U.S. patent number 3,855,588 [Application Number 05/329,852] was granted by the patent office on 1974-12-17 for time reminding machine.
This patent grant is currently assigned to Product Potentials Inc.. Invention is credited to William J. Buckland, Jr., Kevin C. O'Daly.
United States Patent |
3,855,588 |
Buckland, Jr. , et
al. |
December 17, 1974 |
TIME REMINDING MACHINE
Abstract
A time reminding machine wherein this insulating members, such
as business cards, are selectively inserted between normally closed
spring contracts. The contracts are sequentially enabled at
intervals, such as one-quarter or one-half hour, by a time keeping
device to actuate an annunciator.
Inventors: |
Buckland, Jr.; William J.
(Merrick, NY), O'Daly; Kevin C. (Levittown, NY) |
Assignee: |
Product Potentials Inc.
(Hicksville, NY)
|
Family
ID: |
23287292 |
Appl.
No.: |
05/329,852 |
Filed: |
February 5, 1973 |
Current U.S.
Class: |
340/309.4;
968/973; 340/309.7 |
Current CPC
Class: |
G04G
13/026 (20130101) |
Current International
Class: |
G04G
13/00 (20060101); G04G 13/02 (20060101); G08b
007/00 () |
Field of
Search: |
;340/309.4,309.5,309.1
;200/35,36,37,61.19 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pitts; Harold I.
Attorney, Agent or Firm: Shenier & O'Connor
Claims
Having thus described our invention, what we claim is:
1. A time reminding machine including in combination a plurality of
normally-closed manually-operable switches, a time keeping device,
an output circuit, and means responsive to the time keeping device
for sequentially coupling each switch to the output circuit, said
output circuit providing an output signal upon the coupling thereto
of a switch which has been manually operated from its normal closed
position to an open position.
2. A machine as in claim 1 wherein each switch comprises a pair of
normally closed spring contacts and a thin insulating member
adapted to be inserted therebetween.
3. A machine as in claim 1 wherein each switch comprises a pair of
normally closed spring contacts, the machine further including a
thin insulating member adapted to be inserted between the contacts
of a selected pair.
4. A machine as in claim 3 wherein each group of two adjacent pairs
of contacts comprises a centrally disposed U-shaped member, a first
finger normally contacting one U leg of said member, and a second
finger normally contacting the other U leg of said member.
5. A machine as in claim 4 wherein each U leg and its contacting
finger flare apart adjacent their free ends to guide the insertion
of the insulating member therebetween.
6. A machine as in claim 3 wherein alternate groups of two adjacent
pairs of contacts are disposed in alternate planes.
7. A machine as in claim 1 wherein the time keeping device includes
an hour hand mounted on a shaft.
8. A machine as in claim 7 wherein the sequential coupling means
includes a stationary commutator having a plurality of equally
spaced conductive segments, means connecting each switch to a
corresponding segment, and a brush mounted on said shaft and
disposed to contact sequentially the segments of the
commutator.
9. A machine as in claim 7 wherein the sequential coupling means
includes a stationary commutator having a plurality of equally
spaced conductive segments, and a pair of angularly spaced brushes
mounted on said shaft and disposed to contact sequentially the
segments of the commutator.
10. A machine as in claim 7 wherein the number of switches is N and
wherein the sequential coupling means includes a pair of brushes
mounted on said shaft and having an angular spacing of
approximately 180/N.degree. .
11. A machine as in claim 7 wherein the number of switches is N and
wherein the sequential coupling means includes a stationary
commutator having N equally spaced conductive segments, each
segment subtending appreciably more than 180/N.degree. , and the
insulating gap between adjacent segments subtending appreciably
less than 180/N.degree. .
12. A machine as in claim 1 further including time indicia
associated with each switch.
13. A machine as in claim 12 wherein the indicia provide half-hour
increments.
14. A machine as in claim 12 wherein the indicia provide
quarter-hour increments.
15. A machine as in claim 12 wherein the indicia are disposed in
two columns of equal length.
16. A machine as in claim 15 wherein the indicia at the top of the
left hand column represents a whole hour in the region from 6:00 to
9:00 and wherein the indicia at the top of the right hand column
represents a whole hour in the region from 12:00 to 3:00.
17. A machine as in claim 1 further including a top wall provided
with a plurality of slots adapted to receive business cards.
18. A machine as in claim 1 further including a top wall provided
with a calendar pad bearing time indicia.
19. A machine as in claim 1 further including a top wall, wherein
the switches include manual operating members arranged in columns
along the left hand and right hand margins of the top wall and
disposed for movement left and right.
20. A machine as in claim 1 wherein the output circuit includes an
aural annunciator and a visual annunciator.
21. A machine as in claim 1 further including an annunciator, a
bistable circuit, means coupling the bistable circuit to the
annunciator, means responsive to the output circuit for setting the
bistable circuit, a manually-operable spring-loaded switch, and
means responsive to operation of said switch for resetting the
bistable circuit.
22. A machine as in claim 1 wherein the time keeping device
includes a source of reference frequency, a plurality of cascaded
counters, a plurality of display indicators, means coupling the
reference source to the first counter of the cascade, and means
coupling the final counters of the cascade to the respective
display indicators.
23. A machine as in claim 22 wherein at least four numerical
indicators provide a display in hours and minutes.
24. A machine as in claim 22 wherein at least six numerical
indicators provide a display in hours and minutes and seconds.
25. A machine as in claim 22 wherein two numerical indicators
display hours from 1 to 12 and wherein at least one further
indicator selectively provides a display of ante and post
meridian.
26. A machine as in claim 22 wherein the last counter of the
cascade divides by two and is coupled to an indicator selectively
providing the letters A and P, the machine further including an
indicator providing a constant display of the letter M.
27. A machine as in claim 1 wherein the time keeping device
includes a first divide-by-ten counter, a second divide-by-six
counter, a third counter, means including a source of reference
frequency for providing one pulse of fractional second duration
each minute, means responsive to each one-per-minute pulse for
indexing the first counter, means responsive to the first counter
for indexing the second counter, means responsive to the second
counter for providing one pulse of fractional second duration each
hour, means responsive to each one-per-hour pulse for indexing the
third counter, a first and a second manually-operable spring-loaded
switch, means responsive to each operation of the first switch for
providing a first pulse of fractional second duration, means
responsive to each operation of the second switch for providing a
second pulse of fractional second duration, means responsive to
each first pulse for indexing the first counter, and means
responsive to each second pulse for indexing the third counter.
28. A machine as in claim 27 wherein the means providing the
one-per-minute pulses includes a fourth divide-by-ten counter, a
fifth divide-by-six counter, means including a source of reference
frequency for providing one pulse of short duration each second of
time, means responsive to each one-per-second pulse for indexing
the fourth counter, means responsive to the fourth counter for
indexing the fifth counter, and means responsive to the fifth
counter for providing the one-per-minute pulses, the machine
further including a third manually-operable spring-loaded switch,
means responsive to each operation of the third switch for
providing a third pulse of fractional second duration, and means
responsive to each third pulse for indexing the fourth counter.
29. A machine as in claim 27 wherein the third counter divides by
10, the machine further including a two state device and means
responsive to the third counter for indexing the two state
device.
