Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF T~IE INVENTION
This invention relates generally to electrical control assemblies
including control switches and the like~ and more particularly to such assemblies
that provide a degree of flexibility as to the various switching functions that
may be combined from common components.
Nearly every installation in lnd~stry involving heavy electrical
equipment such as electrical motors inc:Ludes controls therefor of a low current
type that is electrically connected to solenoid switches of the main electrical
supply lines on the piece of equipment :Ltself. The control ls often remotely
positioned from the equipmen-t to be controlled. A particular control assembly
depends upon the application, of course, and may have various combinations of
push button control switches, rotary switches and indicatiny pilot lights.
Presently, each particular combination of a control assembly is separately manu-
factured and carried in inventory in a completed form.
Therefore, it is a primary object of the present invention to provide
cooperating elements for easy assembly into any one of numerous possible modular
electrical control station combinations.
SUMMARY OF THE INVENTION
Briefly and generally, this primary object is accomplished by the
present invention wherein a housing is provided having a top opening giving
access to its interior, a plurality of cover plates that differ by thè number of~
holes therein being easily snap fitted into the top opening of the housing,
control members in turn being fitable into the openings of the cover plate
(selected from a spring-loaded push button, a rotary switch or a pilot light lens)~
with means provided for snap fitting appropriate electrical contact assemblies
or pilot light socket blocks within said housing at positions with respect to the
openings of the cover plate that permits cooperation with the respective panel
element installed in the opening.
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The result is that only a few different types of parts need to be
manufactured and carried in inventory. The parts are designed to be combined
substantially en~irely by hand through snap fittiny plastic members for providing
a particular desired combination of switches and indica-tor lights~ These combi-
nations may even be made by the ultimate user himself who can maintain a supply
of the few required parts on hand, or they may be assembled to order by the
manufacturer in a manner much more easiLy than heretofore.
Additionally, as part of the present invention, an improved snap
fitting is provided for ~uick and sure assembly of contact blocks and light
socket blocks into the housing without the use of tools. Upright inverted L-
shaped hooks are provided at the bottom of the housing for receipt by mating
receptacles at the bottom of the blocks. Once inserted, the block is moved
along the bottom of the housing to engage the hooks. This movement also
activates a resilient snap lock that prevents further movement of the block
along the base until the snap lock is manually disengaged. This manner of
connecting two elements further has additional applications in other environ-
ments wherein two elements are desired to be connected together.
According to other aspects of the present invention, a particular
rotary knob structure is provided that permits either two or three positive
positions to be maintained by the rotary knob. The adjustment between two or
three positions is easily carried ou-t by hand. Additionally, an improved push
button structure is provided that permits easy insertion and removal by hand of
a spring-loaded push button as.sembly. The rotary knob and push button assembly
cooperate with contact blocks properly placed and connected within the control
assembly housing for carrying out desired switching operations.
Additional objects, advantages and features of the present invention
are given in the following detailed description of its preferred embodiment
which should be taken in conjunction with the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
Fiyure 1 is an exploded view of a control assembly embodying -the
various aspects of -the present invention in a particular example;
Figures lA and lB show alterna-te cover plates to -tha-t shown in
Figure l;
Figure 2 is a cross-sectional view of a ,portion of the assembly of
Figure 1 taken at section 2-2 thereof i,n an assembled form;
Figures 2A and 2B illustrate the connection of parts shown in
Figure 2 after further relative movement therebetween;
Figure 3 shows in plan view the cover plate of Figure l;
Figure 4 is a sectional view of the cover plate of Figure 3 taken
across section 4-4 thereof;
Figure 5 is a sectional view of the cover plate o~ Figure 3 taken
across section 5-5 thereof;
Figure 6 is a cross-sectional view of a portion o~ the assembly of
Figure 1 taken across section 6-6 thereof in an assembled form;
Figure 6~ illustrates a modification of a portion of Figure 6;
E'igure 7 is a cross-sectional view of a portion o the assembly of
Figure 1 taken across section 7-7 thereof when in an assembled form;
Figure 8 is a cross-sectional view of a portion of the assembly o
Figure 1 taken across section 8-8 thereof when in an assembled form; and
Figure 9 is a plan view of the base and retainer assembly of Figure 1
DESCRIPTION OF THE PREFERRED EMBODIMENT
The modular electrical control station construction of the present
invention permits the formation of a large number of differen-t combinations of
control functions into a single type of enclosure with only a few basic component
types Referring principally to Figures 1, 1~ and lB, at least one of each of
the b-sic components us~d as tullding tlocks to form a desired control ststion
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is illustrated. A base 11 has a cover 17 attache~ thereto by screws 13 and 15.
