
holding chamber 81 in the cover 67. Each terminal portion 90
extends through a narrow opening 115 in the cover 67 for holding
the contact assembly 85 while allowing external electrical
connection of the terminal portion 90. When the contact assemblies
85 are positioned in the cover 67, the bosses 97 and contacts 99 on
the contact spring portion 91 are inwardly facing and the contacts
99 are abutting each other.
The indicator 86 is placed in indicator chamber 80 of the cover 67
with the projecting nose 111 facing in a generally forward
direction and the end portion 112 facing generally rear so that the
contact indicating mark 114 may be aligned with an opening 116 (see
FIGS. 1 and 10) in a rear end wall of the indicator chamber 80 to
indicate the operative condition of the contacts 99. For example,
indicia such as a standard contact symbol 117, as shown in FIG. 10,
may be hot stamped or otherwise displayed at the opening 116. The
contact indicating mark 114 is then preferably in the form of a
diagonal line visible through the opening 116 whenever the contacts
99 are closed, forming the standard electrical symbol designating a
pair of closed contacts. When the contacts 99 are open, the contact
indicating mark is moved out of alignment with the opening 116 and
therefore not visible so that the standard electrical symbol for a
pair of open contacts is seen. In this manner, a readily
understandable means for indicating the electrical condition of the
contacts 99 is provided which may easily be seen by looking at the
cover 67 of the contact module 22.
The contact operator 87 is then positioned between the contact
assemblies 85 adjacent the bosses 97 on the contact spring portions
91. With the central portion 100 between the bosses 97, the
projecting nose portion 109 of the contact operator 87 extends
through an aperture 119 (FIG. 12) in a side wall portion of the
base 66. The width of the central portion 100 is sufficiently small
to enable the contacts 99 to remain in abutment.
The torsion spring 89 is held within the torsion spring chamber 79
in the base 66. One leg 120 of the torsion spring 89 has an end
portion 121 which is bent convexly outward to abut the indicator
stop portion 105 of the contact operator 87 and the projecting nose
111 of the indicator 86. This biases the projecting nose 111 toward
a position between the leg portions 101 and toward the rear of the
indicator stop portion 105 of the contact operator 87. When the
indicator 86 is in this position, the contact indicating mark 114
is visible through the opening 116 in the cover 67 and thus
displays the closed condition of the contacts 99.
If the projecting nose portion 109 of the contact operator 87 is
laterally biased, as by a push button cam 29, the contact operator
87 moves in a direction toward the torsion spring 89. The contact
spring camming surfaces 106 apply outward forces to the respective
bosses 97 on the respective contact spring portions 91 of the
contact assembly 85. The interaction of the contact spring camming
surfaces 106 and the bosses 97 cause the contact spring portions 91
to separate, thereby opening the contacts 99. The contact operator
87 drives the projecting nose 111 of the indicator 86 against the
biasing force of the torsion spring 89. The resulting rotational
motion of the indicator 86 moves the contact indicating mark 114
away from the opening 116 to display the open condition of the
contacts 99.
When the projecting nose portion 109 of the contact operator 87 is
released, the contact spring portions 91 apply an inward force
through the bosses 97 to the contact spring camming surfaces 106.
This drives the contact operator 87 in a direction away from the
torsion spring 89 to the position in which the central portion 100
of the contact operator 87 is between the bosses 97 and the
contacts 99 close. The torsion spring 89 biases the projecting nose
111 of the indicator 86 and causes it to follow the contact
operator 87. The resulting rotational motion of the indicator 86
places the contact indicating mark 114 in a position in which it is
visible through the opening 116 and displays the closed condition
of the contacts 99.
During switching operation of the contact module 22 on the push
button switch assembly 11, camming of the projecting nose portion
109 of the contact operator 87 is performed by the push button cam
29 (FIGS. 6-9). The push button cam 29 preferably has four external
camming surfaces 122. Each camming surface 122 has an outer portion
124 coinciding with the outer surface of the push button cam 29
adjacent one end face 62 and slopes inwardly to a recessed portion
125 adjacent the other end face 62.
Mounting the push button cam 29 on the push button stem 25 when a
contact module 22 is affixed at the rear surface 35 of the body 16
positions the rear end portion of the camming surface 122 for
operative interaction with the projecting nose portion 109 of the
contact operator 87. When the push button 14 is depressed, the
forward end portion of the camming surface 122 controls the contact
operator 87.
