U.S. patent number 3,590,225 [Application Number 04/799,451] was granted by the patent office on 1971-06-29 for digital arrow location computer.
This patent grant is currently assigned to Brunswick Corporation. Invention is credited to Patrick J. Murphy.
United States Patent |
3,590,225 |
Murphy |
June 29, 1971 |
DIGITAL ARROW LOCATION COMPUTER
Abstract
A projectile path coordinate computing system for use with a
detecting system wherein a projectile path is scanned by a beam of
energy. The computer includes a binary counter and a clock for
stepping the counter. Gating is provided to allow the clock to
initiate the stepping of the counter at the initiation of the scan
of the projectile path and means are provided for stopping the
counter when the beam of energy is interrupted during its scan by a
projectile so that the count in the binary counter when stopped is
indicative of one coordinate of the position of the projectile
within the scanned path. Means are also provided for translating
the count into an indication of the coordinate of the projectile
within the path.
Inventors: |
Murphy; Patrick J. (Muskegon,
MI) |
Assignee: |
Brunswick Corporation
(N/A)
|
Family
ID: |
25175944 |
Appl.
No.: |
04/799,451 |
Filed: |
February 14, 1969 |
Current U.S.
Class: |
377/5; 377/53;
273/371 |
Current CPC
Class: |
F41J
3/0004 (20130101); F41J 5/02 (20130101); G01S
13/46 (20130101) |
Current International
Class: |
G01S
13/00 (20060101); F41J 5/00 (20060101); G01S
13/46 (20060101); F41J 5/02 (20060101); F41J
3/00 (20060101); G06F 19/00 (20060101); G06m
001/272 () |
Field of
Search: |
;235/92 ;273/102.2
;235/193 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wilbur; Maynard R.
Assistant Examiner: Gnuse; Robert F.
Claims
I claim:
1. A projectile path coordinate computer comprising; a counter
having a predetermined capacity which when exceeded results in
automatic resetting of the counter, means for stepping said counter
at a predetermined rate, means for enabling said counter in
response to the beginning of a scan of a target area, first means
for disabling said counter when a projectile is encountered in said
target area and whereby the accumulated count therein is a measure
of the time in the scan when a projectile was encountered and thus
a measure of the position of the projectile in the target area, and
second means for disabling said counter when its predetermined
capacity is exceeded so that said counter is held in a reset
condition until said enabling means again enables said counter to
thereby synchronize the stepping of the counter and the scan of the
target area, said counter comprising a binary counter and said
stepping means comprising a clock; movable indicator means; binary
coded means associated with said indicator means for providing a
count representative of the position of said indicator means; means
for comparing the count in said counter and the count provided by
said binary coded means; and means for operating said indicator
means responsive to said comparing means when said first disabling
means is operative.
2. A projectile coordinate computer according to claim 1, wherein
said indicator means includes a bidirectional motor; means
responsive to said enabling means for initially preparing said
motor to drive in one direction; and means responsive to said
comparing means for preparing said motor to drive in the other
direction when said comparing means determines a match of the count
in said counter with the count provided by said binary coded
means.
3. A pair of projectile coordinate computers according to claim 1
for ascertaining two coordinates of a projectile path; and further
including means responsive to the first disabling means of both
said computers for precluding movement of the indicator means of
both of said computers except when the first disabling means of
both of said computers is operative.
4. A pair of projectile coordinate computers according to claim 3,
further including projectile counting means; projectile
count-indicating means responsive to said projectile counting
means; and means responsive to the first disabling means of both of
said computers for stepping said projectile counting means when
both said first disabling means are operative.
5. A pair of projectile coordinate computers according to claim 3,
wherein indicator means of both said computers include a common
point indicator lamp; and means for extinguishing said lamp
whenever one of said indicator means is moving.
6. A pair of projectile coordinate computers according to claim 3,
wherein the indicator means of both said computers are adapted for
cooperative movement relative to a target indicator having a
"bull's-eye," and separate "bull's-eye" indicating means operative
in response to the movement of the indicator means of both said
computers to a bull's-eye position on said target indicator.
7. A pair of projectile coordinate computers according to claim 3
wherein the indicator means of both said computers are adapted for
cooperative movement relative to a target indicator and separate
indicating means operative in response to the movement of the
indicator means of both of said computers to a predetermined region
on said target indicator for providing a separate indication
thereof.
8. A pair of projectile coordinate computers according to claim 7
wherein said separate indicating means comprises a first electrical
contact located in proximity to target indicator and at a
predetermined position with respect to said predetermined region, a
second electrical contact movable with both of said indicator means
and positioned to make electrical contact with said first
electrical contact when both of said indicator means are at said
predetermined region, and signal means energizable in response to
said second electrical contact electrically contacting said first
electrical contact.
9. A projectile coordinate computing system comprising a detecting
means for providing information relative to two coordinates of the
position of a projectile within a path, said detecting means
including a pair of spaced scanners, one for each coordinate, for
cyclically scanning said path and detecting projectiles therein,
and two separate computing systems for receiving information
relative to each coordinate respectively; each of said systems
including a binary counter, clock means for driving the binary
counter, gating means responsive to the beginning of the scan by
the associated scanner for permitting the counter to be driven by
the clock, means responsive to the detection of the projectile in
the path by the associated scanner for precluding the clock from
driving the counter, and means for stopping the counter at binary
zero until said gating means responds to the initiation of the
subsequent scanning cycle.
