U.S. patent number 3,684,850 [Application Number 05/040,591] was granted by the patent office on 1972-08-15 for programmable lever switch with snap-in detachable cam detent means.
This patent grant is currently assigned to Guardian Electric Manufacturing Company. Invention is credited to Charles J. Kaderbek, Frank S. Vojir.
United States Patent |
3,684,850 |
Kaderbek , et al. |
August 15, 1972 |
PROGRAMMABLE LEVER SWITCH WITH SNAP-IN DETACHABLE CAM DETENT
MEANS
Abstract
A programmable lever switch has a frame with a pivotally
attached lever for manually switching electrical contact leaves by
means of switching fingers. The fingers are rigidly attached to one
end of the lever. A pair of programmed cam inserts are detachably
secured to the frame and engage a detent roller joined between the
switching fingers and biased away from the lever. Each pair of cams
controls the type of switching action of the lever switch upon
displacement of the lever.
Inventors: |
Kaderbek; Charles J. (Winfield,
IL), Vojir; Frank S. (Berwyn, IL) |
Assignee: |
Guardian Electric Manufacturing
Company (N/A)
|
Family
ID: |
21911816 |
Appl.
No.: |
05/040,591 |
Filed: |
May 26, 1970 |
Current U.S.
Class: |
200/557; 200/295;
200/556 |
Current CPC
Class: |
H01H
19/62 (20130101); H01H 23/28 (20130101); H01H
2011/0043 (20130101); H01H 11/0006 (20130101) |
Current International
Class: |
H01H
19/00 (20060101); H01H 23/28 (20060101); H01H
19/62 (20060101); H01H 23/00 (20060101); H01H
11/00 (20060101); H01h 023/30 (); H01h
023/02 () |
Field of
Search: |
;200/166SD,166J |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Vanderhye; Robert A.
Claims
What is claimed is:
1. A programmable lever switch comprising, in combination:
a supporting frame having an opposing pair of windows defined in
said frame,
a lever pivotally secured to said frame and pivotal about a fixed
point with respect to said frame to at least two switching
positions having a first operable end and a second contact
switching end,
electrical contact means on said frame for selective engagement
with said second end of said lever,
linkage means secured to said contact switching end, and,
detachable programming cam insert means detachably secured by snap
in locking tab means in said windows, in said frame for engaging
with said linkage means for controlling the switching action of
said lever switch.
2. The device of claim 1 wherein said programming cam means
comprise two cam windows of self-lubricating molded plastic having
said tab means rigidly secured to said cam windows for detachably
securing said cam windows within the frame windows defined in said
frame.
3. The device of claim 1 wherein said programming cam insert means
include a cam surface insert means for a momentarily returning said
lever to a central lever position when said lever is displaced away
from said central lever position.
4. The device of claim 1 wherein said programming detent cam insert
means includes a cam surface insert means for locking said lever
into lever position distinct from the central lever position such
that a predetermined locked contact is effected between said
contact means.
5. The device of claim 1 including lamp means for illuminating said
programming cam insert means detachably secured to said supporting
frame.
6. The device of claim 1 including a letter code embossed on said
programming cam means such that the program of such said switch in
a particular lever position may be easily identified by reference
to said letter code.
7. In a lever switch of the type having a frame having a pair of
opposing windows defined in said frame and a contact engaging lever
mounted for pivotal motion on said frame about a fixed point with
respect to said frame, the improvement comprising, in combination,
linkage means for said lever, interchangeable cam insert means
comprising a pair of cams of self-lubricating molded plastic having
tab means rigidly secured to said cams for snap in locking of said
cams to permit engagement of said cams with said lever through said
linkage means and provide for interchangeable combinations of
momentary and locked switching actions by said lever switch.
8. The improvement of claim 7 including cam surface means defined
in said cams engaging said linkage means and controlling movement
of said lever such that said lever may not be moved without
application of a minimal switching force.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to a programmable lever switch for
momentarily switching or continuing a contact made by the
displacement of the lever. Two-way and three-way lever switches can
be used in a variety of applications. For example, such a switch
may be employed in a machine tool in which it is desirable to have
an automatic operation set or an operation manually terminable by
an operator. Such a switch may provide momentary making of a
circuit when a switch lever is displaced in one direction and a
locked or continuous making of another circuit when the switch
lever is displaced in another direction. Known prior art switches
can provide these functions. However, once a switch has been
constructed to respond or operate in a predetermined manner, it is
not adaptable for use where a different switch function is
required.