Thus, the identity of the rear end portion of the camming surface
122 determines whether the contacts 99 in the corresponding contact
module 22 will be normally open or normally closed. Normally closed
contacts result when the rear end portion of the camming surface
122 is the recessed portion 125. In this configuration, the nose
portion 109 of the contact operator 87 projects into the recess so
that the central portion 100 of the contact operator 87 is between
the bosses 97 and the contacts 99 are closed. Operation of the push
button switch assembly 11 by depressing the push button 14 shifts
the push button cam 29 in a rearward direction thus moving the
outer portion 124 of the camming surface 122 into alignment with
the projecting nose portion 109 of the contact operator 87. The
camming surface 122 outwardly biases the contact operator 87 and
thereby causes the contact spring camming surfaces 106 to open the
contacts 99 in the manner previously described herein. Release of
the push button 14 allows the contacts 99 to reacquire their
normally closed configuration.
If the rear end portion of the camming surface 122 is the outer
portion 124, the projecting nose portion 106 of the contact
operator 87 is biased into the contact module 22 so that, as
hereinbefore indicated, the contacts 99 are normally open.
Depressing the push button 14 shifts the recessed portion 125 into
alignment with the projecting nose portion 109 and allows the
contacts 99 to close. Release of the push button 14 reestablishes
the normally open configuration of the contacts 99.
In the preferred embodiment of the push button switch assembly 11,
four camming surfaces 122 are provided on each push button cam 29,
corresponding to the maximum number of contact modules 22 which may
be used. With a particular cam 29, from zero to four normally
closed contacts may be provided by orienting that number of camming
surfaces 122 with the recessed portion 125 as the rear end portion.
Oppositely oriented camming surfaces 122 would produce normally
open contacts. If desired, the identification mark 65 on the push
button cam 29 (see FIG. 6) may be a number designating the number
of normally closed contacts provided by that particular cam. It
should be readily apparent that, since each push button cam 29 may
be mounted on the push button stem 25 in either of two
orientations, reversed front to back, those camming surfaces 122
which, in one orientation, produce normally closed contacts would,
in the opposite orientation, produce normally open contacts. Those
camming surfaces 122 which, in the first orientation, produced
normally open contacts would, when reversed, produce normally
closed contacts. Thus a push button cam 29 producing four normally
closed contacts in one orientation, such as that illustrated in
FIG. 4, would produce no normally closed contacts in its other
orientation. A cam producing three normally closed contacts in one
orientation, (not illustrated) would produce one normally closed
contact in its other orientation. A cam producing two normally
closed contacts, such as the one illustrated in FIGS. 6-9, would do
so in either orientation. In this manner, all possible switching
combinations can be provided for the push button switch assembly 11
with only three different push button cams 29.
An illuminated push button switch assembly 11I is illustrated in
FIGS. 16-18. Its construction is similar to that of the push button
switch assembly 11, as can be seen by comparing FIGS. 16 and 18
with FIGS. 1 and 3 respectively. Parts common to both embodiments
have been similarly numbered.
The push button stem 25 has a longitudinal opening 126 therethrough
(see FIG. 3) with a narrow portion 127 defining a rearwardly
directed shoulder 129. The opening 126 is adapted to receive a lamp
130 (see FIG. 19), a pair of lamp terminals 131 and a lamp terminal
holder 132. The lamp 130 may be of either the incandescent or neon
type and is preferably substantially cylindrical in shape having an
insulating base 134 and a pair of lamp contacts 135 located on
opposite sides of the lamp 130.
Each lamp terminal 131 is preferably stamped and formed of a
conductive material, such as brass, and has a substantially planar
forward portion 136 with an outwardly bent end portion 137 to
facilitate insertion of lamp 130. Each forward portion 136 may be
provided with an enlarged portion 139 bent to conform to the shape
of the lamp contact 135. Each forward portion 136 is outwardly
displaced from an attachment portion 140 which has an outwardly
bent attachment tang 141 for interaction with the lamp terminal
holder 132. Rear end portions 142 of the lamp terminals 131 are
inwardly bent to provide respective contact surfaces 144.
The lamp terminal holder 132 is molded of a suitable insulating
material, such as polycarbonate resin, and is substantially
cylindrical in shape with a tongue 145 extending essentially
rearwardly therefrom. An enlarged central portion 146 of the lamp
terminal holder 132 defines a forwardly directed shoulder 147. A
pair of alignment notches 149 are preferably formed on opposite
sides of the forward end portion of the holder. A pair of
longitudinal openings 150 are provided in the lamp terminal holder
132 to accommodate the attachment portions 140 of the lamp
terminals 131 (see FIG. 18). An outer wall portion 151 of each
opening 150 has a rearwardly directed shoulder 152 formed therein
for interaction with one of the attachment tangs 141 to secure the
lamp terminal 131. Side portions 154 of the tongue 145 are
broadened to enhance the strength of the tongue 145.
The lamp terminal holder 132 is inserted from the rear through the
longitudinal opening 126 in the push button stem 25, with the
tongue 145 rearwardly extended, until the shoulder 147 of the
holder 132 abuts the shoulder 129 in the push button stem 25. The
holder 132 must be oriented to align the alignment notches 149 with
corresponding alignment bosses 155 (see FIG. 5) molded in the
narrow portion 127 of the longitudinal opening 126 in the push
button stem 25. Interaction of the alignment notches 149 and
alignment bosses 155 fixes the orientation of the lamp terminal
holder 132 within the push button stem 25 and prevents rotation of
the holder 132.
