U.S. patent number 3,736,390 [Application Number 05/206,665] was granted by the patent office on 1973-05-29 for rotary switch assembly with printed circuit rotor and multilayer housing features.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Joseph LaRue Lockard.
United States Patent |
3,736,390 |
Lockard |
May 29, 1973 |
ROTARY SWITCH ASSEMBLY WITH PRINTED CIRCUIT ROTOR AND MULTILAYER
HOUSING FEATURES
Abstract
A rotary switch is provided which is adaptable for being stacked
in multiple layers for multi-function use by a single control
shaft. A printed circuit board and a brush member are supported in
a dust-proof housing in contacting relation and means are provided
for rotating one of the board and the brush relative to the other
to any of a predetermined number of distinct positions.
Additionally, the inputs and outputs of the switch are all aligned
in a single plane.
Inventors: |
Lockard; Joseph LaRue
(Harrisburg, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
22767401 |
Appl.
No.: |
05/206,665 |
Filed: |
December 10, 1971 |
Current U.S.
Class: |
200/11DA; 200/14;
200/307; 200/11G; 200/284 |
Current CPC
Class: |
H01H
19/115 (20130101); H01H 19/64 (20130101); H01H
19/585 (20130101) |
Current International
Class: |
H01H
19/00 (20060101); H01H 19/11 (20060101); H01H
19/64 (20060101); H01H 19/58 (20060101); H01h
019/58 (); H01h 021/78 () |
Field of
Search: |
;200/11,14,166SD,166CT,166J,168K,11DA,11K,11G,168T |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; J. R.
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. In a switch having a housing, a printed circuit board mounted
for displacement in said housing, at least one electrical contact
protruding externally of said housing and having a brush portion
protruding into said housing and engaging said printed circuit
board for electrical engagement on a selected electrical circuit
provided on said printed circuit board upon displacement of said
printed circuit board, and means mounted in said housing for
displacing said printed circuit board, the improvement comprising:
a pair of bearing surfaces fixedly located on said housing and
abutting and supporting opposite sides of said printed circuit
board and retaining said circuit board therebetween and preventing
warping of said printed circuit board.
2. The structure as recited in claim 1, wherein said printed
circuit board is displaceable about an axis of rotation, said
bearing surfaces are circular rims, said rims encircle and axis of
rotation of said printed circuit board, and said rims abut and
support said printed circuit board circularly about its axis of
rotation to prevent warping of said printed circuit board.
3. The structure as recited in claim 2, wherein, said rims are
relatively thin to provide bearing surfaces of relatively small
areas upon which the printed circuit board is slidably supported
for relatively low sliding friction.
4. The structure as recited in claim 1, and further including: at
least one additional electrical contact protruding externally of
said housing and having a brush portion protruding internally into
said housing and engaging said printed circuit board for selective
electrical engagement with a selected electrical circuit provided
on said printed circuit board.
5. The structure as recited in claim 4, wherein, said housing has a
flat planar portion, and all of said electrical contacts protrude
from said housing only through said flat planar portion for making
electrical connections externally of said housing.
6. The structure as recited in claim 4, wherein, said housing
includes an internal detent portion, and further including: a gear
mounted in said housing for selective engagement in said detent
portion, thereby positively locating said printed circuit board in
selected positions determined by selective engagement of said gear
in said detent portion.
7. The structure as recited in claim 1, wherein, said housing
includes detent means, and further including: a gear mounted in
said housing for displacement and having a portion displaceable
into selected engagement in said detent means, thereby positively
locating said printed circuit board in a selected positions defined
by the selected engagement of said gear in said detent means.
8. The structure as recited in claim 4, wherein, said electrical
contacts include electrical wire-receiving portions protruding
externally of said housing for making electrical connections
externally of said housing.