30. A machine as in claim 1 wherein the sequential coupling means
includes a plurality of logic circuits having at least one input,
means connecting each switch to the input of a corresponding logic
circuit, and means responsive to the time keeping device for
sequentially controlling the logic circuits.
31. A machine as in claim 30 wherein the time keeping device
includes an hours counter and a fractional hours counter, wherein
each logic circuit has a second and a third input, and wherein the
sequential controlling means includes means coupling the hours
counter to the second input of each logic circuit and means
coupling the fractional hours counter to the third input of each
logic circuit.
32. A machine as in claim 1 wherein the time keeping device
includes an hours counter, a fractional hours counter having a
maximum count not less than two nor greater than 30, and a minutes
counter having a maximum count not greater than 30 nor less than
two, the product of the maximum counts of the fractional hours and
minutes counters being equal to 60, and wherein the sequential
coupling means includes means responsive to the hours and the
fractional hours counters, the machine further including a first
manually-operable selector switch having a number of positions
equal to the maximum count of the minutes counter, means coupling
the minutes counter to the selector switch, means responsive to the
selector switch for providing a first master control signal, and
first means responsive to the first signal for governing the
coupling of any switch of said plurality to the output circuit.
33. A machine as in claim 32 wherein the sequential coupling means
includes a logic circuit having at least one input and means
sequentially coupling each switch of said plurality to the logic
circuit input, and wherein the governing means includes means
responsive to the signal for controlling the logic circuit.
34. A machine as in claim 32 wherein the means providing the master
control signal includes a bistable circuit and means responsive to
the selector switch for setting the bistable circuit.
35. A machine as in claim 32 wherein the means providing the master
control signal includes a bistable circuit and means responsive to
the time keeping device for resetting the bistable circuit at a
predetermined time less than 60 seconds after each minute.
36. A machine as in claim 35 wherein the resetting means includes
manually operable means for adjusting said predetermined time.
37. A machine as in claim 32 further including a second
manually-operable selector switch having a number of positions
equal to the maximum count of the minutes counter, means coupling
the minutes counter to the second selector switch, means responsive
to the second selector switch for providing a second master control
signal, and second means responsive to the second signal for
governing the coupling of any switch of said plurality to the
output circuit.
38. A machine as in claim 37 wherein the output circuit includes a
two state device and means responsive to the two state device for
selectively controlling the first and second governing means.
39. A machine as in claim 37 wherein the output circuit includes a
two state device and wherein the first and second governing means
comprise a first and a second logic circuit each having at least
one input, means coupling the first signal to the input of the
first logic circuit, means coupling the second signal to the input
of the second logic circuit, means responsive to one state of the
two state device for enabling the first logic circuit and disabling
the second logic circuit, and means responsive to the other state
of the two state device for disabling the first logic circuit and
enabling the second logic circuit.
40. A machine as in claim 37 wherein the output circuit includes a
two state device, a gating circuit, a holding circuit, means
including the gating circuit for coupling the two state device to
the holding circuit, and means for enabling the gating circuit at a
predetermined time less than 60 seconds after the minutes counter
provides its maximum count.
41. A machine as in claim 37 wherein the output circuit includes a
two state device, a gating circuit, a holding circuit, means
including the gating circuit for coupling the two state device to
the holding circuit, and means for enabling the gating circuit at a
predetermined time less than 60 seconds after each minute.
42. A machine as in claim 1 wherein the output circuit includes a
two state device, a relay having a winding and at least a pair of
contacts, means responsive to the two state device for selectively
energizing the relay winding, a first and a second electrical
receptacle, and means including the relay contacts for selectively
energizing the first and second receptacles.
43. A machine as in claim 42 further including a first visual
indicator connected in shunt with the first receptacle and a second
visual indicator connected in shunt with the second receptacle.
44. A machine as in claim 1 wherein each switch comprises a pair of
contacts, at least one contact being moveable, and means
resiliently biasing said moveable contact against the other
contact.
45. A machine as in claim 1 wherein each switch comprises a pair of
normally closed contacts, at least one contact comprising a spring
member.
46. A machine as in claim 45 further including a thin insulating
member adapted to be inserted between the contacts of a selected
pair, wherein the spring member of each switch is provided with a
flaring free end to guide the insertion of the insulating
member.
47. A machine as in claim 1 further including time indicia
associated with each switch wherein the indicia are disposed in a
plurality of columns of equal length.
48. A machine as in claim 1 further including a top wall provided
with a plurality of slots adapted to receive business cards,
wherein the slots are disposed in a plurality of columns of equal
length.
Description
BACKGROUND OF THE INVENTION
Time reminding machines of the prior art employ a rotating drum or
drums. Cards are inserted into appropriate receptacles carried by
the drum, or mechanical dogs mounted at the periphery of the drum
are manually actuated. Such devices are bulky, heavy, easily
damaged, and subject to loss of the time keeping function if the
drum is accidentally displaced by a person brushing by.
SUMMARY OF THE INVENTION
One object of our invention is to provide a time reminding machine
which operates electrically and has no mechanically rotating
drum.
Another object of our invention is to provide a time reminding
machine wherein thin insulating members such as business cards are
selectively inserted between pairs of normally closed spring
contacts.
Still another object of our invention is to provide a time
reminding machine which may be set to any desired minute of the
hour rather than merely to such intervals as 1/4 or 1/2 hour.
A further object of our invention is to provide a time reminding
machine which is small in size, light in weight, and of simple and
inexpensive construction.
Other and further objects of our invention will appear from the
following description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form part of the instant
specification and which are to be read in conjunction therewith and
in which like reference numerals are used to indicate like parts in
the various views:
FIG. 1 is a plan view of a first embodiment of our invention;
FIG. 2 is a side view taken along the line 2--2 of FIG. 1 with
parts broken away;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 1;
FIG. 6 is a schematic sectional view taken along the line 6--6 of
FIG. 5;
FIG. 7 is a plan view of a second embodiment of our invention;
FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7;
FIG. 9 is a schematic view showing the time keeping circuit of the
embodiment of FIG. 7;
FIG. 9a is a diagrammatic view showing the arrangement of lamps for
producing the numerical display of the embodiment of FIG. 7;
FIG. 10 is a schematic view showing the remaining electrical
circuitry of the embodiment of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIGS. 1, 2, and 3 of the
drawings, a housing includes a top plate 17, a bottom plate 17a and
a side plate 17b. The top plate 17 is provided with a cutout for
the face 14 of a clock having a minute hand 14a and an hour hand
14b which may be either mechanically or electrically driven. Top
plate 17 is also provided with cutouts for an indicator lamp 18 and
a reset button 19. Along the lefthand margin of plate 17 are slots
for a series of twelve manually operable slide switches indicated
generally by the reference numeral 20. Along the righthand margin
of plate 17 are slots for a further series of 12 manually operable
slide switches indicated generally by the reference numeral 21. A
calendar pad 22 is centrally positioned on top plate 17. Along the
left hand margin of the calendar are time indicia 22a for each half
hour running from 8:00 to 1:30 which are aligned with the slide
switches 20. Along the right hand margin of the calendar are time
indicia 22b for each half hour running from 2:00 to 7:30 which are
aligned with the slide switches 21. Each slide switch has an
operating button, such as 20a and 20b, which is adapted to be moved
left and right. The operating buttons are normally positioned
adjacent the margins of top plate 17 but may be moved toward the
calendar pad when an alarm is desired at an appropriate half-hour
interval. For example, in FIG. 1, switch 20a has been actuated; and
an alarm will be sounded at 12:00. Similarly, for the switches 21,
an alarm will be sounded at 3:30.
