Snap-in arrangement for mounting devices in a support panel aperture

The snap-in arrangement includes a resilient locking flange and a resilient skirt located on the outer end of and extending from the opposite sides of a bushing which extends from a switch frame mounted on a switch base of an electrical toggle switch assembly and pivotally supports a toggle lever for actuating switch contacts housed on the switch base. The locking flange, which terminates in a lip, is first inserted through a square or rectangular support panel mounting hole and is hooked over one edge of the hole. The lip abuts the front of the panel and cooperates with a ridge provided on the bushing body and adapted to abut the back of the panel to secure one side of the bushing on the panel. The switch assembly is thereafter rotated relative to the back of the panel so that the outer portion of the skirt can be squeezed through the mounting hole and the skirt thereafter returns toward an undeflected condition. The side of the bushing including the skirt is secured on the panel by the cooperation of a shoulder on the skirt adapted to bear against the front of the panel and a bearing surface provided on a resilient retainer member and adapted to bear against the back of the panel. In one embodiment the retainer member is an integral extension of the skirt and in other embodiments the retainer member is formed integrally with the bushing body.

BACKGROUND OF THE INVENTION 
This invention relates to push-in or snap-in mounting means for mounting a 
device in the hole of a mounting panel and, more particularly, to such 
mounting means adapted for use with electrical devices, such as a toggle 
switch or the like. 
Push-in or snap-in mounting means for mounting devices such as toggle 
switches and other electrical components in a hole provided in a bulkhead 
or support panel are known. Many prior art panel mounting means have 
relatively complex constructions, require special tools for mounting 
and/or the mount does not provide a smooth and neat appearance at the 
front of the panel. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide a snap-in mounting arrangement 
which is adapted for mounting devices, such as electrical switches and the 
like, in a support panel mounting hole and which is arranged to facilitate 
simple and quick installation of the device without special tools. 
Another object of the invention is to provide such a snap-in mounting 
arrangement which permits the device to be installed in a square or 
rectangular mounting hole from the back of the panel and presents a smooth 
and neat appearance from the front of the panel. 
A further object of the invention is to provide such a snap-in mounting 
arrangement which is arranged to accommodate support panels of different 
thicknesses. 
The snap-in arrangement provided by the invention includes a bushing having 
an outer end portion to be received in the mounting hole of a support 
panel on which the device is to be mounted and carrying a part which is to 
be accessible from the front of the panel after mounting. The snap-in 
arrangement further includes a resilient locking flange flaring from the 
outer end portion of the bushing on a first side of the bushing toward the 
device and terminating in a lip adapted to bear against the front side of 
the panel, one or more ridges on the first side of the bushing adapted to 
abut the back of the panel, a resilient, inwardly deflectable skirt 
extending from the top portion of the bushing on the opposite or second 
side of the bushing toward the device and having a shoulder adapted to 
abut the front side of the panel at the opposite side of the mounting hole 
and a resilient retainer member located on the second side of the bushing 
and having one or more surfaces adapted to bear against the back of the 
panel at the opposite side of the panel. 
After the flange has been inserted through the mounting hole, the lip 
thereof cooperates with a bushing ridge to secure the first side of the 
bushing on the panel. As the skirt is thereafter pushed into the opposite 
or second side of the mounting hole, it is deflected inwardly to permit 
passage through the hole and then snaps back toward an undeflected 
condition where the shoulder thereof abuts the front of the panel at the 
second side of the mounting hole and cooperates with a bearing surface of 
the retainer member to secure the second side of the bushing on the panel. 
When the mounting hole is square or rectangular, the flange and skirt 
cover the sides of the hole and the opposite ends of the bushing body 
substantially completely fill the hole, thereby presenting a smooth and 
neat appearance at the front of the panel. 
The retainer member can be formed as an integral extension of the skirt or 
be separate from the skirt and formed integrally with the second side of 
the bushing. In order to accommodate panels having different thicknesses, 
the first side of the bushing can be provided with a plurality of ridges 
which are spaced at different distances from the flange lip and the 
retainer member can be provided with a plurality of serrations or steps 
which are spaced at different distances from the skirt shoulder. 