Accordingly, it is desirable to provide a new and useful
programmable lever switch adapted for momentarily or continuously
making and breaking electrical contacts in accordance with a
desired program of switching functions. It is also desirable to
have such a switch wherein the program or switch functions are
easily altered so that a different predetermined program may be
provided for the lever switch. It is further desirable to provide
such a switch having a programming device which is easy and
inexpensive to manufacture and operate.
SUMMARY OF THE INVENTION
In a principle aspect this invention takes the form of a
programmable lever switch, comprising, in combination, a supporting
frame, a lever pivotally secured to the frame and pivotal to at
least two switching positions having a first operable end and a
second switching end, electrical contact means on the switch for
selective engagement with the second end of the lever, linkage
means secured to the contact switching end, and detachable
programming cam means in said frame for engaging with the linkage
means for controlling the switching action of the lever switch. The
cam means include a cam surface upon which the linkage means ride.
When the lever is displaced from the equilibrium, the contact
switching end displaces the electrical contact means and the cam
surface cooperates with the linkage means for alternatively (1)
momentarily returning the lever to equilibrium or (2) locking the
lever in a position displaced away from its equilibrium or neutral
position.
In a preferred embodiment of the present invention, the programming
cam means comprise two cam windows molded of self-lubricating
plastic having gripping tab means rigidly secured to the cam
windows for detachably securing the windows to the supporting
frame.
BRIEF DESCRIPTION OF THE DRAWINGS
There is shown in the attached drawing, a presently preferred
embodiment of the present invention, wherein like numerals refer to
like elements, and wherein:
FIG. 1 is a front view of the programmable lever switch of the
present invention showing the lever displaced from its central or
neutral position;
FIG. 2 is a side view of the device of FIG. 1;
FIG. 3 is an end view of the device of FIG. 1;
FIG. 4 is a cross-sectional view of the upper portion of the
programmable lever switch taken substantially along the line 4--4
of FIG. 2;
FIG. 5 is a cross-sectional view of the upper portion of the
programmable lever switch taken substantially along the line 5--5
of FIG. 1;
FIG. 6 is a cross-sectional view of the frame of the lever switch
and programming cam inserted therein taken substantially along the
line 6--6 of FIG. 1;
FIG. 7 is a perspective view of the frame and a particular
detachable programming cam of the present invention; and
FIGS. 8 - 15 are frontal views of alternative preferred embodiments
of the detachable programming cam of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 and FIG. 2 show front and side view respectively of a
programmable lever switch 18 embodying the principles of the
present invention. Referring principally to these figures, the
device includes a supporting frame or mounting bracket 20 which may
be formed from cold rolled carbon steel. Bracket 20 is U-shaped
having two legs 21 and 23 and connecting run 28. First window 22
and second window 24 symetrically opposite thereof are defined on
legs 21 and 23 respectively. A threaded mounting bushing 26 is
rigidly secured to the connecting run 28 of the bracket 20. Hex nut
30, lock ring 32, and knurled nut 34, are provided only for
positioning and mounting of lever switch 18 to a panel.
A switching lever 36, shown displaced in lever position A in FIG.
1, is pivotally secured to bushing 26 by lever pivot pin 38. The
lever 36 may be displaced in an arc about the axis of lever pivot
pin 38 from lever position A through lever position C. As shown in
FIG. 1, the lever 36 assumes a position perpendicular to connecting
run 28 in lever position B or neutral position. Lever 36 is
angularly displaced to one side of lever position B in lever
position A and to the other side of lever position B in lever
position C.
As will be more fully described, the displacement of the lever 36
causes selective displacement of electrical contact means including
particular flexible electrical conducting leaves 40, 42, 44, 46, 48
and 50 thereby making and breaking electrical circuits between
predetermined leaves. The leaves 40, 42, 44, 46, 48 and 50 are
preferably formed of a flexible metal having high conductivity.
Leaves 40, 42, and 44 are secured in socket 52 and leaves 46, 48
and 50 are secured in socket 54.
