FR2467701A1 - SUCCESSIVE SHOOTING APPARATUS FOR PROJECTILES TO PREDETERMINED POINTS AND PRINTER USING THE APPARATUS - Google Patents

Abstract

The invention relates to an apparatus for synchronizing the aiming and firing of projectiles by a projection device. It relates to an apparatus in which a microphone 10 is connected to a pipe 88 of compressed air which expels a ball 14 held in the yoke 68 of a projection device. When a ball 14 is driven out, the pressure wave is transmitted through line 88 to microphone 100 which creates a signal indicating to a computer which controls the apparatus that a ball has been fired and that, after a determined delay, the projection device can be pointed at another location. Application to ballistic printers.

Description

The present invention relates to a device for pro-

  sequential projectile jection of a printing apparatus

  projectile shock and synchronization apparatus

  pointing and firing of a projection device of a ballistic printer or the like. U.S. Patent Application No. 39,372, filed May 15, 1979, by Benzion Landa discloses a printer which directs a plurality of solid projectiles such as beads of about 1 mm in diameter, in the form of a very fine succession. fast against a printing material such as a tape that covers a sheet of paper. In the

  printer's barrel that is mobile around orthogonal axes

  For the purposes of pointing, balls are introduced

  in an elastic yoke whose diameter is slightly smaller than that of balls and behind which compressed air is transmitted. The ball is pulled after a sufficient thrust exerted on the ball to advance to the side of the barrel and allow the compressed air to relax

  in the barrel and drive the ball outward.

  In the ballistic printer described in the

  mentioned above, it is very important that the

  the projecting device and projectile firing by it are accurately synchronized with respect to each other. If the projection device moves while a ball is advancing in the barrel, the trajectory of the ball is disturbed unpredictably so that the ball hits the printing material outside the target area. If the pointing and firing operations are not synchronized or asynchronous, a large number of balls miss the desired location and give the sheet

  an aesthetically annoying flecked appearance.

  In the ballistic printer described previously,

  the synchronization signal is obtained by means of a

  that turns on a common tree to a rotating blade of

  saw used for the injection of the balls into the

  projection. The disk has openings equidistant at its periphery, in number equal to the number of teeth of the blade. A fixed photodetector placed near the periphery of the disk creates the synchronization pulse. The precision of

  synchronization, in a system of this type, obviously depends on

  of the relationship between the disk openings and the teeth of the blade, and this relationship is hardly obtained in a reliable manner. In such an apparatus, moreover, only the fact that a projectile must have been fired and not the fact that a projectile has actually been fired is detected. The invention relates to a ballistic printer which precisely directs missiles against a printing material.

  It concerns a ballistic printer which

  accurately tracks the pointing and firing of

printing tiles. -

  It also concerns a ballistic printer that

can work at high speed.

  It also concerns a ballistic printer that

is simple and inexpensive.

  More specifically, the invention relates to an apparatus for synchronizing the pointing and firing of the projection device of a microbalactic printer in which

  a suitable sensor, for example a microphone, is used

  for detecting the firing of a ball or other projectile by the projection device. The output signal of the firing sensor is itself used by the system

  control device for the determination of the

  the moment the ball left the mouth of this

  positive projection, it can then be pointed to a new target location. In an advantageous embodiment of the invention, the firing sensor comprises a microphone acoustically coupled to the input which

  transmits compressed air to the pressure chamber of the dis-

  positive projection. In one variant, the firing sensor may comprise a microphone or an optical detector placed

  near the mouth of the projection device. The re

  setting of the pointing device according to

  the actual fire of a projectile by this one allows a

  precise timing of the score and the shot and thus allows

  a high-speed shot, with the same pointing accuracy.