On a bottom surface of the base member 11 is installed a retainer ]9 having
seven parallel rows of tabs that each carry the same elements and extend across
the narrow dimension of the rectangularly-shaped base bot-tom surface.
A contact block 21 is provided with mating connecting members ~or
installation in any one of the seven rows of tabs on the retainer 19. The
contact block 21 is characterized by a spring-loaded mechanical push button 23
on its top surface. The contact block 21 is chosen to be one of two types.
Depression of the button 23 on one type of contact block will cause an internal
electrical connection to be made between its -two external electrical terminals
(normally open type). Another type of contact block 21 will cause an electrical
circuit between its two external terminals to break when the button 23 is pushed
(normally closed type). Two other contact blocks 25 and 27 are also illustrated
in the particular combination of Figure 1 and are individually chosen to be of
the normally closed or normally open type according to the d~sired application.
A lamp socket block 28 attaches to the base 11 by any two adjacent ro~s of tabs
of the retainer 19.
To the housing formed by attachment of the cover 17 to the base member
11 is added a cover plate 29. The cover plate 29 has a downwardly extending wall
along each of its four sides, one such wall denoted by the reference number 31.
At the bottom of that wall is a rib 32. A rectangular opening 33 in the top of
the cover 17 also has downwardly extending walls on each of its four sides, sueh
as the wall 35. The lower portion of each of these cover walls contains either
a groove or a lower most edge matched to receive a mating rib, such as the rib
32. All downwardly extending walls, molded integrally with their associated
part, have some resiliency and thus results in the cover plate 29 securely snap-
ping into place on the cover 17 when the downward extending walls of the cover
plate 29 are inserted into the opening 33. For an additional secure eonneetion,
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metal spring clips 37 and 39 may be used to urge adjoining walls, to which theyare clippea, toward each other.
The cover plate 29 has been shown to be of the type having three
openings, 41, 43 and 45 therein or receiving three difEeren-t panel members.
Alternative cover plates 47 and 49 of Figures lA and lB, respectively, may
alternatively be utilized for appropriate control stations. The cover pla-tes
47 and 49 are of the same size and fit in the same way in the opening 33 of the
cover 17 as does the cover plate 29. The only difference between the cover
plate types is in the number of holes provided for attachment of panel members.
If only two panel members are needed, the cover plate 47 is u-tilized having its
two holes 51 and 53. Similarly, if only one panel member need be utilized, the
cover plate 49 is chosen having a single hole 55.
Figure 1 illustrates one each of three possible panel members utilized
together in a final control station. One of these panel mem~ers is a push
button assembly that includes a push button 57 and a spring 59. The second
panel member illustrated is a rotary switch assembly including a rotary knob 61
that is fixed to a cam element 63 protruding below the hole 43. The third panel
member illustrated in Figure 1 is a panel light lens 65 -that receives light
through the opening 43. The circularly shaped lens 65 snaps into a circular
depression within the cover plate that surrounds the hole 45.
Although a particular combination of components is illustrated in
Figure 1 for discussion pbrposes, the principal advantage of the components is
that they may be combined in many different ways. A push button assembly may be
installed into any one of the holes of the cover plates 29, 47 and 49. Similarly,
the lens 65 can be installed into a depression surrounding any of the holes of
any of the three different cover plates. Because of a slightly more complex
structure, only one of the holes of each of the cover plates is necessarily
formed with associated recesses and grooves for operably receiving the rotary
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knob 61, as described in more detail hereinafter, but each of the holes could
be so structured if desired. It should be noted that any o~ the possible custom
arrangements of the various components illustrated can be made without the use
of any tools except for a screw driver for the three screws illustrated in
Figure 1.
In the particular combination of Figure 1, an electrical pilo-t lamp 67
is connected to the lamp block 28 for shining through the lens 65. The lens 65
can be manufactured in as many different colors as desired. The contact block
21 is positioned on the base 11 under the hole ~1 of the cover plate 29 in the
path of the push button 57. The button 23 of the con-tact block 21 is depressed
when the push button 57 is so depressed. The two contact blocks 25 and 27 are
positioned for their top buttons to be depressed upon rotation of the cam 63 by
the knob 61. The cam 63 ana the contact block top push button sides are coopera-
- tively shaped so that rotation of the cam 63 by the knob 61 will cause one or the
other of the contact blocks 25 or 27 to be depressed, depending upon which
direction the knob is turned from the rest position shown in Figures 1, 7 ana 8.