9. The structure as recited in claim 4, wherein, said housing
includes a first member having grooves each receiving one of said
electrical contacts therein, said grooves each having a shape
conforming to the shape of a corresponding electrical contact for
registration of the corresponding electrical contact fixedly in
position within the groove, and a cover overlying said first member
with said electrical contacts interposed between said first member
and said cover, whereby said electrical contacts are fixedly
retained with respect to said housing.
10. A switch, comprising: a first brush housing member of
electrical insulation material having a plurality of electrical
contacts mounted thereon, said contacts further having electrical
terminal portions protruding externally of said brush housing
member for making desired electrical connections externally of said
brush housing member, a first printed circuit board having
electrical circuits thereon, said contacts having brush portions
protruding internally of said brush housing member and engaging
said printed circuit board, a first cover portion engaging and
covering one end of said brush housing member, said first printed
circuit board being enclosed by and interposed between said first
cover portion and said brush housing member, said first cover
portion including a support means engaging said printed circuit
board, said brush housing member having a first bearing surface
engaging said printed circuit board and cooperating with said
support means to support said printed circuit board therebetween
and thereby prevent warpage of said printed circuit board, covering
means covering another end of said brush housing member, and
displacing means mounted on said switch for displacing said first
printed circuit board relative to said brush portions for
engagement of said brush portions with selected electrical circuits
on said first printed circuit board, said first printed circuit
board being slidably displaceable relative to said support means
and said first bearing surface.
11. The structure as recited in claim 10, wherein, said covering
means includes a second brush housing member abutting said first
brush housing member, a second printed circuit board interposed
between said first and said second brush housing members, said
second printed circuit board being provided with electrically
conducting circuit paths thereon, electrical contact means in said
second brush housing member, said second printed circuit board
being displaceable relative to said electrical contact means to
enable selected electrical engagement of said electrical contact
means with selected electrically conducting circuit paths on said
second printed circuit board, said first brush housing member
having a second bearing surface engaging said second printed
circuit board, said second brush housing member having bearing
surface means engaging said second printed circuit board and
cooperating with said second bearing surface of said first brush
housing member to support therebetween said second printed circuit
board and to prevent warpage of said second printed circuit board,
said second printed circuit board being slidably displaceable by
said displacing means relative to said second bearing surface and
said bearing surface means.
12. The structure as recited in claim 10, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, said first bearing surface is in the form of a circular
rim encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said first printed circuit board and to minimize sliding
friction resulting from displacement of said first printed circuit
board relative to said rim.
13. The structure as recited in claim 10, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, said support means is in the form of a circular rim
encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said first printed circuit board and to minimize the
sliding friction resulting from displacement of said first printed
circuit board relative to said rim.
14. The structure as recited in claim 10, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, and said support means and said first bearing surface are
in the respective forms of circular rims encircling the axis of
rotation of said first printed circuit board, said circular rims
being of relatively thin configurations to minimize the bearing
surface areas engaging said first printed circuit board and to
minimize sliding friction resulting from displacement of said first
printed circuit board relative to said rims.
15. The structure as recited in claim 10, wherein, said brush
housing member is provided with grooves each receiving one of said
electrical contacts therein, each of said grooves having a shape
corresponding to the shape of a corresponding electrical contact
for registration of the corresponding electrical contact fixedly in
position within the groove, said electrical contacts being
interposed between said brush housing member and said covering
means, whereby said electrical contacts are fixedly retained with
respect to said brush housing member.
16. The structure as recited in claim 11, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, and said support means and said first bearing surface are
in the respective forms of circular rims encircling the axis of
rotation of said first printed circuit board, and said circular
rims are of relatively thin configurations to minimize the bearing
surface areas engaging said first printed circuit board and to
minimize the sliding friction resulting from displacement of said
first printed circuit board relative to said rims.
17. The structure as recited in claim 11, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, said support means is in the form of a circular rim
encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said first printed circuit board and to minimize the
sliding friction resulting from displacement of said first printed
circuit board relative to said rim.