After the lamp terminal holder 132 has been positioned, the lamp
terminals 131 are inserted through the forward end of the opening
126 in the push button stem 25. The rear end portions 142 of the
lamp terminals 131 are inserted in the respective openings 150 in
the holder 132 until the attachment tangs 141 on the attachment
portions 140 are in interlocking relation with the respective
shoulders 152 (FIG. 18). After both lamp terminals 131 are in
place, the lamp 130 may be inserted through the front of the push
button stem 25. In this manner access may be had to the lamp 130 so
that it may be inserted, removed or changed while the push button
switch assembly is in place on a panel 12 simply by removing the
push button 14 to expose the forward end portion 38 of the push
button stem 25. It should be clear that, for light from the lamp 30
to be visible, the push button 14 must be formed of a transluscent
or transparent material.
Electrical power for operating the lamp 130 is preferably supplied
through a hollow light module 156 (FIGS. 16-18) having a base 157
and cover 159 (FIG. 16) molded of a suitable insulating material
such as polycarbonate resin. The light module 156 has a size which
enables it to be mounted on the back surface 35 of the body 16,
utilizing the same space required to mount two of the contact
modules 22. Accordingly, two tongues (not shown), each similar to
the tongue 70 on the base 66 of the contact module 22, are provided
on the base 157 of the light module 156 and are positioned for
insertion in two adjacent ones of the arcuate grooves 34. In the
preferred embodiment, the light module 156 is attached to the rear
surface 35 of the body 16 at the positions indicated by Roman
numerals III and IV (see FIG. 2). Therefore, the threaded opening
36a must be located adjacent the arcuate groove 34 at Roman numeral
III opposite the threaded opening 36 nearest Roman numeral IV to
accommodate a pair of threaded fasteners, such as captive screws
160, received in openings in the base 157 of the light module 156.
The combination of tongue in groove and threaded attachment
releasably attaches the base 157 to the body 16. The cover 159 is
ultrasonically welded, or otherwise suitably attached, to the base
157.
A pair of input terminals 161 (FIG. 17) which may be of the push-on
solderless type, are provided in the cover 159 for external
attachment to a source of electric power. A pair of output
terminals 162 (FIG. 18) are provided in the base 157 to supply
operating power to the lamp 130. The input terminals 161 may be
directly connected to the respective output terminals 162 or may be
connected through a resistor or a transformer contained within the
module 156 in a manner well known in the art. These means for
connecting the terminals 161-162 are contained in a cavity (not
shown) within the light module 156. The output terminals 162 are
held in alignment with the push button stem 25 and are so
positioned that the contact surfaces 144 on the rear end portions
142 of the lamp terminals 131 make a sliding electrical contact
with the output terminals 162. The light module 156 and lamp
terminals 131 form a power means for the lamp 130. Proper
orientation of the lamp terminals 131 in the push bottom stem 25,
the push button stem 25 in the body 16, and the light module 156 on
the body 16 insure a proper alignment and interaction of the
contact surfaces 144 and the output terminals 162. As can be seen
in FIG. 18, sliding contact is maintained between each contact
surface 144 and its corresponding output terminal 162 when the push
button 14 is extended or depressed so that the lamp 130 may remain
illuminated during all operations of the illuminated push button
switch assembly 11I. If desired, the light module 156 may be
powered through one of the contact modules 22 so that it will be
illuminated in only one of the positions of the push button 14.
Also, the illuminated push button switch assembly 11I may utilize
one normally open and one normally closed contact module 22 to form
a push-to-test unit in a manner well known in the art.
A selector switch embodiment of the present invention is
illustrated in FIGS. 20-23 wherein component parts which are common
to both the selector switch and push button switch assemblies are
given the same identifying numbers used in describing the push
button switch assembly 11.
Referring now to FIG. 20, a selector switch assembly 164 is shown
mounted on a panel 12 and is oriented to have a selector switch
knob 165 extended forwardly of the panel 12.
A lock ring 166 holds the selector switch assembly 164 on the panel
12 by threadably engaging the external threads 20 located at the
forward end portion of the body 16.
Contact modules 22 may be attached to the body 16 at any or all of
the locations indicated by the Roman numerals I, II, III, IV on the
body 16 (see FIG. 21).
The selector switch assembly 164, as best shown in FIGS. 22 and 23,
comprises the selector switch knob 165, a selector switch knob
locking ring 167, the body 16, the internal oil seal 23, a selector
switch stem 168, a pair of index pins 169, an index pin spring 170,
which is preferably in the from of a helical compression spring, a
stop ring 171, the retainer 27, and a selector switch cam assembly
172.