Referring to FIG. 3, there are shown non-conducting sockets 52, 54,
56 and 58. Non-conducting socket 56 is provided for receiving
electrical conducting leaves 56 a, b and c and non-conducting
socket 58 is provided for receiving electrical conducting leaves 58
a, b and c. A U-shaped member 60 is secured to leg 23 of the
bracket 20 for receiving sockets 52, 54, 56 and 58. Any or all of
these sockets 52, 54, 56 and 58 may be connected in any combination
to the lower U-shaped member 60 of the bracket 20 by means of
hexagonal headed screws 62, 64, 66 and 68 respectively. Thus,
different combinations of these sockets provide different switching
functions which may be performed by the programmable lever switch
18. For example, an arrangement of four-pole double throw switching
may be provided by the attachment of all four sockets 52, 54, 56
and 58.
A lamp socket 70 for securing lamp conductors 72 and 74 is rigidly
secured in the base run 76 of the U-shaped member 60 by metal clamp
78. The metal clamp 78 has tapered ridges 80 and 82 defined thereon
for exerting pressure between protruding flanges 84 and 86 of the
U-shaped member 60 and the lamp socket 70. This pressure secures
the lamp socket 70 to the base run 76 of the U-shaped member
60.
Lamp conductors 72 and 74 conduct power to a lamp 88. The lamp 88
is secured to prongs 90 of the conductor 74. The circuit from the
conductor 74 through the lamp 88 is completed through the lower
conducting surface 92 of the lamp 88 and upper conducting surface
94 of the conductor 72 as shown in FIG. 2. The programmable lever
switch 18 may be electrically connected to a device (not shown) to
be controlled by mating the lower portions of the conduction leaves
40, 42, 44, 46, 48 and 50 and lamp conductors 72 and 74 with the
device to be controlled.
The Operation Of the Lever Switch
Referring principally to FIG. 4 and FIG. 5, lever 36 includes a
first operating end 100 and a second contact switching end 101.
Rigidly secured to second end 101 are contact switching fingers 102
and 104. Contact switching fingers 106 and 108 of identical shape
and construction as fingers 102 and 104 are also rigidly attached
to second end 101. Fingers 106 and 108 are not seen because they
are shadowed behind fingers 102 and 104. The operation of the lever
36 will be explained with reference to fingers 102 and 104. The
operation of the lever 36 will be explained with reference to
fingers 102 and 104 and conducting leaves 40, 42, 44, 46, 48 and
50. It is to be understood, however, that contact switching fingers
106 and 108 operate the electrical conducting leaves 56 a, b and c
and 58 a, b and c shown in FIG. 3 in a manner identical to that of
fingers 102 and 104.
The displacement of the lever switch 36 into lever position A
causes first contact switching finger 102 to displace conducting
leaf 42 into contact with conducting leaf 40. Displacement of the
lever 36 to central lever position B causes contact switching
finger 102 to move out of contact with conducting leaf 42, thus
allowing the conducting leaf 42 to return to its normally biased
position in contact with conducting leaf 44. Likewise, displacement
of the lever 36 to lever position C causes contact switching finger
104 to displace conducting leaf 48 from its normally biased
position in contact with conducting leaf 46 into contact with
conducting leaf 50.
Programming detent cam means comprise a pair of cam windows 110
detachably secured in bracket windows 22 and 24 as will be more
fully described. Linkage means for linking the lever 36 to the
programming cams 110 includes a roller 114 and two springs 118. The
construction and operation of each of the springs 118 is identical.
The detent roller 114, is journaled in a channel 115 defined in
second end 101 of the lever 36 for movement therein. A pair of
unconnected loop springs 118 are rigidly secured at ends 120 to the
contact switching end 101 of the lever 36 and ride in spring-loaded
fashion at the other ends 122 against the axle connecting segment
124 of the detent roller 114. In this fashion, the detent roller
114 is biased away from the lever 36 by springs 118 and is
counter-biased towards the lever 36 by the detachable cam windows
110 which act supportably on roller heads 126 of the detent roller
114.
The particular programming detent cam 110 employed in a preferred
embodiment shown in FIG. 7, is one of the type entitled
"Lock-Off-Lock". This title may best be understood by an
explanation of the action of the programming cam 110 with the
detent roller 114. The cams 110 define cam surface means having
indentations 110a, b and c. When the lever 36 is displaced into
lever position A, the roller heads 126 of the detent roller 114 are
thereby biased into indentations 110a of cams 110. As has been
described, the movement of the lever 36 into lever position A
effects the making of a circuit between the electrical conducting
leaves 42 and 40. In this position, the spring 118, biases the
roller 114 into the indentation 110a and the ridges between
indentations 110a and indentations 110b act on the roller heads 126
preventing the lever 36 from the moving out of lever position A.