In addition to the operating buttons, such as 20a or 20b, each
switch includes a slide, such as 23a or 23b, and a thin knife-like
depending portion, 24a or 24b, formed of an insulating material
such as plastic. If desired the actuating button 20a, the slide
23a, and the knife-like depending portion 24a may be integrally
formed of plastic. Slides 23a and 23b operate in a clearance space
provided between the lower surface of top plate 17 and the upper
surface of a slotted slide-retaining member 17d.
Disposed parallel to the side wall 17b is an upstanding
contact-supporting member 17c secured to the bottom plate 17a. A
U-shaped spring contact member 25 is mechanically and electrically
secured to member 17c. Spring contact members 25a and 25b are
electrically isolated from member 17c by insulating members 26a and
26b, respectively. For each of the switches, the pairs of contact
fingers are normally closed. Thus finger 25a normally contacts one
leg of U-shaped member 25; and finger 25b normally engages the
other leg of U-shaped member 25. The ends of each pair of contacts
are flared outwardly in order to tolerate some misalignment between
each pair of contact fingers and the depending knife edges 24a and
24b of the slide switches. As may be seen by reference to FIGS. 1,
3, and 4, when operating button 20a is moved toward the calendar,
insulating knife member 24a separates finger 25a from one leg of
contact member 25, thus opening the normally closed contacts. As
may be seen by reference to FIGS. 2 and 3, the contacting elements
of the switches are staggered in a vertical plane. For example, the
contacts for the 12:00 and 12:30 switches are disposed in a lower
plane which also contains the contacts for the 10:00 and 10:30
switches; while the contacts for the 11:00, 11:30, 1:00, and 1:30
switches are all disposed in an upper plane. The purpose of this
staggering of contacts of adjacent pairs of switches is to afford
clearance between contact finger 25a for the 12:00 switch and the
contact finger for the 11:30 switch and to afford clearance between
contact finger 25b for the 12:30 switch and the contact finger for
the 1:00 switch.
Referring now to FIG. 5, the minute hand 14a is mounted for
rotation on a shaft 15a; and the hour hand 14b is mounted on a
hollow shaft 15b through which the minute hand shaft 15a coaxially
extends. Secured to the back surface of the clock face 14 is an
insulating commutator disc 28 having 24 equal conductive segments
electrically isolated from one another. In FIGS. 5 and 6 only
twelve commutator segments have been shown such as 28a, 28b, 28f,
28g, and 28l. Correspondingly, only 12 of the 24 pairs of switch
contacts have been shown such as 25a, 25b, 25f, 25g, and 25l. An
annular ring of insulating material 16 is press fit on the hollow
hour hand shaft 15b. A brush carrying member 27 is press fit on the
insulating ring 16. Member 27 carries a pair of brush arms 27a and
27b. Secured to arm 27a is a brush 27c; and secured to arm 27b is a
brush 27 d. The brushes 27c and 27d engage the commutator disc at
points which are spaced apart a distance appreciably greater than
the insulating gap between adjacent commutator segments but
appreciably less than the length of a commutator bar. Thus the pair
of brushes will bridge across the insulating gap between adjacent
segments; but will for an appreciable period engage the same
commutator bar. For example, with 24 intervals, each interval will
subtend 15.degree.. The insulating gap between adjacent segments
may be 2.5.degree.; and each commutator segment will subtend
12.5.degree.. The spacing between brushes 27c and 27d is preferably
half the 15.degree. interval or 7.5.degree.. This affords a
5.degree. period during which the brushes engage adjacent segments
and also a 5.degree. period during which the brushes engage the
same segment. A further brush 29 bears against the side of member
27. Brush 29 is supported on an insulating post 29a which is
secured to the back surface of the clock face 14.
Referring now to FIG. 6, each of the segments of commutator 28 is
connected to a corresponding leaf spring contact of a slide switch.
Thus segment 27a is connected to contact member 25a; segment 28b is
connected to contact 25b. The common U-shaped members 25 of each of
the slide switches are grounded by virtue of their connection to
the chassis member 17c. The negative terminal of a source of
potential 32 is grounded; and the positive terminal thereof is
coupled through a resistor 30 to slip ring brush 29. Brush 29 is
also connected to the base of an n-p-n transistor 31, the collector
of which is connected to the positive terminal of battery 32. The
emitter output of transistor 31 is coupled through a buzzer 33 to
ground and is also applied to the setting input of a bistable
flip-flop 34. The output of flip-flop 34 is coupled through lamp 18
to ground. The positive terminal of source 32 is coupled through a
normally open, manually-operable reset switch 19 to the resetting
input of flip-flop 34.
In operation of the embodiment of FIGS. 1 through 6, slide switches
20 and 21 are actuated in accordance with the times of various
appointments. Notes may be entered on the calendar in the spaces
provided to indicate the nature of the appointment. The setting of
these slide switches causes an associated insulating knife edge
such as 24a to be inserted between the normally closed spring
contact fingers of the slide switch, thus open circuiting the
switch.
The segments of commutator 28 are normally maintained at ground
potential by the slide switches. Thus brushes 27c and 27d are
normally maintained at ground potential, which in turn maintains
output brush 29 and the base of transistor 31 at ground potential.
Since the emitter output of emitter follower 31 is also at ground
potential, buzzer 33 is quiescent; and flip-flop 34 is not set.
Thus lamp 18 is extinguished.
In FIG. 6 only twelve intervals have been provided rather than 24
as indicated in FIG. 1. Accordingly, switch 25l may correspond to
11:00, switch 25a may correspond to 12:00, and switch 25b may
correspond to 1:00. Assume that the 12:00 switch 25a has been
actuated so that these contacts are open. Since in FIG. 6 only
twelve intervals are provided, each interval will subtend
30.degree. and represent 1 hour. Brushes 27c and 27d are preferably
spaced apart by half the interval length, or 15.degree.. The
insulating gap between adjacent segments may be 5.degree.; and each
segment will thus subtend 25.degree.. In the position of brushes
27c and 27d shown, the time is 11:50. Brush 27c engages segment
28a; but since switch 25a is open, brush 27c is not effective to
maintain the base of transistor 31 at ground potential. However,
brush 27d engages segment 28 l; and since switch 25l is closed,
brush 27d is effective to maintain the base of transistor 31 at
ground. As the brush-bearing member 27 rotates counterclockwise in
the direction of the arrow, brush 27d will disengage segment 28l at
12:00. At this point brush 27d engages an insulating strip of
commutator 28 which separates segments 28a and 28l. At this time
there is no current path through either of brushes 27c or 27d to
ground. Current through biasing resistor 30 now flows into the base
of transistor 31; and the emitter of transistor 31 rises to a
potential slightly less than that provided at the positive terminal
of battery 32. This actuates buzzer 33 and sets flip-flop 34, which
in turn illuminates lamp 18.