The selector switch knob 165 is preferably molded of a suitable
material, such as polycarbonate resin, and may have any desired
shape and markings and has a forward handle portion 174. A rear end
portion 175 is preferably cylindrical in shape to facilitate
rotation of the selector switch knob 165 within the forward end
portion of the body 16. A substantially cylindrical circumferential
surface 176 extends rearwardly from the forward portion 174 and
preferably has a plurality of attachment tabs 177 formed at a rear
end portion thereof.
The selector switch knob locking ring 167 may be machine formed of
aluminum or other suitable material and has an internally threaded
rear end portion 179 for attachment to the external threads 20 at
the forward end portion of the body 16. The forward end portion of
the selector switch knob locking ring 167 has an internal
circumferential groove 180 therein to accommodate securement of the
selector switch knob 165 through snap fitting of the attachment
tabs 177 on the selector switch knob 165 into the internal
circumferential groove 180 in the locking ring 167. The relative
dimensions of the tabs 177 and groove 180 should allow rotational
movement of the knob 165 within the locking ring 167 so that the
selector switch knob 165 may be operatively secured to the body
16.
The selector switch stem 168 is preferably molded of polyphenylene
oxide, or another suitable material, and has a plurality of
longitudinal grooves 181 formed in a forward end portion thereof.
The grooves 181 interact with splines 182 formed on an inner
surface 184 of the selector switch knob 165 (see FIG. 22) to engage
the selector switch knob 165 and stem 168 during operational
rotational motion within the body 16. The combination of the spline
in groove alignment and the snap fitting relation of the selector
switch knob 165 and locking ring 167 permit ease in alignment and
attachment of the selector switch knob 165, as should be readily
apparent to those skilled in the art.
An enlarged portion 185 of the selector switch stem 168 defines a
forward bearing surface 186 which interacts with the shoulder 30a
in the body 16 (FIG. 22) and a circumferential outer bearing
surface 187 which interacts with the internal wall portion 30 of
the body 16 during rotational motion of the selector switch stem
168. A rearwardly facing side of the enlarged portion 185 serves as
a cam surface 189 (see FIG. 24) having a plurality of oblique cam
faces 190 alternately rising and falling in ratchet fashion around
the cam surface 189 thereby forming peaks 191 with V-shaped
depressions 192 therebetween. The cam surface 189 cooperates with
the index pins 169 and the index pin spring 170 to form a detent
means operating in a manner to be hereinafter described. The
maximum number of positions which may be provided by a 360.degree.
rotation of the selector switch stem 168 is equal to the number of
V-shaped depressions 192 formed on the cam surface 189, as will be
demonstrated. In one embodiment, eight position switching may be
provided, as shown in FIG. 25, by spacing eight alternating peaks
191 and eight V-shaped depressions 192 around the cam surface 189.
Preferably, however, two opposite peaks 191 are eliminated as shown
in FIG. 24, leaving substantially planar surfaces 194. This limits
the detent means to providing four distinct positions for the
selector switch assembly 164 but enables the switch to operate with
maintained positions at one side of a rest position, wherein the
selector switch stem 168 will remain until the selector switch knob
165 is moved to another position, and a momentary position at the
other side of the central portion, from which the selector switch
stem 168 will return to center unless the knob 165 is physically
held in the momentary position of the switch. This embodiment of
the selector switch assembly 164 will be subsequently described
with reference to FIG. 37.
A central portion 195 of the selector switch stem 168 (FIG. 23) has
an axially projecting tongue portion 196 extending rearwardly
toward a cam attachment portion 197 of reduced diameter. The cam
attachment portion 197 has a pair of concentric substantially
cylindrical rings comprising an outer ring 199 (FIG. 24) and an
inner ring 200 which preferably extends rearwardly of the outer
ring 199. A plurality of axially aligned slots 201 are formed in
the outer ring 199. In the preferred embodiment, four slots 201 are
provided. Three of the slots 201 have substantially equal widths
and one slot 201a is narrower than the other slots 201 to aid in
alignment of the cam 172.
Each index pin 169 is preferably molded of a suitable material such
as fluorocarbon filled acetal resin and has an outer portion 202
curved to substantially conform in shape to the internal wall
portion 30 of the body 16 (FIG. 4). A substantially linear spline
204 is formed on the outer portion 202 and aligned for travel in
one of the keyways 31 in the body 16. A forward end portion 205 of
each index pin 169 is shaped to fit within one of the V-shaped
depressions 192 on the cam surface 189 of the selector switch stem
168 and projects inwardly to provide a biasing surface 206 for
receiving the index pin spring 170.
