MXPA06005157A - Fitting for a flexible metal hose - Google Patents

Abstract

A flexible hose assembly (10) formed from corrugated metal tube (16) has a fitting (12) permanently crimped to the end (18) of the hose (14). The fitting (12) includes an elongated stem (30) having a first end (34) adapted to be coupled to an appropriate fitting surface and a second end (36) configured to be received within the hose (14). A sealing member (40) disposed on the second end (36) of the stem seals the fitting (12) between the corrugated metal tube (16) and the stem (30). A ferrule (50) is placed over the hose (14) and is crimped to compress the hose (14) and sealing member (40) between the ferrule (50) and stem (30).

Description

ADAPTER FOR A FLEXIBLE METAL HOSE FIELD OF THE INVENTION The present invention generally pertains to adapters for hose, pipe and other conductors, and more particularly to an adapter for a hose or flexible pipe formed from corrugated metal pipe.

BACKGROUND OF THE INVENTION The flexible hoses formed of corrugated metal pipe are used in many applications where the hose is exposed to various conditions or where the origin of the material transported through the hose requires the use of metal tubing. Advantageously, the corrugations give some degree of flexibility to the metal tube. Typical uses of these hoses include applications where the hose is exposed to extreme heat and cold temperature conditions, where high pressure gas or liquid is transported through the hose, or when the fluid permeability is interest, such as in gas tubing systems, refrigeration systems or the transport of chemical materials. These hoses also provide flexibility to fixed tube systems, for example, where adjacent fixed pipes must be joined together, and help reduce vibrations in dynamic environments, such as various environments of heavy machinery or automobiles, all while maintaining integrity in these rigorous applications. With flexible hoses formed of corrugated metal tubing, it is of utmost importance to ensure that the hoses are constructed in a fluid tight form, particularly in locations where the adapters are attached to the hose to attach the hose to a structure that transports fluid or to another hose. In the past, several adapters for the corrugated metal tube of flexible hoses were secured through welding, brazing, or other fusion type procedures, or by deforming the corrugated metal tube to create a flange that can be mechanically subject to an adapter, which can be a screwed compression assembly. For example, U.S. Patent No. 6,276,728 is directed to an adapter for use with corrugated tubing where the tubing is deformed when secured to the adapter. US Patent No. 5,638,869 is directed to a hose connection that is both limited and welded to secure a corrugated metal hose to the adapter. These previous adapters are generally cost and time consuming to install and are more prone to rod consistency than the varied levels of experts who install the adapters. These variations result in inconsistent quality of the resulting hose assemblies. Accordingly, there is a need for an adapter that can be used with flexible hoses formed of corrugated metal tubes that overcomes these and other disadvantages of the prior art.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides an adapter configured to be permanently limited to the end of a flexible hose formed of corrugated metal pipe. The corrugated metal tube has an inner surface that is delineated by the corrugations, and the adapter includes an elongated tubular rod with an end configured to be inserted into the hose. The other end of the rod is adapted to be coupled with a corresponding adapter surface. A sealing member is adjusted to be received within the hose between the corrugated tube and the rod, and has an external surface that is delineated to conform to the inner surface of the corrugated tube. The adapter further comprises a splint configured to be received on the end of the hose and to be limited to the hose thereby securing the adapter to the end of the hose. In one embodiment, the splint and the rod have corresponding coiled portions to securely screw the splint to the rod prior to limitation. Advantageously, the cast-in connection helps maintain the relative potions of the splint and rod during limitation of the adapter and couples the rod and splint together as an integrated single unit that resists separation in severe service applications. In another embodiment, one end of the splint has an outer diameter that is initially larger than the outer diameter of the other end of the adapter. The splint is configured to be uniformed to reduce the larger diameter end to be approximately in diameter to the initially smaller end. In another aspect of the invention, a flexible hose assembly includes a corrugated metal tube with a braided metal cover. An adapter, as described above limited to one end of the hose on the tube and cover. Even in another aspect of the invention, a method of securing an adapter to the end of a flexible hose formed of the corrugated metal tube includes inserting a marking member into the corrugated metal tube, placing a ferrule over the end of the hose by inserting the end of a rod through the ferrule and into the sealing member disposed in the hose, and limiting the ferrule to compress the corrugated metal tube and the sealing member between the ferrule and the rod. These and other features, objects and advantages of the invention will be more fully apparent to those skilled in the art in view of the following description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded perspective view of an illustrative embodiment of a flexible hose and adapter according to the present invention. Figure 2A is a cross-sectional view of the hose and adapter of Figure 1, prior to assembly and limitation. Figure 2B is a cross-sectional view of the hose and adapter of Figures 1 and 2A, after assembly.