Shock mitigation utilizing quiescent cavitation

Patent metadata

Field	Value
Publication number	US-11401993-B1
Application number	US-202017023423-A
Country	US
Kind code	B1
Filing date	Sep 17, 2020
Priority date	Sep 17, 2020
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

There is provided a device for mitigating physical shock to an object to which it is attached. The device includes a body having a through-bore extending from one end to another. A sliding mass is positioned within the bore hole such that it can slide within the through-bore. A first end cap is slidingly disposed in said body hollow volume at one end of the body, and a second end cap is slidingly disposed at the other. End cap and body combination is filled with a liquid. Responsive to an impact along the body axis, one of the end caps is partially displaced into the body and at least a portion of the liquid changes phase from a liquid phase to a vapor phase.

First claim

What is claimed is:

1. A device comprising:
a body having a first end and a second end, wherein said body has a through-bore extending from said first end to said second end, defining a hollow volume;
a sliding mass having an aperture formed longitudinally therethrough centrally located within said body, said sliding mass being capable of sliding within said body hollow volume;
a first end cap slidingly disposed in said body hollow volume at said first end of said body;
a second end cap slidingly disposed in said body hollow volume at said second end of said body; and
a liquid disposed in said hollow volume of said body and in said sliding mass aperture;
wherein, responsive to an impact along a longitudinal axis of said body, at least one of said first and second end caps is partially displaced into said body and momentum of said liquid and sliding mass causes at least a portion of said liquid to change phase from a liquid phase to a vapor phase; and
wherein:
said body has a plurality of longitudinal ridges on an interior surface of said body, each ridge of said plurality of longitudinal ridges extending from said first end to said second end of said body;
said body has a plurality of stopper ridges centrally located on the interior surface of said body, each ridge of said plurality of stopper ridges being displaced from said first end and said second end of said body;
said sliding mass has a plurality of grooves formed therein at a periphery of said sliding mass corresponding to said plurality of longitudinal ridges and said plurality of stopper ridges;
said first end cap has grooves formed around a periphery thereof corresponding to said plurality of longitudinal ridges, said first end cap being slidingly disposed in said body hollow volume on said plurality of longitudinal ridges at said first end of said body; and
said second end cap has grooves formed around a periphery thereof corresponding to said plurality of longitudinal ridges, slidingly disposed in said body hollow volume on said plurality of longitudinal ridges at said second end of said body.

2. The device of claim 1 , wherein said plurality of stopper ridges limit displacement of said end cap into said body.

3. The device of claim 1 , wherein said sliding mass is able to move within said body along said longitudinal ridges and said stopper ridges.

4. The device of claim 1 , wherein:
said first end cap has a bleed channel formed therein providing communication from an interior defined by said body hollow volume, said first end cap, and said second end cap and an exterior of said body, said first end cap, and said second end cap; and
further comprising a plug positionable in said first end cap bleed channel to seal said first end cap bleed channel.

5. The device of claim 4 , wherein:
said second end cap has a bleed channel formed therein providing communication from the interior defined by said body hollow volume, said first end cap, and said second end cap and an exterior of said body, said first end cap, and said second end cap; and
further comprising a second plug positionable in said second end cap bleed channel to seal said second end cap bleed channel.

6. A device comprising:
a body having a first end and a second end, wherein said body has a through-bore extending from said first end to said second end, defining a hollow volume;
a sliding mass having an aperture formed longitudinally therethrough centrally located within said body, said sliding mass being capable of sliding within said body hollow volume;
a first end cap slidingly disposed in said body hollow volume at said first end of said body;
a second end cap slidingly disposed in said body hollow volume at said second end of said body; and
a liquid disposed in said hollow volume of said body and in said sliding mass aperture;
wherein, responsive to an impact along a longitudinal axis of said body, at least one of said first and second end caps is partially displaced into said body and momentum of said liquid and sliding mass causes at least a portion of said liquid to change phase from a liquid phase to a vapor phase; and

wherein:
said first end cap has a first retaining groove formed on an outer surface of said first end cap;
said second end cap has a second retaining groove formed on an outer surface of said second end cap;
said body having a first protrusion extending inwardly into said body hollow volume and into said first end cap retaining groove to limit axial movement of said first end cap; and
said body having a second protrusion extending inwardly into said body hollow volume and into said second end cap retaining groove to limit axial movement of said second end cap.

7. The device of claim 6 , wherein:
said body has a first aperture formed therein proximate to said body first end and a second aperture formed therein proximate to said body second end;
said first protrusion is a first set screw positioned in the body first aperture; and
said second protrusion is a second set screw positioned in the body second aperture.

8. A device comprising:
a body having a first end and a second end, wherein said body has a through-bore extending from said first end to said second end, defining a hollow volume;
a sliding mass having an aperture formed longitudinally therethrough centrally located within said body, said sliding mass being capable of sliding within said body hollow volume;
a first end cap slidingly disposed in said body hollow volume at said first end of said body;
a second end cap slidingly disposed in said body hollow volume at said second end of said body; and
a liquid disposed in said hollow volume of said body and in said sliding mass aperture;
wherein, responsive to an impact along a longitudinal axis of said body, at least one of said first and second end caps is partially displaced into said body and momentum of said liquid and sliding mass causes at least a portion of said liquid to change phase from a liquid phase to a vapor phase; and

wherein:
said first end cap has a bleed channel formed therein providing communication from an interior defined by said body hollow volume, said first end cap, and said second end cap and an exterior of said body, said first end cap, and said second end cap; and
further comprising a plug positionable in said first end cap bleed channel to seal said first end cap bleed channel.

9. The device of claim 8 , wherein:
said second end cap has a bleed channel formed therein providing communication from the interior defined by said body hollow volume, said first end cap, and said second end cap and an exterior of said body, said first end cap, and said second end cap; and
further comprising a second plug positionable in said second end cap bleed channel to seal said second end cap bleed channel.

Assignees

• Us Navy

Inventors

• Daily David J
• Mcqueen Sarah E

Classifications

• F16F2234/02

  cylindrical · CPC title

• F16F2222/12

  Fluid damping · CPC title

• F16F9/006 Primary

  characterised by the nature of the damping medium, e.g. biodegradable (variable viscosity damping adjustment F16F9/53) · CPC title

• F16F7/1034

  of movement of a liquid · CPC title

• F16F7/1017

  by fluid means · CPC title