U.S. patent number 3,663,774 [Application Number 05/121,095] was granted by the patent office on 1972-05-16 for key operated switch.
This patent grant is currently assigned to Motorola, Inc.. Invention is credited to Alvin Feder.
United States Patent |
3,663,774 |
Feder |
May 16, 1972 |
KEY OPERATED SWITCH
Abstract
A key operated switch is provided having a locking portion
operative in response to insertion of a key to unlock and rotate. A
nonconductive actuation cylinder is coupled to and rotates with the
lock. This actuation cylinder has a conductive contact bar mounted
therein, and has a key slot through the center. Circuit means are
provided for connecting the actuation cylinder contact bar and
external circuitry when the actuation cylinder is rotated. The key
is provided having a first portion for insertion into the lock
means for unlocking and rotating the same, and a second portion for
insertion through the actuation cylinder key slot. The second
portion is operative to inhibit portions of the circuit means from
engaging the actuation cylinder contact bar.
Inventors: |
Feder; Alvin (Skokie, IL) |
Assignee: |
Motorola, Inc. (Franklin Park,
IL)
|
Family
ID: |
22394499 |
Appl.
No.: |
05/121,095 |
Filed: |
March 4, 1971 |
Current U.S.
Class: |
200/43.06;
340/543 |
Current CPC
Class: |
H01H
27/06 (20130101) |
Current International
Class: |
H01H
27/06 (20060101); H01H 27/00 (20060101); H01h
027/00 () |
Field of
Search: |
;200/42R,44,45 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jones; H. O.
Claims
I claim:
1. A key operated switch including in combination; lock means
having a first and second portion, said lock means operative in
response to insertion of a key to unlock and allow rotation of said
first portion with respect to said second portion, an actuation
cylinder coupled to said lock means and rotatable therewith, said
actuation cylinder including contact means therein, and having a
key slot therethrough, circuit means for providing electrical
contact with external circuitry, said circuit means being coupled
to said actuation cylinder and engaging said actuation cylinder
contact means when said lock means first portion is rotated and, a
key having a first portion for insertion into said lock means for
unlocking and rotating same, and a second portion for insertion
through said actuation cylinder key slot, said second portion
operative to inhibit portions of said circuit means from engaging
said actuation cylinder contact means.
2. The key operated switch of claim 1 further including housing
means adapted to support said lock means, said actuation cylinder,
and said circuit means.
3. The key operated switch of claim 2 wherein said circuit means
includes circuit board means for providing electrical contact with
said external circuitry, and a plurality of resilient conductive
means mounted to said circuit board means for making electrical
contact with said actuation cylinder contact means.
4. The key operated switch of claim 3 wherein said actuation
cylinder is electrically nonconductive and said contact means is
conductive said actuation cylinder including a plurality of guide
channels in the cylindrical surface, parallel to the cylinder axis,
for guiding said resilient conductive means, said contact means
having portions extending into said guide channels for contacting
said resilient conductive means, said actuation cylinder key slot
extending into said guide channels, said key when inserted through
said actuation cylinder key slot having portions extending into a
plurality of said guide channels, for bearing against the resilient
conductive means in said guide channels when rotated to inhibit
contact with said contact means.
5. The key operated switch of claim 4 wherein said key includes; a
first portion having notches cut therein for actuating said lock
means, and a second portion having notches cut therein at
predetermined locations for allowing contact between a
predetermined number of said resilient conductive means and said
contact means, said second portion inhibiting contact between the
remainder of said resilient conductive means and said contact
means.
6. The key operated switch of claim 5 wherein said circuit means
includes a plurality of circuit boards each having a plurality of
resilient conductive means mounted thereto said resilient
conductive means being formed from spring wire.
7. The key operated switch of claim 6 wherein said contact means in
said actuation cylinder is a contact bar, extending parallel to the
axis of said actuation cylinder and perpendicular to said guide
channels, said contact bar having a portion extending into said
guide channels for contacting said resilient conductive means.
8. The key operated switch of claim 7 wherein said plurality of
circuit boards is two circuit boards.
9. The key operated switch of claim 8 wherein said housing includes
first and second identical sections and a retaining plate, said
identical sections being coupled together, and said retaining plate
being secured to said sections at one end thereof for retaining
said lock means, circuit means, and actuation cylinder in assembled
relation.
10. A key operated switch including in combination; lock means
operative in response to insertion of a key to unlock and allow
rotation thereof in a predetermined arc to a first position,
contact means coupled to said lock means and rotating therewith,
circuit means for providing electrical contact with external
circuitry, said circuit means including resilient conductive means
coupled to said contact means when said lock is rotated to said
first position and, a key having a first portion for insertion into
said lock means for unlocking and rotating same, and a second
portion in operative association with said resilient conductive
means to inhibit particular of said resilient conductive means from
engaging said contact means when said lock is in said first
position.
11. The key operated switch of claim 10 further including a housing
means adapted to support said lock means, said contact means, and
said circuit means.