It is often convenient that one of the contact blocks 25 and 27 be a normally
open type and the other be a normally closed type.
Referring to Figures 2, 2A and 2B, the structure permitting a tooless
snap connection of a contact block or lamp socket block to the retainer 19 of
the base 11 is illustrated. Each of the seven rows of upstanding tabs~of the
retainer 19 include two upwardly extending inverted L-shaped hooks 71 aDd 73 as
well as a resilient tab 75 that normally extends upward upon its hinge connection
with the retainer 19. Each of the hooXs 71 and 73 contains an orthogonally
upright portion and a terminal portion integral therewith that is substantially
parallel to the plane of the retainer plate 19 but spaced a distance thereabore.
Each of the contact and lamp socket blocks, such as the contact block
21 being illustrat:ed, includes two apertures 77 and 79 spaced apart in si~e to
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fit, respectively, downward over the hooks 71 and 73. As the block 21 is
pushed downward against the force of the resilient tab 75, it is pushed
against the sur~ace retainer 19, as shown ln Figure 2A. The b]ock 21 is
then moved laterally across the narrow dimension of the retainer 19 until
its bottom wall is held within the hooks 71 and 73, as shown in Figure 2B.
Of course, the upper portion of the hooks 71 and 73 are spaced ~ust far
enough above the surface of the retainer 19 to permit the wall of the block
21 to securely fit thereunder.
As shown in Figure 2B, once the block 21 is moved as far as per-
mitted by the hook 73, the tab 75 is permitted by a notch 81 at one end
of the block 21 to resiliently return to an upright position. When in the
position shown in Figure 2B, the block 21 is securely fastened to the re-
tainer 19 until a time that the tab 75 is pushed downward to permit the
reverse sliding movement of the block 21 and lifting up from the hooks 71
and 73.
As can best be seen from Figure 9, the hooks 71 and 73 have dif-
ferent widths in plan view. The apertures 77 and 7~ in the bottom of a
block 21 similarly have different matching widths, thereby assuring that
the block will be oriented in the correct direction when inserted. The
three connecting elements of each of the seven rows of the retainer 19 are
similarly shaped and oriented for identical operation with a block to be
connected therewith.
Referring again to Figure 9, the rows of the connecting elements
are shown with the various holes of the cover plates 29, 47 and 49
(Figures 1, lA and lB) shown in dotted outline in order to illustrate
the relative position therebetween. The hole 45 of the three hole plate
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29 is positioned so that the panel member selected therefor cooperates
with a block or blocks attached to the ~irst two rows of connecting ele-
ments of the retainer 19 (rows numbered from right to left). The center
hole 43 of the three hole plate 29 and the hole 55 of the one hole plate
49 are superimposed in the position to cooperate with the blocks attached
to either or both of the fourth and fifth rows of connecting elements of
the retainer 19. The hole 41 in the three hole plate 29 cooperates with
only the seventh row of connecting elements. An eighth row could be added
to the retainer 19 for operation with the opening 41 as well, if desired.
The hole 51 of the cover plate 47 is similarly associated with;the fifth
and sixth rows of contact elements and the hole 53 of that same plate is
associated with the second and third rows.
Referring principally to Figures 3 and 4, a shape common to all
of the holes in the cover plates may be described. Using the hole 41 as
an example, it is formed of a circular portion 41a having a center at the
center of the hole structure about which remaining structural features of
the hole are symmetrical. On either side of the circular opening 41a are
two additional circular openings 41b and 41c having lesser diameters than
the opening 41a and having their centers removed along the length of the
cover plate 29 from the center of the opening 41a. All three openings
overlap, to form a single opening having a long direction in the long
direction of the rectangular cover plate 29. Surrounding the hole 41 is
a circular walled portion 81 and yet surrounding that is a circu~ar
walled portion 83 extending upward to the top surface of the cover plate
29. The centers of the walled portions 81 and 83 are concentric with the
cen'ter of the opening 41
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ReEerring principally to Figure 6, the construction and operation
of a push button panel member is described. The push button 57 is made
of a unitary base portion 85 and two downwardly extending prongs 87 and 89
that form a stem of the push button assembly. Snapped onto the base 85
is a cap member 91. A selection of cap members may be provided as part of
the components available for assembling particular control stations. The
caps may be of various colors and may carry notations such as "start" and
"stop". It is sometimes desirable to have the push button extend Eurther
outward from the control station, so a second set of different sized caps,
such as that shown in Figure 6A as cap 93, may be provided. The cap 93
has a larger thickness than the cap 91 but they both snap onto the base
85 of the push button assembly in the same manner.
