US3747896A

US3747896A - Electromechanical flare launch and jettison device

Info

Publication number: US3747896A
Application number: US00155168A
Authority: US
Inventors: R Botzum
Original assignee: Northrop Grumman Corp
Current assignee: Northrop Grumman Corp; Northrop Grumman Systems Corp
Priority date: 1971-06-21
Filing date: 1971-06-21
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

Apparatus for launching a vehicle-towed pyrotechnic type flare or similar structure incorporating means for launching, automatically braking, and enabling the flare to be jettisoned from the end of a line attached to a tow reel when desired.

Description

United States Patent 11 1 Botzum 1451 July 24, 1973 ELECTROMECHANICAL FLARE LAUNCH AND JETTISON DEVICE [75] Inventor: Richard A. Botzum, Chania Island Crete, Greece [73] Assignee: Northrop Corporation, Los Angeles,

Calif.

[22] Filed: June 21, 1971 [21] Appl. No.: 155,168

[52] US. Cl 254/150, 273/105.3, 40/215 [51] Int. Cl B66d 1/30 [58] Field of Search... 254/150, 166;

[56] I I References Cited UNITED STATES PATENTS Hopper 273/1053 2,923,549 2/1960 Hopperetal ..273/10s.3

Primary Examiner-Evon C. Blunk Assistant Examiner-Merle F. Maffei A Attorney-Harold L. Fox and Willard M. Graham [57] ABSTRACT Apparatus for launching a vehicle-towed pyrotechnic type flare or similar structure incorporating means for launching, automatically braking, and enabling the flare to be jettisoned from the end of a line attached to a tow reel when desired.

5 Claims, 5 Drawing Figures ELECTROMECHANICAL FLARE LAUNCH AND JETTISON DEVICE The subject invention pertains to launching a towed article, and more particularly to equipment incorporating means for launching the article, automatically stopping, and then jettisoning the article whendesired.

It has long been the desire to automatically launch, brake, and finally jettison a pyrotechnic flare or towed target from a moving vehicle, and especially from an aircraft. Often it becomes necessary to execute the above functions in connections with pilotless drones or from piloted aircraft in which the pilot or crew is relieved of the aforesaid functions.

Briefly the device encompasses means whereby the flare is first launched and its movement arrested (relative to movement with respect to the plane from which it is launched) and finally jettisoned when desired. These functions are performed remotely or with minimum assistance by the operator in the airplane on which the flare is mounted. The flare is held in its initial position by a finger forwardly canted with respect to the axis of the towing reel, before starting its launch operation. A motor associated with the towing mechanism constitutes an electric motor functioning as a motor, later as a generator for braking and subsequently as a motor for jettisoning the flare or signal.

An object of the present invention is to disclose a launching mechanism in which a tow reel is retained in its original position until rotated by the motor.

Another object is to provide an auxiliary cable functioning to retain the towing cable in its initial position until the motor is activated starting its paying-out operation.

Another object is to provide means effective to automatically arrest paying-out when the cable reaches sub stantially its full extent.

Another object is to disclose means whereby the flare may be jettisoned when desired.

Although the characteristic features of the present invention are particularly pointed out in the appended claims, the invention itself, also the manner in which it may be carried out, will be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of this application and in which:

FIG. 1 is a plan view of the apparatus disclosed herein.

FIG. 2 is a side elevation view of the device of FIG. I viewed as indicated by the line 22 in FIG. 1.

FIG. 3 is a view of the forward end of the tow cable shown in FIGS. 1 and 2.

FIG. 4 is a schematic diagram of a circuit which may be used with the above apparatus.

FIG. 5 is a detailed showing of the slot formed in the towing reel and its relationship with respect to the axis of the reel.

Referring to the drawings, FIGS. 1 and 2 show a preferred embodiment of a flare launching facility as dis closed herein and indicated by the numeral 11. Principal components of the facility 11 include a flare, main and auxiliary towing lines, towing reel, electric motor and

gear train

12, 14, 16, 17, 18 and 19, respectively.

The flare 12 or target is housed in a hollow cylindrical housing 21 which is secured to fixed structure 22 such as the main body of an aircraft, etc. The flare 12 is normally towed by the main nylon cable 14 in a conventional manner. Prior to launching the flare 12, the

line 14 is wound on the reel 17 and retained thereon by the auxiliary cable 16. In this respect the cable 14 is secured to the nose of the flare 12 by means of a ball bearing (swivel) 24. The rear end of auxiliary cable 16 is also secured to the nose of the flare 12.

