HK1197559B - End connector for high pressure high temperature reinforced rubber hose - Google Patents

Abstract

An improved swage fitted end connector for high pressure large diameter reinforced flexible rubber hose utilizing sine-wave locking of the reinforcement and carefully machined internal grippers to cause a portion of the reinforcement wire to connect directly to the connector and particularly suited to the petrochemical and drilling industries is disclosed. A connector for use with high temperature-high pressure large diameter wire reinforced rubber hose is discussed along with other embodiments. All connectors will withstand the rated burst pressure and temperature of the hose without pumping off or leaking; thus, any hose that utilizes the improved device will fail before the connector pops off of the hose. Two alternate embodiments are discussed.

Description

End connector for high-pressure high-temperature reinforced rubber hose

Technical Field

The present invention relates generally to the reinforced rubber hose industry and, in particular, to swaged hose couplings for terminating large diameter, high pressure, flexible reinforced rubber hoses used in energy, marine, petrochemical and similar industries and which are specifically designed for use at high temperatures where the rubber softens when exposed to heat and begins to creep.

Background

High pressure rubber hoses are used in many instances in industry, but are used in particular in the mining, construction, energy, marine and petrochemical industries. Flexible rubber hoses are used to convey fluids at different pressures and temperatures between two points; one or both of the two points may be movable relative to each other or relative to another fixed point in space. The current use of these rubber hoses is beginning to use increasingly higher liquid transfer temperatures that severely affect the reinforced rubber hose. Basically, the rubber starts to soften and creep at high temperatures, making the entire hose system problematic.

The tubing at both points is usually metal (or some other form of fixed pipe) and flexible hoses must be attached to the tubing at both ends. This requires a coupling at each end of the hose.

In the drilling industry, a flexible rubber hose runs between a pump line system on the rig and a kelly coupled to the rotating drill string. The pump system forces drilling fluid from the center of the drill pipe down and back through the wellbore in order to flush cuttings away from the wellbore (with attendant wellbore stability, etc.). In this case, the flexible hose is subjected to high pressure. High pressure is required not only for delivering drilling fluid into the wellbore, but also for overcoming the static return head pressure — the deeper the wellbore, the higher the pressure.

The rotary drilling hose is subject to further stress because it is suspended within a derrick boom supported at either end by metal couplings on the hose, and the kelly moves up and down thousands of times more or less during the drilling operation. This means that the hose is stressed at the metal coupling (in addition to being stressed throughout its length). Therefore, to protect personnel and equipment and to maintain pressure, a highly reliable bond between the hose and the coupling is required. If the hose breaks loose from the coupling, it may easily fall off and cause severe damage to the rig floor of the rig. In a similar manner, if the hose breaks, circulation may be lost, causing a blowout.

In order to obtain high pressure flexible rubber hoses (the term rubber is used in a broad sense and does not refer specifically to naturally occurring rubber), hose manufacturers add reinforcement materials. The hose will thus consist of an inner sealing membrane (fluid-tight element) or an inner tube, a reinforcing element, an outer rubber element and finally some kind of wear-resistant covering. The inner tube may be rubber, nylon, plastic, corrugated metal or similar types of materials. The reinforcing element may be polyester or similar organic material, carbon fibre or similar high tech material, or metal (steel) typically in the form of wires or cables. The reinforcement is usually used in multiple layers called "stacks" and is usually made of high tensile steel.

Hose manufacturers employ different types of reinforcement, which are set to an even number of layers (i.e., 2 layers, 4 layers, 6 layers, etc.), and use a grading system to specify the burst pressure of the hose. For example, in the rotary drilling industry, class C hoses have a minimum burst pressure of 10,000psi, class D hoses have a minimum burst pressure of 12,500psi, and class E hoses have a minimum (guaranteed) burst pressure of 18,750 psi. The C-stage and D-stage hoses are 2-ply hoses, but there are some 4-ply D-hoses. Most class E hoses are 4-ply. Swaged end connections for two-ply hoses are currently available, so the prior art covers the burst pressure range for C and D hoses, except that at high temperatures, the effect of rubber creep causes the connection to fail. (object of the invention.)