Other objects, aspects and advantages of the invention will become apparent 
upon reviewing the following detailed description, the drawings and the 
appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Illustrated in FIGS. 1, 2 and 7 is an electrical toggle switch assembly 10 
incorporating a snap-in mounting means of the invention. The toggle switch 
assembly 10 includes a snap-in bushing 12, a toggle lever 14, a switch 
frame 16 and an insulating switch base 18 (illustrated schematically by 
dashed lines) which houses electrical contacts (not shown). The switch 
base 18 and the toggle lever 14 are of conventional design so a detailed 
illustration and description of the structural features thereof are not 
necessary for a full understanding of the invention. For example, the 
Miller U.S. Pat. No. 3,146,330, issued Aug. 25, 1964, illustrates a toggle 
switch assembly including a switch base and toggle lever arrangement 
adaptable for use in the invention. 
The switch frame 16 has a generally rectangular top 20 and a pair of 
depending legs 22, 24, one at each end. Located on the lower end of each 
leg 22 and 24 is one or more tabs 26 which, upon assembly of the switch 
frame 16 on the switch base 18, are bent over into engagement with the 
switch base to securely retain in the switch frame on the switch base with 
the top 20 covering the open top of the switch base. 
The bushing 12 includes a main body 28 which has a generally rectangular 
cross section and is suitably mounted, at the lower end, on the top 20 of 
the switch frame 16 coaxially with an aperture 30 provided in the switch 
frame 16. While various mounting arrangements can be used, in the specific 
illustration, a relatively thin annular extension 32 is provided on the 
lower or inner end of the bushing body 28 and this extension is swaged 
into tight engagement with the underside of the switch frame 16. If 
desired, the bushing 12 and the switch frame 16 can be formed as a 
one-piece unit, such as by molding from a suitable insulating 
thermoplastic material, and the unit is suitably mounted on the switch 
base 18, such as by rivets or bolts extending through the switch base. 
The bushing 12 has a central bore 34 for receiving the toggle lever 14 
which has an external handle and extends through the bushing bore 34 with 
the lower end thereof extending into the switch base for actuation of 
switch contacts, for example, as disclosed in the above-identified Miller 
Patent. The toggle lever 14 also includes an enlarged spherical portion 36 
which bears against a constricted portion 38 of the bushing 34 to afford 
pivotal movement of the toggle lever relative to the bushing during 
actuating movement thereof. 
The bushing 12 includes an integral push-in or snap-in means which is 
arranged to permit the outer or top end portion of the bushing to be 
pressed through a rectangular or square mounting hole 40 in a bulkhead or 
support panel 42 on which the switch assembly 10 is to be mounted from the 
rear or back side and thereafter serves to assist in securing the switch 
assembly on the support panel. 
Located on the opposite sides of the bushing 12 for this purpose is a 
resilient locking flange 44 and a resilient skirt 46. As viewed in FIG. 1, 
the locking flange 44 is located on the right side of the bushing 12, 
flares outwardly from the outer or top end of the bushing 12 toward the 
switch frame 16 and terminates in a locking lip 48 which is adapted to 
bear against the front side 50 of the panel at one side of the mounting 
hole 40. 
The right side of the bushing body 28 is provided with at least one ridge 
having a laterally extending shoulder or surface 52 which is spaced from 
the lip 48 at a distance approximating the thickness of the support panel 
42 and is adapted to abut the back side 54 of the support panel adjacent 
the mounting hole. The ridge surface 52 cooperates with the flange lip 48 
to secure one side (i.e., the right side as viewed in FIG. 1) of the 
bushing 12 on the support panel. Preferably, as shown in the drawings, the 
right side of the bushing 12 is provided with a plurality of ridges with 
the abutting surfaces 52 thereof being located in vertical, 
parallel-spaced relation to each other and spaced from the lip 48 at 
different distances so as to accommodate a range of different panel 
thicknesses. That is, whatever this panel thickness might be over a 
predetermined range, e.g., 1/32 to 1/4 inch, one of the ridge surfaces 52 
will abut the back side of the support panel. 