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates an illustrative flexible hose assembly 10 includes an illustrative adapter 12 in accordance with the present invention. The flexible hose assembly 10 includes a flexible hose 14 formed of corrugated metal pipe 16 having a first end 18 configured to receive the adapter 12. In the embodiment shown, the metal pipe 16 has annular corrugations, however it will be recognized that the corrugated ones alternatively can be formed in a spiral form, known in the art. The hose 14 further includes a cover 20 that surrounds an outer surface 22 of the tube 16 and extends the length of the hose 14. In the embodiment shown, the cover 22 is a braided metal cover, as shown in the art. Due to the corrugations formed in the metal tube 16, the external and internal surfaces 22, 24 of the tube 16 have undulatory, profiled surfaces. The adapter 12 is configured to be limited to the first end 18 of the hose 14 and includes an elongate tubular rod 30, a sealing member 40, and a ferrule 50. A first end 34 of the rod 30 is configured to be coupled with a surface of corresponding adapter, such as the mounting flange of a machine or a coupling for attaching the flexible hose 14 to another hose or conductor. In this regard, it will be recognized that the first end 34 of the rod 30 may be adapted to engage with any corresponding adapter surface configuration as may be desired. The second end 36 of the rod is adjusted and formed to be received within the interior of the corrugated metal tube 16. The adapter 13 further comprises a tubular sealing member 40 adapted to be received on the second end 36 of the rod 30 and having an outer surface 32 formed to correspond to the inner surface 24 of the corrugated metal tube 16. In the illustrative embodiment shown, the external surface 42 of the sealing member 40 has corrugations that engage the inner surface 24 of the tube corrugated 16. Advantageously, the outer surface 46 of the sealing member 40 seals against the outer surface 40 of the rod 30 and the outer surface 42 of the sealing member 40 seals against the inner surface 24 of the corrugated metal tube 16. The second end 36 of the rod 30 may further include one or more angular prongs 48 formed on the outer surface 46 to increase the carrying capacity of the adapted r assembled 12 at the end 18 of the flexible hose 14. The adapter 12 further includes a splint 50 having a first end 52 configured to receive the second end 36 of the rod 30 therethrough, and a second end 54 configured to receive the first end 18 of the flexible hose 14 so that the ferrule 50 can be limited to secure the adapter 12 to the flexible hose 14. As used herein "limiting" means the deformation of a workpiece, such as a splint , in a radially inward direction through the application of radial compressive forces. This is distinguished from "sink", which is the deformation of a work piece made by forcing the work piece through a constriction die. It has been determined that, due to the properties of softer materials typically used in sinking operations, limited splints exhibit better hose retention characteristics than the corresponding sunken adapters. further, limiting the splint to the hose requires fewer steps to achieve the same reduction, compared to sinking, and therefore is a more efficient procedure. In the embodiment shown, the rod 30 further includes external threads 60 formed on the outer surface 46 of the rod 30 between the first and second ends 34, 36. The first end 52 of the ferrule 50 is formed with internal threads 62 which engage with the external threads on the rod 30 to thereby allow the rod 30 to be threadedly coupled to the ferrule 50. Advantageously, the rod 30 can be recessed to the ferrule 50 to maintain the relative positions of the rod and the ferrule 50 while the adapter 12 is limited to the end 18 of the hose 14. The threaded coupling rod 30 and the ferrule 50 form an integrated unit that resists separation during use in severe service conditions. The rod 30 includes an annular rim 66 near the threads 60 and extending radially outwardly from the outer surface 46 of the rod 30. In this configuration, the rim 66 on the rod 30 serves as a positive high when the rod 30 is threaded coupled to splint 50. In order to provide a sufficient engagement surface in the splint 50, the first end 52 of the splint 50 is curved. The splint 50 further comprises enlarged circumferential ribs 70 formed on an inner surface 72 of the splint 50 to improve the support integrity of the splint 50 while not unduly linking the ability to limit the splint 50 to the flexible hose 14. As clearly shown in Figure 2A, one end 52 of the splint 50 has a first outer diameter D1 and the second end 54 of the splint 50 has a second external diameter D2 initially larger than the first diameter D1. The second larger diameter