18. The structure as recited in claim 11, wherein, said first
printed circuit board is rotatably displaceable about an axis of
rotation, said first bearing surface is in the form of a circular
rim encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said first printed circuit board and to minimize the
sliding friction resulting from displacement of said first printed
circuit board relative to said rim.
19. The structure as recited in claim 11, wherein, said switch is
provided with detent means, and said displacing means is provided
with a gear displaceable into selected engagement within said
detent means for locating said first and said second printed
circuit boards in selected positions defined by the selected
engagement of said gear within said detent means.
20. The structure as recited in claim 19, wherein, said switch
includes a projecting stop member, and said gear member is
engageable against said stop member to limit displacement of said
gear member.
21. The structure as recited in claim 11, wherein, said first brush
housing member includes a plurality of grooves each receiving one
of said electrical contacts therein, said grooves each having a
shape conforming to the shape of a corresponding electrical contact
for registration of the corresponding electrical contact fixedly in
position within the groove, and said covering means overlying said
first brush housing member with said electrical contacts generally
interposed between said first brush housing member and said
covering means whereby said electrical contacts are fixedly
retained with respect to said first brush housing member.
22. The structure as recited in claim 11, wherein, said brush
housing member, said first cover portion and said covering means
define on said switch a planar portion, and said electrical
contacts and said electrical contact means protrude from said
planar portion for making electrical connections externally of said
switch.
23. The structure as recited in claim 11, wherein, said second
brush housing member includes a plurality of grooves receiving said
electrical contact means therein, said grooves having shapes
conforming to the shapes of said electrical contact means for
registration of the electrical contact means fixedly in positions
within the grooves, and means overlying said second brush housing
member with said electrical contact means generally interposed
between said second brush housing member and said lastmentioned
means, whereby said electrical contact means are fixedly retained
with respect to said second brush housing member.
24. The structure as recited in claim 4, wherein, said electrical
contacts include pluggable portions for pluggable connection
externally of said rotary switch.
25. A rotary switch comprising: a housing; a printed circuit board;
at least one electrically conducting brush means; means for
supporting said printed circuit board and said at least one brush
means in contacting relation within said housing; means for
rotating said printed circuit board to one of a predetermined
number of distinct positions; a circular array of detents formed in
a plane on an interior surface of said housing; a gear disposed
within said circular array of detents in the same plane and having
at least one projecting compressible tab for engaging in said
detents; means connecting said gear and said printed circuit board
for providing simultaneous rotation thereof; means for rotating
said gear from outside said housing; and said housing further
comprising, one end cover for rotatably receiving said printed
circuit board therein, a brush housing member connectable with said
one end cover in substantially dust-free relation and having means
therein for supporting the brush means with portions thereof
extending therefrom in a common plane, another end cover
connectable to said brush housing member in substantially dust-free
relation, means on said another end cover for connecting said
housing on a panel with said means for rotating said printed
circuit board projecting through said panel to a side thereof
opposite said housing, and sealing means on said another end cover
sealing said means for rotating said printed circuit board to
provide a substantially dust-free environment in said switch
housing.
26. The structure as recited in claim 11, wherein said second
printed circuit board is rotatably displaceable about an axis of
rotation, said second bearing surface is in the form of a circular
rim encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said second printed circuit board and to minimize the
sliding friction resulting from displacement of said second printed
circuit board relative to said rim.
27. The structure as recited in claim 11, wherein said second
printed circuit board is rotatably displaceable about an axis of
rotation, said bearing surface means is in the form of a circular
rim encircling said axis of rotation, and said rim is of relatively
thin configuration to minimize the bearing surface area thereof
engaging said second printed circuit board and to minimize the
sliding friction resulting from displacement of said second printed
circuit board relative to said rim.