Each of the prongs 87 and 89 of the push button assembly-have,
respectively, enlarged outwardly extending portions 95 and 97 at their
lower extremities. These portions join the main part of the stems ~7
and 89 by a ledge which, when the push button is installed as shown in
Figure 6, serve to limit travel of the push button assembly away from the
front of the cover plate 29. The outside surfaces of the enlarged por-
tions 95 and 97, however, are tapered inwardly toward their button edges
so that the knob stem can be inserted through the hole 41. The stems 87
- and 89 are resilient enough that they can be pressed together for fitting
the enlarged portions 95 and 97 through the hole 41. After such insertion,
an 0-ring spacer 99 may be placed in the gap between the prongs 87 and 89
in order to prevent them from moving together when it is not desired for
them to do so.
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As can be seen best by the perspective view of Figure 1, the
prongs 87 and 89 of the push button structure are elongated in width.
This elongated shape matches that of the hole 41 and provides enough
width for operating two contact blocks simultaneously, if desired. The
spring 59 is normally in a compressed state between the underslde of the
push button base 85 and the region of the cover plate 29 surrounding the
hole 41 within the depression Bl.
Referring to Figure 5, the rotating knob receiving structure of
the cover plate 29 surrounding the opening 43 will be described. This
structure is provided around at least one hole of every cover plate and
permits the rotating knob to be maximally utilized. In a ledge adjoining
circular depressions 81'and 83' are arcuate grooves 101 and 103. Each of
these grooves has the same radius with respect to the center of the hole
43 and has a arcuate extent of somethi~g less than 180 . The arcuate
grooves 101 and 103 are equally spaced around a complete circle; that is,
there is equal space between them on either side.
` As further structure for a knob assembly operation, two circulardepressions 105 and 107 are provided on one side of the hole 43 and in
the button of the circular portion 81'. On the other side of the hole
43 are three such deprassions 109, 111 and 113. All of these five circular
depressions have their centers on a circle with its center coincident with
that of the hole 43. The two depressions 105 and 107 are positioned in
one 180 segment of that circle and the other three depressions 109, 111
and 113 are positioned on the other 180 segment of that circle.
Referring principally to Figures 7 and 8, the structure of the
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knob that cooperates with the just described features of the cover plate
29 will be described. A sprlng loaded detent 115 is carried by the knob
61 at a positionto engage any of the circular depressions 105 through 111
of Figure 3. The bottom of the detent 115 is rounded so that the knob is
not prevented from moving past such an engagement but rather the detent
115 merely provides a positive position that the operator can feel. When
in any of the depressions 101, 105, 109 and 113, the detent 115 also main-
tains the cam 63 in a position holding down the top button of one of the
contact block 25 and 27.
A slide 117 (Figure 8) is provided within the knob 61. It has at
a lower extremity thereof a projection 119 that is radially positioned for
riding in either of the grooves 103 or 101 (Figure 3) of the cover plate
29. When the projection 119 is riding in the groove 103, the knob 61 will
have three positive positions since the detent llS will move among the
circular holes 109, 111 and 113 of the cover plate 29. The finite arcuate
extent of the groove 103 prevents the knob from being rotated any further
than that. If for a particular installation, however, a rotary knob having
only two positive positions is desired, then the slide 117 of the knob is
lifted upward to disengage the projection 119 from the groove 103. The
knob is then rotated 180 and the slide 117 again depressed back into the
knob for its projection 119 to engage the slot 101. The upward limit of
the slide 117 is shown in dotted outline in Figure 8. These features per-
mit a single rotary knob structure to be used for two or three position
operation rather than requiring two different component structures to be
built.
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Although the various aspects of the present invent:Lon have been
described with respect to a particular preferred embodiment thereof, it
will be understood that the invention is entitled to protection within the
full scope of the appended claims. For instance, although certain of the
aspects of the present invention have been described with respect to a
particular modular electricalcontrol station assembly where they have a
high degree of utility, it will be recognized that these features have a
broader application in other environments and applications as well.
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