  Other features and advantages of the invention

  will be better understood by reading the description

  which will follow examples of embodiment and with reference to the accompanying drawings in which: Figure 1 is a partial front elevation of the projection device and the associated assembly of positioning of the ballistic printer, when the device of projection is in neutral position; Figure 2 is a partial sectional view of the projection device and ball injection device of the ballistic printer, taken along line 2-2 of Figure 1; Figure 3 is a block diagram of the control circuit of the projection device shown in Figure 1;

  Figure 4 is a partial elevation of the

  projection device of the ballistic printer, having a variant of a firing sensor;

  Figure 5 is a partial elevation of the

  ballistic printer projection device with another variant of the firing sensor; and Fig. 6 is a flowchart of a control routine used by the circuit shown in Fig. 3.

  Figures 1 and 2 show a way of realizing

  printer with the general reference 10 and

  in which a projection device carrying the reference

  12 is intended to direct projectiles such as balls 14 against a ribbon 16 covering a

  sheet of paper 18 disposed on a tray 20, successively

  tively. The balls 14 may have for example a diameter of 0.8 mm so that they give a stain size on the paper of 0.3 mm in diameter. Two vertical pivots 22

  carried by a ring 24 support the device 12 of pro-

  jection so that it can move around a vertical axis

  tical pivoting while two fixed horizontal pivots 26 support the ring 24 and accordingly the projection device 12 so that it can move around a horizontal axis. The projection device 12 can therefore pivot independently about a horizontal axis or X and

  around a vertical axis or Y so that it directs successive

  the balls fired 14 against the

ribbon 16.

  A deflection rod 28, displaced along the axis

  X by an acting set of X represented by

  3, door with its head 30 against a portion of the projection device 12 placed in front of the vertical pivot axis so that the projection device can rotate the desired angle about the axis

  Y. Similarly, a deflection rod Y 32, displaceable

  in the direction of the Y axis by an actuating element or member Y diagrammatically shown on the

  FIG. 3, door with its head 34 against a part of the disc

  positive projection 12 placed in front of the pivot axis

  horizontally so that the projection device pivots by the desired angle in the Y direction. A traction spring 36 holds the projection device 12

  in intimate contact with the two heads 30 and 34 of the

put into action.

  As shown in FIG. 3, the actuation devices 38 and 40 are controlled by a computer 42 of suitable type, for example a microcomputer.

  "Intel" 8048 or other, associated with the printer 10. The

  38 and 40 transmit position X and Y signals representing the instantaneous displacement of the rods 28 and 32,

  the computer 42 which itself transmits signals

  rection LX and Y so that the rods 28 and 32 take

  new positions, when these differ from the posi-

  current conditions. The construction and operation of the elements 38 and 40 of actuation, although they do not

  part of the invention, are set out in detail in the

Z_

246770È1

  aforementioned United States Patent Application No. 39372.

  As shown in Figure 2, in the device

  ball injection of the printer 10 which carries the reference

  Generally 44, a rotary saw blade 50 having teeth 52 guides them. balls 14 which must be drawn to the left in the figure along a channel 46 formed in a guide 48. A motor 54 of ball advance shown schematically in Figure 3, drives the blade 50 clockwise under the command of an advance signal of

  balls from the computer 42. The balls 14

  born along channel 46 in this way penetrate into

  a second guide 56 which injects them at the rear of the device

  projection 12 as described in more detail in the

continuation of this memoir.

  The projection device 12 has a body 58 which

  has a conical hole 60 which houses the barrel 62 of the dis-

  positive projection. This barrel 62 which is formed of a suitable elastic material, has a conical outer surface corresponding to the conical hole 60 so that the barrel is automatically positioned in the body or housing 58. The barrel 62 has a length of about 3 mm in the embodiment considered and it has a cylindrical bore 64 whose diameter is slightly greater than that of the balls 14. The bore 64 is formed from the front of the barrel,

  towards the rear, until a frustoconical portion 66 which de-

  mouth in a cylindrical sphincter or breech 70, having an orifice 68 whose normal diameter, as indicated

  in broken lines in Figure 2 is slightly lower than

than that of the balls 14.

