No-Skive Hydraulic Hose Coupling with Improved Hose Retention and Sealing

• US 20120007356A1
• Filed: 06/28/2011
• Published: 01/12/2012
• Est. Priority Date: 07/06/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Menor, Eric D.
• Granted Patent: US 9,217,527 B2
• Time in Patent Office: Days
• US Class Current: 285/257
• CPC Class Codes: F16L 33/01 adapted for hoses having a multi-layer wall
• CPC Class Codes: F16L 33/2076 by plastic deformation
• CPC Class Codes: Y10T 29/49908 Joining by deforming

Abstract

A hydraulic hose coupling, and method of assembling a coupling to a hydraulic hose are disclosed. The hydraulic hose and coupling assembly is designed to attach a coupling to a hydraulic hose in a no-skive fashion. Moreover, it does so with greatly enhanced sealing and retention capabilities relative to the currently available products. This is accomplished in many ways, some of which include the provision of a plurality of hose retention and sealing zones within the coupling, each of which include various combinations of radially inwardly directed barbs and radially inwardly and outwardly directed surface features on the inner stem of the coupling. With specific regard to the zone primarily directed to sealing, it includes a radially inwardly directed barb which works in conjunction with a straight cylindrical surface flanked by first and second radially inwardly directed recesses. But providing such structure, the inner liner of the hydraulic hose is compressed to a degree greater than any other zone, but at the same time mechanical strain in the liner is relived through the use of such recesses. Moreover, by providing barbs which are longer and more narrow in the first and second zones, the first and second zones provide improved retention capability. This is in combination with the surface features of first and second zones working in concert with the longer, narrower barbs to cause enhanced wire deflection and thus greater retention strength.

Claims

1. A hydraulic hose and coupling assembly, comprising:

a hydraulic hose having a inner elastomeric liner, a reinforcing layer comprised of a plurality of metallic wires surrounding the inner elastomeric liner, and an outer elastomeric cover surrounding the metallic reinforcing layer; and

a coupling secured to the hydraulic hose, the coupling including an inner stem inserted into the hose and in engagement with the inner elastomeric liner and an outer ferrule surrounding the outer elastomeric cover, the outer ferrule including a plurality of radially inwardly extending barbs, the inner stem including a plurality of radially inwardly directed recesses and radially outwardly directed serrations, at least one of the barbs being aligned so as to be positioned toward the inner stem and being flanked by at least two of the recesses, and at least one of the bards being aligned so as to be positioned toward one of the serrations.

2. The hydraulic hose and coupling assembly of claim 1, wherein the plurality of barbs are provided in first, second, third and fourth circumferential rows radially inwardly extending from the ferrule, and wherein the row of barbs aligned so as to be flanked by at least two recesses is the third row of barbs, and the row of barbs that are aligned with one of the radially outwardly protruding serrations of the inner stem is the first row of barbs.

3. The hydraulic hose and coupling assembly of claim 2, wherein the third row of barbs includes tips having widths equal to about the width of two of the metallic wires, and heights equal to about the thickness of the hose cover plus one of the metallic wires.

4. The hydraulic hose and coupling assembly of claim 2, wherein each of the recesses flanking the third row of barbs has a depth equal to about half the thickness of the liner.

5. The hydraulic hose and coupling assembly of claim 2, wherein the distance between the third and fourth rows of barbs is about the width of eight of the metallic wires, the distance between the second and third rows of barbs is equal to about the width of ten of the metallic wires, and the distance between the first and second rows of barbs is equal to about the width of ten of the metallic wires.

6. The hydraulic hose and coupling assembly of claim 2, wherein the second row of barbs include tips having widths equal to about the width of one of the metallic wires, and heights equal to about the thickness of the hose cover plus one and a half of the metallic wires.

7. The hydraulic hose and coupling assembly of claim 2, wherein the second row of barbs is aligned with one of the radially inwardly extending recesses in the inner stem, and wherein the recess aligned with the second row of barbs has a depth equal to about twenty percent of the liner thickness and a width equal to about three times the second row barb thickness.

8. The hydraulic hose and coupling assembly of claim 2, wherein the first row of barbs includes tips having widths equal to about the width of one of the metallic wires, and heights equal to about the thickness of the hose cover plus two of the metallic wires.

9. The hydraulic hose and coupling assembly of claim 2, wherein the serration aligned with the first row of barbs has a width equal to about three of the metallic wires.

10. The hydraulic hose and coupling assembly of claim 2, wherein the fourth row of barbs includes tips having widths equal to about the width of three of the metallic wires, and heights equal to about the thickness of the hose cover plus one half of a metallic wire.