The stop ring 171 is preferably stamped from steel and has a
plurality of radially protruding ears 207 preferably equal in
number to, and adapted to respectively fit in, the enlarged rear
portions of the keyways 31 in the internal wall portion 30 of the
body 15 (FIG. 4) in abutting relation with the surfaces 32. A
substantially circular central opening 209 in the stop ring 171 has
a diameter which will rotatably hold the cam attachment portion 197
of the selector switch stem 168 and has an arcuate recess 210 to
accommodate the tongue portion 196 of the selector switch stem 168.
As will become apparent, various stop rings 171 may be selected to
provide desired operation.
Interaction of the tongue portion 196 and the arcuate recess 210
permits rotation of the selector switch stem 168. The width of the
recess 210 determines the maximum amount of angular travel of the
selector switch stem 168 and, accordingly, the number of positions
available in a particular selector switch configuration. Since
eight positions can be provided in one complete revolution, the
selector switch stem 168 must rotate 45.degree. between positions.
Therefore, to provide two positions for the selector switch
assembly 164, the arcuate dimension of the recess 210 must be
45.degree. plus an amount equal to the angular width of the tongue
portion 196 of the selector switch stem 168. A three position
switch requires a 90.degree. throw and each additional position
requires that another 45.degree. be added to the size of the recess
210. The maximum size of the recess 210 is needed for an eight
position stop ring for which the size would be 315.degree. in
addition to the angular width of the tongue portion 196.
The selector switch cam assembly 172 is preferably molded of a
suitable material such as fluorocarbon filled acetal resin and has
a base portion 211 and a cam portion 212 which are separately
formed and connected together by ultrasonic welding or other
desired means. The base portion 211 is preferably substantially
cylindrical in shape with a central opening 214 dimensioned to
effect an interference fit with the inner ring 200 of the cam
attachment portion 197 of the selector switch stem 168 and an outer
dimension sufficient to effect an interference fit with the outer
ring 199 (see FIG. 22). A plurality of bosses 216 are formed on the
base portion 211 and are preferably aligned with, and equal in
number to, the slots 201 in the outer ring 199 of the cam
attachment portion 197 on the selector switch stem 168. In the
preferred embodiment, three bosses 216 are aligned with, and
dimensioned to fit respectively within, the three slots 201 and a
fourth and narrower boss 216a is dimensioned to fit within the slot
201a in the outer ring 199 (see also FIG. 25). Because each boss
216 is too wide to fit within the narrower slot 201a, a one-way fit
is provided for the base portion 211 of the selector switch cam
assembly 172 with respect to the cam attachment portion 197 of the
selector switch stem 168.
In assembling the selector switch assembly 164, the selector switch
stem 168 is first placed into the rear of the opening in the body
16 with the longitudinal grooves 181 forwardly directed. The
selector switch stem 168 does not have splines for riding in the
keyways 31 in the body 16, as does the push button stem 25 (see
FIG. 4), and is therefore free to rotate within the body 16.
The two index pins 169 are preferably inserted into the body 16 at
locations 180.degree. apart (see FIG. 26) for uniform biasing by
the index pin spring 170. In the preferred embodiment, the index
pins 169 are positioned so that the splines 204 ride respectively
in the keyways designated 31a in FIG. 26.
The index pin spring 170 is placed in the body 16 and positioned
around the selector switch stem 168 with the forward end portion of
the index pin spring 170 abutting the biasing surfaces 206 of the
index pins 169.
The stop ring 171 is placed in the body 16 behind the index pin
spring 170 and urged forwardly until the ears 207 are positioned
within the enlarged rear portions of the keyways 31 in the internal
wall portion 30 of the body 16 abutting the surfaces 32. The stop
ring 171 is then staked or otherwise locked in place.
The insertion of the stop ring 171 compresses the index pin spring
170 so that it applies a forwardly directed force which firmly
biases the index pins 169 against the cam surface 189. The
combination of index pins 169 and spring 170 and the cam surface
189 forms a detent means for maintained positions of the selector
switch stem 168. When the selector switch stem 168 is rotated, as
to change the condition of the contacts operated thereby, one of
the cam faces 190 is pressed against one face of the forward
portion 205 of each index pin 169. Interaction of the spline 204 on
the outer portion 202 of each index pin 169 and the keyway 31a in
the body 16 holds each index pin 169 against lateral motion so that
the cam faces 190 drive the index pins 169 in a rearward direction,
opposing the biasing force applied by the index pin spring 170.
When an index pin 169 has passed over a peak 191, it is driven in a
forwardly direction by the index pin spring 170 and is biased
against the next cam face 190, thereby aiding the rotation of the
selector switch stem 168 until the index pin 169 is positioned at
the base of the next V-shaped depression 192. In this manner, the
positions of the selector switch assembly 164 are distinctly
defined to facilitate ease and sureness of operation while changing
positions and to releasably hold the selector switch stem 168 in
each position.
