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Publication numberUS2697325 A
Publication typeGrant
Publication dateDec 21, 1954
Filing dateJul 24, 1944
Priority dateJul 24, 1944
Publication numberUS 2697325 A, US 2697325A, US-A-2697325, US2697325 A, US2697325A
InventorsSpaulding Wallace P
Original AssigneeSpaulding Wallace P
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Powder igniter
US 2697325 A
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Description  (OCR text may contain errors)

1954 w. P. SPAULDING POWDER IGNITER Filed July 24, 1944 United States PatentO POWDER IGNITER Wallace P. Spaulding, Cumberland, Md., assignor to the United States of America as represented by the Secretary of War Application July 24, 1944, Serial No. 546,336

8 Claims. (Cl. 60-35.6)

This invention relates to an igniter for igniting the propulsion charge 'of a rocket projectile.

Prior art igniters utilized to ignite a rocket propulsion charge comprising a stack of disks or washers of powder stnmg on a rod and axially supported within a rocket motor of a rocket projectile have not been very satisfactory. This was due primarily to the inability of such igniters to obtain uniform ignition. It is appreciated that in this type of propellent assembly it is extremely difiicult to obtain uniform ignition, and particularly simultaneous ignition, of the entire area of the contiguous surfaces of the disks. One form of prior art igniter utilized a plurality of muslin bags containing black powder which were electrically fired by a squib. Such bags extended longitudinally of the chamber and were positioned around the outer periphery of the propellent assembly. Obviously to obtain complete ignition of the propellent laminations a sizable quantity of black powder had to be used, resulting in relatively high ignition pressures with consequent damage to the propellent charge. Further, uniform ignition could not be consistently attained because the direction of flow of the hot gases liberated by the black powder is generally axially of the combustion chamber thus minimizing the propagation of the flash radially between the disks.

Accordingly, it is an object of this invention to provide an igniter for a powder charge to uniformly and simultaneously ignite the entire charge.

A particular object of this invention is to provide an igniter to uniformly and simultaneously ignite a rocket propulsion charge comprising a laminated stack of disks or washers of propellent powder.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig. 1 is a longitudinal sectional view of a rocket projectile embodying this invention.

Fig. 2 is a detailed view showing the construction of one form of igniter.

Fig. 3 is a view similar to Fig. 2 showing an alternate type of construction utilizing longitudinal strips of combustible material.

Fig. 4 is a cross sectional view taken along the plane 4 4 of Fig. 3.

While it will be apparent to those skilled in the art that this invention has application generally in all types of rockets, it is particularly well adapted for use 1n rockets employing laminated propellents and is so disclosed.

Referring to the drawing wherein like characters refer to similar parts there is shown a rocket projectile embodying this invention. A cylindrical motor chamber 1, one end of which terminates in a nozzle 2 of well known Venturi construction, is provided to house the elements of the projectile. An ogival head 3 is secured to the forward end of rocket motor 1 as by threads 4, and contains the pay load which may consist of a high explosive, a chemical grenade or the like. A propellent charge 5 comprising a plurality of disks or washers 6 of suitable propellent material is axially mounted withm rocket motor 1 by a tube 7, threaded at each end, which is passed thru the single axial perforation 8 in each of the disk-like powder grains 6. Tube 7 is screwed into an axial threaded hole 9 provided in the base of head 3. The stack of individual powder grains or disks 6 strung on the tube 7 are preferably retained on such tube by a wishelr 10 and a nut 11 screwed onto the free end of tu e The laminar or contiguous surfaces of each disk or washer 6 of propellent material are more or less screened from any type of igniter. However, it is apparent that an ignition system located within the center of the charge would be best adapted to effect ignition of such charge.