10. A projectile coordinate computing system and indicating means
comprising: a computer including timing means; means for cyclically
scanning a path in which a projectile may pass and for providing a
signal indicative of the detection of the projectile in said path;
means responsive to the initiation of the scanning of said path by
said scanning means for initiating the operation of said timing
means; means responsive to the detection of a projectile in said
path by said scanning means for stopping said timing means whereby
the condition of said timing means provides an indication of a
coordinate of the projectile within said path; movable indicating
means, including a bidirectional drive motor, responsive to said
timing means for determining the condition of said timing means and
indicating the same as a coordinate for the position of a
projectile within said path; and switch means operated by said
computer for conditioning said motor for movement in one direction
during a first portion of a scan and for conditioning said motor
for movement in the other direction during a second portion of a
scan.
11. The projectile coordinate computing system of claim 10 wherein
said indicating means includes a movable indicator and feedback
means for providing information relative to the position of said
indicator, comparing means for comparing the condition of said
timing means and said information provided by said feedback means,
and said switch means includes means responsive to said means for
initiating operation of said timing means for normally conditioning
said motor to move in one direction, and means responsive to said
comparing means for conditioning said motor to operate in the other
direction when said comparing means determines a match between the
conditions of said timing means and said feedback means.
12. The projectile coordinate computing system of claim 11 wherein
said motor means comprises a direct current rotary motor and said
switch means includes a first switching device connected to a
source of power and to one side of said motor, a second switching
device connected to the other side of said motor and the other side
of said source of power, means responsive to the operation of said
first switching device for operating said second switching device;
a third switching device connected to said one side of said source
of power and to said other side of said motor, a fourth switching
device connected to said one side of said motor and said other side
of said source of power, and means responsive to the operation of
said third switching device for operating said fourth switching
device; and means for alternately operating one of said first and
third switching devices.
13. The projectile coordinate computing system of claim 12 wherein
all of said switching devices comprise transistors.
Description
BACKGROUND OF THE INVENTION
In the recent past, efforts have been directed toward provision of
automated archery lanes, particularly for indoor use, involving a
target remote from a firing line constructed in a way such that
arrows do not remain impaled in the target but fall free for
collection to be returned automatically to the archer at the firing
line. In preferred systems, the target is constructed to be
penetrable so that neither the target nor the arrow is
substantially damaged by target penetration. Behind the target
there is a suitable backstop which is usually yieldable in a way to
absorb the energy of the arrow so that the latter stops and falls
downwardly to an appropriate means for directing the arrow to a
return conveyor. The return conveyor has preferably been in the
form of a conveyor belt means which delivers the arrows to a
container adjacent the firing line and accessible to the archer so
that he merely has to remove an arrow from the storage container,
fire at the target and await return of the arrow to the storage
container. The return may be accomplished in a matter of a few
seconds so that the archer may effectively practice his sport with
only one or two arrows, if desired. Because the arrows do not
remain impaled in a target for inspection by the archer, it has
been contemplated in such systems that there would be a sensing
apparatus for determining the location of the arrow hit in the
target and controlling an indication means adjacent the firing line
for showing the archer where the arrow struck the target.
SUMMARY OF THE INVENTION
The invention relates to a computing system for computing the point
of passage of a projectile along a path and in the exemplary
embodiment, the same is adapted to be used with a projectile
detecting means which scans the path in which the projectile
passes. The system includes a computer comprised of a binary
counter and a clock for stepping the binary counter. Gating is
provided so that when the detecting system initiates the scan of
the path, a synchronizing pulse is provided to permit the clock to
begin to step the counter. Gating is also provided for stopping the
counter when the detecting system ascertains that a missile has
been found in the path so that the count on the counter is
indicative of the position on the path along one coordinate of the
projectile. Means are also provided which halt the counter at a
zero count level when no missile in the path has been detected so
that the counter will await the next synchronizing pulse from the
detecting system.
Normally, two such systems will be used so that two coordinates of
the projectile within a path may be ascertained. In such a case,
two indicating means having a common point indicator are driven by
a motor responsive to a logic system receiving command position
information from both of the binary counters. A binary coded disc
feeds back position information of each indicator and movement of
both indicators is stopped when the actual position information
provided by the binary code disc matches the count in the binary
counter.
Additional features include interlocking of the two computing
systems so that spurious signals such as electrical noise received
by one computation system will not cause the feeding of erroneous
information to the associated indicator. Additionally, the system
includes a separate indicator for indicating when a so-called
"bull's-eye" has been obtained.
Further features include a projectile counter which provides an
indication of the number of projectiles fired at a target and means
whereby the point indicator is disabled during movement of the
indicating means with which it is associated so that indications
during the transition of the indication from one point to a
subsequent point will not be present.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an archery installation, looking
down a pair of lanes toward a pair of targets from a position
adjacent an arrow quiver;
FIG. 2 is a perspective view partly broken away, illustrating a
housing for the targets, backstops and arrow collectors for
delivering arrows to a return conveyor;
FIG. 3 is a perspective view of the targets and scanning system
looking from the rear of the housing with parts broken away;
FIG. 4 is a plan view of the scanning system;
FIG. 5 is a fragmentary vertical section of a housing for a light
source, rotary mirrors, inclined mirrors and photocells;
FIG. 6 is a fragmentary vertical section of the housing for the
mirrors and light source and photocells.
FIG. 7 is a logic diagram with certain elements shown in schematic
form of the computing circuit for ascertaining one coordinate of
the position of a projectile within a path;
FIG. 8 is a plan view of a binary coded disc which provides actual
indicator position information for feedback purposes; and
FIG. 9 is a block diagram illustrating the manner in which an
indicating system is operated by two of the computers illustrated
in FIG. 7.