Since uniformity and reproduceability are generally required in
switching programs for contacts operated by a selector switch, the
stop ring 171 must be positioned so that the arcuate recess 210 has
a fixed, reproduceable position. Also, if a two, three or four
position selector switch assembly 164 uses the preferred selector
switch stem 168, with the planar surfaces 194 on the cam surface
189, the arcuate recess 210 must be placed so that the index pins
169 do not travel across the planar surfaces 194 while the selector
switch stem 168 is rotating between maintained selector switch
positions, since the planar surfaces 194 would not permit any
distinction between the positions nor provide detent means for
retention of the selector switch stem 168 in one of those
positions. In the preferred embodiment (see FIG. 21), the stop ring
171 is positioned so that the arcuate recess 210 fits over the
tongue portion 196 of of the selector switch stem 168 while the
tongue portion 196 is midway between Roman numerals I and II on the
rear surface 35 of the body 16 and one end shoulder 217 of the
arcuate recess 210 is aligned with Roman numeral II.
The retainer 27 is placed over the body 16 at the rear surface 35
with the tab 52 aligned with and held in the recess 54. The
retainer 27 is staked in position or affixed by other suitable
means. The selector switch cam assembly 172 is then attached to the
cam attachment portion 197 of the selector switch stem 168 as
previously described.
In this manner, two, three or four position or, with the alternate
embodiment of the selector switch stem, up to eight position
maintained switching operation may be provided for the selector
switch assembly 164.
The cam portion 212 of the selector switch cam assembly 172 must be
able to provide many different switching programs for up to four
contact modules 22 in the two, three and four position standard
modes of operation. Standard switching programs are well known in
the art and generally require the use of many different molded cams
and necessitate the stocking of a large variety of parts, sometimes
as many as one type of cam for each program.
The preferred embodiment of the selector switch assembly 164 uses
cam portions 212 having two distinct forms illustrated as cam
portions 212a and 212b in FIGS. 27 and 28, respectively, to provide
the desired switching programs. The selected cam portion 212 may be
attached to the base portion 211 by ultrasonic welding or other
desired means in any orientation required for a particular
program.
The cam portion 212a (FIG. 27) has a pair of cam lobes 219 of
substantially equal size and the cam portion 212b (FIG. 28) has a
large cam lobe 220 and a small cam lobe 221. When the selector
switch cam assembly 172 is assembled and in place on the selector
switch stem 168, the cam lobes 219, 220 and 221 extend outwardly a
sufficient distance to bias the contact operator 87 (FIG. 12)
sufficiently to open the contacts 99. Those areas of the cam
portion 212 between the cam lobes allow the contacts 99 to remain
closed. Thus, for use in conjunction with an eight position switch,
the cam portion 212a provides four closed positions (indicated by
the symbols C in FIG. 27) and four open positions (indicated by the
symbols 0 in FIG. 27). The cam portion 212b (FIG. 28) provides six
open positions and two closed positions.
The versatility of the selector switch camming means of the present
invention is illustrated in FIGS. 29 and 30 which show two
different possible orientations in which the cam portion 212a may
be utilized on identical selector switch assemblies 164 with the
selector switch stem 168 having the same orientation in both
figures. The Roman numerals I, II, III and IV represent the
positions of four sets of contacts for the purpose of this
illustration.
The orientation of the cam portion, 212a shown in FIG. 29, provides
for opening the contacts at positions I and IV while the contacts
at positions II and III remain closed. The orientation of the cam
portion 212a shown in FIG. 30, which is obtained by shifting the
cam portion 212 through an angle of 45.degree. from the position
shown in FIG. 29 before attaching it to the base portion 211,
provides for opening the contacts at positions II and IV while the
contacts at positions I and III remain closed.
Let us consider the cam portions 212a as illustrated in FIGS. 29
and 30 to be attached to a selector switch stem in the central
position of a three position switching program. If the selector
switch stem and attached cam portion 212a in FIG. 29 are shifted
one switch position in the direction indicated by the arrow 222,
the contacts at I close, the contacts at II open and the condition
of the contacts at III and IV remains unchanged. It the cam portion
212a is shifted from the central position one switch position in
the direction opposite that indicated by the arrow 222, the
condition of the contacts at I and II remains unchanged while the
contacts at III open and the contacts at IV close. It should be
clear to those skilled in the art that a one position or 45.degree.
shift in the position of the cam portion 212a relative to the
selector switch stem, as shown in FIG. 30, yields a totally
distinct switching program.
In a similar manner, the cam portion 212b can be made to produce
another two switching programs. Also, if either cam portion 212 is
shifted by multiples of 90.degree. from a particular orientation,
the switching programs are correspondingly shifted to different
sets of contacts. It should be noted here that although the
foregoing discussion has been in the context of a three position
selector switch, the same relationships also apply to two, four or
more position switches.