28. The structure as recited in claim 11, wherein said second
printed circuit board is rotatably displaceable about an axis of
rotation, said bearing surface means and said second bearing
surface are in the respective forms of circular rims encircling
said axis of rotation, and said rims are of relatively thin
configurations to minimize the bearing surface areas thereof
engaging said second printed circuit board and to minimize the
sliding friction resulting from displacement of said second printed
circuit board relative to said rims.
29. The structure as recited in claim 10, wherein said brush
housing member, said first cover portion and said covering means
define a flat planar portion of said switch, said electrical
contacts protrude from said flat planar portion for making
electrical connections externally of said switch.
30. The structure as recited in claim 25, wherein said switch
further includes at least another brush housing member interposed
between said another end cover and said means for supporting said
printed circuit board, a printed circuit means in said another
brush housing member, electrical contact means in said another
brush housing member having brush means contacting said printed
circuit means, and said printed circuit means being rotatable
together with said printed circuit board by said means for rotating
said printed circuit board to one of a predetermined number of
positions.
31. The structure as recited in claim 30, wherein said
first-mentioned brush housing member includes a first bearing
surface abutting and slidably supporting said printed circuit
board, said first-mentioned brush housing member includes a second
bearing surface slidably abutting and supporting said printed
circuit means, and said another brush housing member includes a
third bearing surface slidably supporting said printed circuit
means.
32. The structure as recited in claim 30, and further including
additional electrically conducting brush means mounted in said
another brush housing member and in contact with said printed
circuit means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to rotary switches and more
particularly to an improved multilayer rotary switch of compact
construction for high-density switch applications.
2. Prior Art
In the past, rotary switches have been bulky and heavy usually
hand-constructed items which were difficult to wire and were
subject to being easily damaged if accidentally dropped, or even by
dust and dirt in the storage or operational environments thereof
entering the switch housing and causing short-circuiting to occur
therein. These former switches accordingly were not entirely
satisfactory for high-density applications for these reasons, but
more primarily because of their size which normally precluded the
use of a plurality of such switches being used together to
accomplish multiple functions simultaneously and because the inputs
and outputs thereof were not aligned, such that a large area was
needed to provide suitable connections thereto. With the advent of
integrated and miniaturized circuits, a need now exists for a
compact and compatible rotary switch capable of satisfying the
requirements incidental thereto.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
novel and improved rotary switch of compact construction for use in
high-density switch applications.
Another object of the present invention is to provide a rotary
switch which is compact, easily assembled at low cost, and yet
which is not readily subject to being damaged.
Still another object of the present invention is to provide a
rotary switch being encapsulated to prevent access of dust or dirt
and thereby being substantially safe from being short-circuited
therewithin.
Yet another object of this invention is the provision of a rotary
switch of compact construction designed to facilitate stacking with
like switches to permit an increased number of functions to be
performed through operation of a single control knob in a minimum
amount of space.
A further object of the invention is the provision of a compact
coded rotary switch which is dust-proof, less complex and expensive
to manufacture than present coded switches, less subject to damage,
and being readily coupled in stacked relation with similar switches
to increase the number of functions which may be performed through
a single control in a minimum amount of space.
Yet a further object of this invention is the provision of a
compact decimal version rotary switch being dust-proof and not
readily subject to damage, and being stackable with similar
switches to permit an increased number of functions to be performed
through operation of a single control shaft, while having minimum
space requirements.
The foregoing and other objects are attained according to one
aspect of the present invention by a rotary switch, the parts of
which generally are composed of plastic materials, comprising a
coded printed circuit board rotatably disposed in a given plane in
a dust-proof housing, a plurality of elongate brush members
associated therewith being fixedly secured in the housing so that
the brush end thereof is always pressed against the printed circuit
board with the other end extending from the housing and lying in
the same plane as the board, and an operating shaft projecting from
the housing being perpendicularly oriented relative to the printed
circuit board and connected thereto for rotating the same from
outside the housing. Within the housing, the operating shaft is
connected to the printed circuit board through a disc-like member
positioned on the shaft in parallel relation with the board for
being rotated therewith in conjunction with the board and having
compressible tabs formed on the periphery thereof which engage a
plurality of detents formed in a circular pattern on an inside wall
portion of the housing, whereby the shaft may be turned to place
the rotatable printed circuit board in a plurality of distinct
positions wherein different coding functions are established
between the printed circuit on the board and the brushes. The
housing exterior is further designed so that a plurality of the
housings may be readily secured together in an end-to-end, or
stacked, relation such that a corresponding plurality of printed
circuit boards may be simultaneously rotated by a single operating
shaft projecting through all of the housings to increase the number
of functions that may be accomplished by maneuvering a single
control knob.