Referring to ejection of the flare 12 housed in the housing 21, the ejection device is shown and is indicated in its entirety by the numeral 29. A spring tube 31 is fixedly secured to the flare housing 21 substantially as shown in FIG. 1. The tube 31 is closed at its forward end and contains a compressed helical wound spring 32 retained herein by a cylindrical pad-like member 35. The pad 35 carries a pin 33 which operates in aligned longitudinally extending slots 25 in the housing 21 and spring tube 31. The pin 33 seats in the rear end of a flare groove 30 formed in the nose portion of the flare l2. Mounted in the foregoing manner, it will be apparent that the spring 32 and pin 33 will provide a rearward propelling force on flare 12 at the beginning of the launching.

When launching the flare 12 from the housing 21, the flare is ignited in any conventional method.

The auxiliary cable 16, up to this time, functions as a retaining member retaining the flare 12 in the housing 21. In this respect it will be noted that the auxiliary cable 16 is looped around a retaining finger 23 having a fixed inclined relation with respect to an end flange of the reel 17. During the first half-revolution of the reel 17, the cable 16 will be released by the finger 23 allowing the flare 12 to move from the housing 21 under the influence of the spring 32, and also assisted by aerodynamic forces acting thereon slightly later.

The facility 11 continues to pay-out the main cable 14 under control of the motor and drag forces until reaching the apparatus shown in FIG. 3.

A wire braid (covering) 41 contacts a flapper switch 42, which is mounted on an insulated spring-loaded arm 20 bearing against the turns of line 14 on reel 17, and actuates the flapper switch 42 shown in FIG. 2. Actuation of the flapper switch renders effective a portion of the electrical circuit, shown in FIG. 4, in a way acting to arrest pay-out of the flare 12. Components acting to arrest rearward travel of the flare 12 are shown in FIG. 3. Approximately the last 20 inches of the cable 14 (dimension A) is covered with conducting wire braid 41. Secured to the terminal end of the cable 14 is a spherical ball member 43. It will be understood that, the ball 43 is received in a slot 28 formed in the same flange of the reel 17 as the finger 23. Referring to FIG. 5 it will be seen in addition to electrically braking rotation of the reel 17 in a manner presently explained, the terminal (inboard) end of slot 28 is located so that the direction of pull of the line 14 has a dead center relation with respect to the reel 17. The above feature plus the braking of the motor 18 effectively stop the unwinding operation of the reel 17 at a position shown in FIG. 5.

Thus it will be seen that unwinding operation of the reel 17 will be effectively arrested for the reasons explained and to be further explained as the disclosure progresses.

in the motor 18 becoming operational through relay contact 50.

Accordingly the slot 28 rotates clockwise (FIG. 5) releasing cable 14 from the slot 28 and thereby jettisoning the flare 12. The manner in which the electric circuit functions will be more fully explained as the disclosure progresses.

A description of the various components comprising the facility 1 1 and the relationship thereof having been described a better understanding of their operation will be forthcoming from the following description of their operation.

Referring to FIG. 4 an electric circuit allowing the facility 11 to function in the above manner is disclosed and is identified in its entirety by the numeral 34. The circuit 34 operates on 28 V.D.C. current, for example, and includes conductors 36-40 and 44-47 inclusive,

relays

48 and 49, and

switches

51 and 52.

The electrical motor 18 is rendered operational by closing the start switch 51. During this phase of operation current flows through conductor 47, switch 51, conductor 36, normally closed relay 49,

conductors

37 and 38, energizing the motor 18, and returns to ground via the conductor 39. This represents current flow at the time auxiliary cable 16 is being released and the flare 12 is reaching its towed position.

The reel 17 continues to pay-out line 14 in the manner previously explained until the flapper switch 42 contacts the wire braid 41. At this time relay 49 is actuated, the motor 18 is automatically slowed to a stop; current flowing through

conductors

38a, 39a, switch 42, braid 41, and metal spool 17 to ground. The motor 18 is thus disconnected from the power source resulting in the motor 18 acting as a generator or brake for the flare 12 by reason of a resistor 53 being shorted across it. The flare 12 is thus towed at a predetermined distance behind the facility 11.