As viewed in FIG. 1, the skirt 46 is located on the left side of the 
bushing 12, flares outwardly from the top end of the bushing toward the 
switch frame 16 and terminates in an inner or lower end 55 spaced from the 
switch frame 16. The skirt 46 has a shoulder 56 adapted to abut the front 
side of the support panel at the side of the mounting hole 40 opposite to 
the locking flange 44. The skirt 46 also has an integral extension 58 
extending downwardly from the shoulder 56 and including at least one 
serration 57 (FIG. 1) having a laterally extending bearing surface 60 
(FIG. 7) which is spaced from the shoulder 56 at a distance approximating 
the thickness of the support panel 42 and is adapted to bear against the 
back side of the support panel adjacent the mounting hole. The serration 
bearing surface 60 cooperates with the skirt shoulder 56 to secure the 
other side (i.e., the left side as viewed in FIG. 1) of the bushing 12 on 
the support panel 42. Preferably, as shown in FIG. 1, the skirt extension 
58 is provided with a plurality of serrations with the bearing surfaces 60 
thereof being located in vertical parallel-spaced relationship to each 
other and spaced from the skirt shoulder 56 at different distances so as 
to accommodate a range of different panel thicknesses in the same manner 
as the ridges on the right side of the bushing body 28. 
During mounting, the switch assembly 10 is cocked relative to the rear of 
the support panel 42 and the right side of the bushing 12 is first 
inserted through the mounting hole 40 to hook the locking flange 44 in 
place on the front of the panel 42. The switch assembly 10 is then rocked, 
i.e., rotated clockwise as viewed in FIG. 1, to snap the left side of the 
bushing 12 into the mounting hole. That is, as the switch assembly 10 is 
moved clockwise, the outer tapered surface of the skirt 46 engages the 
edge of the mounting hole 40 and is cammed or deflected thereby inwardly 
towards the bushing body 28 so that the outer end portion of the skirt 46 
can be inserted through the mounting hole. When the skirt shoulder 56 is 
moved past the top edge of the mounting hole 40, the skirt 46 snaps back 
towards a left deflected position where the shoulder 56 abuts the front 
side of the mounting panel and a serration bearing surface 60 bears 
against the back side of the mounting panel adjacent the left side of the 
mounting hole 40. As shown in FIGS. 2 and 7, the bushing body 28 is 
dimensioned so that its opposite ends 59 and 61 substantially fill the 
mounting hole 40. 
In order to improve the retention force provided by the bushing snap-in 
arrangement, a metallic leaf spring 62 can be mounted between the bushing 
body 28 and the skirt 46 with one end affixed to the bushing body and the 
free end bearing against the inside surface of the skirt extension 58 so 
as to urge a portion of the skirt extension beneath the shoulder 56 into 
engagement with the corresponding wall of the mounting hole 40, and 
thereby also urge the opposite side of the bushing body into engagement 
with the corresponding wall of the mounting hole 40. 
To minimize fabrication cost, the bushing, including the locking flange and 
the skirt, of the embodiment illustrated in FIGS. 1, 2 and 7 and of the 
other illustrated embodiments to be described, can be formed as a 
one-piece unit from a relatively rigid, electrically insulating, synthetic 
thermoplastic material, such as "Lexan" marketed by General Electric. 
FIGS. 3-8 illustrate alternate constructions for the bushing. In all of 
these alternate constructions, the right side of the bushing is arranged 
and functions in the same manner as bushing 12 in the embodiment 
illustrated in FIGS. 1, 2 and 7. 
In the embodiment illustrated in FIGS. 3 and 8, a resilient snap-in skirt 
66 is provided on the left side of the bushing 12a. The skirt 66 
terminates in a shoulder 68 which is adapted to bear against the front 
side of the panel 42 when the switch assembly 10 is mounted thereon. 
Extending from the left side of the bushing body 28a, generally beneath 
the skirt 66, is an outwardly bowed, resilient, retainer member 70 which 
is integrally connected at the lower end to the lower portion of the 
bushing body 28a and has a free upper end so as to afford deflection 
relative to the bushing body. The retainer member 70 includes at least one 
and preferably a plurality of serrations 72 which are arranged to function 
in the same general manner as the serrations 57 on the skirt extension 58 
of the embodiment illustrated in FIGS. 1, 2 and 7. That is, each serration 
72 has a laterally extending bearing surface 74 (FIG. 8) which is adapted 
to abut the back side of the panel 42 adjacent the mounting hole 40 and to 
cooperate with the skirt shoulder 68 to retain the left side of the 
bushing 12a on the panel in the same general manner as described above for 
the embodiment illustrated in FIGS. 1, 2 and 7. A biasing means (not 
shown) can be mounted within the spacing 76 between the retainer member 70 
and the bushing body 28a for urging a bearing surface 74 of the serrations 
72 into engagement with the edge of the mounting hole 40 and thereby 
enhance the retention force provided by the retainer member 70. 