12. The key operated switch of claim 10 wherein said contact means
is an electrically nonconductive actuation cylinder having a
plurality of guide channels in the cylindrical surface thereof for
guiding said resilient conductive means, said guide channels being
parallel to one another and perpendicular to the cylinder axis, an
electrically conductive contact bar mounted in said cylinder
parallel to said cylinder axis, said contact bar having a first
surface extending into said guide channels for contacting said
resilient conductive means when said lock is rotated to said first
position, and a key slot for accepting said key second portion,
said key slot extending parallel to said cylinder axis and having a
portion extending into said guide channels.
13. The key operated switch of claim 12 wherein said circuit means
includes a plurality of circuit boards each having a plurality of
resilient conductive means mounted thereto, said resilient
conductive means being formed from spring wire.
Description
BACKGROUND
Certain types of communication systems, for example police
vehicular status systems, and certain types of credit card
recording systems, such as credit card sales of gasoline, require a
remote unit to transmit the identification number of the user to a
central location. The signal transmitted is usually a binary coded
form of the decimal digit identification number. The remote unit
must therefore be capable of accepting a device which has the
user's number stored therein, and which programs the unit to send a
signal representing the binary coded form of the decimal digit to a
central location. One system previously employed used credit cards
and credit card readers. The credit cards are easily bent out of
shape and destroyed.
Another system uses a plug-in type printed circuit module and the
associated circuitry for sending a signal representing the binary
coded decimal digit. The plug-in module is cumbersome to carry and
easily damaged. A third system employs a key and a switch,
activated by insertion of the key. Such systems can easily be
operated by an improper key.
SUMMARY
It is an object of this invention to provide a key operated
switch.
Another object of this invention is to provide a key operated
switch which cannot be activated until unlocked by the correct
key.
Yet another object of this invention is to provide a key operated
switch wherein each use wipes the switch contacts.
Still another object of this invention is to provide a key operated
switch which must be unlocked and rotated in a predetermined arc
before the switch contacts are activated.
In practicing this invention a key operated switch is provided
which has a locking portion operative in response to insertion of a
key to unlock and rotate. A nonconductive actuation cylinder is
coupled to and rotates with the lock. The actuation cylinder has a
conductive contact bar mounted therein and a key slot through the
center. Guide channels are cut in the cylindrical surface
perpendicular to the axis of the cylinder. Circuit boards are
provided having resilient conductive springs mounted thereon. The
springs are positioned in the guide channels of the actuation
cylinder and contact the actuation cylinder contact bar when the
cylinder is rotated. One of the springs can have an operating
potential coupled thereto from the external circuitry. This
potential is coupled through the contact bar to the other
conductive springs and then to the external circuitry.
A key is provided which has a first portion for insertion into the
locking device for unlocking and rotating the same. A second
portion of the key is inserted through the actuation cylinder key
slot. This second portion has an edge which extends into the guide
channels. The edge has notches cut therein which align with certain
of the guide channels when the key is properly inserted. The
notches are cut in accordance with the desired binary coded decimal
digit or number to be transmitted. If a notch is cut in the key to
correspond to a particular guide channel, the resilient springs
will be allowed to contact the actuation cylinder contact bar
allowing a potential to be coupled through the spring to the
external circuitry. If there is no notch cut in the key edge, the
resilient conductive spring will be lifted by the key edge
extending into that guide channel, and contact with the actuation
cylinder contact bar will be inhibited. The absence of a potential
coupled to the external circuitry by the spring represents a binary
one. The presence of a potential represents a binary zero.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the key operated switch with the
key inserted and shown in the two positions;
FIG. 2 is an exploded perspective view of the key operated switch
of FIG. 1;
FIG. 3 is a section view of the actuation cylinder shown in FIG. 2,
along the section lines indicated as AA;
FIG. 4 is a plan view of a key used in the key operated switch.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the key operated switch is shown with key 10
inserted into key slot 11 of actuation cylinder 12. The dotted
lines show key 10 in its alternate, unlocked, position. FIG. 1
shows the parts of the switch described below, in assembled
relation.
Referring to FIG. 2, the exploded perspective view of the switch
allows all of the component parts to be seen. Lock 15 includes a
first portion 16, known as a lock housing, and a second portion 17,
positioned within the first portion, known as a lock cylinder. A
locking mechanism, located within lock cylinder 17, locks cylinder
17 and housing 16 together. Housing 16 and cylinder 17 are unlocked
and allowed to rotate with respect to one another by inserting the
correct key, such as key 10, into slot 18 of lock cylinder 17. In
the embodiment shown, lock housing 16 and lock cylinder 17 can
rotate 90.degree. with respect to one another. Lock housing 16 has
a flat portion 19 which, when the switch is assembled, acts as a
key to prevent lock housing 16 from rotating along with lock
cylinder 17. A shoulder 21 on lock housing 16 prevents lock 15 from
being pulled backward out of its housing when assembled. A washer
20, secured to the rear surface of lock cylinder 17, rotates with
lock cylinder 17. Washer 20 prevents lock 15 from being pulled
forward out of its mounting, just as shoulder 21 of lock housing 16
prevents lock 15 from being pulled backward out of its housing.
