Switch construction with integral mounting clips

An electrical switch mounting structure includes a housing for the switch, terminals on the exterior of the housing, a substrate incorporating an opening into which the housing is inserted, conductive elements on the base which contact the terminals upon insertion of the housing, and elastic mounting members which both retain the housing in the base and assure contact between the terminals and the conductive elements.

BACKGROUND OF THE INVENTION 
This invention relates to electrical switches or other electrical 
components and, more particularly, to the means of connecting such 
components to the circuits to which they interface. While electrical 
switches have been used for a variety of purposes and have taken many 
forms, the means used to connect them to external electrical circuits have 
been limited. Previously used connections have included the use of 
soldered, welded or crimped terminals and other connectors such as 
threaded fasteners which are used to complete the conductive path between 
the terminals of the component and the external circuit. In each of these 
methods of connection, the means used to connect the switch to an external 
circuit involves a substantial number of parts and significant manual 
labor and/or manufacturing steps associated with the connection process. 
When this multiplicity of manufacturing steps, connecting components and 
labor is added to the mounting labor and components, it can be seen that 
the installation of the switch in most subassemblies utilizing them 
represents significant cost and complexity in the manufacturing process. 
With the increased automation of manufacturing processes and high cost of 
skilled labor, it has become very desirable to develop components and 
assemblies which can be simply and reliably assembled by machines or 
unskilled labor in a relatively small number of operations. As described 
above, the current systems for connecting switches to external circuits 
and mounting the switches in subassemblies do not readily lend themselves 
to this type of automated process, so there is a need for an economical, 
simple, easily assembled mounting and connection system for switches. 
SUMMARY OF THE INVENTION 
The present invention provides substantial improvements over present switch 
assembly concepts and provides solutions to all of the problems noted 
above related to switch mounting and connection systems which have been 
previously available. The invention provides simple and reliable onestep 
installation and connection for a wide variety of switch types, including 
those which are actuated by external means and which may incorporate 
multiple actuation subassemblies. 
The invention provides this advantageous capability by incorporating into 
the switch housing both the terminals to connect to an external circuit 
and a switch mounting concept providing positive retention of the switch 
mount in a substrate and a means of positively urging contact between the 
terminals on the switch mount and conductive means built into the 
substrate. The invention accomplishes these desirable effects by 
advantageously using a unique configuration of resilient switch body 
mounting arms. This configuration, in combination with a compatible 
opening in the substrate, positively retains the switch after insertion. 
Once installation is completed, the resilient switch body mounting arms 
urge the switch body in the direction of insertion, thereby bringing 
terminals incorporated into the base of the switch housing in contact with 
a conductive printed circuit on the substrate. The printed circuit is 
configured to correspond to the configuration of the terminals and is on 
the side of the substrate facing the terminals. The terminals are formed 
to provide a contact area in a relatively small footprint of the terminal, 
thereby increasing the contact pressure and precisely locating the area to 
which the printed circuit formed on the substrate must conform. 
It can be readily seen that the configuration of the various components of 
the invention may take a variety of forms, including various shapes of 
openings into which the switch body is to be inserted, various 
arrangements and configurations of terminals and various types of elastic 
arms formed into the housing of the switch, which satisfy the requirement 
to both positively retain the switch and urge the switch axially in the 
direction of insertion during the mounting process. Naturally, the actual 
configuration of each of these components may be altered to best suit the 
purposes for which the switch and its connections are adapted. 
While the above is intended as a description of the invention, other 
advantages to the invention will be apparent to those skilled in the art 
and they may adapt the invention to various purposes as the utility of the 
invention becomes known to them. Therefore, the above description should 
not be considered limiting and should only be considered in light of this 
specification and the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in the exemplary drawings, referring first to FIG. 1, the present 
invention is embodied in a switch body 10 having terminals 12 and elastic 
mounting means 14 designed to urge terminal 12 contact with a conductive 
portion 16 on substrate 18 after insertion of switch body 10 through 
opening 20 in substrate 18, the elastic mounting means 14 further 
retaining the switch body external mounting surface 19 against substrate 
18. 
Elastic mounting means 14 are designed to perform two functions: 1) to 
positively lock external mounting surface 19 of switch body 10 against 
substrate 18 once it has been inserted through opening 20, and 2) to 
thereafter positively urge terminals 12 against conductive portion 16 of 
the substrate. Conductive portion 16 may advantageously be made by 
deposition or forming a metal layer in a selected pattern on said 
substrates by any of a variety of well known processes such as photo 
etching. These functions are accomplished by constructing elastic members 
14 as cantilevered curved beams eminating from the switch body 10 in such 
a way that they are progressively deflected as switch body 10 is inserted 
in opening 20 in substrate 18 until terminals 12 are brought in contact 
with conductive surface 16. The length of elastic members 14 are designed 
to that notch 22 is reached as switch body 10 reaches its mounted 
position, thereafter snapping back to their extended positions. In that 
position, detent 32 of cantilevered arm 24 provides constant tension 
against surface 28 of the substrate 18, thereby urging terminals 12 
against the conductive portion 16 of the substrate. 