If an attendant is within hearing distance of the buzzer, he will
go to the machine and throw the 12:00 switch operating button 20a
to the left. This closes contacts 25a. Since brush 27c now lies
well in engagement with segment 28a, the base and hence the emitter
of transistor 31 will be returned to ground potential; and buzzer
33 will be rendered quiescent. However lamp 18 will remain
illuminated, since flip-flop 34 is a bistable device and maintains
the last state to which it was set or reset. The attendant will now
note the nature of the appointment written on calendar 22 in the
12:00 position and take appropriate action. Once this action has
been taken, the attendant may then momentarily depress the
spring-loaded reset button 19 which resets flip-flop 34 and
extinguishes lamp 18. If no attendant is within hearing distance of
buzzer 33, then it will continue to sound for 40 minutes until
12:40. At this time the leading brush 27c will engage segment 28b;
and the normally closed switch 25b will return the base and hence
the emitter of transistor 31 to ground potential. Buzzer 33 will be
rendered quiescent. However, lamp 18 will remain illuminated until
an attendant momentarily depresses the spring-loaded reset button
19 to reset flip-flop 34.
It will be appreciated that where commutator 28 has 24 segments,
buzzer 33 will sound for at most twenty minutes out of each half
hour interval. If desired, 48 slide switches and corresponding
commutator segments may be provided at 15 minute intervals each
corresponding to 7.5.degree. rotation of the hour hand shaft.
Brushes 27c and 27d are preferably spaced apart by 3.75.degree.;
the insulating gap between adjacent segments may be approximately
1.25.degree.; and each segment would accordingly subtend
approximately 6.25.degree.. Buzzer 33 would then sound for at most
ten minutes out of each fifteen minute interval.
Referring now to FIG. 7, we provide an electronic time keeping
device with a digital indicator indicated generally by the
reference numeral 14. The indicated time is "AM 8:17:46". Beneath
the seconds display is a manually-operable advance button 37.
Beneath the minutes display is a manually-operable advance button
38; and beneath the hours display is a manually-operable advance
button 39. Along the left hand margin of top plate 17 are time
indicia 22a for each quarter hour running from 7:00 to 12:45. Along
the right hand margin of the top plate are time indicia 22b for
each quarter hour running from 1:00 to 6:45. Indicia 22a cooperate
with 24 horizontally-extending slots indicated generally by the
reference numeral 20; and indicia 22b cooperate with 24
horizontally-extending slots indicated generally by the reference
numeral 21. For example, slot 20a corresponds to a time of 12:00;
and slot 20b corresponds to the time 12:15.
Referring now to FIGS. 7 and 8, slots 20 and 21 are adapted to
receive a business card 24 which is formed of an insulating
material such as heavy paper or light cardboard. Aligned with each
slot is a pair of normally closed spring contact fingers carried by
the bottom plate 17a. When card 24 is inserted in slot 20b, contact
finger 25b is separated from one leg of U-shaped member 25 thus
open circuiting the pair of contacts. Spring contact finger 25a
normally engages the other leg of U-shaped member 25 unless another
card such as 24 is inserted in slot 20a. The U-shaped spring
contact member 25 electrically engages the conducting bottom wall
17a. Spring contact fingers 25a and 25b are electrically isolated
from bottom wall 17a by respective insulating members 26a and 26b.
As may be seen by reference to FIG. 7 the contacts for adjacent
pairs of slots are staggered. Thus the contacts for the 12:00 and
12:15 slots lie in the same plane as the contacts for the 11:00 and
11:15 slots. The contacts for the 11:30, 11:45, 12:30, and 12:45
slots all lie in the same plane. This affords an insulating
clearance between the spring fingers of the 12:15 and 12:30 slots
between the spring fingers of the 12:00 and 11:45 slots.
Referring now to FIG. 9, a wall plug 33 is connected to a source of
60 Hz alternating current of approximately 115 volts. Plug 33 is
connected to the primary winding of a step-down transformer,
indicated generally by the reference numeral 33a, having a
secondary winding one terminal of which is grounded and the other
terminal of which is connected to a power supply 32 and to the
input of a trigger circuit 34. The output of trigger circuit 34
indexes a binary counter 35 providing six outputs and capable of
counting to 63. The 1 and 2 outputs of counter 35 are not used. The
4, 8, 16, and 32 outputs of counter 35 are coupled to the input of
an AND circuit 35a. The output of AND circuit 35a is applied to a
network 35b providing a time delay of 1 millisecond. The output of
delay network 35b resets counter 35 to 0. The output of AND circuit
35a is connected to one input of an OR circuit 36. The output of OR
circuit 36 indexes a ten-stage ring counter 42 and is also
connected to the input of a divide-by-two flip-flop 41 providing an
output at terminal 41a. Ring counter 42 has ten output terminals,
providing the counts of 0 through 9, which are coupled to the input
of a translator 57. The 0 output of counter 42 is connected to a
terminal 42a which indexes a six-stage ring counter 43. Ring
counter 43 has six output terminals, providing the counts of 0
through 5, which are coupled to a translator 58. A five position
selector switch 43a is mounted in the back wall as may be seen by
reference to FIG. 7. The armature of switch 43a may be manually set
to any desired contact from 1 to 5. The 1 output of counter 43 is
connected to the 1 contact of switch 43a. Similarly, the 2 through
5 outputs of counter 43 are connected to corresponding contacts of
selector switch 43a. The armature of switch 43a is connected to a
terminal 43b. The 0 output of counter 43 is coupled through a
differentiating capacitor 45 to one input of an OR circuit 46. The
output of OR circuit 46 is connected to a terminal 46a which
indexes a 10 -stage ring counter 47. Ring counter 47 has ten output
terminals, providing the counts of 0 through 9, which are coupled
to a translator 59. The 0 output of counter 47 indexes a six-stage
ring counter 48. Ring counter 48 has six output terminals,
providing the counts of 0 through 5, which are coupled to a
translator 60. The 0 output of counter 48 is coupled through a
differentiating capacitor to one input of OR circuit 51, the output
of which indexes a 10 -stage ring counter 52. Counter 52 has ten
output terminals, providing the counts of 0 through 9, which are
coupled to the input of a translator 61. The 0 output of counter 52
sets a bistable flip-flop 53. The output of flip-flop 53 is coupled
to a translator 62 and to one input of each of AND circuits 54 and
56. The 2 output of counter 52 is connected to the other input of
AND circuit 54. The AND circuit 54 provides an output at terminal
54a representing 12 o'clock which drives a divide-by-two flip-flop
55. The output of flip-flop 55 is coupled to a translator 63. The 3
output of counter 52 is connected to the other input of AND circuit
56. The AND circuit 56 provides an output indicating 13 o'clock
which is applied to a network 56a providing a time delay of 1
millisecond. The output of delay network 56a resets flip-flop 53
and resets counter 52 to 1.
