Spin dispensing method and apparatus

An airborne spin dispensing apparatus (100,101) and method of dispensing a plurality of sub-units (60) such that the ground plane impact pattern of the plurality of sub-units substantially corresponds to a particular geometric ground target. An onboard microprocessor (24) which receives flight data (26) and a selected target data (28) also has a program store of sub-unit ejection sequences each of which corresponds to a particular target impact geometry. The microprocessor (24) selects an appropriate sub-unit ejection sequence in accordance with the flight and selected target data and effects a release of the sub-units (60) from the spinning apparatus such that their ground impact pattern substantially matches the geometry of the ground target.

BACKGROUND OF THE INVENTION 
This invention generally relates to the field of dispensing and more 
particularly to a method and apparatus for spin dispensing sub-units of a 
group in a manner to achieve a desired and predetermined dispersion impact 
pattern of the group over a particular ground target area. 
This invention may be applied to both commercial and military applications. 
In a commercial application for example, the sub-units of the spin 
dispensing apparatus may comprise receptacles for carrying particulate 
material of the type including chemical fertilizers, insecticides, 
fungicides and the like which are dispersed over crop areas. The sub-unit 
receptacles are dispersed by the spin dispensing apparatus such as to 
impact a crop area in a particular predetermined geometric pattern and 
thus to achieve maximum coverage and efficient use of the materials over 
the crop area. Alternatively in a military application, the sub-units of 
the spin dispensing apparatus may comprise small mines, bomblets, 
grenades, or other type explosive ordnance or submunition. These type 
submunitions are dispersed in a controlled and predetermined manner over a 
target area to achieve an effective impact pattern for a particular 
geometric target area and thus optimizes target destruction. 
The spin dispensing apparatus of this invention may be carried to a target 
area, whether a commercial or military application, by various type 
transport vehicles. For example, the apparatus may be carried in a 
self-propelled and guided drone or rocket-type vehicle or it may be 
launched from an aircraft in the vicinity of the target. The apparatus may 
also be carried in a projectile which is fired from a distant ground-based 
launching device. Alternatively, the apparatus may be affixed to a 
relatively stationary platform such as for example an aircraft. The 
particular configuration of the transporting vehicle will be dictated by 
the type of application and this will be apparent to persons having 
knowledge and skill in the art; suffice to say that the spin dispensing 
apparatus of this invention may be carried to a particular target area 
such as to present its most advantageous orientation to the target and 
thus accomplish the desired task. 
SUMMARY OF THE INVENTION 
It is in accordance with one aspect of the invention an object to provide a 
method of dispensing a plurality of sub-units from an airborne apparatus 
in a manner to achieve a desired and predetermined dispersion impact 
pattern of the sub-units over a particular geometric ground target area, 
the method comprising the steps of: mounting a plurality of sub-units in a 
balanced arrangement about a longitudinal axis of the apparatus, each 
sub-unit having an associated electronically controlled release means to 
effect ejection of the sub-unit from the apparatus; providing an on-board 
microprocessor having a store of particular sub-unit ejection sequences 
indicative of various specific impact geometries; spinning the apparatus 
about its longitudinal axis; providing flight data and a selected target 
data to the microprocessor such that a particular sub-unit ejection 
sequence is selected which substantially corresponds to the particular 
ground target geometry; and releasing the sub-units according to the 
microprocessor selected sub-unit ejection sequence. 
