US3797394A

US3797394A - Chaff dispenser, method of dispersing chaff

Info

Publication number: US3797394A
Application number: US00287954A
Authority: US
Inventors: J Thurston; G Adams
Original assignee: Thiokol Corp
Current assignee: ATK Launch Systems LLC
Priority date: 1972-09-11
Filing date: 1972-09-11
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

A chaff dispenser for signals and other uses, which ejects from a moving craft and disperses the signal material after a pre-set delay time, comprises an outer case, a canister holding the chaff and explosive charge, a timer, and a parachute. Upon ejection, the timer measures the delay time, releases itself and the parachute which pulls the canister from the outer case. The canister explodes to disperse the chaff. The invention herein described was made in the course of or under contract with the U.S. Air Force (Contract F33657-72-C-0136).

Description

[ Mar. 19, 1974 United States Patent 91 Thurston et a1.

3,049,080 8/1962 Schermu1y............ 3/1973 Wi1lis..........

[ CHAFF DISPENSER, METHOD OF DISPERSING CHAFF Thurston..................,......:..102/356 [75] Inventors: James R. Thurston, Brigham City;

Gary Adams Perry both of Utah Primary Examiner-Robert F. Stahl Thiokol Chemical Corporation, Bristol, Pa.

Attorney, Agent, or Firm-R0bert J Grassi [73] Assignee:

[57] ABSTRACT A chaff dispenser for signals and other uses, which [22] Filed: Sept. 11, 1972 Appl. No.: 287,954

ejects from a moving craft and disperses the signal material after a pre-set delay time, comprises an outer case, a canister holding the chaff and explosive charge, a timer, and a parachute. Upon ejection, the timer measures the delay time, releases itself and the EW WE 5 1 H1 3 3 4 44 3 53 3; H ,w 7 ,4 4 i B0 3 2 6 01 l 6 v 7 7CW 3 .0 N M 1 0 1m mm ac r Hue Us L he... C d s xm UIF 211 2 8 555 12121 parachute which pulls the canister from the outer case. The canister explodes to disperse the chaff The invention herein described was made in the course of References Cited UNITED STATES PATENTS or under contract with the US. Air Force (Contract 3,593,664 Davis et a1. 102/356 F33657-72-C-0136). 3,143,965 3,095,814

8/1964 La Pointe 7/1963 Jansen et al. 10 Claims, 5 Drawing Figures PATENTEB KM! 19 M4 SHEET 2 0F 2 FIG 5 FIG 3 CIIAFF DISPENSER, METHOD OF DISPERSING CIIAFF BACKGROUND OF THE INVENTION 1. Field of the Invention An aerial signal and illuminant device, particularly for dispensing chaff.

2. Description of the Prior Art A flare using a parachute to guide and slow the descent of a flare unit ejected from a moving craft, as described in U.S. Pat. 3,593,664, is not applicable for rapid display of a signal in a fixed pattern at a predetermined time and distance from a moving craft. In flares the objective is to keep the flare burning as long as possible while slowly descending.

In signal display and chaff dispersements, the objective is to rapidly display a signal of a particular pattern at a predetermined time and distance from charge, moving craft. This requires delaying the dispersion of the signal until the predetermined distance from the craft is reached, and then rapidly dispersing the chaff in a particular signal pattern while the chaff holder is still in motion.

This invention solves the problem by using a specially constructed dispenser. The dispenser has a container means to hold the chaff material and an explosive charge and the container means fits into an outer case which also has a parachute or other pulling means and a timer. The dispenser ejects from the moving craft, and the timer measures the delay time, then springs away from the dispenser pulling out the parachute which then pulls out the container means and activates it to explode and disperse the chaff in a signal pattern.

SUMMARY OF THE INVENTION A chaff dispenser, suitable for ejecting from a launching unit, comprises an outer case, a releasable timer means for measuring a pre-set delay time, a container means for holding and dispersing the chaff, and a first pulling means for removing the container means from the outer case and activating it. The releasable timer means movably attaches to the outer case, and is adapted to attach to the launching unit. The releasable timer means releases itself from the outer case after measuring the pre-set delay time. The container means for holding and dispersing the chaff movably mounts within the outer case. The first pulling means attaches to the releasable timer means and to the container means for holding and dispersing the chaff. The releasable timer means is attached to the launching unit when the dispenser is placed therein. Upon ejection, the timer means measures the pre-set delay time, then releases itself and activates the first pulling means to pull the container from the outer case, which activates the container to disperse the chaff in a predetermined pattern when the container means is separated from the outer case.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows the operation of a chaff dispenser.