The positive output terminal 32a of the direct-current power supply
is connected to one contact of each of switches 37, 38, and 39. The
other contact of switch 37 is grounded through a resistor 40a and
is connected through a differentiating capacitor 40 to the other
input of OR circuit 36. The other contact of switch 38 is grounded
through a resistor 44a and is coupled through a differentiating
capacitor 44 to the other input of OR circuit 46. The other contact
of switch 39 is grounded through a resistor 49a and is coupled
through a differentiating capacitor 49 to the other input of OR
circuit 51. Translators 57 through 61 each provide seven outputs
for actuating the seven lamps of a numerical display. The outputs
of a translator 57 drive the seconds display. The outputs of
translator 58 drive the tens-of-seconds display. The outputs of
translator 59 drive the minutes display. The outputs of translator
60 drive the tens-of-minutes display. The outputs of translator 61
drive the hours display. The outputs of translator 62 drive the
tens-of-hours display. The positive output terminal 32a of the
power supply continuously energizes two small lamps which indicate
a colon between the hours and minutes display and continuously
energizes two further small lamps which indicate a colon between
the minutes and seconds display. Terminal 32a further continuously
energizes a lamp or lamps which display the letter M to the left of
the tens-of-hours display. The outputs of a translator 63 are
coupled to a display indicator immediately to the left of the M
display which selectively provides the letters A or P.
FIG. 9a shows the arrangement of lamps for each of the variable
indicators of display 14 including the six indicators for hours,
minutes, and seconds and the additional indicator for A or P which
cooperates with the constant M indicator to provide the resultant
display of either "AM" or "PM". Lamps 1, 2 and 3 extend
horizontally at the bottom, middle, and top, respectively, of the
indicator. Lamps 4 and 5 extend vertically along the left-hand
margin of the indicator with lamp 4 being uppermost and lamp 5
being lowermost. Lamps 6 and 7 extend vertically along the
right-hand margin of the indicator with lamp 6 being uppermost and
lamp 7 being lowermost.
Translator 63 provides only six outputs for lamps 2 through 7,
since lamp 1 is not required for the A/P indicator. Terminal 32a
constantly excites lamps 2 through 6 of the A/P indicator.
Flip-flop 55 selectively drives lamp 7 of the A/P indicator.
Translator 62 provides only two outputs. Flip-flop 53 selectively
excites lamps 6 and 7 of the tens-of-hours indicator. For this
indicator, lamps 1 through 5 may be omitted, since no 0 is
displayed for the tens-of-hours for time between 1:00:00 and
9:59:59.
Preferably translator 61 is so constructed that a 1 output from
counter 52 illuminates lamps 4 and 5 of the hours display.
Preferably translator 60 is so constructed that a 1 output from
counter 48 illuminates lamps 6 and 7 of the tens-of-minutes
display. Preferably translator 59 is so constructed that a 1 output
from counter 47 illuminates lamps 4 and 5 of the minutes display.
Preferably translator 58 is so constructed that a 1 output from
counter 43 illuminates lamps 6 and 7 of the tens-of-seconds
display. Preferably translator 57 is so constructed that a 1 output
from counter 42 illuminates lamps 4 and 5 of the seconds
display.
The time-constant of differentiating capacitor 40 in conjunction
with the input resistance of OR circuit 36 may be one millisecond.
The time-constant of differentiating capacitors 44 and 49 in
conjunction with the input resistances of OR circuits 46 and 51 may
each be one millisecond. The time-constants of differentiating
capacitors 45 and 50 in conjunction with the input resistances of
OR circuits 46 and 51 may each be 1 millisecond.
In operation of the time keeping circuit of FIG. 9, trigger circuit
34 provides a positive output during each positive half cycle of
the alternating-current voltage excursion across the secondary
winding of step-down transformer 33a. Thus binary counter 35 is
indexed at a rate of 60 times per second. Counter 35 is
successively indexed from the count of 0, where all six outputs are
at ground potential, to the count of 59, where the 4 output is at
ground potential and the remaining five outputs are positive. When
the count of 60 is reached, the four most significant outputs are
positive and the two least significant outputs are at ground
potential. The AND circuit 35a now provides an output. One
millisecond later, delay network 35b provides an output which
resets counter 35 to 0; and the output of AND circuit 35a drops to
ground potential. The one millisecond rectangular output pulse of
AND circuit 35a is also coupled through OR circuit 36 to index the
seconds counter 42. Each time ring counter 42 cycles through the
count of 0, counter 43 is indexed. Each time that counter 43 cycles
through the count of 0, counter 47 is indexed through
differentiating capacitor 45 and OR circuit 46. Each time that
counter 47 cycles through the count of 0, counter 48 is indexed.
Each time that counter 48 cycles through the count of 0, counter 52
is indexed through differentiating capacitor 50 and OR circuit
51.
When the hours counter 52 cycles through the count of 0, as in
going from 9 o'clock to 10 o'clock, flip-flop 53 is set. At 12
o'clock, AND circuit 54 provides an output which indexes
divide-by-two flip-flop 55 to change the display from AM to PM or
from PM to AM. At 13 o'clock, AND circuit 56 provides an output. 1
millisecond later, delay network 56a provides an output which
resets flip-flop 53 and resets counter 52 to 1, thus changing the
hours display from 13 o'clock to 1 o'clock and causing the output
of AND circuit 56 to drop to ground potential. Hence AND circuit 56
provides a rectangular output pulse of one millisecond
duration.
The normally-open spring-loaded push button switches 37, 38, and 39
are manually depressed or tapped at any desired rate to advance the
seconds, minutes, and hours and thus set the time indication to its
proper value. Preferably the seconds are set first, since there is
always a carry over from the tens-of-seconds into the minutes. The
minutes are then set, since there is a carry over from the
tens-of-minutes into the hours. Finally the hours may be set. It
will be appreciated that as many as 23 depressions of the hours
setting button 39 may be required in order properly to set the
AM/PM display which is indexed each twelve hours. Buttons 37 and 38
need not be depressed or tapped more than fifty-nine times each.
The provision of the differentiating capacitors 40, 44, 49, 45 and
50 insures that 1 millisecond pulses may be coupled through OR
circuits 36, 46, and 51 both from the time keeping counters 35, 43,
and 48 and from the manual advance switches 37, 38, and 39 without
interferences, since there is little likelihood of pulse overlap.
The pulses from the differentiating capacitors are decaying
exponentials of a generally triangular shape.
Referring now to FIG. 10, the output of flip-flop 53 is coupled to
an inhibiting input of AND circuits 65, 66, and 67 and to an
enabling input of AND circuits 68, 69, and 54. The 0 output of
counter 52 is connected to an enabling input of AND circuit 68. The
1 output of counter 52 is connected to an enabling input of AND
circuits 65 and 69. The 2 output of counter 52 is connected to an
enabling input of AND circuits 66 and 54. The 3 output of counter
52 is connected to an enabling input of AND circuit 67. The output
of AND circuit 65 at terminal 65a represents 1 o'clock. The output
of AND circuit 66 represents 2 o'clock. The output of AND circuit
67 represents 3 o'clock. The 4 through 9 outputs of counter 52
respectively represent 4 o'clock through 9 o'clock. The output of
AND circuit 68 represents ten o'clock. The output of AND circuit 69
represents 11 o'clock. The output of AND circuit 54 at terminal 54a
represents 12 o'clock.