Typically, a hose manufacturer manufactures flexible hoses according to a specific order from a purchaser specifying the length, diameter, pressure, grade of use, and end connection required. These flexible hoses are commonly referred to as "hose assemblies with end connections" or "hose-up hose (hose) assemblies". This term is used in industry.

In a fitted hose assembly with an end connection, the manufacturer terminates the rubber hose during the manufacturing process in a metal fitting (end connection) specified by the purchaser. Thus, the manufacturer would manufacture an inner rubber membrane (first skin layer (cardas)) and its bonded inner sealant layer (innerduct) and terminate this assembly within the end connector. The manufacturer would then add wire reinforcement as needed with each reinforcing wire (or cable) terminating in an end connector. Hose manufacturers typically employ two techniques for terminating the reinforcing wires in or on the end connectors themselves, but these techniques are beyond the scope of this discussion. Finally, an outer rubber layer (second skin layer) and an outer covering (covering) are formed around the reinforcing wires or cables, and the whole product is hardened to obtain a bonded product. It should be noted that high temperature rubber creep will occur in the assembled hose, leading to failure at high temperatures.

It is time consuming to manufacture hose assemblies with fitted end connections, and often such hoses are almost immediately required by the industry. To meet this demand, a separate industry, known as local market distributors, has evolved. The local market distributor holds bulk reinforced hoses-hoses without connectors-in stock. The purchaser will specify hose requirements to the local market distributor-diameter, length, pressure rating, and end connection. The local market distributor then removes the bulk reinforced rubber hose from inventory, cuts the hose to the required length, and places a coupler at each end of the hose. Bulk hoses of varying lengths are available from hose manufacturers, and the actual bulk length (between 90 feet 27m and 110 feet 34 m) will depend on the mandrel used by the manufacturer.

Depending on the method used to "place" the end connector onto the hose, the resulting hose is referred to as a swaged or crimped hose, wherein the use of the term "place" includes both swaging and/or crimping operations. It should be noted that swaging and crimping achieve similar end results.

The prior art of swaging (or crimping) connectors has been developed to use outer ferrules with nodes (internal ridges) that are compressed around the end of a reinforced hose around a stem that is inserted into the end of the hose. The wand may or may not have barbs which are intended to improve the "grip" between the hose and the end connection. Typically, the outer layer of hose rubber is "skived", meaning that the outer layer of rubber is removed, revealing the reinforcement (but some local distributors do not shave).

The reinforced hose is actually held within the end connector by the ridges of the ferrule which grip the reinforcement via compression of the hose against the wand. The compression operation (swaging or crimping) of the ferrule against the reinforcement and against the inner rod creates severe stress and strain within the inner tube.

The development of high pressure swaged end connections for rubber hoses has been in progress for many years, and this technique has developed protective gloves from low temperature and/or low pressure to high temperature and/or high pressure applications: but the high temperatures are becoming higher, especially in the drilling industry, as wells become deeper. The hose diameter varies and the manufacturer/supplier of the connection realizes that the pull-off force (pump-off force) on the fitting is proportional to the inner diameter of the hose and the pressure applied.

As explained in U.S. patent 7,388,090 to Baldwin et al, which is incorporated by reference in its entirety in this disclosure, most of the standard prior art uses a serrated wand with rearwardly facing teeth that grips the inner liner of the hose to retain the wand within the hose. In addition, this technique also uses a series of ridges in the ferrule that bite into the outer layer of the hose and reinforcement and may cause the teeth (or barbs) of the stem to bite further into the liner.

Baldwin et al explain that standard techniques can lead to catastrophic failure of the reinforcing cable (or wire) because the sharp edges of the connector damage the reinforcement. To overcome this fundamental failure, Baldwin et al proposed an invention consisting of a "corrugated" ferrule and a stem that joined an end connector to the flexible reinforced rubber hose, forming a "double sine wave lock" between the ferrule and the stem, but formed primarily within the ferrule (see u.s.7,388,090). The ferrule and stem are welded together at the coupling end, leaving an opening that receives a reinforced rubber (elastomer) hose in much the same way as a normal "crowned" ferrule and "barbed" stem fitting. The "bump" of the ferrule and the high point of the stem have a sinusoidal shape-a wave-rather than having straight sides. The wave pattern has the appearance of a ripple on the pond created by throwing a stone into the water.

