Abstract A hydraulic mitigator comprises a relatively massive hollow housing having two coaxial bores, the second bore being larger than the first. A shaft partially extending outside the housing rides in the first bore while a piston which is connected to the shaft rides exclusively within the second bore. The larger bore is filled with a fluid of a known density and a space is provided between the bore and the outer rim of the piston to enable the piston to be propelled through the fluid. The portion of the shaft which extends outside the housing is provided with an enlarged plate which is intended to be struck by the projectile. Any force directed at the plate will be only partially transmitted to the housing, the remainder being dissipated in propelling the piston through the fluid. Thus by properly selecting the density of the fluid and the size of the space between the piston and the bore, one can impose a predetermined deceleration force to the projectile. If the mitigator is spinning at the moment of impact such a spin can be partially transmitted to the projectile. This is accomplished by providing a pin and groove coupling means between the housing and the shaft in order to impart some of the angular acceleration force of the massive housing to the relatively lightweight shaft.
A hydraulic mitigator for providing linear deceleration and angular spin to an impacting projectile comprising: a. a hollow housing having a first bore and a second bore; b. a shaft partially extending outside said housing and riding within said first and second bore; c. a piston connected to said shaft and riding within said second bore; d. a fluid confined within said second bore; e. means for sealing said second bore to prevent the escape of said fluid; f. a space between the outer rim of said piston and the wall of said second bore to enable said fluid to transfer to both sides of said piston completely fill said second bore; and g. an enlarged plate firmly secured to that end of the shaft which normally extends outside said housing, whereby a projectile impacting said plate will be decelerated at a predetermined rate; and h. a groove located within said first bore and a pin secured to said shaft and extending into said groove such that a predetermined portion of angular acceleration of said housing will be coupled to said shaft.
Claim 2
Dependent Claim
182 words
A hydraulic mitigator for providing linear deceleration and angular spin to an impacting projectile comprising: a. a hollow housing having a first bore and a second bore; b. a shaft partially extending outside said housing and riding within said first and second bore; c. a piston connected to said shaft and riding within said second bore; d. a fluid confined within said second bore; e. means for sealing said second bore to prevent the escape of said fluid; f. a space between the outer rim of said piston and the wall of said second bore to enable said fluid to transfer to both sides of said piston completely fill said second bore; and g. an enlarged plate firmly secured to that end of the shaft which normally extends outside said housing, whereby a projectile impacting said plate will be decelerated at a predetermined rate; and h. a groove located within said first bore and a pin secured to said shaft and extending into said groove such that a predetermined portion of angular acceleration of said housing will be coupled to said shaft.
Claim 3
Dependent Claim
36 words
The hydraulic mitigator of claim 1 wherein said groove is helical and extends along the length of said first bore, whereby a predetermined portion of angular acceleration of said housing will be transmitted to said shaft.
Claim 4
Dependent Claim
20 words
The hydraulic mitigator of claim 1 further comprising spring means to reset said shaft to an extended position after impact.
Claim 5
Dependent Claim
30 words
The hydraulic mitigator of claim 1 wherein said housing has a greater mass than the combined mass of said shaft and plate, thereby increasing the effective mass of said shaft.
Claim 6
Dependent Claim
16 words
The hydraulic mitigator of claim 1 wherein said first bore and said second bore are coaxial.
Claim 7
Dependent Claim
16 words
The hydraulic mitigator of claim 5 wherein said second bore is larger than said first bore.