Thus, electrical conducting leaves 40 and 42 are caused to be
"locked" into contact.
By the application of pressure to the first end 100 of the lever
36, an upward force is exerted by the indentations 110a on the
roller heads 126. The detent roller 114 moves responsively within
channel 115 toward the first end 100 of the lever 36. When the
detent roller 114 rises to a sufficient level within the channel
115, the lever 36 is caused to jump into lever position B where the
roller heads 126 are again biased away from the lever 36 into cam
indentations 110 b. This is the "off" position of the switch in
which the conducting leaves 40, 42, 44, 46, 48 and 50 retain their
normally biased positions. By a second application of pressure on
the first end 100 of the lever 36, the roller heads 126 of the
detent roller 114 are caused to rise towards the first end 100 of
the lever 36 and out of the cam indentations 110 b. When the lowest
portion of the roller heads 126 reach the level of the ridges
between indentations 110b and indentations 110 c, the lever 36 is
caused to jump into lever position C where the springs 118 bias
roller heads 126 of the detent roller 114 into contact with cam
indentations 110 c. In this position, contact switching finger 104
displaces electrical conducting leaf 48 away from its normally
biased position and into contact with conducting leaf 50. The
circuit made between conducting leaves 48 and 50 is "locked" such
that it will not be broken without application of pressure on the
first end 100 of the lever 36.
Detachable Programming Cam
The following description will refer to a single cam 110. It is to
be understood, however, that the programmable lever switch 18 of
this invention includes a pair of cams 110 inserted into windows 22
and 24 respectively and that second cam 110 is a mirror image of
first cam 110. Thus, the following description will be applicable
to both cams 110.
Referring to FIG. 6 and FIG. 7, the cam 110 of this invention has
tab means 135 for detachably securing the cam 110 to window 22. The
cam 110 includes an upper horizontal run 127, lower horizontal run
128 and vertical runs 127 a and 128 a. Rigidly secured to run 127
is a raised surface 129. Abutment tab 130 and inclined gripping
tabs 131 are molded to the raised surface 129. The lower run 128
also has a raised surface 132 rigidly secured thereto and abutment
tab 133 and gripping tabs 134 molded to the raised surface 132.
The tab means 135 of this invention provide a cam 110 which may be
easily inserted into and detached from bracket window 22 by the
application of pressure. When the cam 110 is inserted into window
22, tabs 130 and 133 provide abutments for the cam 110 against
window 22. Tapered shoulders 136 and 137 are defined in window 22
and are complementary to inclined tabs 131 and 134 respectively.
The tapered shoulder 136 is held securely intermediate abutment tab
130 and inclined tabs 131. Tapered shoulder 137 is held securely
intermediate abutment tab 133 and inclined tabs 134. The raised
segments 129 and 132 facilitate the depression of programming
detent cam 110 against shoulder 137 for easy insertion into and
detachment from window 22 of cam 110.
Types of Programming Cams
A variety of interchangeable programming detent cams or plastic
inserts are shown in FIG. 8 through FIG. 15 constructed according
to the principles in this invention. Each of the programming detent
cams 140, 142, 144, 146, 148, 150, 152 and 154 employ tab or
interlocking means 135 as described above in relation to
programming detent cam 110, and differ from cam 110 only in respect
to the cammed surface indentations. Cams 110, 140, 142, 144, 146,
148, 150, 152 and 154 may be conveniently, and inexpensively
produced from molded plastic, preferably of the self-lubricating
type. For example, a material known as Delrin AF produced by E. I.
Dupont de Nemorus & Co. or the engineering equivalent thereof
may be employed. Such a material provides a degree of lubricity,
thus facilitating movement of the roller 114.
Cam 140 shown in FIG. 8 provides "momentary-off-momentary"
switching functions. Inclined surfaces 140 a and 140 c and
indentation 140 b are defined in cam 140. Inclined surfaces 140 a
or 140 c exert a lateral component of force on roller 114 when the
lever 36 is displaced into lever position A or C respectively. This
force component causes the lever 36 to return to neutral lever
position B where roller 114 is biased into indentation 140 b. From
the foregoing it should be appreciated that cam 140 causes
electrical contact between leaves 40 and 42, or between 48 and 50
to be made as long as the lever is displaced into lever position A
or C respectively.