It is in accordance with another aspect of the invention an object to 
provide an airborne apparatus for dispensing a plurality of sub-units in a 
manner to achieve a dispersion impact pattern over the target which 
closely approximates a particular geometric ground target area, the 
apparatus comprising in combination: a vehicle body framework having a 
longitudinal axis and defining a forward end, a rearward end, and a 
payload section between the forward and rearward ends; a plurality of 
sub-units individually mounted in the payload section in a balanced 
pattern about the longitudinal axis; means associated with each sub-unit 
to hold the sub-unit within the payload section during flight of the 
apparatus and adapted for releasing the sub-unit in response to an 
electrical ejection signal; means at the rearward end to impart spinning 
motion to the dispensing apparatus about its longitudinal axis; a control 
module including a power supply and a microprocessor, the microprocessor 
having a store of particular sub-unit ejection sequences which are 
indicative of various specific target geometries and the power supply 
providing the required power to the microprocessor and to the means for 
effecting release of the sub-units from the dispensing apparatus; sensor 
means providing flight data and spin rate data to the microprocessor as 
the apparatus approaches the target; and means providing a signal 
indicative of the particular geometric target to the microprocessor; said 
microprocessor providing a sub-unit ejection sequence signal to the 
plurality of means adapted for releasing each sub-unit such that the 
plurality of sub-units are ejected from the spinning dispenser apparatus 
in accordance with the ejection sequence signal.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings, FIG. 1 illustrates a transport vehicle of a 
general type which may be adapted for carrying the spin-dispensing 
apparatus which comprises the present invention. The transport vehicle is 
generally indicated by reference numeral 10 and may include a forward nose 
piece 12, a rearward tail assembly 14, and a center section 16 which is 
the payload-carrying section of the vehicle. As hereinbefore mentioned, 
the transport vehicle 10 may be a self-propelled and guided vehicle and in 
this configuration the forward nose piece 12 may include appropriate 
guidance electronics 12a while the rearward tail assembly 14 may include 
appropriate propulsion means 14a. In an alternative configuration, the 
vehicle 10 may be carried aloft by an aircraft and launched in the manner 
of a bomb and thus directed towards the intended target. In any of the 
conceivable configurations of the transport vehicle 10, the vehicle may be 
adapted to house and carry the spin-dispensing apparatus which comprises 
the present invention and therefore the scope of the invention is not 
considered limited by the type and/or configuration of the transport 
vehicle 10. 
The spin-dispensing apparatus is more specifically shown in FIGS. 2 and 3 
of the drawings and is indicated generally by reference numeral 100. FIG. 
2 illustrates a disengagement of the spin-dispensing apparatus 100 from 
its transport vehicle 10, which vehicle separates itself in a well known 
and understood manner such that the spin-dispensing apparatus 100 
continues on towards an intended target. Generally, a spin dispensing 
apparatus 100 comprises a control module 20, a spin generating means 30, 
and a payload section 40. 
Referring now to FIG. 3 of the drawings, the payload section 40 is the most 
obvious part of the spin dispenser 100. The payload section 40 comprises a 
plurality of individual sub-units 60, which are arranged in a balanced 
pattern about a central core structure 42. The axis of the core 42 is 
indicated by line Ax--Ax and this is also the spin axis of the dispensing 
apparatus 100. While any number of sub-units 60 may comprise the payload 
section 40, this description and the drawing will be limited to a 
two-layered grouping indicated generally by reference numerals 62 and 64 
respectively. The first group 62 comprises 12 sub-units 60 positioned on a 
circular tray-like base 44 which is rigidly affixed to the core structure 
42. The second group 64 comprises six sub-units 60 and these are 
positioned on a circular tray-like base 46 which is also rigidly affixed 
to the core structure 42 in a spaced axial position from the first group 
62. While the groups 62 and 64 are shown in FIG. 4 as being positioned at 
different radial distances from the core 42, this arrangement is not a 
requirement of the invention. For example, both groups 62,64 may comprise 
the same number of sub-units 60 and these may be positioned at the same 
radial distance from the core 42. Therefore, the invention is not 
considered limited by the number or arrangement of the sub-units 60 which 
may comprise the payload section 40. 
Continuing with respect to FIG. 3, the sub-units 60 are each individually 
positioned and held in position by a release means 50 which may be any 
type of electronically controlled mechanism adapted for a fast response 
release time of a particular sub-unit 60 to which it is associated. A 
specific release means 50 which worked well in test firings of a prototype 
dispenser comprised a simple cable 52 which encircled each respective 
sub-unit 60 and which included a clamp and guillotine-type wire cutter 54. 
Upon electrical actuation of the wire cutter 54, a simultaneous ejection 
of the associated sub-unit 60 was effected. Other possible release means 
50 will become apparent to those persons skilled in the art suffice to say 
that the release means 50 is an electrically actuated device and/or 
mechanism which effects a simultaneous ejection of an associated sub-unit 
from the spin dispenser 100. 
The spin generating means 30 may comprise radially extending fins 32 which 
are of a configuration such that the airstream imparts a rotation to the 
spin dispenser 100 about the Ax--Ax axis. The fins 32 may be adapted for a 
radial extension from a folded or packaged position when the dispenser 100 
is housed in its transport vehicle 10. This may be accomplished by various 
techniques including a mechanical or electrical operation or by an 
automatic ram-air extension when the spin dispenser 100 is released by the 
transport vehicle and generates its own airstream. In any event, the spin 
generating means 30 may be specifically configured such as to generate a 
particular spin rate to the dispenser 100. 
