Rotary switch

A rotary switch construction wherein a stator has a pocket for receiving a rotor. The rotor has a flexible rim which permits it to snap-fit into the pocket of the stator. A plurality of angled surfaces on the stator compress the rotor rim as it is inserted into the pocket of the stator. Retainer means are provided to hold the rotor in the stator. The rotor further includes a plurality of stop pairs. The stator has a single, fixed stop which is disposed between the stops of one of the pairs on the rotor. The rotor stops have variable arcuate spacing so that, depending on which pair of stops spans the fixed stop, the degree of rotational freedom of the rotor can be selected. In another aspect, the rotary switch includes means on the rotor for fastening the rotor blade in place.

SUMMARY OF THE INVENTION 
This invention relates to rotary switches. 
A primary object of the present invention is a rotary switch which is 
inexpensive to manufacture yet reliable in operation. 
Another object is a rotary switch which can be adapted to be used either as 
a momentary type switch or as a multi-position index type switch. 
Another object is a rotary switch in which the number of index positions 
can be varied, depending on the initial orientation of the rotor. 
Another object of the present invention is a rotary switch wherein the 
rotor can be inserted into the stator with a snapfit arrangement which 
will retain the rotor. 
Another object is a rotary switch wherein the rotor has means for retaining 
the rotor blade in position. 
Another object is a rotary switch which can be adapted to carry additional 
stator sections. 
Another object is a rotary switch wherein the rotor and stator are formed 
of suitable plastic material. 
Other objects will appear in the ensuing specification, drawings and claims 
.