FIG. 2 shows a side view of a chaff dispenser equipped with a parachute.

FIG. 3 shows a cutaway view of a canister.

FIG. 4 shows a side view of a chaff dispenser equipped with a parachute and a gas generator.

FIG. 5 shows a side view of one end of a chaff dispenser equipped with a safety means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the chaff dispenser 10 is shown in FIG. 1. When the dispenser l0 ejects, the releasable timer means 11 starts and measures the pre-set delay time, and then springs away and pulls out the first pulling means, parachute 12, from the outer case 13. The parachute 12 pulls out and activates the container means for holding and dispersing the chaff, canister 14, which contains an explosive charge and chaff material 15. When the canister 14 clears the outer case, the explosive charge detonates and disperses the chaff 15.

The term chaff, in this invention, refers to any dispersable material, or article, such as dyes, fluorescent or phosphorescent powders or granules, reflective materials such as aluminum strips of foils, etc. which could be used for signals, markers, or reflectors.

One embodiment of a chaff dispenser 10 is shown in FIG. 2. The chaff 15 packs into a container means for holding and dispersing the chaff, which in this embodiment is canister 14, which has the same shape as the outer case 13, preferably a cylindrical shape. The canister 14 has a canister shell 16, preferably of plastic materials, for example phenolic paper or thin metal sheeting, i.e., aluminum which connects to a first end cap 17, and a second end cap 18 by connecting means such as drive lock pin 19. A center tube 21 containing an explosive charge 20 attaches to the

end caps

17 and 18 by threads, welding, or epoxy bonding. Within one end of the center tube 21 there is a detonator charge 22 which fires the explosive charge 20. Lanyard connects to sear pin 23, these being the means for initiating the detonator charge 22 when the canister 14 is pulled from the outer case. The sear pin 23 fits within one end of the center tube 21. End cap 18 holds a first pulling means, parachute 12, which attaches by its riser 24 to the end cap 18. This attachment can be by bonding with an adhesive, or by attachment to a screw or a ring. The sear pin 23 activates the container means of this embodiment when the container means 14 is pulled out of the outer case by the first pulling means.

The canister 14 fits within the outer case 13, the walls 25 of which attach to a bottom plate 26 and to a top plate insert 27. The bottom plate 26 can integrally attach by welding or bonding, but the preferred method is by pressing the ends of the outer case wall 25 over an O-ring retainer 60 into a groove 28. The top plate insert 27 can be an integral part of the outer case wall 25, but preferably is a separable piece which welds or bonds to the outer case wall 25. This insert 27 has an outer lip groove 29. An adjustable timer 11, such as a spring-wound type with detent arms 30 or lugs, or other releasable locking means as described in U.S. Pat. No. 3,595,664, fits within the insert 27, with detent arms 30 engaged within the outer lip groove 29. A spring 31 in a compressed state lies between the timer 11 and the end cap 18. A lanyard 32 attaches to the timer 11 and to the top of the parachute 12. The timer 1 1 has a timer starter 33, such as a rotatable knob which activates upon pulling by a second pulling means, lanyard 34, which connects to the launching unit. The releasable timer means comprises the adjustable timer 11, with its releasable locking means 30, the detent arms, spring 31 and lanyard 32.

In operation, the lanyard 34 is connected to the launching unit and pulls the knob 33 when the dispenser ejects. The timer measures the predetermined delay time, i.e., from 0.2 to 2 seconds, then the detent arms or other timer locking means disengages from the groove 29 and the spring 31 forces the timer from the outer case 13. The timer l1 pulls the parachute 12 out of the end cap by means of lanyard 32. The wind force upon the parachute coupled with the forward momentum of the dispenser pulls the canister 14 out of the outer case 13 and the canister 14 is activated when lanyard 70 pulls the sear pin 23 to fire the detonator charge 22, which detonates the explosive charge 20. The explosive force disperses the chaff 15 in a predetermined shape.