In another aspect, the rotary switch of the present invention is
embodied in a decimal version, wherein a fixed printed circuit
board is provided within the housing and a brush member connected
to the operating shaft is rotatably disposed thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the
present invention will be more fully appreciated as the same
becomes better understood from the following detailed description
when considered in connection with the accompanying drawings, in
which like reference characters designate like or corresponding
parts throughout the several views, and wherein:
FIG. 1 is an exploded perspective view of a switch constructed
according to the present invention illustrating the arrangement of
the various elements thereof in which they will be assembled,
including the housing, a coded printed circuit board, a plurality
of brushes associated therewith within the housing and a control
shaft designed for rotating the coded printed circuit board;
FIG. 2 is a perspective view of the interior of one end cover of
the housing shown in FIG. 1, illustrating the detents formed
therein, and an internal gear adapted to be disposed therewithin
for rotary movement between these detents;
FIG. 3 is a perspective view of the interior of another embodiment
of a housing end cover, similar to that shown in FIG. 2, but being
provided with stop members for preventing full revolution of the
control shaft;
FIG. 4 is a side elevational view in cross section of the switch
illustrated in FIG. 1 being shown in its assembled condition, with
a control knob affixed to the projecting end of the control
shaft;
FIG. 5 is a sectional view of the switch shown in FIG. 4, taken
along the line A--A thereof, wherein the detented housing end cover
of FIG. 2 is employed;
FIG. 6 is a sectional view of the assembled switch shown in FIG. 4
taken along the line A--A thereof, wherein the detented housing end
cover having stop members integrally formed therein is
employed;
FIG. 7 is a perspective view of a stacked array of a plurality of
the switch assemblies illustrated in FIGS. 1 and 4;
FIG. 8 is a side view of a portion of the switch shown in FIGS. 1
and 4, illustrating one manner of providing an electrical
connection to a terminal of a brush member thereof;
FIG. 9 is a perspective view illustrating another manner of
providing electrical connection to the terminals of the brush
members of the switch shown in FIG. 1, wherein the pin sections
thereof are bent back to receive posts;
FIG. 10 is an exploded perspective view of another embodiment of a
switch constructed according to the present invention, wherein a
decimal version printed circuit board is provided; and
FIG. 11 is a side elevational cross-sectional view of a portion of
the switch illustrated in FIG. 10, showing the connection of a
circular spring-like brush member to the printed circuit board
thereof.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Referring now to the drawings, and more particularly to FIG. 1
thereof, a housing for the switch of the present invention is shown
being composed of three separate pieces, preferably constructed of
a plastic material either by molding or stamping, and including an
end cover member 10, a central brush housing member 11 and an
opposing end cover member 12, each having a flat planar portion
configuration so that when the pieces are assembled they define a
flat planar portion on the switch as illustrated in the
drawings.
The end cover member 10 is provided with a circular upstanding rib
13 which is adapted to be received in a mating hollow recess 14,
shown in FIG. 4, of the central housing member 11, and with a
plurality of indentations 15 along the interior of the bottom edge
thereof for receiving corresponding projecting tabs 16 of the
central housing member 11, also shown in FIG. 4, during assembly of
the central housing member 11 onto the end cover member 10. A
central recess 17 is also provided in the end cover member 10 for
receiving a disc member 18 preferably constructed of a plastic
material, the purpose of which will be described later. As shown in
FIG. 1, the disc member 18 is formed with a central opening 19
having a square cross-sectional configuration.