DETAILED DESCRIPTION
Referring now particularly to FIGS. 1 and 2, there is illustrated a
substantially complete installation for two automated archery lanes
side by side in which the entire apparatus is disassemblable and/or
portable to permit removal from the floor surface utilized in order
to leave it free for use for other purposes. As shown, the
installation includes an arrow storage quiver 10 adjacent the
firing line 11 adapted to serve two adjacent lanes 12 and 13 in
that it is constructed to hold arrows as at 15 in upright
positions, either point up or fletching up, conveniently disposed
for easy access by archers on both lanes. Targets for both lanes
are provided in housing 18 located remotely from the firing line 11
and supported on wheels which facilitate adjustment of the housing
toward and away from the firing line to permit adjustment in the
length of the range.
In order to provide a target on each lane, the wall of the housing
18 facing the firing line is formed with a pair of large
rectangular openings as at 19 and 20 and each aperture is closed by
a penetrable screen 22 adapted to carry a target pattern as at 24
and constructed in a manner to permit arrows to pass through the
screen without substantial damage to the screen or to the arrows.
In a preferred form, the penetrable screen 22 comprises a plurality
of vertically disposed closely adjacent flexible strands anchored
at the top and bottom to the housing 18. For example, the strands
may be 1/8 inch natural rubber or vinyl strands which provide both
a suitable surface for the target and also long life with repeated
arrow penetration. The target 24 may be painted on the screen 22 or
may be an image projected onto the screen. The latter form has the
advantage that the form of the target may be readily changed as
desired.
At the rear of the housing 18, behind the target screens 22 there
are suitable backstop means as at 28. As illustrated, each of the
backstop means 28 is in the form of a free hanging net disposed in
front of a fixed net in a manner such that the energy of the arrows
fired through the target screens is absorbed by the backstop means
in a manner to stop the arrow without damage to the arrow or the
backstop, as a result of which the arrow falls downwardly for
return toward the firing line. Other backstop means may be utilized
and one acceptable form includes the use of a free hanging bed of
many strands of flexible material such as plastic tubing in
sufficient numbers to provide a relatively thick barrier to the
passage of arrows and yet have sufficient flexibility to absorb the
energy of the arrows without rebound of the arrows.
The sidewalls and the top of the housing 18 may be suitably covered
with appropriate material as at 29.
From the backstop means 28, the arrows fall downwardly toward
suitable means for directing arrows from both lanes toward a
central common return conveyor. As illustrated, the arrow gathering
or collecting means in each lane comprises an endless conveyor as
at 30 having a width substantially equal to the distance between
the screen 22 and the backstop 28 and disposed to travel from the
outer edge of the housing toward the center of the housing as
represented by indicating arrow 32. The cross conveyor belts 30 are
each arranged to pass about a pair of long support and drive
rollers as at 34 and 35 on housing 18 at least one of which is
arranged to be rotated by suitable drive means as at 36. Arrows
fall from the backstop means 28 to the cross conveyors 30 as
illustrated at 38, for example. While the arrows shown are disposed
with the pointed ends leading for return to the firing line, some
of the arrows fall from the backstop with the fletched end disposed
toward the firing line, and the arrow return system is adapted to
handle either arrangement easily. In practice, substantially more
arrows return point first than fletching first.
The cross conveyors 30 deliver fallen arrows to a centrally
disposed common arrow return conveyor 40 including an endless
conveyor belt 41 supported adjacent the firing line on an idler
roller associated with the quiver 10, and adjacent the housing 18
by a drive pulley on a motor 43. Intermediate the idler roller and
the drive pulley, the long upper and lower reaches of the arrow
return conveyor are supported by a channel structure 45. The
arrangement is such that the conveyor belt 41 is driven at a
relatively rapid rate so that arrows are returned in a matter of a
few seconds and are thrown into the quiver 10 with sufficient force
to reach the storage positions 15.
In order to detect the position of an arrow relative to the target
24 as the arrow passes through the penetrable screen 22, there is
an arrow detection system in the housing 18 including a housing 48
located centrally between the apertures 19 and 20 and including a
light and optical scanning system for sweeping two beams of light
across each target area to provide two angular measurements in the
forms of angular coordinates for indicating the position of the
arrow. For example, as seen in FIG. 2, one beam of light is swept
across the right-hand target area from an effective starting
position represented by line 49 to an effective finish position
represented by line 50. Each light beam is directed toward a
reflective strip on housing post 51. Preferably the detection
system is used for purposes of controlling and indicating means
associated with the quiver 10 and including an indicator face for
each lane as at 52 and 53 bearing an image as at 54 simulating the
target 24. In a preferred form the indicator includes an indicator
light movable about the indicating face and controlled by the arrow
detection system.
The scanning system can best be understood with reference to FIGS.
3--6. As viewed in FIG. 3, the scanning unit, generally designated
100, is interposed between the targets 24 of the adjacent lanes 12
and 13. As will be seen hereinafter, the scanning unit 100 includes
an upper scanner 102 and a lower scanner 104 and both scanners are
operative to scan both of the lanes 12 and 13.
On the outboard side of the lane 13 and opposite from the scanning
unit 100, there is located a pair of vertically oriented
retroreflective tapes 106 and at the upper extremity of each of the
tapes 106 there is located a start photocell 108.
Similarly, at the outboard side of the lane 12 and opposite the
scanning unit 100, a pair of similar tapes 106 are located and at
the lower extremity of each tape 106 there is provided a start
photocell 108.
The retroreflective tapes 106 for each of the lanes 12 and 13 are
horizontally spaced and the lower scanner 104 is adapted to project
a rotating beam of light at the rearmost tape 106 associated with
the lane 13 as well as the forwardmost tape 106 associated with the
lane 12. The upper scanner 102 is adapted to project a rotating
beam of light at the forwardmost tape 106 associated with the lane
13 and the rearmost tape 106 associated with the lane 12. Stated
another way, the beams of light provided by both the scanners 102
and 104 are in a generally vertical plane which is slightly askew
to a position normal to the length of the lanes 12 and 13 with the
plane of the beam of the upper scanner 102 being askew in the
direction opposite from the direction in which the plane containing
the beam of light from the lower scanner 104 is askew.
