Articulated coupling for piston sealing device

Patent metadata

Field	Value
Publication number	US-10487825-B2
Application number	US-201815902660-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 27, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

An articulated coupling is provided for a piston sealing device for a piston which includes a fixed skirt and a sliding skirt interconnected by a mechanical inter-skirt connection for axially compressing a continuous extensible segment under the action of a sliding skirt spring, the coupling replacing, on the one hand, the fixed skirt by a ball-joint skirt and providing, on the other hand, a troncospherical piston end which cooperates with a skirt troncospherical bearing surface provided on the ball joint skirt while an articulation unit interposed between the inter-skirt mechanical connection and the piston and/or between the connection and the sliding skirt.

First claim

The invention claimed is:

1. An articulated coupling ( 1 ) for a piston sealing device ( 2 ) for a piston ( 3 ) that operatively delimits a fluid chamber ( 5 ) inside a cylinder ( 4 ), comprising:
a piston head ( 6 ) with a piston bearing face ( 8 ) at a first side for exerting a force on transmission means ( 9 ), and a compression face ( 10 ) at a second side, opposite the first side, that opens into the fluid chamber ( 5 ) for receiving a pressure of a fluid ( 11 );
a fixed skirt ( 7 ) positioned at the compression face ( 10 );
a sliding skirt ( 12 ) configured to be fitted in the cylinder ( 4 ) at an extension of the piston head ( 6 ) at the second side of the piston head at the compression face ( 10 ) and surrounding a longitudinal axis of the piston head ( 6 ), said sliding skirt ( 12 ) being connected to the piston head ( 6 ) by an inter-skirt mechanical connection ( 13 ) configured to permit movement of the sliding skirt ( 12 ) in longitudinal translation with respect to the piston head ( 6 ), a pressure transmission channel ( 14 ) formed inside the sliding skirt ( 12 ) and traversing entirely through the sliding skirt ( 12 ) in an axial direction of the longitudinal axis;
a continuous extensible segment ( 15 ) interposed between the fixed skirt ( 7 ) and the sliding skirt ( 12 ), said continuous extensible segment ( 15 ) having a segment inner cylindrical face ( 16 ) arranged to be subjected to the pressure of the fluid ( 11 ) through the pressure transmission channel ( 14 ), a segment outer cylindrical face ( 17 ) arranged to come into contact with the cylinder ( 4 ), a fixed skirt-side segment axial face ( 18 ) arranged to be held in sealing contact with the fixed skirt ( 7 ), and a sliding skirt-side segment axial face ( 19 ) arranged to be held in sealing contact with the sliding skirt ( 12 ); and
a sliding skirt spring ( 20 ) arranged to urge the sliding skirt ( 12 ) closer to the fixed skirt ( 7 ) and to axially compress the continuous extensible segment ( 15 ),
wherein the fixed skirt ( 7 ) is formed as a ball-joint skirt ( 22 ), traversed axially by the inter-skirt mechanical connection ( 13 ) and interposed between the continuous extensible segment ( 15 ) and the piston head ( 6 ), said ball-joint skirt ( 22 ) including, at a piston head-side of the ball-joint skirt ( 22 ), a swiveling skirt ( 23 ) arranged to be in sealing contact with the piston head ( 6 ), and at a sliding skirt-side of the ball-joint skirt ( 22 ), a swiveling skirt ( 25 ) arranged to be in sealing contact with the continuous extensible segment ( 15 ), the sliding skirt spring ( 20 ) arranged to hold a stack formed of the ball-joint skirt ( 22 ) and the continuous extensible segment ( 15 ) clamped between the sliding skirt ( 12 ) and the piston head ( 6 ),
wherein the compression face ( 10 ) of the piston head ( 6 ) is provided with a troncospherical piston end ( 21 ), a center of the troncospherical piston end ( 21 ) constituting a portion positioned in vicinity of the longitudinal axis of the piston ( 3 ),
wherein the swiveling skirt ( 23 ) has a troncospherical skirt bearing surface ( 24 ) with a shape that is complementary to a shape of the troncospherical piston end ( 21 ), a contact between said troncospherical skirt bearing surface ( 24 ) and said troncospherical piston end ( 21 ) forming a ball joint around which the ball-joint skirt ( 22 ) is rotatable so as to self-orient with respect to the piston ( 3 ), and
wherein articulation means ( 40 ) is interposed between the inter-skirt mechanical connection ( 13 ) and the piston ( 3 ) and/or between said connection ( 13 ) and the sliding skirt ( 12 ).