D2 facilitates the installation of the first end 18 of the flexible hose 14 within the second end 54 of the splint 50 where after that the splint 50 can be deformed by limiting the splint 50 so that the second diameter D2 is approximately equal to the first diameter D1, thereby compressing the first end 18 of the flexible hose 14 and the sealing member 40 between the ferrule 50 and the second end 36 of the rod 40, as illustrated in Figure 2B. While the splint 50 has been shown and described here as having a second outer diameter D2 which is initially larger than the first outer diameter D1, it will be recognized that the splint may alternatively be formed with a uniform outer diameter adjusted to be received on the hose 14, wherein after that the entire length of the splint is limited to secure the adapter 12 to the hose 14. In general, the splint 50 must be limited in an amount sufficient to compress the hose 14 so that the hose 14 is retained through the adapter 12 while preventing puncture of hose 14, particularly corrugated metal tube 16. In an illustrative embodiment, splint 50 is limited to an amount that is sufficient to compress seal member 40 to approximately 15% to 25% of its wall thickness. In order to obtain a sufficient limitation, the splint 50 must be made of a metal material that is not too soft. In an illustrative embodiment, the material of the splint 50 has a hardness of at least 150, as measured by a Brinell hardness test. While the geometry of the rod 30 can be varied to accommodate hoses of different size 14, the wall thickness of the second end 36 of the rod 30 must be sufficient to withstand the imitation pressure. In the illustrative embodiment, the wall thickness of the second end 36 of the rod 30 is less than about 0.31 cm. Similarly, the wall thickness of the splint 50 should not be excesly long to thereby avoid exces limiting forces necessary to limit the splint 50. In an illustrative embodiment, the wall thickness of the splint 50 is not greater than about 0.15 to 0.25 cm. Advantageously, the adapter 12 of the present invention can be limited to the end 18 of a flexible hose 14 formed of corrugated metal pipe 16 to provide a fluid fit connection between the adapter 12 and the flexible hose 14. In addition, the adapter 12 can be limited directly to the first end 18 of the hose 14 without requiring modification of the hose 14, such as tearing the cover materials including the interlaced metal cover 20. Illustrative flexible hose assemblies, which have limited adapters according to the present invention, they were manufactured and tested. Each flexible hose has a 5.0 cm braided cable, wide corrugated, annular metal hose manufactured by Witzemann U. S. A. LLC, Warren Ml. The hose was calculated by 26-01 kg / cm2 at 21.11C. Both the splint and the rod portions of each adapter were formed of ASTM 316 stainless steel. In one test, the adapters were limited to both ends of a hose, one end limited with a silicone sealing member, the other end having a sealing member of Buna League. The hose assembly was subjected to a helium leak test using an MD-490-S helium leak detector. The hose assembly was loaded using 100% helium at 7.03 kg / cm2 for 28 minutes. None of the leaks were detected. The hose assembly was subsequently hydrostatically tested to assess the integrity of the limited adapters. At 126.54 kg / cm2, the hose failed at an intermediate location on the adapters (that is, the hose failed before the adapters). A second illustrative hose assembly was subjected to a vacuum leak test. The limited hose assembly was charged to 25 mtorr with helium and then vacuum-ejected to 1x10"8 atm / cc / sec while the hose was monitored with a gas leak detector susceptible to be detected NIST. In another aspect of the invention, a method for securing an adapter 12 to a flexible hose 14 having a corrugated mental tube 16 comprises inserting a tubular sealing member 40 into the corrugated metal tube 18, placed in a ferrule. 50 on the end 18 of the corrugated metal tube 16, inserting end 36 of a rod 30 inside the sealing member 40 into the corrugated metal tube 16, and limiting the ferrule 50 to compress the corrugated metal tube 16 and the member sealing 40 between the ferrule 50 and the rod 30. In another embodiment, a method of securing an adapter 12 to a flexible hose 14 further comprises threadedly coupling the ferrule 50 and the rod 30. The ferrule 50 and l The rod 30 can be threadedly engaged before inserting the end 36 of the rod 30 into the sealing member 40 located within the corrugated metal tube 16, while simultaneously placing the ferrule 50 on the end 18 of the corrugated metal tube 16, or the ferrule 50 and the rod may be threadedly engaged after the end 36 of the rod 30 was inserted into the sealing member 40. Even in another aspect of the invention, a hose assembly according to the present invention is formed by the methods described above. While the present invention has been illustrated through the description of the illustrative embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The advantages and additional modifications will be readily appreciated by one skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatuses and methods and illustrative examples shown and described. Accordingly, deviations from such details can be made without departing from the spirit or scope of the general inventive concept.