The foregoing relation is illustrated in FIG. 4 wherein the beam of
light generated by the upper scanner 102 is designated 110 while
the beam of light generated by the lower scanner 104 is designated
112.
The retroreflective tapes 106 are commercially known as "3M Brand"
photoelectric scanning tape sold by Minnesota Mining and
Manufacturing Company and have the property of returning the light
directly to its origin regardless of the striking angle. As a
result, when a beam of light strikes the retroreflective tape 106,
the beam of light will be reflected back towards its source without
regard to the angle that the beam of light initially impinged upon
the tape. The retroreflective tapes 106 are also of a sufficient
length so that a moving beam of light from the upper scanner 102
will be able to completely sweep across the targets 24 and be
returned to the upper scanner 102 provided that the beam has not
been broken by a projectile such as an arrow. Similarly, the
retroreflective tapes 106 associated with the lower scanner 104
have a length to provide the same capability with respect to the
beam of light provided by the lower scanner 104. With reference to
FIG. 3, the beams of light from the scanners 102 and 104 rotate in
a counterclockwise direction.
Turning now to FIGS. 5 and 6, the construction of the scanning unit
100 may be seen. A vertically elongated housing 120 is provided and
within the same at about the vertical midpoint thereof, there is
mounted a double ended laser 122 of conventional construction. Also
located within the housing 120 is a power source 124 for the laser
122.
The double ended laser 122 may be of the type obtainable from
Optics Technology, Inc. of Palo Alto, California and has the
ability to provide two coaxial light beams, one from each end, of
very narrow size. One such light beam is utilized by the upper
scanner 102 while the other light beam is utilized by the lower
scanner 104.
The use of the double ended laser 122 allows the scanning of two
areas with but a single energy source. Furthermore, the laser is
capable of producing light beam having a diameter significantly
smaller than that of an arrow and with a high energy level so as to
maximize system activity.
The manner in which the light beam from the laser 122 is utilized
will now be described in conjunction with the lower scanner 104
with the understanding that the construction of the upper scanner
102 is identical. A mounting plate 126 within the housing 120
supports, near its lower end, a high-speed synchronous motor 128
having a rotary output shaft 130 to which a mirror 132 is affixed.
The mirror 132 is externally silvered on both of its sides and,
when driven by the motor 128, will rotate to deflect the beam of
light from the laser 122 in a sweeping path just behind the target
24 (FIGS.) 3 and 4) to the retroreflective tapes 106 with which it
is associated on both of the lanes 12 and 13. In the exemplary
embodiment, the synchronous motor 128 operates at 3,600 r.p.m. and
the silvering of both sides of the mirror results in a scan rate of
7,200 scans per minute.
The laser 122 is located directly above the mirror 132 and arranged
so that the beam of light emanating from one end thereof is focused
on the mirror to point intersect the axis of rotation thereof.
Interposed between the laser 122 and the mirror 132 is an inclined,
totally silvered mirror 134 having an aperture 136 therein through
which the beam of light from the laser 122 may pass to the mirror
132. The mirror 134 is located at an angle so that a beam of light
reflected by the mirror 132 towards the mirror 134 and not passing
through the aperture 136 will be directed toward a lens 138 mounted
on the plate 126 which then focuses the reflected beam of light on
a stop photocell 140.
Finally, the housing 102 is provided with windows 142 adjacent to
the mirror 132 through which the laser beam may be reflected by the
mirror 132 externally of the housing to the tape 106.
From the foregoing description, it will be appreciated that
normally the photocell 140 will be illuminated whenever the beam of
light 112 provided by the lower scanner 104 is sweeping across the
confines of the target 24. This is due to the fact that as the
mirror 132 rotates to sweep the beam of light 112, and the latter
impinges upon the retroreflective tape 106, the light beam will
then be reflected back to the mirror 132 and, in turn, to the
mirror 134 to be focused by the lens 138 on the photocell 140. The
only time during the scan of the target 14 that the photocell 140
will not be illuminated is when the beam of light 112 is broken.
This will occur when a projectile is within the scanned area and
breaks the beam of light 112. Accordingly, the photocell 140
provides an indication of the time when the beam of light is broken
by a projectile.
In order to insure that the beam of light is broken by a
projectile, it is necessary that the angular velocity of the
sweeping beam of light be such that it will completely scan the
target area 14 before projectiles can pass through the plane in
which the light beam rotates. When, as is the case with the
exemplary embodiment, the scanning system is intended for use in
detecting arrows, the above-mentioned scan rate is sufficient to
detect even the shortest arrows now used, even if shot at the
target at the highest velocity obtainable with current bows.
Projectiles having a shorter length than arrows and/or fired at the
target at higher velocity than a high velocity arrow, are capable
of detection using the principles of the invention. For such
shorter projectiles and/or higher velocity projectiles, it will, of
course, be necessary to increase the scan rate and it may also be
desirable to use extremely high quality photocells that are
extremely sensitive to rapid changes in illumination as when the
beam of light is broken by the projectile.
Returning to FIG. 3, it will be observed that the location of the
start photocell 108 is such that for the direction of rotation of
each light beam 112 or 110, the photocell 108 will be briefly
illuminated at the beginning of each sweep of the beam of light
across the target. As a result, the photocells 108 provide a signal
indicating when in time a scanning cycle has been initiated.
Because synchronous motors 128 are used to drive the beam of light
through its scan, the rate of the scan is constant. It can be
determined when the scan was initiated and when in the scan the
beam was interrupted by interrogating the photocells 108 and 140
and thus, the angular position of the beam of light at the time it
was interrupted can be determined to thereby provide information
relative to one coordinate of the point of impact of the projectile
on the target 24.
