Ammunition and explosives – Shells – With range increasing means
Reexamination Certificate
1999-06-14
2001-04-10
Tudor, Harold J. (Department: 3641)
Ammunition and explosives
Shells
With range increasing means
C102S202000, C102S380000, C060S256000
Reexamination Certificate
active
06213023
ABSTRACT:
The present invention relates to a base bleed unit.
A base bleed unit is previously known, for example by SE-A-340 076, whereby for example an artillery projectile can be given an increased shooting range by a reduction of the air drag at the base plane of a projectile by means of the so called base-bleed-action. According to this previously known arrangement, a base bleed unit includes a gun powder charge for generation of desired mass flow, and an igniter charge located in an opposed relationship to a gas outlet opening.
A similar type of a base bleed unit is disclosed in U.S. Pat. No. 4,213,393. A further developed base bleed unit is disclosed in U.S. Pat. No. 4,807,532, and is primarily different from the above mentioned and previously known solutions by the location of the igniter charge adjacent to the base plane, i.e. the plane by which the mass flow is ejected. According to a preferred embodiment, the igniter charge is centrally located, and having a number of surrounding outlet holes for the base drag reducing gas generated by existing gun powder charge.
The object of the present invention is to disclose a base bleed unit, improved in relation to prior art, which removes the problems caused by deformation of the mass flow generating gun powder charge due to influence of acceleration forces. To locate the igniter charge in an opposed relationship to an outlet opening as disclosed in SE-A-340 076 or U.S. Pat. No. 4,213,393 results in a considerably reduced ignition effect as compared to a location adjacent to an outlet opening, since, for example, the combustion flame from the igniter charge is guided towards existing outlet openings at the base plane, and problems also occur in case that the igniter charge should become loose under influence from acceleration forces. In the embodiment according to U.S. Pat. No. 4,807,532, the mass flow generating gun powder charge may, due to deformation caused by acceleration partly or completely cover the outlet nozzles, and thereby change intended flow properties. Problems caused by this deformation have also resulted in restrictions with regard to allowed muzzle speed for projectiles arranged with known types of base bleed units, and thus a reduced trajectory length. According to the present invention, a preferred location of the igniter charge is provided in combination with an extremely good support for the mass flow generating gun powder charge, which on one hand secures good ignition of the gun powder charge, and on the other hand prevents formation of cracks and damage to the gun powder charge. This results in accurate control of the trajectory length and extremely small dispersion, which are most desirable features. Furthermore, the drive charge of the weapon can be arranged without previous restrictions related to muzzle speed, which results in a possibility to a further increase of the trajectory length. The present invention also discloses an advantageous way of locating the igniter charge of the base bleed unit. The base bleed unit according to the present invention also facilitates improved possibility of choosing suitable chemical composition of the mass flow generating gun powder charge as well as the igniter charge due to the very favourable supporting properties offered for both the gun powder charge and the igniter charge.
The base bleed unit according to the present invention comprises a surrounding housing surrounding at least one mass flow generating gun powder charge, and having a number of outlet holes extending through a rear wall of the housing surrounding a substantially centrally arranged igniter charge adjacent to said rear wall, and it is mainly characterized in that a centrally located member, which substantially has the shape of a truncated cone, is arranged extending from the internal surface of the rear wall, arranged abutting a portion of the mass flow generating gun powder charge adjacent in relation to the rear wall, said member also surrounding the outlet holes and the igniter charge.
REFERENCES:
patent: 3387560 (1968-06-01), Mertens
patent: 3698321 (1972-10-01), Wall
patent: 4213393 (1980-07-01), Gunners et al.
patent: 4807532 (1989-02-01), Andersson et al.
patent: 4807535 (1989-02-01), Schilling et al.
patent: 4846071 (1989-07-01), Franzen et al.
patent: 340076 (1975-10-01), None
Jacobson Price Holman & Stern PLLC
Tudor Harold J.
LandOfFree
Base bleed unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Base bleed unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Base bleed unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2478731