A flat circular printed circuit board member 20 having a coded
circuit etched on one face thereof is positioned in the recess in
the end cover member 10 defined by the upstanding rim 13 thereof.
The printed circuit board 20 also is provided with a central
through-opening of a square-shaped configuration.
In assembling the switch, the central housing member 11 next is
positioned on the end cover member 10 with the tabs 16 thereof
being inserted into the indentations 15 as previously described.
The rim 13 registers within recess 14. As shown in FIG. 4, the end
cover 10 includes an annular rim 21 radially spaced of the rim 13
against which the circuit board 20 abuts. The housing member 11
includes an annular rim 21' which is similar to and in opposing
relationship to the rim 21 when the cover 10 and housing member are
assembled. The rims 21 and 21' cooperate to abut and retain the
circuit board 20 therebetween, and to prevent warpage of the
circuit board. The rims 21 and 21' are also relatively thin so as
to provide bearing surfaces of relatively small areas upon which
the circuit board is supported for relatively low friction slidable
rotation. The yet open end of the central housing member 11 also is
provided with an upstanding rib member 22 which is adapted to be
received in a mating recess in the opposing end cover 12 when
assembled. In addition, a central diametrical opening 23 is
provided in the central housing member 11 for permitting access of
brush contact members 24 to the printed circuit board 20. As
illustrated in FIG. 1, the brush members 24 are formed as curved
portions on the ends of carrier strip tabs 25 of a special
configuration, being elongate in nature and having a right-bend 26
formed therein intermediate the length thereof and a wire-receiving
piece 27 at the other end. To accommodate the carrier strip tabs
25, the central brush housing member 11 has a plurality of parallel
grooves 28 formed therein, each having a block 29 which is adapted
to fit within the bend 26 of a carrier strip tab being received in
the groove. Thus, when the carrier strip tabs 25 are placed into
the grooves 28, the bends 26 are placed over the blocks 29 so that
the curved brushes 24 lie in contact with the printed circuit board
20 and the wire-receiving pieces 27 protrude through the flat
planar portion of the switch.
Next, a control shaft 30 having an axial square-shaped opening in
one end thereof for receiving a rod 31 of square cross-section is
projected through a central opening in the end cover member 12. On
the interior surface of the end cover member 12, a recess 32 is
formed, as shown in FIG. 2, the periphery of which is somewhat
tooth-shaped to provide a plurality of detents 33 for engagement by
a gear member 34. The gear member 34 is a substantially ring-shaped
piece having a diametrical arm 35 in which a square-configured
central opening 36 is provided, and a pair of diametrically opposed
projecting tabs 37 on the outer periphery thereof which are
receivable in the detents 33 and are compressible to such an extent
to permit being snapped from one set of detents to an adjacent set
of detents upon rotation of the gear member 34. Thus, the detent
control 33 and the housing member 12 are of one piece construction
for compactness and for elimination of a plurality of separate
parts to simplify assembly.
The end cover members 12 having the gear member 34 disposed in the
recess 32 thereof fits onto the central brush housing member 11,
with the projecting circular rib 22 of the central member 11 being
received in an annular groove 38 formed about the detented-recess
32 of outer end cover member 12. When positioned together in this
manner, the square-configured rod 31 projects loosely through the
opening 23 in the central brush housing member 11, and tightly fits
within the corresponding square-configured openings in the printed
circuit board 20 and the disc member 18, so that any rotation
imparted to the control shaft 30 is operable to cause rotation of
the printed circuit board 20 therewith. The shaft 30 thus provides
an axis of rotation about which the printed circuit board 20 is
rotatably displaceable. Simultaneously, of course, the gear 34 is
rotated when a sufficient turning force is provided for snapping
the projecting tabs 37 between adjacent sets of detents 33.