  A cavity 72 formed in the body 58 behind the conical hole 60 houses a loading guide 76 which bears against a shoulder 74 at the connection of the hole 60 and the cavity 72. The guide 76 has a central orifice 78 whose diameter is slightly greater than that of a ball 14, for example 0.01 mm. A seal 80 having a cavity 72 is placed behind the guide 76 and is held away from it by spacers 82. An elastic clamp 84 placed in an annular cavity 86 holds the seal in position. The seal 80 has a central passage 87 whose diameter is substantially equal to that of a ball 14, this passage 87 starting from the outlet of the guide 56 and being aligned with the orifice 78 of the guide 76. An air inlet 88 compressed at a pressure of 4 to 6 bar is formed in the wall of the body 58 and opens into an antechamber formed between the guide 76 and the seal 80. The arrangement of the projection device is such that the rear of the barrel 62 is located away from guide 76 so that a room 92

under pressure is delimited.

  A cam 94 of designation of the assembly 12 is mounted on a small front end of the body 58 of the projection device. This cam 94 is shaped so that it has a profile allowing the sliding

  heads 30 and 34 of the actuators.

  The computer 42 is programmed in a known manner

  professionals in order to implement a sub-

  program as shown in Figure 6, ensuring the successive direction of N balls 14 against the ribbon 16, to

  selected locations (X1, Y1) to (XN, YN). Such a sub

  program can for example be used for printing

  of a particular trait of a character, transmitted to the

  by an input device such as a keyboard 106.

  After entering the subroutine (block 114) the program

  first sets an index I to 1 (block 116). Then, the

  gram allows the operation of the motor 54 in advance of

  balls (block 118) so that the blade 50 begins to introduce

  to draw the balls. After the advance validation of the balls, the program ensures the proper transmission of signals

  output AX and AY to sets 38 and 40 for

  X and Y (block 120) so that these point

  positive projection on a location that is initial-

ment (X1, Y1).

  During operation of the ballistic printer, if the apparatus is in the idle state, the blade 50 has advanced the balls in such a position that the anterior ball cooperates with the breech 70 and forms a seal with it, allowing the increase of the pressure in

  Chamber 92. Three balls behind this marble ball

  a ball 14 is at the rear of the seal 80 and cooperates with the ball 14 which is about to leave

of the guide 56.

  When the blade 50 rotates, the force applied by a tooth 52 is transmitted to the row of balls 14,

  between the ball in breech 70 and the

  ball on which the tooth exerts a force so that the ball of the breech is dislodged. In this way,

  the air of the pressurized chamber 92 expands in the

  64 and drives the ball 14 with an output speed of 20 to 40 m / s. When the first ball has been pulled, the next ball moves and sets into the hole 68 forming a seal, and the pressure in the chamber 92 again increases to an equal value

  at the initial pressure of 4 to 6 bars.

  A lateral duct 96 forming a T-connection to

  the air inlet 88 acoustically connects the inlet to a chamber

  wherein a suitable pressure-sensitive type microphone 100 such as a piezoelectric microphone, a capacitive microphone or the like is provided. The pressure drop in the chambers 90 and 92 when the ball 14 is drawn propagates in the form of a wave the

  along the air inlet 88 and duct 96 to the chamber

  bre 98 in which it causes the creation of a signal

  going to the negative values, transmitted by the micro-

  100. Under the control of this microphone signal, a

  detector 104 deflanc of any type well known in the tech-

  Such a differential circuit, followed by a Schmitt trigger followed by a monostable multivibrator, transmits a synchronization pulse to the computer 42. Preferably, the air inlet 88 has a narrowing 102 upstream of the leads 96 so the

  pressure drop can be easily detected.

  microphone table 100. The lateral duct 96 and the

  part of the air inlet 88 connecting the conduit 96 to the disc

  Positive 12 projection should be relatively short

  so that an undesirable delay is minimum.

