US3687222A — Device for damping the noise produced by a gas je…

Claim 1

Independent Claim 275 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet, each such element having a free upstream edge and a free downstream edge relative to the direction of the gas jet; control means for moving each of said silencer elements between an operative silencing position in which said silencer element projects with negative incidence into said jet in the manner of a scoop with said free upstream edge disposed nearer the center line of the jet than is said downstream edge, and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means for supporting said element in said positions mounted for movement with respect to said fixed structure and carrying the silencer element pivotable thereon about an axis located intermediate the free edges of said element with the center of pressure of the jet impinging on the element at a point downstream of said axis, whereby in use the silencer element is subjected to a pressure thrust tending to pivot it about said axis in a direction to reduce said negative angle of incidence in the jet, said supporting means including stop means thereon for engaging a cooperating stop portion on the silencer element, thereby to limit the pivotal motion of said silencer element about said axis in said direction and determine the incidence angle of said element when in its projected operative position; and actuating means for moving said support means with respect to said fixed structure and thus move said silencer element between its operative and inoperative positions.

Claim 2

Dependent Claim 275 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet, each such element having a free upstream edge and a free downstream edge relative to the direction of the gas jet; control means for moving each of said silencer elements between an operative silencing position in which said silencer element projects with negative incidence into said jet in the manner of a scoop with said free upstream edge disposed nearer the center line of the jet than is said downstream edge, and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means for supporting said element in said positions mounted for movement with respect to said fixed structure and carrying the silencer element pivotable thereon about an axis located intermediate the free edges of said element with the center of pressure of the jet impinging on the element at a point downstream of said axis, whereby in use the silencer element is subjected to a pressure thrust tending to pivot it about said axis in a direction to reduce said negative angle of incidence in the jet, said supporting means including stop means thereon for engaging a cooperating stop portion on the silencer element, thereby to limit the pivotal motion of said silencer element about said axis in said direction and determine the incidence angle of said element when in its projected operative position; and actuating means for moving said support means with respect to said fixed structure and thus move said silencer element between its operative and inoperative positions.

Claim 3

Dependent Claim 30 words

A silencer device as claimed in claim 1 wherein said control means further include spring means for biasing said silencer element at least partially away from its projected operative position.

Claim 4

Dependent Claim 49 words

A silencer device as claimed in clAim 2 wherein said spring means biases said silencer element at least to a position at which said stop means and cooperating stop portion are out of engagement and said element is free to assume a position of neutral incidence in said jet.

Claim 5

Dependent Claim 77 words

A silencer device as claimed in claim 1 wherein said support means is hingedly connected to said fixed structure, and said actuating means includes a toggle lever comprising two lever arms which are articulated at one end to each other and at the other end respectively to said fixed structure and said support means, said toggle lever having its arms in aligned extended relation when said supporting means supports said silencer element in its projected operative position.

Claim 6

Dependent Claim 87 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet; actuating means for moving each of said silencer elements with respect to said fixed structure between an operative silencing position in which it projects into said jet and an inoperative retracted position; and spring means for biasing said silencer element at least partially away from its operative projected position in the event of failure of said actuating means.

Claim 7

Dependent Claim 87 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet; actuating means for moving each of said silencer elements with respect to said fixed structure between an operative silencing position in which it projects into said jet and an inoperative retracted position; and spring means for biasing said silencer element at least partially away from its operative projected position in the event of failure of said actuating means.

Claim 8

Dependent Claim 46 words

A silencer device as claimed in claim 5 in which each of said silencer elements is carried by a supporting means hingedly connected to said fixed structure through a pivot axis, and said spring means includes an element which experiences torsion stress around said pivot axis.

Claim 9

Dependent Claim 49 words

A silencer device as claimed in claim 5 wherein each silencer element in its projected operative position is disposed with negative incidence in said jet in the manner of a scoop with its free upstream edge extending nearer the center line of the jet than its free downstream edge.

Claim 10

Dependent Claim 31 words

A silencer device as claimed in claim 7 wherein said spring means biases said element at least to a position in which said element has substantially neutral incidence in said jet.

