US 5,671,869 AGranted

Fiber chaff disseminator

AssigneeThe United States of America as represented by the Secretary of the Army

InventorsMark L. G. Althouse, Kevin J. Wilcock

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Abstract

A chaff disseminator for uniformly distributing short fibers into the air r disrupt enemy radar tracking in an air combat situation. Such fibers are typically 3 to 25 microns in diameter and cut to 1/8 to 1/2 inch in length. Fiber concentration and output are regulated by changing the air flow direction in a hopper while keeping the total air flow volume constant. A load of fibers in the hopper is raised by an upward airflow causing the load to tumble and reducing the packing density of the fibers at the edge of the load. The reduced packing density permits lower speed horizontal airflows to pull off fibers for dissemination. A fluid bed is created depending by a series of small holes drilled in the bottom of the hopper, by regulation of the airflow along the lid of the hopper and by air jets mounted along the bottom front edge of the hopper. A baffle which the load compressed and directs the cross load airflow.

Claims20

Dependent claims

A fiber chaff dispenser which comprises:

a.) a hopper capable of containing a mass of fiber chaff, the hopper comprising a single, continuous bottom and rear wall member whose cross section is generally an arc of a circle, and a front panel and two side panels attached to the bottom and rear wall member to form a substantially enclosed vessel having an open top;
at least the bottom portion of the bottom and rear wall member having a plurality of airholes therethrough;
the front panel having a single exit port for the fiber chaff;
b.) a hinged lid attached to said hopper and extending a distance sufficient to substantially completely cover the open top;
c.) means for lifting the lid a distance above the open top to thereby provide an airflow ingress to the hopper;
d.) a dispensing chamber comprising a wall interior to the hopper spaced from and substantially parallel to the plane of the front panel, said chamber extending from the bottom portion of the bottom of the exit port and extending to a point below the hopper top;
e.) baffle means inside the hopper spaced a distance behind the dispensing chamber, the baffle spanning the width of the hopper between each of the two side panels and extending the distance to the bottom and rear wall member;
f.) an airflow control channel extending along the curvature of the bottom and rear wall member and positioned over the airholes at the bottom portion thereof, said channel providing means to adjust the amount of air flow through said airholes;
g.) a plurality of airjets extending through the bottom portion of the bottom and rear wall member behind the dispensing chamber, said airjets being capable of directing a supply of forced air therethrough into the hopper;
and
h.) blower means attached to the exit port and capable of receiving fiber chaff from the dispensing chamber and blowing said chaff out through a chute.

8 more elements

A method of dispensing fiber chaff which comprises:

I. providing a chaff dispenser which comprises:
a.) a hopper capable of containing a mass of fiber chaff, the hopper comprising a single, continuous bottom and rear wall member whose cross section is generally an arc of a circle, and a front panel and two side panels attached to the bottom and rear wall member to form a substantially enclosed vessel having an open top;
at least the bottom portion of the bottom and rear wall member having a plurality of airholes therethrough;
the front panel having a single exit port for the fiber chaff;
b.) a hinged lid attached to said hopper and extending a distance sufficient to substantially completely cover the open top;
c.) means for lifting the lid a distance above the open top to thereby provide an airflow ingress to the hopper;
d.) a dispensing chamber comprising a wall interior to the hopper spaced from and substantially parallel to the plane of the front panel, said chamber extending from the bottom of the exit port and extending to a point below the hopper top;
e.) baffle means inside the hopper spaced a distance behind the dispensing chamber, the baffle spanning the width of the hopper between each of the two side panels and extending the distance to the bottom and rear wall member;
f.) an airflow control channel extending along the curvature of the bottom and rear wall member and positioned over the airholes at the bottom portion thereof, said channel providing means to adjust the amount of air flow through said airholes;
g.) a plurality of airjets extending through the bottom portion of the bottom and rear wall member behind the dispensing chamber, said airjets being capable of directing a supply of forced air therethrough into the hopper;
and
h.) blower means attached to the exit port and capable of receiving fiber chaff from the dispensing chamber and blowing said chaff out through a chute;
II. causing air to flow into said hopper from at least one of said airflow ingress, said plurality of airholes and said airjets;
said air flow being sufficient to continuously lift fiber chaff in the hopper and supplying the chaff to the blower;
and
III. causing said blower to acquire the chaff from said hopper and expel said chaff out through a chute.

13 more elements

Dependencies are inferred from the claim text.