A plurality of projecting tabs 39 formed on the interior surface of
the opposing end cover member 12 along the bottom edge thereof are
adapted to fit within the lower part of grooves 28 in the central
brush housing member 11, below the blocks 29 therein, when the
cover members are assembled. An upper set of apertures 40, 40' and
40" are respectively provided in the housing members 10, 11 and 12,
as are lower sets of apertures 41, 41', 41" and 42, 42' and 42",
for the purpose of securing the housing members together by
suitable means, such as bolt and nut connection. In this manner,
when so assembled, it may be seen that a dust-proof housing for
enclosing the switch contact elements is provided.
Turning to FIG. 4, wherein the assembled switch is illustrated
being mounted on one side of a panel 43 with the control shaft 30
thereof projecting through the panel, a nut 44 is shown being
threaded onto an externally threaded central projection 45 of the
housing end cover 12 for clamping the switch housing to the panel
43. An O-ring sealing means 46 is shown surrounding the threaded
portion 45 on one side of the panel 43 and a suitable sealing
washer 47 is provided on the other side between the panel 43 and
the securing nut 44. Disposed on the end of the control shaft 30 is
a control knob 48 having a suitably shaped recess for receiving the
end of shaft 30 which, as shown in FIG. 1, has an arcuate portion
thereof cut away, so that rotation of the control knob 48 with a
sufficient force will rotate the control shaft 30 and cause gear
member 34 to move between distinct rotational positions defined by
the detents 33 and the projecting tabs 37, the relationship of
which is most clearly shown in FIG. 5.
In certain cases, it may be desirable to provide a switch of the
character described which is, for example, limited to a number of
preselected positions, and in such cases another embodiment of the
housing end cover 12, as shown in FIGS. 3 and 6 may be provided.
The only distinction between this embodiment and that previously
described is that stop members 50 are integrally formed on the
interior surface of the housing end cover member 12 on the base of
the recess 32 therein. Thus, when the control shaft 31 is rotated
through operation of the control knob 48, the gear member 34 is
caused to turn and is limited in its degree of rotation by the
diametrical arm 35 coming into contact with one or the other of
stop members 50. As shown, rotation through approximately
180.degree. is possible, since one-half of the diametrical arm 35
is formed being of reduced thickness, or cut away on the surface
thereof facing the interior of the end cover 12 such that it is
capable of passing freely over the stop members 50, while only the
other portion of the arm 35 serves to preclude further rotation. It
should be understood, therefore, where it is desirable to permit
nearly complete revolution but to prevent passage through a
predetermined zero-position, only a single stop 50 need be provided
in the end cover 12.
The compact construction provided with the present invention
readily permits stacking of a plurality of the housings formed by
the housing members 10, 11 and 12 in end-to-end relation, such as
illustrated in FIG. 7, in which case if a different code were
provided on each of the printed circuit boards contained therein,
an increased number of functions could easily be performed through
operation of a single control shaft 31, being elongated for the
purpose of extending through all of the stacked housings. Only one
end cover 10 and only one front cover 12 are needed for the entire
stack since a plurality of housing members 11 are stacked directly
in interlocked relationship, such interlocking is accomplished
since the rim 22 of one housing member 11 registers in the recess
14 of an adjacent stacked housing member 11 without a need for any
end cover 10 or front cover 12 therebetween. Thus the rim 22 and
the rim 13 are of similar configuration for registration in a
recess 14 of any housing member 11. Also, the housing member 11 is
provided with a relatively thin annular rim 21" similar to the rim
21 on the end cover 10, so that when an end cover 10 is eliminated
between two stacked housing members 11, the rim 21" of one housing
member 11 will cooperate with the rim 21' of the other stacked
housing member to slidably support a circuit board 20 in the same
manner as the board 20 is supported by the rims 21 and 21' as shown
in FIG. 4. Thus, between stacked housing members 11, the cover 10
can be eliminated, with an adjacent housing member 11 performing
the functions of the cover plate 10. This results in a compact
assembly with the control shaft 31 being supported only at its
ends, by one end cover 10 at one end, and by one housing member 12
at the other end. With only one housing member 12 required, only
one detent control 33 is needed for an entire assembly of stacked
circuit boards 20.