The 5 output of minutes counter 47 is connected to one input of
each of AND circuits 70a and 70b. The 1 output of counter 48 is
connected to the other input of AND circuit 70b; and the 4 output
of counter 48 is connected to the other input of AND circuit 70a.
The outputs of AND circuits 70a and 70b are coupled to the inputs
of an OR circuit 70c, the output of which indexes a divide-by-four
ring counter 71. Counter 71 has four output terminals representing
the counts of 0 through 3. The 0 output of counter 48 resets
counter 71 to 0; and the 3 output of counter 48 resets counter 71
to 2.
For each of the 48 card slots 21 and 22, we provide a corresponding
AND circuit 72, of which only eight have been shown to simplify the
description. The AND circuits 72a, 72b, 72and 72d correspond to the
slots for times 12:00, 12:15, 12:30, and 12:45, respectively. The
AND circuits 72e, 72f, 72g, and 72 h correspond to the slots for
times 1:00, 1:15, 1:30, and 1:45, respectively. The 12 o'clock
terminal 54a is connected to one input of each of AND circuits 72a
through 72d. The 1 o'clock terminal 65a is connected to one input
of each of AND circuits 72e through 72h. The 0 output of ring
counter 71 is connected to a second input of each of AND circuits
72a and 72e. The 1 output of counter 71 is connected to a second
input of each of AND circuits 72b and 72f. The 2 output of counter
71 is connected to a second input of each of AND circuits 72c and
72g. The 3 output of counter 71 is connected to a second input of
each of AND circuits 72d and 72h. The positive terminal 32a of the
power supply is connected through a resistor 73a to a third input
of AND circuit 72a. Positive terminal 32a is similarly connected
through respective resistors 73b through 73h to a third input of
AND circuits 72b through 72h. The third input of AND circuit 72a is
normally grounded through spring contact 25a which cooperates with
slot 20a. Similarly the third input terminals of AND circuits 72b
through 72h are normally grounded through spring contacts 25b
through 25h respectively.
The outputs of AND circuits 72a through 72h are all connected to
one input of an AND circuit 75, which receives a second input from
a bistable flip-flop 82. The output of AND circuit 75 is connected
to one input of each of OR circuits 88a and 88b and to the setting
input of a bistable flip-flop 34. The output of AND circuit 75
further indexes a divide-by-two flip-flop 74 having a low output
impedance. The output of divide-by-two flip-flop 74 is coupled to
ground through the actuating winding 77 of a relay having
single-pole double-throw contacts 77a. The output of flip-flop 74
is further coupled through a bilateral gate 89 to a holding circuit
90, comprising a bistable flip-flop having a high output impedance.
Holding circuit 90 drives an enabling input of an AND circuit 76b
and an inhibiting input of an AND circuit 76a. The outputs of AND
circuits 76a and 76b are coupled to an OR circuit 76c, the output
of which is applied to the setting intput of flip-flop 82.
Terminal 46a, which provides indexing pulses to minutes counter 47,
is also connected to the indexing input of a 15 -stage ring counter
81. Counter 81 has fifteen output terminals providing the counts of
0 through 14. The output of OR circuit 70c resets counter 81 to 0.
The output of OR circuit 88a is connected through buzzer 33 to
ground; and the output of OR circuit 88b is connected through lamp
18 to ground. Positive terminal 32a is coupled through reset switch
19 to the resetting input of flip-flop 34. The output of flip-flop
34 is connected to one input of each of AND circuits 86 and 87. The
output of AND circuit 86 is connected to the other input of OR
circuit 88b; and the output of AND circuit 87 is connected through
a resistor 87a to the other input of OR circuit 88a. Output
terminal 41a of divide-by-two flip-flop 41 is connected to the
other input of AND circuit 86; and the 0 output terminal 42a of
counter 42 is connected to the other input of AND circuit 87.
One line from wall plug 33 is connected to the armature of relay
contacts 77a. The other line from wall plug 33 is connected to one
terminal of a receptacle 78a and to one terminal of a receptacle
78b. As may be seen by reference to FIG. 7, receptacles 78a and 78b
are mounted in the front wall of our machine. The normally-closed
relay contact 77a is connected to the other terminal of receptacle
78b; and the normally-open relay contact 77a is connected to the
other terminal of receptacle 78a. The terminals of receptacle 78a
are shunted by a neon glow lamp 79a connected in series with a
resistor 79c. The terminals of receptacle 78b are shunted by a neon
glow lamp 79b connected in series with a resistor 79d. As may be
seen by reference to FIG. 7, glow lamps 79a and 79b are also
mounted in the front wall of the machine. Also mounted in the front
wall are a pair of 15 position selector switches 80a and 80b, the
armatures of which may be manually set to any desired contact from
0 to 14. The 0 output of counter 81 is connected to the 0 contacts
of switches 80a and 80b. Similarly, the 1 through 14 outputs of
counter 81 are connected to corresponding contacts of selector
switches 80a and 80b. The armature of switch 80a is connected
through a differentiating capacitor 80c to an enabling input of AND
circuit 76b; and the armature of switch 80b is connected through a
differentiating capacitor 80d to an enabling input of AND circuit
76a. The 14 output of counter 81 is connected to one input of an
AND circuit 83. Terminal 43b is connected through a differentiating
capacitor 82a to the resetting input of flip-flop 82, to the other
input of AND circuit 83, and to one contact of a single-pole
double-throw slide switch 84. The output of AND circuit 83 is
connected to the other contact of manually operable switch 84. The
armature output of switch 84 enables bilateral gate 89 to conduct
in both directions. As may be seen by reference to FIG. 7,
vertically sliding switch 84 is mounted in the front wall between
selector switches 80a and 80b. The time-constants of capacitors
80c, 80d, and 82a in conjunction with their associated load
resistances may each be 1 millisecond.
As may be seen by reference to FIGS. 7 and 10, receptacle 78a, glow
lamp 79a, and selector switch 80a are disposed on the left side of
the front wall, while selector switch 80b, glow lamp 79b, and
receptacle 78b are disposed on the right side of the front wall.
Preferably selector switch 80a rotates clockwise for increasing
counts in the manner shown for selector switch 80b. The
counterclockwise rotation of switch 80a shown in FIG. 10 is only
for the purpose of simplifying the interconnections between
switches 80a and 80b.
In operation of the circuit of FIG. 10, AND circuits 65, 66, and 67
provide hour outputs for 1, 2, and 3 o'clock, respectively. The AND
circuits 68, 69, and 54 provide hour outputs for 10, 11 and 12
o'clock, respectively. The hour outputs for 4 through 9 o'clock are
directly provided by corresponding outputs of counter 52. The AND
circuit 65 is required to distinguish 1 o'clock from 11 o'clock;
AND circuit 66 is required to distinguish 2 o'clock from 12
o'clock; and AND circuit 67 is required to distinguish 3 o'clock
from 13 o'clock. It will be recalled in conjunction with FIG. 9
that components 52 and 53 provide a 13 o'clock output from AND
circuit 56 for 1 millisecond before being reset to 1 o'clock by the
output of delay network 56a.