In another embodiment of the invention, a lug pin 36 fits into and connects the end cap 17 of the canister 14 with the bottom plate 26 of the outer case 13, and Ianyard 37 attaches to the lug pin 36. This lug pin prevents the accidental actuation of the dispenser unit by holding the canister within the outer case, even if the parachute is activated. The lug pin 36 is pulled out by lanyard 37 prior to placing the dispenser in the launching unit. The lug pin 36 and lanyard 37 comprises the first safety means for preventing the container means from being pulled out of the outer case until the pulling means is actuated. In place of the lug pin 36 and Ianyard 37, a bolt can be used which screws into the canister.

Another embodiment shown in FIG. 4 employs gas pressure obtained from a gas generator 40 and a parachute 12 to pull the canister 14 from the outer case 13. The gas generator 40 is sufficient in itself to force the canister 14 from the outer case 13. It can be used alone. As shown, a lanyard 41 connects to the gas generator sear pin 42 and the parachute 12. The lanyard 41 pulls the gas generator sear pin 42 when the timer 11 releases and pulls out the parachute. The gas generator sear pin 42 activates the generator 40 and the gas pressure builds up and forces canister 14 out of the outer case 13.

Another embodiment, shown in FIG. 5, has a safety pin 50 attached to lanyard 51, which attaches to the bottom plate 26 of the outer case 13. This safety pin 50 prevents the primer discharge pin 23 from being pulled out during assembly. When the canister 14 pulls away from the outer case 13, lanyard 51 pulls out the safety pin 50, which allows firing of the detonator charge 22 by release of sear pin 23. The safety pin 50 and lanyard 51 comprise a second safety means to prevent the detonator from initiating until the container means is completely pulled out of the outer case.

In dispersing the chaff, the chaff 15 is loaded into the dispenser, the dispenser is put into the launching unit, and the releasable timer means is attached to the launching unit, and then the dispenser is launched. In one embodiment, aluminum strips were loaded into the dispenser and dispersed with a PETN explosive charge loading of 150 grains per foot of cord. The canister was 4 inches in diameter and 3.5 inches in length.

This invention is not limited by the embodiments but by the claims, for equivalents can be substituted without departing from the scope of this invention.

We claim:

1. A dispenser for chaff, suitable for ejecting from a launching unit, which comprises in combination:

an outer case,

a releasable timer means for measuring a pre-set delay time, movably attached to the outer case, and adapted to attach to the launching unit, and to release itself from the outer case after measuring the delay time,

a container means for holding and explosively dispersing the chaff, movably mounted within the outer case, and activated when removed from the outer case, and

a first pulling means for removing the container means from the outer case, said first pulling means connected to the releasable timer means and to the container means, the dispenser adapted and constructed to start the releasable timer means to measure the delay time upon ejecting of the dispenser, and then release itself and activate the first pulling means to pull the container means from the outer case which activates the container means to explosively disperse the chaff.

2. The chaff dispenser, as in claim 1, wherein the container means for holding and dispersing the chaff is a canister which comprises:

a canister shell with a cylindrical tube shape,

a first end cap adapted to hold the first pulling means,

and attached to one end of the canister shell,

a second end cap attached to the other end of the canister shell,

connecting means for connecting the canister shell to the first and second end caps,

an explosive charge,

a detonator charge,

a center tube adapted to hold the explosive charge and detonator charge therein, one end of the center tube connected to the first end cap, and the opposite end of the center tube connected to the second end cap, and

a means for initiating the detonator charge when the container means is pulled out of the outer case, the chaff being held within the space formed by the canister shell, the first and second end caps, and the center tube.

3. The chaff dispenser, as in claim 2, wherein the chaff dispenser further comprises:

a first safety means for preventing the container means from being pulled out of the outer case until the pulling means is actuated.

4. The chaff dispenser, as in claim 3, wherein the container means for holding and dispersing the chaff further comprises:

a second safety means to prevent the primer from detonating until the container means is completely pulled out of the outer case.