  After the pointing device 12 projection, the subroutine waits (block 122) a signal from the micro-

  phone 100 indicates that the ball 14 has been fired. The sub

  program then commands a delay (block 124) long enough that the ball 14 that has just been pulled out of the device 12 projection. In the device 12 shown, a delay of about 0.3 milliseconds after firing from the cylinder head is sufficient for the ball 14 to run the full length of the bore 64.

  subroutine checks I to see if it is equal to N, in-

  while N balls have already been fired (block 126).

  If there are still more balls to shoot (that is, if I is less than N), the subroutine increases I by one.

  unit (block 128) and returns to block 120 so that the

  Positive projection can aim for a new location.

  The subroutine continues in this loop comprising blocks 120 to 128, at a rate of 2000 times per second or

  more, depending on the speed of advance of the balls,

  that N balls have been fired, and at this time, the routine prevents the operation of the ball advance motor 54 (block 130) and returns to the program which

  ordered the subroutine (block 132).

  Although there is shown a microphone 100 acoustically coupled to the air inlet 88 as a device

  advantage of fire detection, other devices

  come too. Thus, a microphone 108 can be placed near the outlet of the barrel 64 as shown in FIG. 4 so that it detects the pressure wave created by the air

  which relaxes in the barrel when a ball 14 is total-

  hunted. In a variant where appropriate, the ball 14 can be optically detected when it leaves the barrel 64, by projecting a light beam from a source 110 transversely to the path of the ball that comes out.

  and by detecting the beam by a suitable photodetector

  Fig. 5. These variants are less desirable, however, than the microphone 100 shown in Fig. 2 because they do not detect the firing of the ball 14 before the ball has actually left the barrel 64. This delay, coupled with the delay which is inevitably added due to the operation of the external control circuit, limits the maximum frequency of fire that can be obtained with properly timed pointing and firing. It should also be noted that instead of the sets or elements 38 and 40 of actuation controlled by

  correction signals aX and AY, it is possible to use cir-

  controlled slaves having internal control loops which are directly controlled by the X and Y positron signals. In this case, since the control loop is located outside of the computer 42, it must simply be programmed in order to that it transmits the X and Y signals of the basic positions rather than the correction signals

AX and Y.

  Thus, the invention has the indi-

  previously. The ballistic printer precisely directs projectiles against a printing material,

  by precisely synchronizing the pointing and firing

  projectiles. The printer can work at high speed

  while being simple and inexpensive.

  Of course, various modifications may be made by those skilled in the art to the devices which have just been described as non-limiting examples only.

  without departing from the scope of the invention.

246770.1

Claims (17)

  Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized in that it comprises a projection device (12) having a bore (64) and a yoke (68) of smaller diameter than that of the bore, a device forming a pressure chamber (92) behind the cylinder head, a device (88) for transmitting compressed gas to the chamber (92), a device (76) for introducing a projectile into the chamber,   cylinder, the projectile (14) being maintained amo   in the cylinder head (68) despite the action of the compressed gas   in the chamber, a device intended to dislodge   the cylinder head so that the gas in the chamber (92) can   launching the projectile along the bore and out of the projection device (12) in free flight to a first point, a device (100) for detecting changes in the pressure of the gas in the chamber (92), and a device   (38, 40) controlled by the detection device (100) and.   for changing the position of the projection device (12) so that it projects a second projectile to   a second point, the device which changes the position   only after a predetermined delay which suffices   made the first projectile come out of the bore.   2. Apparatus for successively firing projectiles   predetermined points, said apparatus being   characterized in that it comprises a device (12) for the successful firing   the cessation of solid projectiles, this firing device (12) -   comprising a device for forming a region under pressure (92) behind a projectile to be fired, this region   receiving compressed gas via a conduit (88), a device   tif (68) for normally retaining the projectile so that it is not forced out by the pressure of said region, and a device for exceeding the force exerted by the retaining device so that the pressure of said region can launch the projectile from the firing device, a device (100) for detecting pressure variations at a location along the remote conduit (88).   of said region, a device (102) forming a constriction   in the conduit at a point upstream from said location, a device (38, 40) for pointing the firing device so that a projectile is fired at one of said points, and a device (42) controlled by the disc   detector (100) and for controlling the operation of   pointing device.   3. Apparatus for firing successive projectiles   predetermined points, said apparatus being   characterized in that it comprises a device (12) for the successful firing   the cessation of solid projectiles, this firing   taking a device for forming a pressurized region (92) behind a projectile to be fired, this region   receiving compressed gas via a conduit (88), a device   tif (68) for normally holding the projectile so that it does not move despite the pressure in said   region, and a device designed to overcome the   biased by the retaining device so that the pressure of said region launches the projectile out of the firing device, a device (100) for detecting pressure variations at a certain location of the duct (88) remote from said region, a device ( 38, 40) of the firing device so that a projectile is pulled towards one of said points, and a device (42) controlled by the detection device (100) and intended to control the   operation of the pointing device.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized in that it comprises a device (12) for firing successive solid projectiles, comprising a device for   forming a pressurized region (92) behind a projection   pulling device, a device (68) intended to maintain normal   the projectile so that it can not move   despite the pressure in said region, and a device for exceeding the force applied by the   retained so that the pressure of the region launches the   jectile out of the firing device, a device (100) of 2467701.   detecting variations in pressure in said region, a device (38, 40) for pointing the firing device so that it fires a projectile towards one of said points,   and a device (42) controlled by the detecting device   and intended to control the operation of the device pointing.   5. Reciprocal shotgun of projectiles   predetermined points, said apparatus being   characterized in that it comprises a device (12) for the successful firing   solid projectile cessation comprising a bore device (64) and a projectile launching device along the bore, the launching device   creating a pressure wave after the triggering of the   projecting the projectile along the bore, a device (100) for detecting the pressure wave, a device (38, 40) for pointing the shot device so that it fires a projectile towards the one of said points, and a device (42) controlled by the detection device and intended for   to control the operation of the pointer device itself floor.   6. Apparatus for successively firing projectiles at predetermined points, said apparatus being characterized in that it comprises a device (12) for firing successive solid projectiles, a device (108) for acoustically detecting the firing of a projectile by the firing device, a device (38, 40) for pointing the firing device so that it fires a projectile at one of said points, and a device (42) controlled by the detection device   acoustics and intended to control the functioning of the ment of the pointing device.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized in that it comprises a device (12) for firing successively   solid projectiles, a device (110, 112) for detecting   optical firing of a projectile by the firing device, a device (38, 40) for pointing the firing device so that it fires a projectile towards one of said points,   and a device (42) controlled by the detecting device   optical system and intended to control the operation of pointing device.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized in that it comprises a device (12) for firing successive solid projectiles, a device (100) for detecting   firing of a projectile by the firing   (38, 40) pointing the firing device so that it   fires a projectile at one of the points, and a   device (42) controlled by the detection device and des-   to control the operation of the pointer device. floor.   9.Appliance for applying a print material.   on a support, characterized in that it comprises a device for holding the support, a device (12) for firing successive solid projectiles towards the support from a location remote from the latter, a device   (100) for detecting the firing of a projectile by the   firing device (12) a positioning device (38, 40)   of the firing device so that a projectile strikes a   desired placement of the support, and a controlled device (42)   by the detection device and intended to control   even the operation of the positioning device.