In the embodiment illustrated in FIGS. 4 and 5, a resilient snap-in skirt 
78 is provided on the left side of the bushing 12b. The skirt 78 includes 
a shoulder 80 which serves the same general function as the skirt shoulder 
56 of the embodiment illustrated in FIGS. 1, 2 and 7, and a finger 82 
extending downwardly from the shoulder 80. Extending integrally from the 
inner or lower portion of the left side of the bushing body 28b is a pair 
of laterally spaced, resilient retainer members 84, each of which curves 
or bows outwardly from the bushing body 28b and is integrally connected at 
the opposite ends to the bushing body 28b. Each of the retainer members 84 
has at least one and preferably a plurality of serrations 86 (FIG. 4) 
which are arranged to function in the same manner as the skirt extension 
serrations 57 of the embodiment illustrated in FIGS. 1, 2 and 7. That is, 
each serration 86 has a laterally extending bearing surface 88 (FIG. 5) 
which is adapted to abut the backside of the panel 42 adjacent the 
mounting hole 40 and to cooperate with the skirt shoulder 80 to retain the 
left side of the bushing 12b on the panel in the same general manner as 
described above for the embodiment illustrated in FIGS. 1, 2 and 7. 
The skirt finger 82 extends into the spacing 90 between the retainer member 
84 and bears against one wall of the mounting hole 40 (FIG. 4) to urge the 
right side of the bushing body 28b into engagement with the opposite side 
wall of the mounting hole 40 and thereby minimize lateral movement of the 
switch assembly relative to the panel 42 after mounting. As with the 
embodiment illustrated in FIGS. 3 and 7, a biasing means (not shown) can 
be mounted in the spacing 92 between each retainer member 84 and the 
biasing body 28b for urging a serration bearing surface 88 thereof into 
engagement with the edge of the mounting hole 40 and thereby enhance the 
retention force provided by the retainer member 84. 
In the embodiment illustrated in FIGS. 6 and 9, a resilient snap-in skirt 
94 is provided on the left side of the bushing 12c. The skirt 94 includes 
a shoulder 96 which serves the same general purpose as the skirt shoulders 
56 and 80 of the embodiments illustrated in FIGS. 1, 2 and 7 and FIGS. 4 
and 5, respectively, and a pair of laterally spaced tongues 98 extending 
downwardly from the shoulder 96. Extending upwardly from the inner or 
lower portion of the left side of the bushing body 28c is a resilient 
retainer member 100 which flares outwardly from the bushing body 28c and 
includes an upper end portion which fits into the spacing 102 between the 
skirt tongues 98 as best shown in FIG. 9. The retainer member 100 
preferably has a truncated triangular shape and the spacing 102 between 
the skirt tongues 98 has a corresponding shape to accommodate the upper 
end portion of the retainer member 100. 
As with the other illustrated embodiments, the retainer member 100 has at 
least one and preferably a plurality of steps or serrations 104 (FIG. 6) 
which are arranged to function in the same general manner as the 
serrations in the other illustrated embodiments. That is, each serration 
104 has a laterally extending bearing surface 106 (FIG. 9) which is 
adapted to abut the back side of the panel 42 adjacent the mounting hole 
40 and to cooperate with the skirt shoulder 96 to retain the left side of 
the bushing 12c on the panel in the same general manner described above. 
The skirt tongues 98 serve the same general function as the skirt finger 
82 of the embodiment illustrated in FIGS. 4 and 5. As with the other 
illustrated embodiments, a biasing means (not shown) can be mounted in the 
spacing 108 between the retainer member 100 and the bushing body 28c for 
urging a serration bearing surface 106 into engagement with the edge of 
the mounting hole and thereby enhance the retention force provided by the 
retainer member 100. 
While the preferred embodiments have been illustrated and described in 
detail, it will be apparent to those skilled in the art that various 
changes and modifications can be made thereto to adapt the invention to 
various uses without departing from the scope of the appended claims.