At such time as the flare 12 is burned out, or it becomes necessary to jettison the flare or target for any other reason, release switch 52 is closed to actuate relay 48, allowing current to flow through conductor 46, switch 52, conductors 45, conductor 44, relay contact 50,

conductors

37a and 38, motor 18 and return to ground via conductor 39. Thus the motor 18 once again starts, rotating the slot 28 so that the ball 43 will be released from the slot 28. The line 14 is thus freed and falls away from the facility 11.

The circuit 34 may be operated manually by the pilot of the plane or operated remotely if the facility 11 is utilized in a drone or the like.

Summarizing the operation of the facility 11, it will be seen that the electric motor first rotates the reel 17 from the initial position shown in FIGS. 1 and 2. Its rotation is later stopped as the flapper 42 contacts the wire braid 41, (FIG. 3) and still later the motor is energized again upon the closing of release switch 52 to effect the jettisoning of the flare l2.

I claim:

1. In a device, mounted on a moving vehicle or the like, for launching, towing, and jettisoning a flare or like structure, comprising:

a. powered apparatus including a towing reel of a spool-like configuration;

b. a primary tow line wrapped around the reel with the free end of said primary tow line secured to the nose portion of a flare;

c. an auxiliary line, one end of which is also secured to the nose portion of the flare;

d. and means securing the other end of said auxiliary line to said reel functioning to retain the flare in its original position and release said auxiliary line from said reel upon the first half revolution in an unwinding direction.

2. Apparatus as set forth in claim 1:

a. in which the means securing the other end of said auxiliary line to said reel is fixedly secured to said reel and constitutes a finger member;

b. the initial position of said finger having a forwardly canted relationship with respect to the end of said towing reel and also with respect to the forward progress of the vehicle.

3. Apparatus as set forth in claim 2 including:

a. an electric motor and electrical circuit for providing power for said device;

b. said primary tow line constituting a non-conductor of electrical current;

c. a terminal end portion of said primary tow line on said reel being covered with a good conductor of electricity;

d. and said electrical circuit including a flapper switch adapted to close a portion of said circuit resulting in said electric'motor stopping at such time as said flapper switch contacts said good electrical conducting material.

4. Apparatus as set forth in claim 3:

a. in which said principal tow line constitutes a nylon cord.

5. Apparatus as set forth in claim 4:

a. in which said reel is of unitary construction including a pair of spaced circular end flanges and an axial portion extending between said end flanges;

b. one of said end flanges having a slot therein extending chordwise of said one flange, opening on the periphery thereof and terminating off-center of said one flange;

c. the terminal end of said primary tow line exceeding the width of said slot;

d. and said terminal end being received in said slot, prior to the winding of said primary tow line of said reel, whereby the reel will be automatically stopped in the absence of rotation of said motor and the tow line held in said slot until said motor is reactivated.

Claims

1. In a device, mounted on a moving vehicle or the like, for launching, towing, and jettisoning a flare or like structure, comprising: a. powered apparatus including a towing reel of a spool-like configuration; b. a primary tow line wrapped around the reel with the free end of said primary tow line secured to the nose portion of a flare; c. an auxiliary line, one end of which is also secured to the nose portion of the flare; d. and means securing the other end of said auxiliary line to said reel functioning to retain the flare in its original position and release said auxiliary line from said reel upon the first half revolution in an unwinding direction.

2. Apparatus as set forth in claim 1: a. in which the means securing the other end of said auxiliary line to said reel is fixedly secured to said reel and constitutes a finger member; b. the initial position of said finger having a forwardly canted relationship with respect to the end of said towing reel and also with respect to the forward progress of the vehicle.

3. Apparatus as set forth in claim 2 including: a. an electric motor and electrical circuit for providing power for said device; b. said primary tow line constituting a non-conductor of electrical current; c. a terminal end portion of said primary tow line on said reel being covered with a good conductor of electricity; d. and said electrical circuit including a flapper switch adapted to close a portion of said circuit resulting in said electric motor stopping at such time as said flapper switch contacts said good electrical conducting material.

4. Apparatus as set forth in claim 3: a. in which said principal tow line constitutes a nylon cord.

5. Apparatus as set forth in claim 4: a. in which said reel is of unitary construction including a pair of spaced circular end flanges and an axial portion extending between said end flanges; b. one of said end flanges having a slot therein extending chordwise of said one flange, opening on the periphery thereof and terminating off-center of said one flange; c. the terminal end of said primary tow line exceeding the width of said slot; d. and said terminal end being received in said slot, prior to the winding of said primary tow line of said reel, whereby the reel will be automatically stopped in the absence of rotation of said motor and the tow line held in said slot until said motor is reactivated.