TUNED MECHANICAL STABILIZER

• US 3,563,335 A
• Filed: 03/17/1969
• Issued: 02/16/1971
• Est. Priority Date: 03/17/1969
• Status: Expired due to Term

• Current Assignee: Holmes, John F., Lawrence C. Frederick
• Original Assignee: Holmes, John F., Lawrence C. Frederick
• Inventors: Holmes, John F., Frederick, Lawrence C.
• Application Number:
  US04/807,821
• Time in Patent Office: 701 Days
• US Class Current: 181/198
• CPC Class Codes: B63B 39/14 for indicating inclination or duration of roll

Abstract

There is herein disclosed a tuned mechanical stabilizer for suspension of transducers from ships. The transducer is affixed to one end of a shaft, the other end of which is provided with a fixed counterweight and an adjustable tuning weight whereby the natural period of the transducer-stabilizer assembly may be tuned such as to substantially exceed the roll-pitch period of the vessel and thereby isolate the transducer from vessel pitch and roll.

Claims

1. Apparatus for isolating a transducer from rotational oscillations comprising:

a counterweight;

a rigid member coupling said transducer to said counterweight;

means for supporting said coupling member such that it is free to rotate about a preselected center of rotation; and

a tuning weight disposed at a preselected position on said coupling member such as to tune said apparatus to a preselected period of oscillation greater than that of oscillations from which said transducer is to be isolated.

2. Apparatus as recited in claim 1 wherein:

said tuning weight is adjustably disposed on said coupling member such that said natural period of oscillation may be adjusted according to the relationship where;

T is the natural period of oscillation of said apparatus;

I is the moment of inertia of said apparatus about said center of rotation;

W3 is the weight of said tuning weight; and

L3 is the distance between the center of mass of said tuning weight and said center of rotation.

3. Apparatus as recited in claim 1 wherein:

said supporting means comprises a gimbal assembly having orthogonal axes of rotation which pass through said center of rotation.

4. Apparatus as recited in claim 1 wherein:

said transducer is rotatably coupled to said coupling member; and

further including means for rotating said transducer about said coupling member.

5. Apparatus as recited in claim 4 wherein:

said rotating means comprises azimuth and zenith control motors disposed in said counterweight and coupled to said transducer through said coupling member.

6. Apparatus for suspending an acoustic transducer from a floating vessel comprising:

a counterweight;

a rigid member coupling said transducer to said counterweight and disposed through the hull of said vessel;

means for supporting said coupling member from said vessel such that it is free to rotate within angular limits about a preselected center of rotation; and

a tuning weight disposed at a preselected position on said coupling member such as to tune said apparatus to a preselected period of oscillation greater than the natural pitch and roll period of said vessel.

7. Apparatus as recited in claim 6 wherein:

said supporting means comprises a gimbal assembly having orthogonal axes of rotation which pass through said center of rotation.

8. Apparatus as recited in claim 6 wherein:

said center of rotation is disposed in the plane at which said coupling member passes through said hull of said vessel.

9. Apparatus as recited in claim 6 further including:

acoustically transmissive protective means affixed to said hull wherein said acoustic transducer is free to move within said angular limits.

10. Apparatus as recited in claim 9 wherein:

said protective means comprises an acoustically transmissive dome filled with an acoustically transmissive medium having a specific viscosity of no greater than water.