It has been found that, although a limited number of switching
program combinations can be provided by a single cam portion 212,
selector switch cam assemblies 172 yielding substantially all
generally used combinations of switching programs can be produced
by stacking two cam portions 212 in various orientations relative
to the base portion 211 as is shown in FIG. 31. When a double
stacked selector switch cam assembly 172a is used, one, two or
three contact modules 22 are operated by a forward cam portion 212f
and the remaining contact modules 22 are operated by a rear cam
portion 212r. The forward cam portion 212f is attached to the base
portion 211 and the rear cam portion 212r is attached to the
forward cam portion 212f. In this manner, each cam portion 212 may
be individually oriented relative to the base portion 211.
As has been hereinbefore indicated, the selector switch cam
assembly 172 is dimensioned so that the cam portion 212 (the
forward cam portion 212f in the case of the double stacked cam
assembly 172a) is operatively aligned with the projecting nose
portion 109 of the contact operator 87 in the contact module 22.
Therefore, the operative dimensions of the contact module 22 must
be altered to enable the rear cam portion 212r to operate the
contact operator 82. It can be clearly seen, with reference to
FIGS. 12 and 14, that the contact operator 87 is symmetrical about
a longitudinal axis through the indicator stop portion 105 except
for the nonsymmetrical projecting nose portion 109. Therefore, if
contact operator 87 is rotated 180.degree. around the longitudinal
axis, its operation is not altered except that the projection nose
portion 109 is shifted rearwardly to the position shown by a dashed
line in FIG. 12 and indicated as 109a. This orientation of the
contact operator 87 within a contact module 22 aligns the
projecting nose 109a with the rear cam portion 212r (FIG. 31) for
operative interaction therewith. Thus it should be readily apparent
that by varying the identity and orientation of the forward and
rear cam portions 212 and by properly selecting which cam portion
212 will operate each contact module 22, substantially any desired
switching program may be provided by only three different parts,
the cam portions 212a and 212b and the base portion 211.
If desired, the selector switch assembly of the present invention
may be adapted for use as a momentary switch, a configuration in
which the selector switch stem 168 has a rest position and a
position on one or both sides of the rest position from which
spring return means returns the selector switch stem 168 to the
rest position upon release of the selector switch knob 165.
The momentary selector switch assembly 164m, shown in FIGS. 32 and
33, is substantially similar to the maintained selector switch
assembly 164 of FIGS. 22 and 23 except that certain additions and
deletions of parts of parts have been made. The index pins 169 and
index pin spring 170 are not used in the momentary selector switch
assembly 164m. No detent means is required as no switch position
must be maintained. Instead, a return spring 224 and return spring
support 225 are used to return the selector switch stem 168 to its
rest position during operation.
The return spring 224 is shown in FIG. 34 and is preferably a wound
stainless steel torsion spring having outwardly turned feet 226 at
its end portions.
The return spring support 225 (FIGS. 35 and 36) is preferably
stamped and formed from strip steel and has a pair of annular leg
portions 227 spaced axially apart and connected by a generally
planar bight portion 229. Each leg portion 227 preferably has an
inwardly turned tang 230 along one side portion thereof opposite
the tang 230 on the other leg portion 227. Aligned slots 231 are
preferably provided through both leg portions 227 centrally of the
bight portion 229.
The return spring 224 is inserted between the leg portions 227 of
the return spring support 225 with each foot 226 of the return
spring 224 engaging one of the tangs 230 on the return spring
support 225 as shown in FIG. 32. Preferably, the return spring 224
is under tension in this position to assure that the feet 226 will
be properly positioned and held against the tangs 230.
A momentary selector switch stop ring 171m is provided with an
upstanding tab 232 (see FIG. 32). The stop ring 171m (for the
purposes of this example, a three position stop ring) is placed in
the body 16 and around the selector switch stem 168 with the tab
232 rearwardly directed. The stop ring 171m is aligned in the same
manner as previously described in relation to the stop ring 171 for
the maintained selector switch.
The selector switch stem 168 is oriented so that the tongue portion
196 is in the rest position and the return spring 224 and return
spring support 225 are placed over the selector switch stem 168
with the tongue portion 196 through the aligned slots 231. Now the
tab 232 on the stop ring 171m abuts one foot 226 of the return
spring 224 on the same side as the corresponding tang 230 on the
return spring support 225 abuts the same foot 226.
A momentary selector switch retainer 27m has an upstanding tab 234
on a forward face thereof (FIG. 33). When the retainer is placed on
the body 16, the tab 234 abuts the other foot 226 of the return
spring 224 on the same side as the corresponding tang 230 on the
return spring support 225 abuts the same foot 226.
Thus a three position momentary selector switch assembly 164m is
formed. When the knob 165 and, correspondingly, the selector switch
stem 168 are rotated in either direction, the return spring support
225 also rotates, due to the engagement of the tongue portion 196
in the aligned slots 231. This causes a corresponding motion of the
return spring 224.