The cam 142 of FIG. 9 is "locked-locked" cam. Indentations 142 a
and 142 c at opposite ends of the cam 142 lock the lever 36 in
lever position A when the lever 36 is displaced into position A and
in lever position C when lever 36 is displaced into position C. The
ridged surface 142 b of the cam 142 prevents the lever 36 from
remaining in lever position B by causing a condition of unstable
equilibrium. The slightest deflection of the lever 36 causes the
lever to lock into lever position A or C.
Cam 144 of FIG. 10 provides a two-position "momentary-locked"
program. Displacement of the lever 36 into lever position A causes
the contact switching finger 102 to effect a "momentary" electrical
circuit between electrical conducting leaves 40 and 42. The
inclined surface, 144aexerts a lateral force component on the
detent roller 114 causing the lever 36 to return to "locked" lever
position where roller 114 is biased into indentation 144c.
The cam 146 of FIG. 11 is the symetric opposite of cam 144 having a
"locked-momentary" program. Accordingly, the equilibrium position
of the lever 36 having programming cam 146 inserted in the switch
18 is lever position A. In this position the detent roller 114 is
biased into indentation 146 a. Displacement of the lever 36 into
lever position C effects "momentary" contact between electrical
conducting leaves 48 and 50 by contact switching finger 104. The
inclined surface 146c exerts a lateral force component on detent
roller 114 causing the lever 36 to return to equilibrium in lever
position A.
Cam 148, shown in FIG. 12, provides a two-way switch having a
"locked-off" program. The vertical surface 148c prevents the lever
36 from being displaced into lever position C. In neutral or "off"
lever position B, the detent roller 114 is biased into indentation
148b. Displacement of the lever 36 into lever position A causes
contact switching finger 102 to effect a circuit between electrical
conducting leaves 40 and 42. In this position the lever 36 is
"locked" by indentations 148a. The cam 150, shown in FIG. 13, is
the symetric opposite of cam 148. Accordingly, this cam provides a
two-way switch having an "off-locked" program.
Cam 152 of FIG. 14 provides a three-position switch having a
"momentary-off-locked" program. With cam 152 inserted into window
22, the lever 36 is in neutral or "off" mode in lever position B
and the detent roller 114 is biased into indentation 152b.
Displacement of the lever 36 into lever position A causes contact
switching finger 102 to effect a "momentary" circuit between
electrical conducting leaves 40 and 42. The inclined surface 152a
of the cam 152 exerts a lateral component of force on the detent
pin 114 causing the lever 36 to return to lever position B.
Displacement of the lever 36 into position C causes contact
switching finger 104 to effect "locked" contact between electrical
conducting leaves 48 and 50. In this position, the detent roller
114 is locked into indentation 152c.
Cam 154 of FIG. 15 is the symetric opposite of cam 152.
Accordingly, cam 154 provides a three position switch program
having a "locked-off-momentary" program.
The indentations of the above-described cams determine the number
of lever switching positions and their effect on the electrical
conducting leaves. The angular variations between inclined surfaces
and indentations in the cams prevent the lever 36 from being
accidentally displaced. The operator must exert a certain minimum
force on the operating end 100 of the lever 36 in order to displace
it from an equilibrium position. This arrangement not only prevents
accidental displacement of the lever 36, but insures a smooth and
quick lever switching action because of the impulse force which is
released when the detent pin 114 rides out of an indentation in
response to a force on the operating end 100 of the lever switch
36.
The programmable lever switch of this invention is available with
an illuminating lamp 88 as has been described. An additional
feature of the invention is the embossing of a letter code
representing the cam program on the translucent surface of the
programming cam. For example, the cam 152, shown in FIG. 14, has
the embossed letter M as an abbreviation for "momentary" beneath
the inclined surface 152a, the embossed letter O as abbreviation
for "off" beneath the indentation 152b, and the embossed letter L,
as abbreviation for "locked" beneath the indentation 152c.
To better enable the operator to determine the particular program
mode of the switch in a given lever position, the undersurface 160
of contact switching end 101 of the lever 36 is available with a
predetermined color treatment which reflects a predetermined color
from the illuminated lamp 88 when the lever 36 is in a
predetermined position.
It is to be understood that the embodiment of the invention which
has been described is merely illustrative of one application of the
principles of the invention. Numerous modifications may be made to
the disclosed embodiment without departing from the true spirit and
scope of the invention.
* * * * *