Turning now to FIGS. 8 and 9, there are shown different methods of
electrically connecting the brushes 24 exteriorally of the housing
which may be employed with the compact and unique construction of
the present invention. In FIG. 8, for example, an electrical wire
may be bent in a conventional manner and inserted into the
wire-receiving piece 27 of the carrier strip tabs 25, which then is
compressed thereabout. In FIG. 9, however, the wire-receiving
pieces 27 are shown being bent back for receiving terminal posts,
such that a plug-in adaptation would be possible. It is noted, in
this respect, that the inputs and outputs, or all of the carrier
strip tabs 25, are positioned in one plane to facilitate plugging
the same into a printed circuit board.
Another embodiment of the present invention is illustrated in FIGS.
10 and 11, wherein a decimal version is provided. In this
embodiment, a housing member 51 provides a recess 52 for receiving
a printed circuit board 53, with a tab 54 projecting from the
recess 52 being engaged with an aperture 55 in the printed circuit
board. A thin disc-like piece 56 having a central square-configured
opening and a plurality of pins projecting from one face thereof is
fixed to one face of the printed circuit board 53 with the pins
thereof extending through a central opening 57 in the board being
received in corresponding pin openings in a thin washer element 58
on the printed circuit side of the board 53. A ring brush member 60
is engaged between the washer member 58 and a plug 61 having a
central post extending through an opening of the brush ring 60 and
a base member having pin openings therein for receiving the pins of
the disc member 56 and extending through the washer member 58. The
base and post portions of the plug member 61 are provided with a
continuous through opening of square configuration for receiving a
control shaft 31 of the type described hereinbefore. The brush ring
60 accordingly is rotatably fixed on the printed circuit board
53.
Referring more particularly to FIG. 11, the brush ring 60 is shown
having arcuate arms 62 and 63 extending in opposite circumferential
directions which are bent in the direction of the printed circuit
board so that the ends thereof engage the board. The one arm 62 is
at a lesser radial distance from the brush ring center than the
other arm 63, such that it is always in engagement with an annular
conductive area 64 on the board 53 positioned about the central
opening 57 therein. The other arm 63 is adapted upon rotation of
the brush ring 60 to engage a different one of a plurality of
conductive areas 65 on the printed circuit board, whereby different
circuits may be connected according to the rotating of the control
shaft to preselected different rotary positions.
With this embodiment, an end cover, not shown, must be provided on
the side of the housing member 51 opposite the printed circuit
board 53, and another end cover 66 having the same detent and
internal gear arrangement as described above must be provided for
the printed circuit board side of the housing member 51. These end
covers must of course be different than the end covers 10 and 12
above, especially along the bottom edges thereof, so that they
conform to the housing member 51 to provide a dust-proof enclosure.
Obviously, the outputs of the printed circuit board 53 may be made
for plugging the same into a printed circuit board or they could be
provided with spaced tabs for breaking conventional wire
connections.
With the embodiments described hereinabove, it should be clear that
the objects of this invention have been achieved. Further, in order
to vary the code of any of the switches described herein, it is
only necessary to change the printed circuit board, which may be
accomplished at the time of manufacture. The number of detent
positions is determined by the code, or the design of the
conductive area of the printed circuit board. Because of the
plastic material used in manufacturing the parts, the switch is
less susceptible to damage, and its novel arrangement of elements
makes the switch more adaptable to various applications, while at
the same time being very compact.
Obviously, many modifications and variations are possible in light
of the above teachings. It is to be understood, therefore, that
within the scope of the appended claims the invention may be
practiced otherwise than is specifically described herein.
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