DESCRIPTION OF A PREFERRED EMBODIMENT 
This invention is directed to an economical rotary switch. The switch is 
shown generally at 10 in FIG. 1. The switch comprises a stator 12 and a 
rotor 14, only the shaft of which can be seen in FIG. 1. The stator 12 
includes a circular body portion 16 and a central bushing 18, an end 
portion of which may be threaded as shown. The bushing is used for 
mounting the switch. Alternately, the bushing could have a smooth surface 
for use with a push-on fastener. In this connection a post 20 extending 
from the body portion 16 of the stator may be used to assist in orienting 
the switch when it is mounted. 
The body portion 16 and the bushing 18 are connected by three web members 
22, 24 and 26 as shown in FIG. 5. The underside of the web 22 includes a 
fixed stop which has stop faces 28a and 28b. The purpose of the stop will 
be explained below. The underside of the main body portion 16 has a 
plurality of radial slots 30 including holes 32 for receiving and 
fastening the short contact clips (not shown). The body portion 16 also 
has three upraised surfaces 34 which extend outwardly from the main plane 
of the body portion 16. At the inside edge of the upraised surfaces 34 is 
a slanted surface 36 which terminates at a lip 37 (FIG. 3). The slanted 
surfaces 36 assist in the insertion of the rotor 14 as will be more fully 
explained below. 
Looking at FIG. 3, it can be seen that the interior of the body portion 16 
of the stator 12 forms a pocket 38 for receiving the rotor. The pocket is 
defined by the underside of the webs 22, 24 and 26 together with an 
annular surface 40 and retainer means 42. The annular surface 40 includes 
a plurality of detents 44 which define specific switch positions. The 
detents 44 are equally spaced around the annular surface. 
The rotor 14 is best seen in FIGS. 3 and 4. The rotor includes a shaft 46 
protruding from a central hub portion 48. A flexible rim 50 encircles the 
hub 48. The rim 50 is attached to the hub by three spokes 52. Three index 
bumps 54 are formed on the perimeter of the rim 50. When assembled the 
index bumps 54 cooperate with the detents 44 to define the various switch 
positions (FIG. 2). The rotor includes a plurality of stops 56, 57, 58, 
59, 60 and 61 which are attached to the hub 48. As best seen in FIG. 4, 
the stops are arcuately spaced. The spacing of the stops is arranged so 
that varying degrees of rotation can be obtained, as will be more fully 
explained below. 
FIGS. 4 and 5 show the switch contacts or clips. The rotor carries a rotor 
blade 62. This blade has a main circular portion 64 and a wiper portion 
66. A plurality of legs 68 extend from the circular portion 64 and into 
holes 70 in the hub of the rotor. The rotor includes a sleeve 72 for 
fastening the rotor blade 62 to the rotor. Prior to fastening of the rotor 
blade, the sleeve 72 is a cylindrical member, generally co-axial with the 
axis of the shaft 46. The main circular portion 64 of the blade defines a 
central opening which permits the blade to fit over the cylindrical 
sleeve. The legs 68 are inserted into holes 70 and then the sleeve 72 is 
swaged over a portion of the blade to hold it in place. This is best shown 
in FIG. 3. The swaging can be accomplished by either an ultrasonic 
deformation operation or a heating operation. The sleeve provides an 
inexpensive means for fastening the rotor blade. 
FIG. 5 shows a long or common clip 74 which is fastened to the body portion 
16 of the stator by a rivet 76. The long clip extends inwardly where it 
contacts the circular portion 64 of the rotor blade 62. The wiper 66 of 
the rotor blade contacts one of the short clips (not shown) which are held 
in the slots 30. 
The rotor 14 and the stator 12 are assembled in a manner indicated by the 
arrow in FIG. 3. In preparation for insertion of the rotor into the 
stator, the index bumps 54 are aligned with the slanted surfaces 36. As 
the rotor is pressed into the stator, the slanted surfaces 36 compress the 
flexible rim 50. This permits the rim to clear the retaining means 42. 
When the rim is fully inserted past the lip 37 it will snap back to nearly 
its original position. As best seen in FIG. 2, the retaining means 42 then 
overlaps the rim 50 to hold the rotor in place. The rotor shaft 46 extends 
through the opening in the bushing 18 and the rim 50 of the rotor is held 
in the stator pocket 38. 
The index bumps 54 engage the detents 44 when the rotor is fully inserted 
to define the indexed positions of the switch. When it is desired to 
change positions, the flexibility of the rotor rim 50 allows the bump to 
flex out of engagement with one detent and then snap into engagement with 
the next detent. The detents, and therefore the index positions of the 
switch, are arcuately spaced by a unit angle. In the embodiment shown the 
unit angle is 30.degree. making it possible to have as many as twelve 
index positions. 
The number of available index positions in a particular switch can be 
varied between two and twelve. The fixed stop 28 and the rotor stops 56-61 
combine to limit the rotation of the rotor to the desired number of 
positions. The rotor stops are spaced such that every multiple of the unit 
angle (between two and twelve) is defined by the angle between some pair 
of stops. When the rotor is initially inserted, the pair of stops having 
the desired unit angle multiple, and therefore the desired number of index 
positions, is arranged to span the fixed stop. In other words, the fixed 
stop is located between the stops having the desired unit angle multiple. 
For example in FIG. 2, the fixed stop 28 is disposed between a pair of 
rotor stops, in this case the stop pair 56 and 57. The arcuate spacing of 
this stop pair is 60.degree. so the unit angle multiple is two. Thus, the 
stop pair 56, 57 permits the rotor to rotate between two indexed 
positions. In one of these positions the stop 56 engages the stop face 
28a, as shown in FIG. 2. In the other position the stop 57 engages the 
stop face 28b. Thus when the stop pair 56, 57 spans the fixed stop 28 the 
rotary switch is a two-position switch. 
The various combinations of rotor stop pairs provide the other unit angle 
multiples. Pair 58, 59 is spaced 90.degree., a unit angle multiple of 
three, so this pair provides a three-position switch. Pair 60, 61 is 
spaced 120.degree. and provides a four-position switch. The unit angle 
multiples five through twelve require that one or more of the stops be 
removed. The plastic material allows the stops to be sheared off. The 
following table shows the stops that must be removed to obtain a given 
number of switch positions. 
______________________________________ 
stop pair spanning fixed stop 
# of switch 
remove (reading clockwise in FIG. 4 
positions stops from 1st stop to 2nd stop) 
______________________________________ 
5 61 60,56 
6 60,61 59,56 
7 56,61 60,57 
8 59,60 58,61 
9 59,60,61 58,56 
10 58,59,60,61 
57,56 
11 56,57,58,61 
60,59 
12 56,57,58,59,61 
60 
______________________________________ 
It will be noted that the twelve-position switch leaves only one stop on 
the rotor. As used herein this will be considered a "pair" of stops since 
opposite side of the stop will contact the fixed stop 28. Only one stop 
pair is operative in a given switch. The orientation of the rotor when it 
is inserted determines which pair will span the fixed stop and thus be the 
operative pair. Thus the same rotor can be used to provide a 
variable-position switch. Of course, the number and spacing of the pairs 
could be other than that shown. In an alternate configuration, the rotor 
stops could be insertable in the rotor hub 48 at different locations to 
vary the amount of rotational freedom. 
An alternate embodiment of the rotary switch is shown in FIG. 6. In this 
embodiment the switch 78 has a stator 80 and a rotor 82. These parts may 
be essentially the same as those previously described with the exception 
of an additional stub shaft 84 on the rotor. The stub shaft carries an 
additional rotor blade (not shown) for a second stator section 86. The 
second section 86 is attached to the first stator section 80 by a pair of 
strut spacers 88. The strut spacers fit in holes 90 in the first stator 
section and in holes 92 in the second section. FIGS. 7 and 8 show the 
details of the strut spacers. Each spacer has an elongated member 94 with 
a pair of wings 96 extending therefrom. The wings fit into slots 97 (FIG. 
5) to prevent relative rotation between the stator sections. An upraised 
portion 98 extends from the elongated member 94 at either end. This 
upraised portion assists in holding the strut in the holes in the first 
and second stator sections. 
A further alternate embodiment is shown in FIGS. 9-11. This switch has a 
spring return so the switch is a momentary type rather than the fixed 
position type shown above. A modified rotor is shown in FIG. 9 at 100. It 
will be noted the protrusions 102 on the rim 104 have a flattened surface. 
Thus the protrusions 102 do not engage the detents as do the index bumps 
54. Also, two of the spokes 106 have spring-receiving notches 108. The 
spring itself is shown in FIG. 11. It has a generally circular portion 110 
with legs 112 depending therefrom. There is a gap between the legs which 
can be partially closed when the spring is compressed. 
Looking at FIG. 10, the spring fits generally on top of the web members, 
with the spring legs engaging the webs 114 and 116 of the stator. The legs 
112 also extend downwardly so that they lie in notches 108 of the rotor. 
When the rotor is turned one leg of the spring is moved by the rotor 
toward the other which is held fixed by the stator web. The extent of the 
rotation is limited by stops 118 abutting a fixed stop 120. When the rotor 
is released the spring returns to the position shown in FIG. 10. 
It will be realized that whereas a practical and operative device has been 
shown and described, nevertheless, many changes may be made in size, shape 
and disposition of parts without departing from the spirit and scope of 
the invention. It is therefor desired that the description and drawings be 
taken in a broad sense as illustrative and diagrammatic rather than as 
limiting the invention to the specific showings.