A nonconductive actuation cylinder 12, is positioned against lock
15. When in assembled relation, end 25 of cylinder 12 has a
depression 24 which accepts the raised end 26 of lock cylinder 17
on lock 15. Actuation cylinder 12 has a key slot 11 which extends
through the center, along the axis. With a key, such as key 10
shown in FIG. 4, inserted through cylinder 12 into lock 15, lock
cylinder 17 of lock 15 will unlock allowing lock cylinder 17 and
cylinder 12 to rotate together in a 90.degree. arc.
Actuation cylinder 12 has guide channels 27 cut into the
cylindrical surface. Referring to FIG. 3 there is shown a section
view of cylinder 12 taken along the section lines AA in FIG. 2.
Conductive contact bars 28 are embedded into cylinder 12, and
positioned parallel with the axis of cylinder 12. Conductive
contact bars 28 have a surface 29 which extends into guide channels
27. Key slot 11 of actuation cylinder 12 also extends into the
guide channels adjacent contact bars 28.
Circuit means 32 are provided for connecting the switch to the
externally operated circuitry. Circuit means 32 includes a printed
circuit board 33 having printed circuitry 34 thereon. Terminals 35
secured to printed circuitry 34 are used for connecting the switch
with the desired externally operated circuitry. Resilient
conductive springs 36 are mounted on printed circuit boards 33, and
coupled to printed circuitry 34. When circuit means 32 are
assembled into the switch, resilient conductive springs 36 are
positioned in guide channels 27 of actuation cylinder 12. Guide
channels 27 maintain springs 36 in their proper position,
preventing the springs from touching or interferring with one
another.
A housing for holding lock 15, actuation cylinder 12 and circuit
means 32 in assembled relation consists of first and second housing
sections 40 and 41. Sections 40 and 41 are made identical to one
another in order to reduce construction costs and ease the
manufacturing process. The sections are positioned upside down with
respect to one another, and attached to one another by screws 42.
Circuit means 32 each have a portion sandwiched between sections 40
and 41 with screws 42 passing through openings 37 to hold the
rearward portions of circuit means 32 in assembled relation. Flat
portion 19 of lock cylinder 16 keys with flat portion 52 of
housings 40 and 41 to prevent rotation. Shoulder 21 seats in recess
53 of housing portions 40 and 41 to prevent lock 15 from being
pulled out of the housing.
Front retainer plate 45 is secured to the ends of housing sections
40 and 41 by screws 46. Slots 47 in plate 45 accept tabs 48 of
printed circuit board 33, retaining the front end of printed
circuit boards 33, and therefore circuit means 32, in proper
alignment. Opening 49 in plate 45 allows the raised portion at end
51 of actuation cylinder 12 to extend therethrough, and retains the
remaining portion of actuation cylinder 12 in assembled relation
between housing sections 40 and 41, and against lock 15.
Key 10, shown in FIG. 4, includes a first and second section, 55
and 56 respectively, shown separated by dashed lines. The first
section inserts into and unlocks lock 15. The second section
inserts into actuation cylinder 12. Edges 57 of key 10 extend into
guide channels 27 of actuation cylinder 12. Notches 58 are cut into
edges 57 of second section 56 in accordance with the desired binary
coded decimal digit which is to be transmitted to the externally
operated circuitry.
In operation, section 55 of key 10 is inserted through actuation
cylinder 12 into lock 15, unlocking the lock housing 16 and lock
cylinder 17. The key is rotated 90.degree. as shown in FIG. 1 to
its fully unlocked position. As key 10 is rotated, edges 57 of
second section 56 on key 10, bear against resilient conductive
springs 36 on circuit means 32, prohibiting contact with surface 29
of conductive contact bar 28 in cylinder 12. Where notches 58 have
been cut into second section 56 of key 10, the resilient spring
contacts 36 which align with these notches will be allowed to
contact conductive contact bar 28. A main contact 38 provides a
ground or other reference potential which is conducted through
contact bar 28 to the contacted springs 36. This potential is
coupled through printed circuitry 34 to terminals 35 of circuit
means 32. From terminals 35 the potential is coupled to the
externally controlled circuitry where it may be used to represent a
binary zero. The resilient conductive springs 36 which are not in
contact with conductive contact bar 28 will represent the other
binary value.
Requiring full rotation of cylinder 12 before actuation of the
externally operated circuitry causes resilient conductive springs
36 to be wiped or slid across top surface 29 of conductive contact
bar 28 with each usage. This prevents oxidation of the conductive
springs and contact bar which could cause the switch to
malfunction. The full rotation of the lock and cylinder before
actuation of the external circuitry prevents accidental operation
of the switch by insertion of a wrongly coded key.
As can be seen, a key operated switch has been provided which
cannot be activated until unlocked by the correct key. Activation
of the circuitry will not occur until the rotating portion of the
lock and the actuation cylinder have been rotated in the full
predetermined arc. Rotation in the full predetermined arc causes
the switch contacts to be wiped by the contact bar thus preventing
oxidation which could lead to improper operation.
* * * * *