The 'double sine wave locking' invention locks all of the plies of the hose reinforcement within the end connection and between the stem, the inner skin, the reinforcement and the ferrule, being compressed against the ferrule and the stem in a sine wave fashion to give the fitting an overall strength exceeding that of a free standing hose (without end connection) whether or not the hose is under pressure. Class E hoses have a minimum burst pressure of 18,750 psi; the present device will therefore have an overall strength greater than 18,750psi when used in conjunction with a class E hose. (at these pressures, depending on the cross-sectional area, the extraction forces involved reach or exceed 240,000 lbf.) the present invention contemplates the materials forming the ferrule and stem and the relative movement of these materials when attaching the end fitting to the hose, along with the unpredictable nature of the rubber and flexible hose structure, to minimize induced stresses in the hose reinforcement and inner tube. All of these factors, including the sinusoidal shape of the ferrule and stem and the preferred two-step attachment method (internal expansion of the stem followed by external swaging of the ferrule) work together to form the original Baldwin et al invention.

In summary, the original 'double sine wave locking' invention of Baldwin et al utilized a sine wave-like lock in a ferrule and a stem to lock the reinforcement stack and hose into the end fitting by compressing the hose (including the inner skin layer) and reinforcement between the corrugated ferrule and corrugated stem. By deliberately reducing the relative axial displacement between the ferrule and the stem, which often occurs during the attachment operation, the stress and strain on the reinforcement and the tendency of the reinforcement to tear away (or pull away) from the rubber hose are minimized. The relative axial displacement is minimized to produce a sinusoidal-like wave by using high tensile strength steel, minimal non-attachment gaps between the hose and the end connection, and careful design of the nodes, ridge grooves and grooves, while minimizing the radial thickness of the stem and ferrule at critical cross sections and taking into account the resulting strength of the attachment fitting.

Baldwin 'double sine wave locking' has been demonstrated to work with any cable or wire high pressure reinforced hose and in fact the 'fitted' hose has been replaced with an end connector, as a hose utilizing a Baldwin double sine wave end connector will not fail between the hose and the end connector. Any failure of the hose under pressure will be in the hose itself. The end connection will not come loose from the hose: this statement cannot be made for all fitting hoses. Thus, the 'double sine wave locking' Baldwin end connection improves safety in the workplace. Hose loosening and falling will no longer occur in the entire area where equipment is damaged and personnel are injured. However, as with the original Baldwin connection, it experiences high temperature rubber creep and thus its use is limited by the fluid temperature.

In a related improvement to Baldwin sine wave locking, the inventors contemplate whether such a two-step process is required, and whether (relatively) large ridges and grooves are required on the stem. It is known that the actual locking takes place between the ferrule and the reinforcement, while there is some minimal locking (transmission of the extraction force) between the rod and the inner tube onto the reinforcement. If the rod can be designed with small protrusions and if the connection step can be eliminated, an improved device will result. More importantly, the removal of the expansion step will reduce the amount of material movement within the hose during the expansion/swaging process. An improved seal and lock can be created with reduced material movement within the hose itself, resulting in reduced induced stresses. This device will work well with new european light weight high pressure reinforced rubber hoses. This hose uses wire reinforcement and a much thinner inner tube. The inner pipe is a non-leaking flexible conduit through which high pressure fluid passes. The expansion force is transmitted to the reinforcement which prevents the inner tube from bursting. To reduce the overall hose weight, manufacturers now use a thin tube and a thin outer cover and a plurality of spiral wire reinforcements. As these materials become thinner, the movement requirements between the components of the hose (i.e., the inner tube, the reinforcement, and the outer skin layer) become more important.