As mentioned previously, the upper scanner 102 works in an
identical manner but provides information relative to a second
coordinate of the point of impact. By means of a computer that
utilizes information from the photocells 108 and 140 for both the
upper and lower scanners 102 and 104 on one lane, two coordinates
of the point of impact of a projectile are determined, and thus,
the exact point of impact can be determined.
A computer circuit for use in the archery range is seen in FIG. 7
which illustrates, in logic form, the circuitry required to
ascertain one coordinate of the passage of the arrow through the
target. In the preferred embodiment, it is to be understood that
four such circuits are employed to provide two coordinates on each
of two different ranges. It should be further understood that all
gates illustrated are NAND gates which perform various AND and OR
functions, and that the characterization of a gate as, for example,
as an AND gate refers to its function as opposed to its
structure.
The computer includes a conventional clock 300 which acts as a
source of timed electrical pulses as an input to an AND gate 302.
The output of AND gate 302 is connected to the trigger input in the
first stage of a binary up counter. The binary up counter includes
seven stages designated BC-1, BC-2, BC-4, BC-8, BC-16, BC-32 and
BC-64, with a number following the letters representing the count
held in each particular stage. Thus, the maximum count of the
counter is 127 .
When the AND gate 302 is enabled, pulses from the clock 300 will
cause the counter to step. However, when the AND gate 302 is
disabled, the count in the counter will remain the same.
A line to the AND gate 302 is taken from the output of a stop-start
flip-flop 304 which is set to initiate the count coincidentally
with the beginning of the scan of the associated light beam. More
specifically, an input to the set section of the flip-flop 304 is
taken from the output of an AND gate 306 which in turn has one
input taken from an amplifier 308 through an inverter 309. The
amplifier 308 is connected to the photocell 108 which is
illuminated at the beginning of the scan by the rotating beam of
light. Thus, when the photocell 108 is illuminated, the amplifier
308 generates a synchronizing pulse which under certain conditions
is passed by the AND gate 306 to set the flip-flop 304 thereby
causing the count to be initiated.
The AND gate 302 may also be disabled to preclude the counter from
counting. Specifically, the AND gate 302 is disabled whenever the
flip-flop 304 is in a reset condition and such an occurrence will
take place when the photocell 140 has its light beam interrupted by
an arrow passing through the target. The temporary lack of
illumination of the photocell 140 causes a change in signal which
is magnified by an amplifier 310 and passed as an input to the
reset section of the flip-flop 304. Thus, whenever an arrow passes
through the target, the counting of the counter will cease.
It will be recognized that, in view of the speed of the scan of the
light beam, significantly more often than not, the light beam will
pass through a cycle without being interrupted by an arrow. In such
a case, it is desired to stop the counter at binary zero and this
is accomplished by resetting the flip-flop 304 to inhibit the AND
gate 302. To this end, an output from an AND gate 316 is fed as an
input to the reset section of the flip-flop 304. The AND gate 316
includes inputs taken from each of the seven flip-flops BC-1
through BC-64 comprising the counter. Thus, when each of the
flip-flops BC-1 through BC-64 is in a reset condition,
corresponding to a zero count therein, the AND gate 316 will issue
a signal which is passed on to the flip-flop 304 to reset the same
thereby stopping the counting process until the flip-flop 304 is
again set when the photocell 108 is illuminated at the beginning of
a scan.
The period of the clock 300 and the capacity of the counter are
chosen so that the counter will reach its capacity at about the
time the beam of light associated therewith from the scanner 100
terminates its sweep across the target area.
In view of the foregoing, it will be appreciated that the count on
the counter when stopped at any position other than zero count,
will be representative of the position of the associated light beam
within its scanning path in view of the fact that the counter is
started when the scan is initiated and is stopped when an arrow is
detected. As a result, the count on the counter can be used to
provide information for controlling a portion of an indicator and
the condition of the counter is read when necessary to provide such
control information.
As mentioned previously, when the count in the counter is zero, the
AND gate 316 causes the resetting of the flip-flop 304. However, at
all other times, the output signal of the AND gate 316 is at the
opposite level and may be used when other conditions are present to
cause a reading of the counter. To this end, a line from the output
of the AND gate 316 is used as an input to an AND gate 318 together
with a second input from the output of the reset section of the
flip-flop 304. The arrangement is such that when the flip-flop 304
is reset and the count contained in the counter is not zero, the
AND gate 318 will issue a signal to set a flip-flop 320 which
issues a READ signal from an output from its set section.
An output of the flip-flop 320 is also utilized as an input to the
AND gate 306 to inhibit the same whenever the counter is to be
read. This provision is made in order that the counting procedure
cannot be improperly initiated by the beam of light hitting the
photocell 108 at the beginning of a scanning sequence when the
previous scanning cycle had resulted in the detection of an arrow
passing through the target and the indicator has not yet fully
responded. Thus, for the period of time that the flip-flop 320 is
set to cause the reading of the counter, AND gate 306 is inhibited
to thereby preclude the passing of any pulses from the clock 300 to
the counter.
The same output of the flip-flop 320 is also used as in input to an
OR gate 324 which has its output connected through a diode to the
emitter of a unijunction transistor within a unijunction transistor
circuit 322. When the flip-flop 320 is reset, the emitter of the
unijunction transistor is clamped at a level to preclude the
charging of a capacitor 325 from charging. However, when the
flip-flop 320 is set corresponding to a READ condition, the emitter
of the unijunction transistor within the circuit 322 is then placed
at a level whereby a capacitor 325 therein may begin to charge so
that after a predetermined period, the unijunction transistor may
fire to reset the flip-flop 320. Normally, the RC combination in
the circuit 322 should be chosen so that about 5 seconds may elapse
before the unijunction transistor therein is fired to reset the
flip-flop 320 through the circuit just described. However, as will
be seen hereinafter, provision is made for causing resetting of the
flip-flop 320 in a more rapid manner.