11. A hose coupling, comprising:

an inner stem;

an outer ferrule extending from the inner stem and substantially concentric with the inner stem;

a plurality of barbs radially inwardly extending from the outer ferrule toward the inner stem;

a plurality of radially inwardly extending recesses in the inner stem, at least two of the radially inwardly extending recesses flanking at least one of the radially inwardly extending barbs; and

a plurality of radially outwardly extending serrations in the inner stem, at least one of the radially outwardly extending serrations being aligned with at least one of the radially inwardly extending barbs.

12. The hose coupling of claim 11, wherein the plurality of radially inwardly extending barbs include a first, second, third and fourth row of barbs, wherein the first row of barbs are aligned with one of the radially outwardly extending serrations in the inner stem, and wherein the third row of barbs are aligned so as to be flanked by first and second radially outwardly extending recesses within the inner stem.

13. The hose coupling of claim 11, wherein the plurality of radially inwardly extending barbs include canted sides, each of the canted sides having an angle relative to a longitudinal axis of the barbs of no more than fifteen degrees.

14. A hydraulic hose and hose coupling assembly, comprising:

a hydraulic hose having a liner, reinforcement layer, and cover; and

a coupling secured to the hose, the coupling having an inner stem and an outer ferrule, the stem having a substantially cylindrical outer surface interrupted by a plurality of serrations and recesses, the outer ferrule having a plurality of barbs, at least one barb being aligned with one of the serrations, at least one of the barbs being aligned with at least one of the recesses, at least one of the barbs being aligned with the substantially cylindrical outer surface, and at least one of the barbs being aligned with the substantially cylindrical outer surface and being flanked by two of the recesses.

15. The hydraulic hose and hose coupling assembly of claim 15, wherein the consecutive rows of circumferentially arrayed barbs are provided in first, second, third and fourth rows, heights of the barbs decreasing from the first row to the fourth row, and wherein the barbs each have a tip width and wherein the barb tip width increases from the second row to the fourth row.

16. The hydraulic hose and hose coupling assembly of claim 16, further including a first zone between the first row and the second row, a second zone between the second row and the third row, a third zone between the third row and the fourth row, and a fourth zone after the fourth row, wherein the width of the zones decreases from the second zone to the third zone, wherein the amount of wire deflection decreases from the first zone to the fourth zone, and wherein the amount of liner compression increases from the first row to the third row and decreases from the third row to the fourth row.

17. A method of assembling a coupling to a hydraulic hose, comprising:

inserting a coupling into a hydraulic hose, the hydraulic hose having an elastomeric liner, a reinforcing layer surrounding the elastomeric liner, and an elastomeric cover surrounding the reinforcing layer, the coupling having an inner stem and a surrounding ferrule with a hose retention and sealing space therebetween; and

crimping the ferrule toward the stem, a plurality of barbs extending from the ferrule penetrating the cover and engaging the reinforcing layer, a plurality of recesses and serrations extending from the inner stem receiving and penetrating the liner, respectively, the plurality of barbs, recesses and serrations forming a plurality of hose retention and sealing zones; and

relieving strain in the liner within the hose retention and sealing zone having a highest level of liner compression by aligning the barbs of the zone having the highest level of liner compression with a cylindrical surface of the inner stem and flanking the cylindrical surface with first and second recesses.

18. The method of claim 17, further including providing the plurality of barbs in first, second, third and fourth rows of circumferentially arrayed barbs, the first row of barbs compressing the reinforcing layer against a first serration such that the reinforcing layer has a thickness less than the thickness of the reinforced layer prior to assembly, and further including providing the reinforcing layer with a plurality of metallic wires, and wherein the crimping causes the wires to deflect the most within a first of the hose retention and sealing zone between the first and second rows of barbs, second most within a second of the hose retention and sealing zone between the second row and the third row of barbs, third most within a third of the hose retention and sealing zone between the third row and the fourth row of barbs, and the least within a fourth of the hose retention and sealing zone after the fourth row of barbs.

19. The method of claim 18, further including positioning the barbs, recesses, and serrations such that the liner compresses the most in the third zone, second most in the fourth zone, third most in the second zone, and the least in the first zone.

20. A hydraulic hose and coupling assembly, comprising:

a hydraulic hose having a liner, a reinforcement layer surrounding the liner, and a cover surrounding the reinforcement layer; and

a coupling secured to the hydraulic hose and having a proximal end adjacent to an opening of the hydraulic hose and a distal end further removed from the hydraulic hose opening than the proximal end, the coupling including an inner stem and surrounding ferrule defining a hose retention and sealing space into which the hydraulic hose is retained and sealed, the inner stem and surrounding ferrule having surface features defining a plurality of hose retention and sealing zones, the plurality of hose retention and sealing zones each having a Menor Factor, the Menor Factor in each zone decreasing from the proximal end toward the distal end.