Referring to FIG. 9 of the drawings, the control module 20 includes a power 
supply 22 which provides the required power to operate various electronic 
components controlling the spin dispenser operation. The module 20 also 
includes a microprocessor 24 having a store of sub-unit firing sequences 
which determine the geometry of the impact pattern of the ejected 
sub-units 60. The module 20 further includes various sensors (not shown) 
which provide dispenser flight data 26 to the microprocessor 24 such as, 
for example, a velocity sensor, a spin rate sensor, and a pitch sensor. In 
its simplest form, the spin-dispenser apparatus 100 will initially receive 
target data 28 into the microprocessor and this data determines which 
sub-unit firing sequence will be used for a particular target geometry. 
The selected target data 28 may be provided to the spin-dispenser 
microprocessor 24 prior to launch if the target geometry is known. If 
however, the target geometry is not known, such data may be provided via a 
data link to the spin dispenser 100 after it is launched towards the 
target, or alternatively, the control module 20 may include an onboard 
mounted target sensor (not shown) of a conventional type which provides 
the required target data to the microprocessor 24. In any event, the 
microprocessor 24 is programmable such as to select from the store of 
firing sequences, a particular firing sequence 34 such that the ejected 
sub-units 60 impact a target area in the pre-selected geometric pattern. 
Various geometric impact patterns which may be had by way of the 
spin-dispensing apparatus 100 are illustrated in FIGS. 5a-5e and FIGS. 6, 
7, and 8. FIGS. 5a and 6 illustrate the simplest geometric impact pattern, 
that being a longitudinal deployment strategy. Referring also to FIG. 4 of 
the drawings, assume for the purpose of this explanation that the figure 
is a tail end view of the payload section 40 and the spin dispenser 100 is 
traveling horizontally above the ground plane indicated at GP and is 
rotating clockwise in the direction of arrows 48. The dispenser velocity 
is V.sub.D, its pitch angle is "zero" and its spin rate is within the 
range of 500-1000 rpm. In this example, sub-units 60 on opposite sides of 
the module 40 are simultaneously ejected such as to maintain stability of 
the apparatus 100 during flight and the first ejected pair is identified 
by "1A and 1B." As clearly evident in FIG. 4, sub-unit 1A will be ejected 
upwardly while sub-unit 1B will be ejected downwardly. In this 
circumstance, sub-unit 1A will travel farther and longer to reach ground 
impact while sub-unit 1B will travel a shorter distance and thus reach 
ground impact sooner. The points of impact for sub-units 1A and 1B are 
illustrated in FIG. 6 and these will be substantially along the same 
longitudinal line but in a spaced apart relation one to the other. In the 
same manner, sequentially ejected pairs 2A-2B, 3A-3B, etc. are ejected and 
their points of impact are also shown in FIG. 6. 
Referring to FIG. 7, a lateral deployment strategy is illustrated and this 
impact pattern is accomplished by ejecting pair of sub-units 60 at the 
instant when they are in the same vertical plane of the rotating dispenser 
100. For example, instantaneous ejection of sub-units identified by 1AA 
and 1BB will result in their impacting the ground plane the same instant 
of time but laterally displace one from the other. In the same manner 
sequentially ejecting sub-units 2AA-2BB, 3AA-3BB, etc. will result in the 
impact pattern illustrated in FIGS. 5b and 7. Ejecting various of the 
sub-units 60 at other spin angles of the spin dispenser 100 will result in 
developing both longitudinal and lateral separation at ground impact. For 
example, a circular impact pattern of sub-units 60 may be had by an 
instantaneous ejection of the sub-unit group 62 when the pitch angle of 
the spin dispenser 100 with respect to the ground plane is 90 degrees. A 
pitch angle other than 90 degrees will result in elliptical impact 
patterns of various sizes as shown in the FIG. 5d. Thus, it must be 
appreciated that a temporal separation of the sub-units 60 at release from 
the spinning dispenser 100 may be combined with a spatial separation due 
to dispenser travel to obtain an almost unlimited variation in the impact 
pattern geometry. 
As hereinbefore mentioned, the invention is not limited by either the 
number or arrangement of the sub-units 60 in their mounting within the 
payload section 40. To appreciate this fact, reference is made to FIG. 8 
of the drawings wherein a computer simulation illustrates a controlled 
preselection of a plurality of sub-units which were ejected simultaneously 
from a spinning dispenser traveling 400 ft./sec. at a pitch angle of 90 
degrees with respect to the ground plane. The sub-unit groups are 
indicated by reference numerals 72 and 74 and are within the shaded areas. 