The OR gate 324 includes a second input which is similarily
connected to a corresponding flip-flop 320 in the computer circuit
for the second coordinate of projectile path. Thus, when either one
of the two flip-flops 320 is in a set condition, the unijunction
timing circuit 322 will be energized.
Another output of the flip-flop 320 also serves as an input to two
AND gates 326 and 328 which are used to control the direction of
movement of an indicator for one coordinate as will be seen in
greater detail hereinafter.
The computer further includes a directional control flip-flop 330
which provides signals to the AND gates 326 and 328 for the purpose
of determining the direction of movement of the indicator. The
flip-flop 330 includes an input to its set section from the output
of the AND gate 306 which causes the flip-flop 330 to be placed in
a set condition at the beginning of each scanning cycle. As will
become apparent hereinafter, when the flip-flop 330 is in a set
condition, counterclockwise rotation of an indicator drive motor is
called for while when the flip-flop 330 is in a reset condition,
clockwise rotation of the indicator drive motor is called for.
An output from the set section of the flip-flop 330 is taken as an
input to the AND gate 326 while an output from the reset section of
the flip-flop 330 is taken as an input to the AND gate 328.
A third input to both of the AND gates 326 and 328 is taken from
the output of an AND gate 334 which receives its inputs from a
conventional comparator circuit, generally designated 336.
The comparator circuit 336 includes 21 inputs (only three of which
are shown) with seven of the inputs being taken from the outputs of
the reset sections of the flip-flops BC-1 through BC-64 comprising
the counter and seven being taken from the set sections of the
flip-flops BC-1 through BC-64. The other seven inputs to the
comparator 336 are taken from a binary coded position disc shown
schematically at 338.
The coded disc is mounted for rotation and mechanically linked to
the indicator so that its position is changed with a change of the
indicator position.
The coded disc 338 is illustrated in FIG. 8 and is seen to comprise
a circular disc having on one surface thereof seven rows of
conductive segments 339. Beginning outwardly and progressing
radially inward, the rows are designated CD-1, CD-2, CD-4, CD-8,
CD-16, CD-32 and CD-64 and, as is the case with the reference
numerals relating to the counter, the numerals associated with each
of the rows CD-1 -CD-64 correspond to the binary number which the
segment represents. In use, a plurality of brushes 340 are
provided, one for each of the conductive rows CD-1--CD-64 and
provide input signals to the comparator 336 whenever the brush 340
associated with a particular row is on one of the conductive
portions.
Also provided on the coded disc 338 are a pair of segments 341
which are adapted to be contacted by brushes 342 (FIG. 1) when the
coded disc has reached the limit of its rotation in either
direction to provide energization signals to the AND gates 326 and
328 to reverse the motor for the indicator. It is to be noted that
as illustrated in FIG. 8 the conductive segments are provided about
approximately 320.degree. of the disc 338 As will be seen
hereinafter, arms associated with the indicator are adapted to be
moved about an axis approximately 80.degree. and thus, the
mechanical arrangement of the coded disc 338 with respect to such
indicator arms should be that the disc 338 be geared to the
indicator arms at a 4:1 ratio.
Those skilled in the art will recognize the comparator circuit 336
is such that when the count picked off of the coded disc 338 is the
same as that contained in the counter, the AND gate 334 will issue
a signal indicative of the match in the counts. However, whenever
the comparator determines that no match is present, the output
levels of the AND gate 334 will be such as to provide an enabling
input to gates 326 and 328.
The fourth and final input to each of the AND gates 326 and 328 is
received on a line 337 which is taken from the computer which
determines the other coordinate of the point of impact of the
projectile upon the target. Specifically, the line 337 is connected
to the output of the set section of the corresponding flip-flop
320.
As a result of the foregoing, it will be appreciated that the AND
gates 326 and 328 can never be enabled simultaneously and the
particular one of the AND gates 326 and 328 that is enabled depends
upon the condition of the flip-flop 330 assuming that all other
appropriate inputs are present. As a result, the AND gate 326 is
enabled when the flip-flop 320 is set corresponding to a READ
condition, the flip-flop 330 is set to indicate counterclockwise
drive, the output of the AND gate 334 indicates that no match has
been obtained and when the corresponding flip-flop 320 is in the
associated computer circuit is also set.
The conditions for enabling of the AND gate 328 are identical to
that for the AND gate 326 except that flip-flops 330 must be in a
reset condition rather than in a set condition.
As mentioned previously, the flip-flop 330 will normally be in a
set condition from the initiation of each scan cycle until such
time as the AND gate 334 determines that a match exists between the
count picked off of the coded disc 338 matches the count contained
in the binary counter; and that thereafter, the flip-flop 330 will
be in a reset condition. The setting of the flip-flop 330 occurs
when the AND gate 306 sets the flip-flop 304 in the manner
mentioned previously and the resetting of the flip-flop 330 occurs
when the AND gate 334 issues a signal indicative of a match which
is inverted by an inverter 343 and fed through an AND gate 344 to
the reset section of the flip-flop 330. The AND gate 344 is
normally enabled but will be disabled whenever the flip-flop 320 is
in a set condition requiring the reading of the counter for
indication purposes.
