Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to screen assemblies and is concerned partic-
ularly with screen assemblies forming part of gunnery training equipment.
A known form of gunnery training equipment comprises a projector
which projects onto a screen area a moving image serving as a target for a
trainee gunner or infantryman who fires his weapon at the moving target. Move-
ment of the film ceases when the weapon is fired, such synchronisation being
achieved by an acoustic detector (e.g. a microphone) or by electrical means
linked to the trigger of the weapon. The position of a hole in the screen
~formed by the passage of a bullet from the weapon) in relation to the target,
the image of ~hich is now stationar~ on the screen, provides an indication of
marksmanship. As an aid to identifying the position of the hole, the latter
is illuminated by lights which are positioned behind the screen and which are
lit only during the assessment period when the image is stationary.
The presence of holes in the screen from previous shots can naturally
be troublesome and misleading, and an object of the invention is to provide a
screen assembl~ in which the holes from previous shots can be obliterated.
According to the invention there is provided a gunnery training aid
comprising a projector for projecting a moving image of a target onto a screen
assembl~, means for halting the projector when a weapon is fired at the target
and a light for illuminating the side of the screen assembly opposite the pro-
jector to reveal the position of a hole in the screen caused by the firing of
the weapon, the screen assembly comprising a first feed roller and a first
ta~ke-up roller for moving a first sheet of material from the first feed roller
across a screen area and in a first plane to the first take-up roller, and a
second feed roller and a second take-up roller for passing a second sheet of
material from the second feed roller across the screen area and in a second
plane to the second take-up roller, the first and second planes being substan-
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tially parallel and spaced apart by a small distance so that the sheets form
a screen of two overlapping layers over the screen area, with the first and
second sheets being movable in different directions to alter the respective
areas of the sheets in mutually overlapping relationship, and a third feed
roller and a third take-up roller for moving a third sheet of material from
the third feed roller across the screen area and in a third plane to the third
take-up roller, the third plane being parallel and close to the first and
second planes, the first and second sheets being movable in mutually opposite
directions and the third sheet being movable in a direction perpendicular to
said opposite directions3 the third sheet moving to prevent the chance coin-
cidence of a hole in the first sheet and a hole in the second sheet from re-
vealing a false hole on illumination of the screen assembly.
Gunnery training equipment representing a preferred embodiment of
the invention will now be describedJ b~ way of example, with reference to the
accompanying drawingsJ in which:-
Figure 1 is a diagrammatic plan view of the gunnery training equipment;
Figure 2 is a rear perspective view of a screen assembly;
Figure 3 is a sectional viewJ on an enlarged scale and with certain
parts omitted for clarityJ on the lines III^III of Figure 2; and ;~ :
2Q Figure 4 is a fragmentary view looking in the direction of the arrow
A in Figure 3.
Referring to Figure 1, the training equipment comprises a projector 1 ~:
which projects on to the screen assembly 2 a moving image which serves as a
target for trainee gunners or infantrymen 3 who fire their weapons in successionat the moving targetJ ~.
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under the control and supervision of a range of~icer 4
The projector 1 is controlled by electrical control
means having a console 5. Movement o~ the ~ ceases when
each weapon is ~ired, such sy~chronisation being achieved by
an electrical cable 6 linking the weapon and the console 5
or by audible sensing means, such as a microphone~
~ he screen assembly 2 comprises two sheets o~ whi~e
paper, namely a first sheat 7 which extends between a ~irst
vertical feed roller 8 on the right-hand side of ~he screen
assembly 2 (considering the latter ~iewed from the front) and
a first vertical take-llp roller 9 on the left-hand side of the
screen assembly 2, and a second sheat 10 which extends between
a second vertical feed roller 12 on the left-han~ side of the
screen assembly 2 and a second take-up roller 13 on the right-
hand~side of the screen assembly 2. The ~irst take-up roller 9
is rotatably dri~en by an electric motor 14 to cause the ~irst .
sheet.7 to be drawn horizontally (by small increments i~ step-
wise fashi.on) from right to left across the screen, the first
sheet 7 being drawn off the first feed roller 8 and onto the
~irst take-up roller 9. The second take-up roller 13 is
associated with a seco~d electric motor 15 which enables the
second sheet 10 to be drawn horizontally across the screen
from le~t to right, also by s~all. increments in step-wise
fashion.
- - Brakes 16 fitted to the feed rollers pre~ent the sheets
~ 7 and 10 from overrunning on cessation of rotatlon of the
- respecti~e take-up rollers, ensuring ~hat the sheets spanning -
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e screen area are -taut. The two sheets pass around respective
vertical guide rollers (generall.y designated 17) positioned at
the sides of the screen in such manner that the two sheets 7
and 10 span the screen area in closely spaced vertical planes.
A third sheet o paper 18 is arranged behind the two white
sheets 7 and 10 and extends between a.horizontal feed roller 19
at the top of the screen and a horizontal take-up roller 20 at
the ~ottom of the screen. The third sheet of paper 18 is black
and, over the screen area~ occupies.a vertical plane spaced
closely behind the plane occupied by the white sheet 10, as.
shown in Figure 3. Whilst the planes occupied by the three
sheets 7, 10 and 18 are, strictly speakin~, spaced from one
another the three sheets ~.ake light contact. A third electric
motor 22 drives the horizontal take-up roller 20-and causes the
black paper 18 to move vertically downwardly in small increments~
the black paper ~elng drawn off the horizontal feed roller 19 . -
~passing through a nip between the latter and a trough 21) and
thence around ~ horizontai guide roller 23. The black paper
passes downwardly and passes partially around the driven
horizontal take-up roller 20. At each of four positions along
the driven horizontal take-up roller 20, there is disposed a
pair of pressure rollers 24 carried by a cradle 2S supported by
vertical compressi~n springs 26. The rollers 24 bear against
respective sides of the driven horizontal take-up roller 20
and form nips throuah which the black paper 18 is driven. The
described arran~e.~ent of pressure and guide rollers has the : .
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effect of braking the black paper 18 and preventing slackness
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in the black paper 18 over the screen area. Us2d black
paper issuing from the driven horizontal -take-up roller 20
is cut of* wh~n necessary.
The-power drive to the three -take-up rollers 9, 13 and
20 can be disengaged. The roller 20 can be manually rotated
by grippin~ the roller itself whilst handwheels 27 are provided
on the ends of the take-up rollers 9 and 13. In the case of
the two vertical take-up rollers 9 and 13, individual clutches
28 enable disengagement o the drive to be effected, whilst
in the case of the horizontal take-up roller a dog drive may
be disengaged.
The screen assembly is a collapsible, portable unit which
is erected in front of the proiector 1 of the gunnery training
equipment and is electrically linked by a lead 29 to the
central console 5 governing operation o the complete gunnèry
training equipment. After a bullet has punctured all three
sheets of paper (the projector now projecting a stationary
image which has been raised to compensate for projectile drop~
the back lighting is automatically switched on for an assessment
period7 typically four seconds. The three motors 14, 15 and 22
are then energised for a short period, which is preselected by
a timer unit7 each motor causing incremental linear movement
of the corresponding sheet of paper by an amount between
1/4in. and 7/16in. The individual holes in the three sheets
are thùs moved out of registration and the projector is re-
started to project a moving image ready for~the next sequence.
The invention described herein may be used in a~sociation
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with the invention disclosed in our co-pending Application No. 241,938.
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