Claim 11

Dependent Claim 47 words

A silencer device as claimed in claim 5 wherein said actuating means comprises a fluid-operated jack, said jack being provided with restrictor means adapted to throttle the discharge of fluid from the jack when the silencer element is moved from its operative position into its operative position.

Claim 12

Dependent Claim 152 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet; control means for moving each of said silencer elements between an operative silencing position in which it projects into said jet and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means carrying said silencer element and being hingedly connected to said fixed structure through a pivot axis: actuating means for moving said supporting means with respect to said fixed structure to thereby move said silencer element between its operative and inoperative positions: and spring means for biasing said silencer element at least partially away from its operative projected position including a torsion spring coaxially mounted about said pivot axis with one end secured to said fixed structure and the other end secured to said supporting means.

Claim 13

Dependent Claim 152 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet; control means for moving each of said silencer elements between an operative silencing position in which it projects into said jet and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means carrying said silencer element and being hingedly connected to said fixed structure through a pivot axis: actuating means for moving said supporting means with respect to said fixed structure to thereby move said silencer element between its operative and inoperative positions: and spring means for biasing said silencer element at least partially away from its operative projected position including a torsion spring coaxially mounted about said pivot axis with one end secured to said fixed structure and the other end secured to said supporting means.

Claim 14

Dependent Claim 16 words

A silencer device as claimed in claim 10 wherein said torsion spring comprises a cable section.

Claim 15

Dependent Claim 41 words

A silencer device as claimed in claim 10, wherein said supporting means includes a hollow sleeve portion mounted coaxially about said pivot axis, and said torsion spring extends inside said sleeve and has one of its ends secured to said sleeve.

Claim 16

Dependent Claim 47 words

A silencer device as claimed in claim 12 wherein said fixed structure comprises a hollow auxiliary sleeve mounted coaxially about said pivot axis as an extension of said first sleeve, and said torsion spring likewise extends inside said auxiliary sleeve and has its other end secured thereto.

Claim 17

Dependent Claim 51 words

A silencer devicE as claimed in claim 13 wherein the internal surface of at least one of said sleeves is of circular cross-section over part at least of the length thereof and includes a portion of polygonal section for engagement with correspondingly shaped tip at one end of the torsion spring.

Claim 18

Dependent Claim 216 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet, said silencer elements having each a free upstream edge and a free downstream edge relative to the direction of the gas jet; control means for moving each of said silencer elements between an operative silencing position in which said silencer element projects with negative incidence into said jet in the manner of a scoop and in which said free upstream edge is disposed nearer the center line of the jet than is said downstream edge, and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means carrying said silencer element and hingedly connected to said fixed structure; and actuating means for moving said supporting means with respect to said fixed structure to thereby move said silencer element between its operative and inoperative positions, said actuating means including a toggle lever comprising two lever arms which are articulated at one end to each other and at the other end respectively to said fixed structure and to said supporting means, said toggle lever having its arms in aligned extended position when said supporting means supports said silencer element in its operative projected position.

Claim 19

Dependent Claim 216 words

A silencer device for damping the noise produced by a gas jet escaping from a duct, comprising: a fixed structure; a plurality of silencer elements distributed about said jet, said silencer elements having each a free upstream edge and a free downstream edge relative to the direction of the gas jet; control means for moving each of said silencer elements between an operative silencing position in which said silencer element projects with negative incidence into said jet in the manner of a scoop and in which said free upstream edge is disposed nearer the center line of the jet than is said downstream edge, and an inoperative retracted position, said control means including, for each of said silencer elements: supporting means carrying said silencer element and hingedly connected to said fixed structure; and actuating means for moving said supporting means with respect to said fixed structure to thereby move said silencer element between its operative and inoperative positions, said actuating means including a toggle lever comprising two lever arms which are articulated at one end to each other and at the other end respectively to said fixed structure and to said supporting means, said toggle lever having its arms in aligned extended position when said supporting means supports said silencer element in its operative projected position.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1975-08-29	1976-02-28	1976-08-29	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1979-08-29	1980-02-28	1980-08-29	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1983-08-29	1984-02-28	1984-08-29	$7700.00	Window Closed / Lapsed

Device for damping the noise produced by a gas jet escaping from a duct

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