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   to shoot several projectiles in succession, the   positive projection having a cylinder head (68) and a bore   (64) from the bolt (68) to a mouth   shot from which the projectiles emerge after being shot from the breech, a device (38, 40) commanded   by signals and intended to point the device of pro-   jection to those points, a device (42) for the creation   pointing signals corresponding to said points, a device (110, 112) for optical detection of the output   projectiles from the mouth, intended to create 246770.1   firing ranges representative of the firing of projectiles, and a   device (104) controlled by the corresponding firing signal   one of the projectiles and preventing application of the pointing signal corresponding to the next projectile to the pointing device (38, 40) as long as the first projectile   Jectile did not leave the mouth.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   designed to fire projectiles successively, the device   having a cylinder head (68) and a bore (64)   from the breech to a mouth through which   jectiles come out when they have been fired from the bolt, a signal-controlled device (38, 40) for pointing the projection device to fire the projectiles at said points, a device   (42) for creating pointing signals corresponding to   so-called points, a device (108) for acoustically detecting the exit of the projectiles by the mouth, intended for   create firing signals that are representative of the firing   tiles, and a device (104) controlled by the firing signal corresponding to one of the projectiles and intended to prevent   the transmission of the pointing signal corresponding to the   next to the pointing device as long as the first   The first projectile did not leave the mouth.   Apparatus for firing projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   to shoot several projectiles in succession, the   projection head having a yoke (68) and a bore (64) extending from the bolt and joining a mouth through which the projectiles exit when fired from the bolt, a device (38, 40) controlled   by signals and intended to point the device of pro-   jection so that it fires projectiles at said points, a device (42) for creating pointing signals corresponding to said points, a device (100) for detecting the exit of projectiles by the mouthpiece and intended to create firing signals representative of the shot   projectiles, and a device (104) controlled by the   firing signal corresponding to one of the projectiles and intended to prevent the application of the pointing signal corresponding to the next projectile to the pointing device (38,   ) until the first projectile has left the mouth   chure. Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   able to shoot projectiles successively and having a   cylinder head (68) and a bore (64) extending from the cylinder head   than at a mouth through which the projectiles come out   when fired from the breech, a   (38, 40) controlled by signals and intended to   ter the projection device so that it   to said points, a device (42) for creating pointing signals corresponding to said points, a device (100) for acoustic detection of projectile displacement from the yoke (68) and for   create firing signals that are representative of the firing   tiles, and a device (104) controlled by the firing signal corresponding to one of the projectiles and intended to prevent   the application of the pointing signal corresponding to the   next to the pointing device as long as the first   The first projectile did not leave the mouth.   Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized   in that it comprises a device (12) for projecting   for firing multiple projectiles successively, having a yoke (68) and a bore (64) extending from the bolt to a mouth through which the projectiles exit   when fired from the breech, a   (38, 40) controlled by signals and intended to   ter the projection device so that it   jectiles to said points, a device (42) for creating pointing signals corresponding to said points,   a device (100) for detecting the movement of projections   tiles from the breech and intended to create signals   representative of the firing of the projectiles, and a   sitive (104) controlled by the firing signal corresponding to one of the projectiles and intended to prevent the application of the pointing signal corresponding to the next projectile to the pointing device until the first projectile has not leave the mouth.   Apparatus for firing projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   able to shoot projectiles successively and having a   cylinder head (68) and a bore (64) extending from the cylinder head   than at a mouth through which the projectiles come out   when fired from the breech, a   (38, 40) controlled by signals and intended to   ter the projection device so that it   to said points, a device (42) for creating pointing signals corresponding to said points,   a detection device (100) for creating   firing ranges representative of the firing of projectiles, and a   device (104) controlled by the corresponding firing signal   to one of the projectiles and intended to prevent the   cation of the pointing signal corresponding to the projectile   next to the pointing device as long as the first   Jectile did not leave the mouth.   Apparatus for firing projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   for projecting projectiles, a signal-driven device (38, 40) for directing the projection device to projectiles at said points, a device (42) for creating corresponding pointing signals. at said points, a detecting device (108) for generating signals representative of the firing of the projectiles, and a device (104) controlled by the firing signal corresponding to one of the projectiles and for adjusting the application of the signal   corresponding to the projectile according to the pointing machine.   17. Apparatus for firing successive projectiles at predetermined points, said apparatus being characterized   in that it comprises a projection device (12) for   for projecting projectiles, a device (38, 40) controlled by signals and for pointing the projection device to projectiles at said points, a device (42) for generating   a signal corresponding to one of the said points, a   tif (100) for detecting the firing of one of the projectiles, and a device (104) controlled by the detection device and for adjusting the application of the signal to the device pointing.