In a recent series of patent applications (see the above paragraph), Baldwin et al have found that ridges/grooves or nodes/grooves on a shaft can be reduced in size and severity. In fact, the severity of the grooves and recesses in the stem has been reduced to a series of matching small projections which cause a sine wave interlock to occur as the connector is swaged onto the hose. This technique has been commercially successful and works well for thin-walled small diameter hoses at low to moderate temperatures. In fact, the key commercial success is the removal of the internal expansion step, which creates less stress on the inner tube and the reinforcement. This improvement has been described in U.S. provisional application 61/208,531 to Baldwin et al (filed on 2/25/2009), PCT application PCT/US2010/000520 (wipopo/2010/098833-9/2/2010), U.S. national application 13/138,182, and other national applications worldwide. It should be noted that the present disclosure claims priority to U.S. provisional 61/514,596 (filed on 3/8/2011), which is itself a continuation-in-part of U.S. provisional 61/208,531.

However, the problem of rubber creep at high temperatures continues to be problematic, especially in applications that are required to meet some new API standards for drilling hoses. The inventors have found that it is not surprising that a single skiving hose (where the outer cover is simply removed to reveal the reinforcement) will not remain in place as the temperature increases and the rubber within the hose begins to creep. In addition, they found that a simple internal clamp that does not employ techniques to reduce induced stresses on the reinforcement would not solve this problem. Thus, there remains a need for an end connector that will securely grip a reinforcement of a reinforced rubber hose, thereby transferring all of the extraction force to the metal (both the end connector and the reinforcement) while at the same time retaining any 'creeping' rubber or elastomer within the connector/hose assembly, thereby ensuring a leak-proof, highly reliable and safe assembly.

Summary of The Invention

The present invention consists of a series of improvements to the sine wave locking disclosed in U.S.7,338,090 to Baldwin et al, wherein the series of improvements are: adding a series of hose reinforcement holders (beginning at the welded or beveled end of the connection) in the first section of the end connection, the holders making a metal-to-metal contact with the reinforcement; adding an inner tube dam; adding sine wave locking of standard Baldwin et al at the middle end; and a slightly modified (by U.S.7,338,090) end section of the connector towards the hose end of the connector. The reinforcement holder actually holds the hose reinforcement on both sides of the metal reinforcement: this requires "double scraping" or "internal scraping" and external scraping "of the reinforced rubber hose. In addition, these reinforcement holders are inclined such that the pressure exerted directly on the reinforcement decreases (or tapers) from the open end of the connector to the hose end of the in-hose connector held by the connector.

The remainder of the "standard" Baldwin et al sine wave locking concept not only continues to retain the hose within the connector, but also serves to reduce creep of the inner tube and tearing of the inner tube away thereby preventing internal fluid leakage. In addition, the improved bond in the wedge-shaped section of the connector (where the end connector meets the exterior of the rubber hose) continues to reduce creep. An inner tube dam (a key feature) prevents the inner tube from creeping into the reinforcement holder. Because neither the inner tube nor the outer skin layer is allowed to creep, the inner tube dam and the modified wedge section act to prevent internal fluid leakage. Both cold and hot creep are found in the hose: cold creep occurs during or after the swaging operation, while hot creep occurs when the hose is subjected to high temperatures. The stem and ferrule are joined together by a suitable method, such as welding.

The end connection is joined to the reinforced hose in a standard manner involving skiving the outer sheath plus skiving the inner tube. The two scrapers are not of the same length; however, the outer scraping is the same as that required for the standard Baldwin et al device. The internal scraping is only as long as the 'internal gripper'. The hose is carefully placed within the end connector cavity formed between the ferrule and the stem until the shaved hose (inner or outer) rests within the 'inner gripper' section and the end of the inner tube just beyond the point of the last groove and is placed within the last ridge at the terminating end of the connector abutting the dam. The fitting is then preferably double swaged onto the hose by first expanding the stem and then compressing (or swaging) the ferrule. The additional steps of first expanding internally and then swaging reduce the stress on the reinforcement and inner tube and further reduce cold rubber creep. (the reader must remember that the reinforcement used in the rubber hose is a high tensile strength material and therefore it does not react "pleasantly" to deflate (pinching) — deflating can cause strain in the reinforcement material which will cause failure under pressure.) the "inclined" interacting clamps exert a varying force on the reinforcement, with the greatest force applied at the open end of the hose varying to the least force away from the open end.