However, when the selector switch stem 168 is rotated in the
direction indicated by the arrow 235 in FIG. 32, the retainer tab
234 engages its corresponding return spring foot 226 and holds it
against rotation. Thus, as the selector switch stem 168 rotates,
the tension of the return spring 224 is increased, since the tang
230 adjacent the stop ring retainer tab 232 pulls its corresponding
foot 226 and causes it to rotate with the return spring support 225
and selector switch stem 168. When the selector switch stem 168 is
released, the return spring 224 applies sufficient force to pull
the return spring support 225, and with it the selector switch stem
168, back to the rest position.
Similarly, when the selector switch stem 168 is rotated in the
direction opposite that indicated by the arrow 235, the stop ring
tab 232 engages its corresponding return spring foot 226 and holds
it against rotation so that the tension of the return spring is
increased to pull the selector switch stem 168 back to its rest
position upon release of the selector switch knob 165. In this
manner a three position selector switch having a central rest
position and a momentary position on either side may be formed.
It should be apparent from the foregoing discussion that a two
position selector switch may be formed with a rest position and a
single momentary position only to one side thereof by using a two
position momentary stop ring 171m. Because return action is only
desired in one direction, either the stop ring tab 232 or the
retainer tab 234 may be omitted, depending on the side of the rest
position to be used.
To provide a three position selector switch which has a maintained
position on one side and a momentary position on the other side of
a central position, as is illustrated in FIG. 37, both detent means
and spring return means must be included. The detent means must
function only in the maintained position and the spring return
means must function only in the momentary position. Thus, in this
embodiment, the index pins 169 and index pin spring 170 are used as
detent means for the maintained position and the return spring 224
and return spring support 225 are used as spring return means for
the momentary position.
So that the return spring 224 will only function during operation
to one side, either the stop ring tab 232 or the retainer tab 234
is omitted. The tab which is used determines the direction of the
momentary position.
The index pins 169 are positioned within the body 16 so that when
the selector switch stem 168 is in its rest position, the index
pins 169 are at one edge of the planar surfaces 194. When the
selector switch stem 168 is rotated into the momentary position,
the index pins 169 slide across the corresponding planar surfaces
194 so that the detent means is inoperative and does not interfere
with the action of the return spring 224. When the selector switch
stem 168 is rotated into the maintained position, the index pins
169 and index pin spring 170 interact with the cam surface 189 so
that the detent means operates as hereinbefore described. It should
be readily apparent that a momentary-maintained selector switch
with more than one maintained position may be formed by using s
stop ring 171 providing four or more positions.
An illuminated selector switch assembly 164I is illustrated in FIG.
38 and may be of the maintained, momentary or momentary-maintained
variety. As in the illuminated push button switch assembly 11I, the
lamp 130 is held by a pair of lamp terminals 131 which are locked
within the selector switch stem 168 by the lamp terminal holder
132. The rear end portions 142 of the lamp terminals 131 are in
electrical contact with the output terminals 162 of the light
module 156.
To accommodate the lamp assembly, the selector switch stem 168 is
provided with a substantially cylindrically longitudinal opening
235 (see FIG. 22). A rear portion 236 of the longitudinal opening
235 has a narrow section 237 defining a rearwardly directed
shoulder 239 to accommodate assembly of the lamp assembly in a
manner similar to that described for the illuminated push-button
assembly 11I. (see FIGS. 18 and 19)
Since the selector switch stem 168 rotates during operation while
the output terminals 162 of the light module 156 remain stationary,
the formation of the longitudinal opening 235 must enable the lamp
terminals 131 to rotate relative to the selector switch stem 168 so
that the lamp terminals 131 will be in a fixed position for
constant electrical contact with the output terminals 162.
Therefore, the alignment bosses 155 which were used in the push
button stem 25 (see FIG. 5) have not been added to the selector
switch stem 168.
When the illuminated selector switch assembly 164I is put together,
the lamp assembly is positioned so that when the light module 156
is attached to the body 16, the rear end portions 142 of the lamp
terminals 131 are in electrical contact with the output terminals
162 of the light module 156. When the selector switch is operated,
causing the selector switch 168 to be rotated within the body 16,
the light module 156 holds the lamp assembly against rotation so
that the selector switch may be illuminated in any or all of its
positions.
Thus, a switch assembly has been illustrated which has both
push-button and selector switch modes of operation, may be
illuminated or non-illuminated and can provide a large variety of
switching programs. The selector switch mode of operation provides
momentary, maintained and momentary-maintained operation and from
two to eight position switching. The large variety of switching
programs is provided through the use of a minimal number of
different parts. Since the switch assembly can be made very small
and all wiring connections and contact condition indicators are
directed toward the rear, a plurality of assemblies may be
contained in a smaller space than is the case with many prior art
devices. However, it should be noted that the switch assembly of
the present invention is adaptable for use as a larger scale
unit.
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