5. The chaff dispenser, as in claim 4, wherein the releasable timer means comprises:

an adjustable timer having a starter which actuates upon pulling, said timer adapted to measure a preset delay time and connected to the first pulling means,

a releasable locking means for attachment of the timer to the outer case, and operably connected to the timer to release after the timer measures the pre-set delay time, and

a second pulling means attached to the starter of the adjustable timer and adapted to attach to the launching unit when the dispenser is placed therein, said second pulling means actuating the starter of the timer when the chaff dispenser is ejected from the launching unit. 6. The chaff dispenser, as in claim 5, wherein the first pulling means is a parachute.

which is ejected from a moving vehicle to form a well dispersed configuration suitable for decoying a radar guided missile, which dispenser has an outer case and a friable container movably mounted within the case,

7. The chaff dispenser, as in claim 5, wherein the first 5 which comprises:

pulling means is gas pressure.

8. The chaff dispenser, as in claim 7, wherein the first pulling means is gas pressure obtained from a gas generator.

9. The chaff dispenser, as in claim 5, wherein the first pulling means consists of a parachute, and gas pressure operating in unison with the parachute.

10. A method of dispersing chaff from a dispenser pulling the friable container from the outer case after a predetermined time after ejection, said container having therein an explosive charge substantially surrounded by chaff, and

detonating the explosive charge to release the explosive force which disperses the chaff into the predetermined configuration.

Claims

1. A dispenser for chaff, suitable for ejecting from a launching unit, which comprises in combination: an outer case, a releasable timer means for measuring a pre-set delay time, movably attached to the outer case, and adapted to attach to the launching unit, and to release itself from the outer case after measuring the delay time, a container means for holding and explosively dispersing the chaff, movably mounted within the outer case, and activated when removed from the outer case, and a first pulling means for removing the container means from the outer case, said first pulling means connected to the releasable timer means and to the container means, the dispenser adapted and constructed to start the releasable timer means to measure the delay time upon ejecting of the dispenser, and then release itself and activate the first pulling means to pull the container means from the outer case which activates the container mEans to explosively disperse the chaff.

2. The chaff dispenser, as in claim 1, wherein the container means for holding and dispersing the chaff is a canister which comprises: a canister shell with a cylindrical tube shape, a first end cap adapted to hold the first pulling means, and attached to one end of the canister shell, a second end cap attached to the other end of the canister shell, connecting means for connecting the canister shell to the first and second end caps, an explosive charge, a detonator charge, a center tube adapted to hold the explosive charge and detonator charge therein, one end of the center tube connected to the first end cap, and the opposite end of the center tube connected to the second end cap, and a means for initiating the detonator charge when the container means is pulled out of the outer case, the chaff being held within the space formed by the canister shell, the first and second end caps, and the center tube.

3. The chaff dispenser, as in claim 2, wherein the chaff dispenser further comprises: a first safety means for preventing the container means from being pulled out of the outer case until the pulling means is actuated.

4. The chaff dispenser, as in claim 3, wherein the container means for holding and dispersing the chaff further comprises: a second safety means to prevent the primer from detonating until the container means is completely pulled out of the outer case.

5. The chaff dispenser, as in claim 4, wherein the releasable timer means comprises: an adjustable timer having a starter which actuates upon pulling, said timer adapted to measure a pre-set delay time and connected to the first pulling means, a releasable locking means for attachment of the timer to the outer case, and operably connected to the timer to release after the timer measures the pre-set delay time, and a second pulling means attached to the starter of the adjustable timer and adapted to attach to the launching unit when the dispenser is placed therein, said second pulling means actuating the starter of the timer when the chaff dispenser is ejected from the launching unit.

6. The chaff dispenser, as in claim 5, wherein the first pulling means is a parachute.

7. The chaff dispenser, as in claim 5, wherein the first pulling means is gas pressure.

10. A method of dispersing chaff from a dispenser which is ejected from a moving vehicle to form a well dispersed configuration suitable for decoying a radar guided missile, which dispenser has an outer case and a friable container movably mounted within the case, which comprises: pulling the friable container from the outer case after a predetermined time after ejection, said container having therein an explosive charge substantially surrounded by chaff, and detonating the explosive charge to release the explosive force which disperses the chaff into the predetermined configuration.