2. The articulated coupling according to claim 1 , wherein the articulation means ( 40 ) comprises a piston-side swiveling connection head ( 27 ) which terminates an end of the inter-skirt mechanical connection ( 13 ) closest to the piston ( 3 ), said piston-side swiveling connection head ( 27 ) configured so that said inter-skirt mechanical connection ( 13 ) pivots with respect to the piston ( 3 ) and said piston-side swiveling connection head ( 27 ) retains a position with respect to the piston ( 3 ).

3. The articulated coupling according to claim 2 , wherein a center of rotation with respect to the piston ( 3 ) of the piston-side swiveling connection head ( 27 ) and a center of rotation with respect to the piston ( 3 ) of the ball-joint skirt ( 22 ) share a same location with respect to said piston ( 3 ).

4. The articulated coupling according to claim 2 , wherein the piston-side swiveling connection head ( 27 ) is articulated in a swiveling washer ( 41 ) of complementary shape to that of said piston-side swiveling connection head ( 27 ), said swiveling washer ( 41 ) being housed in the piston ( 3 ).

5. The articulated coupling according to claim 2 , wherein the piston-side swiveling connection head ( 27 ) comprises a fluid passage channel ( 29 ) that permits the fluid ( 11 ) to traverse said piston-side swiveling connection head ( 27 ).

6. The articulated coupling according to claim 1 , wherein the articulation means ( 40 ) comprises a sliding skirt-side sliding-swiveling connection head ( 28 ) which terminates an end of the inter-skirt mechanical connection ( 13 ) closest to the sliding skirt ( 12 ), said sliding skirt-side sliding-swiveling connection head ( 28 ) configured to permit said inter-skirt mechanical connection ( 13 ) to pivot with respect to said sliding skirt ( 12 ) and said sliding skirt-side sliding-swiveling connection head ( 28 ) retains a radial position with respect to said sliding skirt ( 12 ), but is movable with respect to the sliding skirt ( 12 ) in the axial direction.

7. The articulated coupling according to claim 6 , wherein the sliding skirt-side sliding-swiveling connection head ( 28 ) comprises a fluid passage channel ( 29 ) that permits the fluid ( 11 ) to traverse said sliding skirt-side sliding-swiveling connection head ( 28 ).

8. The articulated coupling according to claim 1 , wherein the piston head ( 6 ) is traversed from the first side to the second side by an inter-skirt connection tunnel ( 31 ), the inter-skirt mechanical connection ( 13 ) being housed therein with a clearance sufficient to allow the inter skirt mechanical connection ( 13 ) to self-orient with respect to the piston ( 3 ).

9. The articulated coupling according to claim 1 , wherein an outer cylindrical face of the ball-joint skirt ( 22 ) comprises a circular decompression groove ( 32 ).

10. The articulated coupling according to claim 1 , wherein the sliding skirt spring ( 20 ) is housed in a spring cup ( 39 ) which is integral with the sliding skirt ( 12 ), said spring ( 20 ) bearing upon said spring cup ( 39 ) and upon the inter-skirt mechanical connection ( 13 ).

11. The articulated coupling according to claim 1 , wherein the sliding skirt spring ( 20 ) is housed in an added-on spring cup ( 30 ) which bears upon the sliding skirt ( 12 ), said spring ( 20 ) bearing upon said added-on spring cup ( 30 ) and upon the inter-skirt mechanical connection ( 13 ).

12. The articulated coupling according to claim 11 , wherein the sliding skirt spring ( 20 ) bears upon the added-on spring cup ( 30 ) and/or on the inter-skirt mechanical connection ( 13 ) via a spring bearing washer ( 43 ).

13. The articulated coupling according to claim 12 , wherein the spring bearing washer ( 43 ) comprises an axial stop abutment ( 44 ) which determines a minimum length of the sliding skirt spring ( 20 ).

14. The articulated coupling according to claim 1 , wherein the piston ( 3 ) comprises, at a periphery thereof and in vicinity of the troncospherical piston end ( 21 ), a dislocat

Assignees

• Rabhi Vianney

Inventors

• Rabhi Vianney

Classifications

• F01B3/0085

  Pistons · CPC title

• F03C1/0605

  Adaptations of pistons (pump pistons F04B1/124, F04B53/14) · CPC title

• F04B1/124

  Pistons · CPC title

• F04B53/143 Primary

  Sealing provided on the piston · CPC title

• F03C1/0644

  Component parts · CPC title