An igniter embodying the features set forth above is shown in Fig. 1. Such an igniter is formed by wrapping tube 7 spirally with a layer of combustible tape 15 such for example as paper or cellophane, which has a coating of adhesive material 16 applied to the surface facing outwardly with respect to the surface of the tube 7. Each successive turn of the tape is preferably arranged to overlap somewhat and thus secures itself in the spiral form. Tube 7 with its adhesive surface 16 is then immersed in a container (not shown) of finely granulated black powder 17. The powder grains 17 adhere to the adhesive outer surface of the tape and provide a complete coating of the powder about tube 7.

To assemble the tube 7 in the rocket motor 1, the propellent disks 6 are carefully strung on tube 7. An electrical squib 13 preferably shaped in the form of a ring is suitably secured to the forward end of tube 7 and is arranged to be fired by the lead wires 14. Upon ignition of squib 13 the black powder coating 17 is ignited which acts as a quick match to substantially simultaneously and gnilformly ignite the contiguous surfaces of the powder is s.

As illustrated in Fig. 2, a second wrapping of combustible tape 18 may be applied over the black powder coated first Wrapping with the adhesive surface 19 inwardly disposed. Such a construction obviates the possibility of rubbing off any of the adhering powder grains during assembly in the projectile. A further modification in the construction of the igniter, illustrated in Fig. 3, comprises suitably securing longitudinal strips 15' of combustible material to tube 7 having afiixed thereon a layer 21 of igniter mixture secured by a suitable adhesive. Such longitudinal strips 15 may also be wrapped with ag exterior layer of combustible tape 18 as described a ove.

Thus it is readily apparent that an improved igniter for simultaneous and uniform ignition of a propellent charge for a rocket is hereby provided. As only a comparatively small igniter charge is utilized no high ignition pressures are built up within the rocket motor and hence damage to the propellent assembly is avoided.

I claim:

1. In combination, a powder charge having an axial recess, a tubular member extending thru said recess, a tape wrapped around said member, an adhesive coating on the exterior of said tape and a plurality of powder granulations secured to said adhesive coating.

2. An igniter for a powder charge comprising a tubular element, a tape having an adhesive coating on at least one side, said tape being spirally wrapped on said tubular element in overlapping relation with said adhesive coating on the exterior, thereby securing said tape in its spiralled shape, and a plurality of powder granulations secured to said adhesive coating.

3. An igniter as in claim 2 and a second combustible tape having an adhesive coating on one side thereof spirally wrapped over said powder granulations with its said adhesive coating on the inside.

4. An igniter for a powder charge comprising a tubular element, a plurality of strips of tape secured to the surface of said tubular element, a coating of adhesive on the exposed surface of said strips of tape and a plurality of powder granulations secured to said adhesive coating.

5. In a rocket motor, a propellent charge comprising a stack of powder washers, a support rod passing axially thru said stack of powder washers to thereby support said stack within the motor, a tape wrapped around said support rod and lying intermediate said rod and said powder washers, a coating of an igniter composition on the exterior of said tape and an electric squib supported on said rod and arranged to ignite said igniter composition.

6. In a rocket motor, a propellent charge comprising a stack of powder washers, a support rod passing axially thru said stackof powder. washersm thereby support said stack Within the motor, a tape wrapped around said support rod and lying intermediate said rod and said powder washers, an adhesive coatingon the exterior of said tape and a plurality of powder granulations secured to said adhesive coating and an electrical squib constructed in annular form and mounted on said support rod in position to ignite said powder granulations.

7. in a rocket motor, a propellent charge corriprisinga stack of axially perforated discs, at supporting member disposed axially of said 'propellent charge and a coating of igniter material applied to a surface of said supporting member which is adjacent said propellent charge.

8. The manufacture of an igniter for a laminated rocket propellent adapted to be supported by being strung on a central rod, comprising the steps of wrapping spirally on said rod a strip of tape having an adhesive surface, the adhesive surface being outward relative to the. surface of said rod, overlapping the spiral wrappings of adjacent. turns. of said tape. so that. said adjacent. wrap.- pings will be joined by said. adhesive, and immersing the outer surface of said tape into a granulated igniter compound, whereby the granulations will adhere to said adhesive surface.