Referring to FIG. 2, installed switch body 10, after insertion into 
substrate 18 is viewed from the conductive side 16 of substrate 18. 
Conductive layer 16, details of terminals 12 and the configuration of 
conductive portions and nonconductive portion 30 of substrate 18 on 
external mounting surface 19 are illustrated. While a single configuration 
of the combination of terminals and conductive pattern is shown, those 
skilled in the art will see a variety of arrangements of terminals, 
insulative elements and conductive elements which would be useful for 
various purposes. In FIG. 2 a symmetrical configuration is illustrated so 
that the switch may be inserted in either one of two ways and still 
provide the proper connections. Such a configuration is very useful when 
the switches are to be automatically inserted and it is not desirable to 
use special equipment to orient the switches prior to insertion. The 
configuration illustrated also employs insulated lugs 34 which serve to 
protect the terminals during handling and also provide addtiional bearing 
area for stability once the switch is inserted. 
FIG. 3 illustrates a cross section of the installed switch showing a detail 
of the elastic mounting members 14. In this illustration, switch body 10 
has been fully inserted into opening 20 and cantilever arms 24 have 
snapped into their mounted positions after insertion through hole 20 as 
the switch body was inserted. Detents 32 thereafter come in positive 
contact with the face 28 of substrate 18 opposite the conductive portion 
16 of external mounting surface 19 thereby urging switch terminals 12 and 
stabilizing lugs 34 axially against conductive surface 16, thereby 
completing contact between the terminals and the conductive portion of the 
substrate. Elastic mounting elements 14 may take a number of forms 
depending upon the geometry of switch body 10 and the opening 20. In order 
to further stabilize the switch once it is installed, lugs 36 are formed 
into the base of switch 10 to prevent rotation about the invention axis 
after installation is completed. 
FIG. 4 illustrates a view axially along the center line of the switch, 
after installation, looking in the direction of the substrate opposite the 
conducting layer. Here, elastic mounting elements 14 have returned to 
their extended position once the switch has been inserted, thereby 
preventing the switch from being withdrawn through opening 20. 
FIG. 5 illustrates a detail of the terminals 12 on switch body 10 wherein 
the elastic terminal element 38 causes constant tension of the terminal 
against conductive layer 16. The dimple 40 formed in the terminal provides 
both contact with the conductive layer 16 and prevents jamming of the 
terminal into the conductive layer due to the relative low friction of the 
dimple against the conductive layer (caused by the smoothness of the 
spherical dimple formed) compared to an unfinished planar terminal. The 
dimple further enhances reliable contact due to the relatively high 
pressure exerted by the dimple against the conductive layer compared to 
lugs of larger area (e.g., planar surfaces) using the same elastic portion 
of the terminal 38. 
FIG. 6 illustrates a perspective detail of the elastic mounting means 14 
and stabilizing lug 36. As can be seen from this illustration, the purpose 
of stabilizing lugs 36 is to flank the elastic members 14, thereby 
providing a means to prevent rotational action of the switch within 
opening 20 once it has been inserted. This is useful when lugs 34 are only 
configured to prevent movement in an axial direction after insertion in 
order to enhance their terminal function. 
FIG. 7 illustrates a cross section of an alternative arrangement of the 
terminal 12 designed to allow contact with a narrowed conductive area on 
the substrate compared to the configuration of FIG. 1. This configuration 
also has the benefit of providing a variable range of contact pressure due 
to the various configurations in which terminal 12 can be formed. For 
example, the radius of loop 42 and the thickness or widths of terminal 12 
may be altered, thereby changing the spring rate and therefore the 
pressure exerted by dimple 40 against conductive surface 16. 
From the foregoing it will be appreciated that the switch mounting and 
connection system of the invention provides a useful and improved means of 
mounting and connecting electrial switches, especially those which must be 
inserted by machine or with relatively low skilled labor and for which a 
minimum number of parts and operations associated with the insertion and 
connection is desirable. While the invention has been illustrated as a 
means of mounting and connecting switches, it will be appreciated that the 
concept is readily adaptable to various other electronic or 
electro-mechanical devices which require the same simple insertion and 
connection means and which can advantageously use the benefits of the 
present invention. 
While several forms of the invention have been illustrated and described, 
it will also be apparent that various modifications can be made without 
departing from the spirit and scope of the invention. Accordingly, it is 
not intended that the invention be limited except by the appended claims.