The legend which forms a part of the drawing illustrates ejection 
velocities V.sub.e associated with sub-unit groups indicated by the 
various symbols. The difference in the ejection velocities is accomplished 
by mounting the indicated sub-unit groups at different radial distances 
from the spin axis Ax--Ax of the spin dispenser apparatus 100. For 
example, the sub-units indicated by a diamond shape are mounted within the 
payload section 40 at a greater radial distance from the spin axis Ax--Ax 
than the sub-units indicated by the other symbol shapes. The sub-units 
indicated by the black dot are obviously closest to the spin axis, having 
the smallest ejection velocity V.sub.e and traveling the shortest distance 
before impact. From FIG. 8, it can be appreciated that five layered groups 
of sub-units are mounted in the payload section 40 and each group is 
positioned at a different radial distance from the spin axis to thus 
generate a different ejection velocity V.sub.e. In accordance with FIG. 8, 
the sub-unit impact pattern indicated by the shaded areas is accomplished 
by a preselection of the microprocessor store of firing sequences and a 
simultaneous ejection of that sub-unit group. Alternatively, the total 
pattern which also includes the sub-units outside of the shaded areas will 
result from a simultaneous ejection of all of the sub-units stored within 
the payload section 40. 
It may be further appreciated that the five groups of sub-units indicated 
in FIG. 8 by the various symbols may also be positioned at the same radial 
distance from the spin axis Ax--Ax of the apparatus while also creating 
the same impact patterns covered in the shaded areas 72,74. This may be 
accomplished by effecting a timed and sequential ejection of the sub-units 
at varying heights above the ground as the apparatus approaches the ground 
plane. For example, the preprogrammed ejection sequence will effect an 
initial ejection of the group indicated by the diamond symbol and at 
.DELTA.t intervals later will effect ejection of the other remaining 
groups. Accordingly, and because all sub-units are at the same radial 
distance from the spin axis Ax--Ax, all sub-units will be released with 
the same ejection velocity V.sub.e but the diamond symbol group will 
travel a farther distance before impact while the circular dot symbol 
group will travel the shortest distance to impact. The result, of course, 
will be the same as illustrated in FIG. 8 by the shaded areas 72,74. 
Finally, FIG. 10 of the drawings diagramatically illustrates an embodiment 
of the invention wherein a spin dispensing apparatus 101 is carried by and 
mounted to a relatively stationary but airborne platform. The platform is 
generally indicated by ghost lines 70 and may comprise any type of 
aircraft adapted for carrying the apparatus 101 to a designated target 
area. In this configuration the longitudinal axis Ax--Ax is substantially 
vertical with respect to the ground and the apparatus pitch angle 
indicated by ".alpha." in the drawing may vary from zero (horizontal) to 
ninety degrees (shown) with respect to the ground plane GP. According to 
this embodiment, the means to impart a spinning motion to the apparatus 
may comprise a variable speed motor 80 which includes any appropriate 
drive means 82 connected to the payload section 40' in any of the 
well-known techniques. The motor 80 and drive means 82 may be located 
within the confines of the platform 70 and may be affixed as at 84 to be 
relatively stationary with respect to the spinning payload 40'. Further, 
the apparatus control means 20' may also be located within the confines of 
the platform 70 and it includes a microprocessor 24' which functions in 
the same manner as hereinbefore described with respect to FIG. 9 and may 
also provide speed control to the motor 80. The control means 20' however 
may or may not include a power supply as indicated at 22' inasmuch as any 
power requirements may be drawn from power sources which are integral with 
the platform 70. For example, the power requirements for the 
microprocessor 24', the sub-unit release means (not shown), and the motor 
80 may be provided by the power generating means and/or sources of the 
aircraft. Further, it is anticipated that the apparatus 101 may be movable 
along its longitudinal axis from a storage position within the confines of 
the platform 70 to an operative position outside of the platform as 
illustrated in the drawing. 
From the foregoing, it will be recognized that various errors in the system 
may affect the ground impact pattern performance of the ejected sub-units 
60. For example and as alluded to with reference to FIG. 5d, a change in 
pitch angle of the apparatus may not result in a circular impact pattern 
of simultaneously released sub-units but rather will result in an 
elliptical pattern as shown in that figure. Furthermore, and while the 
release of individual sub-units is considered to be tangent to an arc 
described at a radial position of the sub-unit with reference to the axis 
of rotation Ax--Ax, such release may be delayed by various inaccuracies in 
the system. It has been determined, however, that these errors may be 
corrected by introducing compensation into the microprocessor 24. This is 
considered to be within the skill and ability of persons having knowledge 
of the art to which this invention pertains. 
While certain representative embodiments and details have been shown for 
the purpose of illustrating the invention, it will be apparent to those 
skilled in this art that various changes and modifications may be made 
therein without departing from the spirit or scope of the invention.