On each hour, a counter 71 is reset to 0 by the 0 output of counter
48. At 15 minutes past each hour, counter 71 is indexed to 1 by AND
circuit 70b through OR circuit 70c. At half past each hour, counter
71 is reset to 2 by the 3 output of counter 48. At 45 minutes past
each hour, counter 71 is indexed to 3 by AND circuit 70a through OR
circuit 70c.
All AND circuits 72a through 72h are normally disabled by virtue
that the third input is maintained at ground by the normally closed
contacts 25a through 25h. If, as in FIG. 8, a card is inserted into
slot 20b, then contacts 25b will be open-circuited, and positive
terminal 32a will enable the third input of AND circuit 72b through
resistor 73b. When the time reaches 12:00, the positive signal at
terminal 54a will enable the first input of AND circuit 72b.
However, AND circuit 72b will not provide an output, since at this
time only the 0 output of counter 71 is positive. When the time
reaches 12:15, the 1 output of counter 71 becomes positive, thus
enabling the second input of AND circuit 72b. Hence at 12:15, AND
circuit 72b provides an output to AND circuit 75.
Assume for the moment that selector switches 80a and 80b are both
set to 0. Ring counter 81 is indexed once each minute from terminal
46a. Counter 81 is reset to 0 at 15 minutes and at 45 minutes past
each hour by the output of OR circuit 70c. On each hour and at 30
minutes past each hour, ring counter 81 will inherently cycle
through 0 in response to the indexing input from terminal 46a. At
12:15, ring counter 81 will thus be reset to 0. At this time the
armatures of switches 80a and 80b will both become positive,
producing positive output pulses from capacitors 80c and 80d.
Irrespective of the state of holding flip-flop 90, one of AND
circuits 76a and 76b will provide an output pulse which is coupled
through OR circuit 76c to set flip-flop 82, thus enabling AND
circuit 75. Accordingly, at 12:15, the output from AND circuit 72b
is coupled through AND circuit 75, setting flip-flop 34, indexing
flip-flop 74, energizing buzzer 33 through OR circuit 88a, and
illuminating lamp 18 through OR circuit 88b.
Flip-flop 82 receives a reset pulse either 10, 20, 30, 40, or 50
seconds after each minute as governed by the position of selector
switch 43a. Thus if switch 43a is set to 1, terminal 43b will
become positive 10 seconds after each minute. If, as shown in FIG.
9, switch 43a is set to 5, terminal 43b will become positive 50
seconds after each minute.
If between 12:15:00 and 12:15:50, an attendant removes card 24 from
slot 20b in response to buzzer 33, then contacts 25b will close;
AND circuit 72b will be disabled; and the output of AND circuit 75
will drop to ground. At 12:15:50, flip-flop 82 is reset by the
pulse coupled through capacitor 82a from terminal 43b. This
disables AND circuit 75 even though card 24 remains in slot 20b.
The disabling of AND circuit 75, either at 12:15:50 by resetting of
flip-flop 82 or at some earlier time between 12:15:00 and 12:15:50
by removal of card 24 from slot 20b, permits flip-flop 34 to
control lamp 18 and buzzer 33. Flip-flop 34 was set at 12:15:00 and
enables AND circuits 86 and 87. The signal at terminal 41a is
coupled through AND circuit 86 and OR circuit 88b to lamp 18. Since
divide-by-two flip-flop 41 is indexed once each second, lamp 18
will blink on for one second, off for one second, and on for one
second again. The signal at terminal 42a is coupled through AND
circuit 87, intensity-reducing resistor 87a and OR circuit 88a to
buzzer 33. Buzzer 33 will thus emit a reduced intensity sound or
"beep" of one second duration once each 10 seconds. This serves to
alert the attendant when he returns to the machine. Once flip-flop
34 is set, it will remain set until reset switch 19 is momentarily
depressed.
Each time AND circuit 75 provides an output, flip-flop 74 changes
state. This energizes relay winding 77 if it was previously
de-energized, or de-energizes relay winding 77 if it was previously
energized. Relay armature 77a is shown in the unenergized position
of winding 77, where power is applied to receptacle 78b and glow
lamp 79b is illuminated. When winding 77 is energized, relay
armature 77a is drawn to its alternate position where power is
applied to receptacle 78a and glow lamp 79a is illuminated. Our
machine may thus be used as a timing device to control the
application of power to some external electrical load such as a
lamp. For example, assume that cards are inserted in the slots
corresponding to 6:00, 11:00, 12:15, and 12:30; that immediately
prior to 6:00 P.M., the relay armature 77a is in the position
shown; and that the external load such as a lamp is plugged into
the unenergized receptacle 78a. The lamp will be turned on at 6:00
P.M. and will be turned off at 11:00 P.M. The lamp will be turned
on again at 12:15 A.M. and will be turned off again at 12:30 A.M.
The lamp will remain off until 6:00 A.M. at which time it will
again be turned on.
Our machine is not limited to operation at the fifteen minute
intervals corresponding to the time indicia of the card slots.
Instead switches 80a and 80b may be set other than to the 0
positions so that AND circuit 75 provides an output at any desired
minute intermediate the standard 15 minute intervals. Assume, as
shown in FIG. 10, that switch 80a is set to 3 and that switch 80b
is set to 10. In the unenergized position of relay winding 77
shown, glow lamp 79b is illuminated to indicate not only the
energized receptacle 78b but also the selector switch 80b which is
operative to offset the time from the normal fifteen minute
intervals of the slot indicia.
Assume slide switch 84 is in the position shown in FIG. 10. At
12:14, the 14 output of counter 81 partially enables AND circuit
83. At 12:14:50, the pulse from capacitor 82a is coupled through
AND circuit 83 to enable bilateral gate 89. This causes holding
flip-flop 90 to be forced to the same state as flip-flop 74. When
relay winding 77 is not energized, flip-flop 74 provides no output;
and at 12:14:50 the output of holding flip-flop 90 will be forced
to ground potential irrespective of its previous state. This
partially enables AND circuit 76a and disables AND circuit 76b. If
a card 24 is in slot 20b, contacts 25b will be open; and the third
input of AND circuit 72b will be enabled by positive terminal 32a
through resistor 73b. At 12:15, AND circuit 72b will provide an
output partially enabling AND circuit 75. However, at this time
flip-flop 82 provides no output, since it was reset at 12:14:50.
Three minutes after 12:15, there is at 12:18, counter 81 will
provide a 3 output. Armature 80a will thus receive a signal which
is coupled through capacitor 80c to AND circuit 76b. However, AND
circuit 76b will not provide an output, since it is disabled when
the output of holding flip-flop 90 is at ground potential. 10
minutes after 12:15, that is at 12:25, counter 81 provides a 10
output. The armature of switch 80b now receives a signal which is
coupled through capacitor 80d, enabled AND circuit 76a, and OR
circuit 76c to set flip-flop 82. Thus at 12:25, AND circuit 75
provides an output which indexes divide-by-two flip-flop 74, sets
flip-flop 34, continuously illuminates lamp 18 through OR circuit
88b, and continuously actuates buzzer 33 with a high intensity
through OR circuit 88a. The indexing of divide-by-two flip-flop 74
at 12:25 energizes winding 77, moving relay armature 77a to the
alternate position where receptacle 78a is energized and glow lamp
79a is illuminated. 50 seconds subsequently at 12:25:50, a pulse
from capacitor 82a resets a flip-flop 82, disabling AND circuit 75.