Claims (20)

NOVELTY OF THE INVENTION CLAIMS

1. - An adapter for one end of a flexible hose, the hose including a corrugated metal tube having an inner surface, the adapter comprising: an elongated tubular rod having a first end adapted to interconnect to a corresponding adapter surface, and a second end configured to be received in the flexible hose; a splint having a first end configured to receive said second end of said rod, and a second end configured to receive the end of the flexible hose, said splint configured to be limited to the end of the flexible hose to thereby secure the adapter to the hose; and a sealing member adjusted to be received on said second end of said rod and having a profiled outer surface corresponding to the inner surface of the corrugated metal tube.

2. The adapter according to claim 1, further characterized in that it additionally comprises external threads formed in said rod between said first and second ends, and corresponding internal threads formed in said first end of said ferrule, to threadably couple said rod and said splint

3. The adapter according to any of claims 1 or 2, further characterized in that said ferrule is formed with a substantially uniform external diameter adjusted to initially receive the end of the flexible hose.

4. The adapter according to any of claims 1-2, further characterized in that said first end of said splint has a first external diameter, and said second end of said splint has a second outer diameter adjusted to be initially larger than said first external diameter, said splint configured so that said second end can subsequently be deformed to be approximately equal to said first external diameter during the attachment of the adapter to the hose.

5. The adapter according to any of claims 1-4, further characterized in that said ferrule is configured to be limited to an amount that compresses said sealing member to approximately 15% to approximately 25% of its wall thickness.

6. The adapter according to any of claims 1-5, further characterized by additionally comprising circumferential prongs formed on an external surface of said rod, near said second end.

7. The adapter according to any of claims 1-6, further characterized in that it further comprises increased circumferential ribs formed on an internal surface of said ferrule.

8. The adapter according to any of claims 1-7, further characterized in that said ferrule comprises metal material having a Brinell hardness of at least 150.

9. The adapter according to any of claims 1- 8, further characterized in that said splint has a wall thickness no greater than about 0.25 cm.

10. A flexible hose assembly, comprising: corrugated metal tube that includes a first end and an inner surface; and an adapter permanently limited to said first end of said tube, said adapter comprising: a ferrule having first and second ends, said second end of said ferrule that limits said first end of said corrugated metal tube, an elongated tubular rod that comprises a first end adapted to interconnect to a corresponding adapter surface, and a second end extending through said first end of said ferrule and said corrugated metal tube, and a tubular sealing member at said second end of said rod, between said rod and said corrugated metal tube, said sealing member having an undulating outer surface corresponding to said inner surface of said corrugated metal tube.

11. The hose assembly according to claim 10, characterized in that it further comprises an interlaced cover covering said corrugated metal tube and extending below said ferrule so that said cover is limited between said ferrule and said rod.

12. The hose assembly according to any of claims 10 or 11, further characterized in that it additionally comprises external threads formed in said rod, between said first and second ends, and corresponding to internal threads formed in said first end of said splint, for threadedly coupling said rod and said splint.

13. The hose assembly according to any of claims 10-12, further characterized in that said splint is formed with a substantially uniform external diameter adjusted to initially receive said first end of said corrugated metal tube.

14. The hose assembly according to any of claims 10-12, further characterized in that said first end of said splint has a first external diameter, and said second end of said splint has a second external diameter adjusted to be initially greater than said first outer diameter, said ferrule configured so that said second end may subsequently be deformed to be approximately equal to said first external diameter during the limitation of said adapter to said corrugated metal.

15. The hose assembly according to any of claims 10-14, further characterized in that said splint is limited to compress said sealing member up to about 15% to about 25% of its wall thickness.

16. A method of securing an adapter to a flexible hose having a corrugated metal tube, the adapter including a splint, a rod and a sealing member, the method comprising: inserting the sealing member into the tube corrugated metal; placing the splint on the end of corrugated metal tube, inserting one end of the splint into the sealing member disposed within the corrugated metal tube; and limiting the splint to compress the corrugated metal tube and the sealing member between the splint and the rod.

17. The method according to claim 16, further characterized in that it further comprises threadedly coupling the ferrule to the rod.

18. The method according to any of claims 16 or 17, further characterized in that the limitation of the ferrule comprises the sealing member up to about 15% up to about 25% of its wall thickness.

19. A hose assembly formed by a method as described in claims 16-18.

20. A hose assembly that includes a hose formed of a corrugated metal tube, an elongated tubular rod, a ferrule having first and second ends, the second end of the ferrule that limits the end of the corrugated metal tube, rod having a first end adapted to operatively interconnect a corresponding adapter surface and a second end extending through the first end of the ferrule and into the corrugated metal tube, said hose assembly being characterized by: a sealing member which resides radially outwardly of the rod and radially within the corrugated metal tube; the ferrule being limited to compress the sealing member between the rod and the corrugated metal tube to connect the rod and the corrugated metal tube in a fluid adjustment condition.