The purpose of the foregoing is due to the geometry of the
indicator and will be apparent from the following. Normally, the
disc 338 will be in a position dictated by the indications of the
previous shot and will be continuously applying a signal indicating
a particular position count to the comparator 336. The indicator
construction is such that for a lesser count in the counter than
that being picked off of the disc 338 the motor for driving the
indicator should be driven in counterclockwise direction. As a
result, from the time the counter begins to count and before it
reaches the point where the count contained therein is equal to the
count being picked off of the disc 338, the flip-flop 330 will
provide an enabling input to the AND gate 326 and a disabling input
to the AND gate 328. Similarly, the count contained in the counter
exceeds that being picked off of the disc 338, the geometry of the
indicator is such that clockwise rotation of the drive motor is
required. As a result, when the point is reached where the count
contained in the counter corresponds to the count being picked off
of the disc 338, the AND gate 334, sensing the match, will cause
the AND gate 344 to reset the flip-flop 330 so that as the count
contained in the counter increases above that being picked off of
the disc 338, the AND gate 328 will receive an enabling signal
while the AND gate 326 will receive a disabling signal.
As mentioned previously, the input to the AND gate 344 from the
flip-flop 320 is used merely as an inhibiting input. Thus, whenever
it is desired to read the counter to cause the indicator to respond
thereto, the AND gate 344 is inhibited to preclude the flip-flop
330 from being reset when a match is obtained assuming that it has
not already been reset. Stated another way, during the reading of
the counter for moving the indicator, the condition of the
flip-flop 330 cannot be changed.
The motor for driving the indicator is designated 350 and is a
direct current motor so that its direction of rotation depends on
the direction of current flow therethrough.
As indicated schematically, the motor 350 drives the coded disc 338
and also drives an indicator arm. As a result, the position of the
decoder disc 338 and the count picked off of the same is indicative
of the position of the indicator arm associated therewith. Specific
details of arrangement will be described hereinafter.
The indication of the point of passage of an arrow or other missile
through the target is indicated on a target monitor by a movable
display lamp shown schematically at 356 and which is connected to
control circuitry by brushes 357 engaging linear commutator
segments 358. By means to be described in greater detail
hereinafter, the position of the display lamp 356 is altered with
respect to the transluscent target face identical to the target at
which the projectile is aimed and the arrangement is such that the
lamp 356 is illuminated after the computer circuitry has responded
to the information provided thereto by the sensing system.
Thereafter, the position of the lamp is held until the next arrow
or projectile passes through the target and during this period, the
lamp 356 is illuminated. However, whenever the position of the lamp
356 is being changed, it is extinguished.
This is accomplished by connecting one of the commutator segments
358 directly to a source of power and the other to an electronic
switch 359 which is driven by an inverter 360. The inverter 360, in
turn, receives its input from the output of an AND gate 361 which
receives a first input from a line including an AND gate 362 which
has one input taken from the output of the AND gate 326 and another
input taken from the output of the AND gate 328. The arrangement is
such that when both AND gates 326 and 328 are disabled, the AND
gate 362 will ultimately cause the application of one enabling
input to the AND gate 361.
A second input to the AND gate 361 is taken from a line including
an AND gate 362 (not shown) in the computer circuit for determining
the other coordinate. As a result, it will be appreciated that AND
gate 361 will be enabled only when both of the two indicator drive
motors are deenergized, which will be the vast majority of the
time, so that the electronic switch 359 will not illuminate the
display lamp 356 during indicator movement.
An output from the and gate 361 is also fed through an inverter 363
to the emitter of the unijunction transistor within the unijunction
transistor circuit 322. The circuit arrangement is such that when
the AND gate 361 becomes enabled to illuminate the lamp 356, the
unijunction transistor circuit 322 will time out much more rapidly
than the same would be virtue of its connection to the gate 324 to
thereby cause virtually immediate resetting of the flip-flop 320 to
eliminate the READ signal provided thereby to ready the circuit for
the next succeeding arrow.
A further advantage of the just described circuitry is to preclude
spurious signals received by but a single computer circuit from
causing the flip-flops 320 from being set over a prolonged period.
For example, when but a single computer system is triggered as by
electrical noise, it will be appreciated that notwithstanding the
setting of the flip-flops 320 due to the spurious noise signals,
both of the AND gates 326 and 328 will remain disabled as a READ
signal from but a single one of the flip-flops 320 will be
received. Thus, AND gate 361 will continue to remain in an enabled
condition and the output signal thereof will be continuously
applied by the inverter 363 to the unijunction timing circuit 322
in the same manner as when the AND gate 361 switches from a
disabled condition during indicator movement to an enabled
condition when such movement is concluded. Thus, a rapid reset of
the spuriously set flip-flop 320 will occur.
An output from the line including the AND gate 362 is also used to
control an electromagnet brake 364 which, as will be described in
greater detail hereinafter, will immediately stop movement of the
drive of the indicator arm. Electromagnetic brake 364 is energized
through a circuit including a driver 365. The arrangement is such
that whenever no energization of the motor 350 is called for by the
output of either of the AND gates 326 and 328, the electromagnetic
brake 364 will be energized.
The system additionally includes a projectile counter, generally
designated 366 which is comprised of a conventional 3-bit binary
coded up counter including flip-flops AC-1, AC-2 and AC-4. To step
the counter 366, a line to the trigger input of the flip-flop AC-1
is taken through a pulse generator 368 connected to the output of
the AND gate 361. As a result, whenever the AND gate 361 goes from
a disabled to an enabled condition, the pulse generator 368 will
apply a pulse to the counter 366 thereby increasing the count
contained in there by one.
Also provided in the projectile counter is a conventional binary
decimal decoding matrix 370, which, in the exemplary embodiment, is
capable of decoding a count up to decimal six. Counts from one to
five are used to illuminate five lamps L-1--L-5 with the
arrangement being such that the particular lamp L-1--L-5 that is
illuminated indicates the number of projectile that have been
sensed and indicated.
When the counter 366 is stepped to a condition corresponding to
decimal six, an output from the decoding matrix 370 is fed back to
each of the flip-flops AC-1--AC-4 to automatically reset the same.