However, flip-flop 34, which was set at 12:25, causes lamp 18 to
blink on and off for one second intervals each and causes buzzer 33
to be actuated with reduced intensity for a one second interval
once every ten seconds. At 12:29, counter 81 provides a 14 output
which partially enables AND circuit 83. At 12:29:50, a pulse from
capacitor 82a is coupled through AND circuit 83 to enable gate 89.
Holding flip-flop 90 is now forced to a positive output state,
which disables AND circuit 76a and partially enables AND circuit
76b. This renders the armature of switch 80a effective to control
the offset time within a subsequent fifteen minute interval
governed by the card slot. If, for example, a second card is in the
12:30 slot, then at 12:30, AND circuit 72c will provide an output
partially enabling AND circuit 75. However at this time, flip-flop
82 provides no output. Three minutes later at 12:33, counter 81
provides a 3 output. The armature of switch 80a receives a signal
which is coupled through capacitor 80c, enabled AND circuit 76b,
and OR circuit 76c to set flip-flop 82. Thus at 12:33, AND circuit
75 provides an output which indexes flip-flop 74, continuously
illuminates lamp 18, and continuously actuates buzzer 33 with a
high intensity. Relay winding 77 is thus de-energized at 12:33,
permitting armature 77a to return to the position shown, where
receptacle 78b is energized and glow lamp 79b is illuminated. At
12:33:50, flip-flop 82 in reset; but flip-flop 34 causes lamp 18 to
blink on and off and causes buzzer 33 to "beep" intermittently at
reduced intensity. At 12:40, counter 81 provides a 10 output.
Armature 80b will thus receive a signal which is coupled through
capacitor 80d to AND circuit 76a. However AND circuit 76a is
disabled, since holding flip-flop 90 is still in a positive output
state. At 12:44:50, AND circuit 83 enables gate 89; and the output
of holding flip-flop 90 is forced to the ground potential state of
flip-flop 74. This disables AND circuit 76b and partially enables
AND circuit 76a. The armature of switch 80b is now effective to set
flip-flop 82 at ten minutes after such subsequent quarter hour. It
will be appreciated that if there is no card in the 12:45 slot,
then AND circuit 72d will not provide an output at 12:45.
Accordingly, the setting of flip-flop 82 at 12:55 will not produce
an output from AND circuit 75. Flip-flop 82 is reset at
12:55:50.
If the total time interval between successive outputs from AND
circuit 75 is fifteen minutes or greater, then switch 84 should be
in the position shown; and the beginning and end of the time
interval will always be governed by cards in two different slots.
However where the total time interval between successive outputs
from AND circuit 75 is 14 minutes or less, then it is possible that
the beginning and end of the time interval may both occur within
the quarter-hour period of a single card slot. For example, a
fourteen minute interval from 12:15 to 12:29 begins and ends within
the quarter-hour period of the 12:15 card slot. But a 14 minute
interval from 12:14 to 12:28 would be governed by cards in the
12:00 and 12:15 slots; while a 14 minute interval from 12:16 to
12:30 would be governed by cards in the 12:15 and 12:30 slots. For
another example, a 1 minute interval from 12:14 to 12:15 would be
governed by cards in the 12:00 and 12:15 slots. But a 1 minute
interval from 12:13 to 12:14 would be governed by a single card in
the 12:00 slot, while a one minute interval from 12:15 to 12:16
would be governed by a single card in the 12:15 slot.
Where the total time interval is 14 minutes or less and the
interval begins and ends within the quarter-hour period of a single
card slot, then switch 84 must be actuated to its alternate
position; and gate 89 will be enabled 50 seconds after each minute
by the pulse from capacitor 82a. Assume that a card is in the 12:15
slot 20b, that the armatures of switches 80a and 80b are in the
positions shown, that switch 84 is in its alternate position, and
that flip-flops 74 and 90 are both in a positive output state prior
to 12:15. Thus AND circuit 76b is partially enabled. At 12:15, AND
circuit 72b provides an output; but AND circuit 75 is disabled,
since flip-flop 82 was reset at 12:14:50. At 12:18, counter 81
provides a 3 output which is applied through armature 80a,
capacitor 80c, enabled AND circuit 76b, and OR circuit 76c to set
flip-flop 82. Hence at 12:18, AND circuit 75 provides an output
which indexes flip-flop 74, de-energizing winding 77. At 12:18:50,
flip-flop 82 is reset, disabling AND circuit 75; and gate 89 is
enabled to force holding flip-flop 90 to a ground potential output
state. This partially enables AND circuit 76a. At 12:25 counter 81
provides a 10 output which is applied through armature 80b,
capacitor 80d, enabled AND circuit 76a, and OR circuit 76c to set
flip-flop 82. Thus at 12:25, AND circuit 75 again provides an
output. The time interval between successive outputs from AND
circuit 75 at 12:18 and 12:25 is 7 minutes. The second output from
AND circuit 75 at 12:25 indexes flip-flop 74, energizing winding
77. At 12:25:50, flip-flop 82 is reset, disabling AND circuit 75;
and gate 89 is enabled to force holding flip-flop 90 to a positive
output state.
Accordingly when switch 84 is in its alternate position, a single
card slot can provide two distinct outputs from AND circuit 75
where the armatures of switches 80a and 80b are set to different
positions. This feature may be used to advantage where two
appointments are scheduled within the quarter-hour period of one of
the card slots.
It will be seen that we have accomplished the objects of our
invention. We have provided a time reminding machine which operates
electrically and eliminates the mechanically rotating drum of the
prior art. Our machine is compact, of low weight and of relatively
simple and inexpensive construction. Thin insulating members such
as business cards are selectively inserted between pairs of
normally-closed spring contacts providing standard time increments
as for example each half or quarter hour. Our machine is provided
with selector switches so that the time may be set to any desired
minute within the standard time intervals provided by the slide
switches of FIG. 1 or the card slots of FIG. 7.
It will be understood that certain features and subcombinations are
of utility and may be employed without reference to other features
and subcombinations. This is contemplated by and is within the
scope of our claims. It will be further obvious that various
changes may be made in details within the scope of our claims
without departing from the spirit of our invention. For example,
AND circuit 75 may be omitted and the common output of AND circuits
72a through 72h directly connected to circuits 34, 74, 88a and 88b.
The output of flip-flop 82 may then provide a variable voltage to
resistors 73a through 73h in place of the fixed voltage from
terminal 32a of power supply 32. With such alternate construction,
the third inputs of AND circuits 72a through 72h will be disabled,
irrespective of the state of the card slot switches 25a through
25h, until flip-flop 82 is set and its output becomes positive. It
will also be appreciated that we may provide a 24 hour numerical
display instead of a 12 hour display in conjunction with an AM/PM
indication. It will further be appreciated that we may use toggle
switches instead of slide switches and that all switches may be
normally open instead of normally closed. It is therefore to be
understood that our invention is not to be limited to the specific
details shown and described.
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