References C itedj'in tlie'fi le of this patent UNITED STATES PATENTS Number; Name" Date 1,812,010 McBride June 30, 1931 1,897,948 Young Feb. 1'4,.1'933 2,094,552 Lowy Sept. 28, 1937 2,239,051 Pearsall et al. Apr; 22, 1941 FGREIGNJ PATENTS:

Number Country Date 207,540. Switzerland Nov. 15., 1939 503,078 France: Mar. 8,.1920

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1812010 *Dec 3, 1930Jun 30, 1931Mcbride Lewis MShell construction
US1897948 *Oct 15, 1931Feb 14, 1933Fed Lab IncHand grenade or aerial bomb
US2094562 *Feb 20, 1935Sep 28, 1937Fed Lab IncHand grenade
US2239051 *Mar 16, 1939Apr 22, 1941Ensign Bickford CoIgnition device for use with safety fuses or the like
CH207540A * Title not available
FR503078A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2799987 *Dec 31, 1952Jul 23, 1957Edward F ChandlerSolid fuel ramjet projectiles
US2865456 *Aug 22, 1956Dec 23, 1958Specialties Dev CorpPressurizing cartridge and pyrotechnic charge therefor
US2926613 *May 23, 1955Mar 1, 1960Phillips Petroleum CoComposite rocket-ram jet fuel
US2935948 *Feb 14, 1958May 10, 1960American Potash & Chem CorpRocket igniter pellets
US2955535 *May 28, 1958Oct 11, 1960Olin MathiesonIgnition assembly for perforated cylindrical charge
US2974596 *Jun 14, 1957Mar 14, 1961Du PontPropellant grain igniter
US2978308 *Nov 14, 1957Apr 4, 1961Phillips Petroleum CoBonding agent for composite type propellant
US2980021 *Jun 14, 1956Apr 18, 1961Phillips Petroleum CoIgnition of solid rocket propellants
US2990684 *Feb 10, 1958Jul 4, 1961William CohenRod assembled plastic rocket
US3003419 *Jun 6, 1960Oct 10, 1961Mimx CorpRod-type pyrogenic igniter
US3044399 *Aug 4, 1958Jul 17, 1962Aerojet General CoIgniter for solid propellants
US3062147 *Sep 28, 1959Nov 6, 1962Du PontIgniter for solid propellant grains
US3068643 *Apr 21, 1955Dec 18, 1962Camp Albert TRocket with internal rod
US3128600 *May 18, 1960Apr 14, 1964Thiokol Chemical CorpMultilevel solid propellant rocket motor
US3190589 *Dec 13, 1963Jun 22, 1965Svenska Aeroplan AbEjection seat having rocket motor for second stage propulsion
US3236317 *Jul 2, 1962Feb 22, 1966Dresser IndProjectile propelling apparatus for use in high temperature environment
US3274771 *Oct 23, 1961Sep 27, 1966Aerojet General CoHybrid solid and liquid fuel rocket
US3322067 *Feb 4, 1965May 30, 1967Mb AssocApparatus for igniting miniature rockets
US3332353 *Mar 3, 1959Jul 25, 1967Lohr A BurkardtAuxiliary igniter and sustainer
US3421325 *Nov 8, 1961Jan 14, 1969Joseph G Thibodaux JrSolid propellant rocket motor
US4002122 *Mar 2, 1961Jan 11, 1977Mb AssociatesMicrojet fuse
US5322018 *Sep 30, 1993Jun 21, 1994The Ensign-Bickford CompanySurface-initiating deflagrating material
DE1216023B *Apr 25, 1961May 5, 1966Werner Sommerkorn Dipl IngUEberlange Rakete
WO1993011089A1 *Nov 25, 1992Jun 10, 1993William C HaddenSurface-initiating deflagrating material
Classifications
U.S. Classification60/39.47, 60/256, 102/380, 60/39.823
International ClassificationF02K9/95, F02K9/00
Cooperative ClassificationF02K9/95
European ClassificationF02K9/95