Such a condition will occur when flip-flop AC-1 is reset and both
of the flip-flops AC-2 and AC-4 are set.
Provision is also made for manually resetting the counter 366 and
to this end, a normally open switch 372 is also connected to the
flip-flops AC-1--AC-4 such that when a shooter manually closes the
switch 372, the counter 366 will be reset to a zero condition.
While the exemplary embodiment provides counting system having a
capacity of five, it will be appreciated that using the principles
disclosed herein, a greater or a lesser number of projectiles could
be counted and indicated.
Another feature of the system is to provide a separate indication
when a bull' s-eye is achieved. It will be recalled that the lamp
356 illuminating the point of impact of the projectile on the
target on a target monitor is movable and advantage is taken of
this fact to provide an indication when the lamp 356 is positioned
at the bull's-eye region. As shown schematically in FIG. 7, there
is provided a brush 380 movable with the lamp 356 and a contact 382
which is located so as to be contacted by the brush 380 whenever
the lamp 356 is positioned at the bull's-eye region. The brush 380
is electrically connected to the output of the electronic switch
359 so that whenever the same has an output causing lamp 356 to be
illuminated, and when the brush 380 is on the contact 382, a signal
will be applied as an input to a one shot 386 causing the same to
change its condition.
The one shot 386 is constructed to have a relatively long stay in
its unstable state. In the exemplary embodiment, the time period
may be on the order of 2 seconds.
An output from the one shot 386 is, in turn, connected to a lamp
388 which will be illuminated whenever the one shot is in its
unstable condition. Thus, when a bull's-eye has been detected and
the brush 380 contacts to the contact 382 to cause the one shot 386
to change to its unstable state, the lamp 388 will be energized to
indicate that a bull's-eye has been obtained and will remain
energized for 4 seconds, at which time, the one shot 386 will
automatically revert to its stable state.
An output from the one shot 386 may also be used to energize a
relay 390 having normally open contacts 390a in series with a bell
392 across a source of power. Thus, when the one shot 386 switches
to its unstable state, the relay 390 will be energized for 4
seconds to close the contacts 390a and ring the bell 392.
If desired, and when more than one range is used, the bell 392 and
associated circuitry may be common to two adjacent ranges. To this
end, the relay 390 may be energized by another one shot 386 for the
computer circuitry of the adjacent lane (not shown). In this case,
each input to the relay 390 should be provided with isolation
diodes 394 to insure that the obtaining of a bull's-eye on one
range, while causing the bell 392 to be rung, will not cause the
bull' s-eye lamp 388 for the adjacent lane to be illuminated.
Turning now to FIG. 9, the manner in which the computer circuitry
described previously operates an indicator is illustrated in
schematic form. With the exception of the drive means and provision
of the bull's-eye light brush and contact, the indicator takes the
same form as that disclosed in U.S. Pat. No. 3,401,937 to Rockwood
et al. and assigned to the same assignee as the instant
application; and reference thereto is made for the purpose of
incorporating the details thereof herein by reference. For purposes
of the instant invention, it is sufficient to observe that the
indicator includes two movable arms 400 and 402 with the arm 402
carrying a movable carriage 404 which cammingly engages the arm
400. The arrangement is such that when the arms 400 and 402 are
indexed, the carriage 404 will be located approximately below the
point of impact of a projectile on the target to indicate the
same.
Target markings 406 are located on a translucent plate above the
carriage 404 and the latter is provided with the lamp 356 to
pinpoint the spot of impact on the target markings 406. The
carriage 404 also includes the brush 380 and mounted below the
brush 380 is a contact 382 to operate the bull's-eye light. More
specifically, the contact 382 may be located below the bull's-eye
of the target markings 406 so that when the lamp 356 is positioned
under the center of the bull's-eye, the brush 380 will contact the
contact 382 for purposes of energizing the bull's-eye indicating
circuit in a manner described previously.
Each of the arms 400 and 402 includes an identical drive circuit
which is comprised of a motor 350 which drives a gear train 408
through a slip clutch 410. The drive train 408 in turn drives the
respective one of the arms 400 and 402 about an axis 412. The gear
train additionally rotates the coded disc 338 for its respective
computer.
The brake 364 is operative upon an associated one of the gear
trains 408 to stop the same when the conditions mentioned
previously are present.
The manner of operation of the drive systems for each of the arms
400 and 402 is identical and may be described briefly as follows.
When the computer energizes the motor 350 in the manner mentioned
previously, the same will drive the associated gear train 408
through the slip clutch 410 thereby moving the associated one of
the arms 400 or 402 and the associated coded disc 338. When the
coded disc 338 reaches a position wherein the count picked off of
the same matches the count contained in the counter of the
computer, the match signal determined by the associated computer
stops the energization of the associated motor 350 and immediately
energizes the associated brake 364. At this time, all movement of
the gear train 408 is stopped and thus no further movement of the
associated arm 400 or 402 will take place so that the carriage 404,
and thus the indicator light 356, will be located at the correct
position below the target markings 406 and the target monitor. The
motor 350 may continue to coast to a stop and such continued
coasting rotation of the motor 350 will not alter the position of
the gear train which has been braked because of the presence of the
slip clutch 410.
If the bull's-eye has been detected, it will be appreciated that
the carriage 404, and thus the brush 380 will be positioned below
the bull's-eye with the brush 380 making contact with the contacts
382 to energize the bull's-eye circuitry. Lamp 356 will be
illuminated to indicate the position and the position of the arms
400 and 402 will remain in the dictated location until another read
cycle takes place at which time, the lamp 356 will be extinguished
in the manner described previously, the brakes 364 will be released
and the motors 350 operated by their associated computers in the
manner described previously to adjust the position of the arms 400
and 402 to indicate the point of impact of the subsequent
arrow.
* * * * *