When the double swaging process occurs, the grooves on the stem create a biasing force that causes the stiffener to expand into the nodes of the ferrule, creating a sinusoidal wave lock between the stiffener and the ridges and nodes of the ferrule, and a clamp lock with the stiffener. In an alternative embodiment, the double forging step ensures that the inner clamp will first pull gently into the reinforcement during expansion of the rod. Then, when the final forging occurs, the gripper will pull into the reinforcement without damaging the reinforcement, thereby exerting a minimum lock at the open end away from the hose and a maximum lock at the open end of the hose due to the angled nature of the gripper in the ferrule. Another internal clamp alternative embodiment may utilize a proven sine wave locking concept employed in a single scraping section of a connector, and the clamp may be modified accordingly. Similarly, in a section of the hose where only a single shave occurs, the sinusoidal locking is consistent throughout the hose. (Note that the sine wave lock appears very much like a modified (sine x)/x function: i.e., it is not a perfect sine wave.)

During manufacture or at any time, the stem may be coated with a friction reducing material that allows the inner tube of the reinforced hose to slide more freely along the stem during swaging (or crimping) of the connector onto the hose.

Broadly, the present invention utilizes a metal-to-metal lock between the ferrule, the reinforcement of the hose, and the stem that couples the withdrawal force to the connector. Furthermore, the inner tube dam prevents the inner tube elastomer from creeping towards the outboard end (open end) of the connector and thus into the stiffener grip section. Finally, the sinusoidal locking between the ferrule, reinforcement, inner tube and rod, in combination with the improved transition to the hose at the hose end (inboard end) of the connector, further serves to reduce creep of the inner and outer skin layers of the hose.

Brief description of the drawings

Figure 1 shows a cross-section of a typical two-ply cable reinforced flexible rubber hose.

Figure 2 shows a cross-sectional view of a prior art end standard connection with one NTP termination. (this is an old-fashioned connection used for decades.)

Figure 3 shows a cross-sectional view of a ferrule used in an advanced prior art 'double locking sine wave' end connection. ('double locking sine wave' end connectors have been used in the past five years.)

Figure 4 shows a cross-sectional view of a rod used in an advanced prior art 'double locking sine wave' end connector.

Fig. 5 shows a cross-sectional view of a ferrule used in the present invention, which is a general improvement over 'double-locking sine wave' connectors and forms a single-locking sine wave through the reinforcement in the overall device. (Note the similarities between FIGS. 3 and 5 with respect to the 'gripper section')

Figure 6 shows a cross-sectional view of a rod used in the present invention, which is a general modification to the 'double locking sine wave' connector. (Note the similarities between FIGS. 4 and 6 with respect to the 'gripper section', but note that the barbs on the stem in FIG. 4 are not present on the stem of FIG. 6.)

FIG. 7A is a conceptual view of the present device with internal expansion showing the various "interaction zones" between the collar and the shaft.

FIG. 7B is similar to FIG. 7A and is an alternative embodiment without internal expansion.

Figure 8 shows the present device before any expansion or swaging of the double shave hose partially inserted into the connector has occurred.

Figure 9 shows the present device before any expansion or swaging of the double shave hose fully inserted into the connector has occurred. Note how the inner tube rests in the rod against the inner tube dam.

Figure 10 shows the present device fully expanded and swaged. Note the 'sine wave' lock obtained between the ferrule, reinforcement wire and rod in the gripper section and the sine wave lock obtained between the ferrule, reinforcement and inner tube and rod in the remaining section of the end connection. Note how the nodes in the ferrule align with the grooves on the stem as the stem expands and as the ferrule contracts under the two-step swaging operation.

Description of the preferred embodiments

Figure 1 shows a standard weight D-cable two-ply reinforced hose. An E-hose will typically have 4 interlocking reinforcement plies. The cross section of the european light weight wire reinforced hose is not shown; however, it is similar to figure 1 except that there are 6 interlocking wire laminations and the inner tube will comprise a thin layer of rubber.

A prototype of the invention is shown in fig. 7, and a ferrule of a preferred prototype of the invention is shown in cross-section in fig. 5 and is made up ofAnd machining the molded 80-tube. It must be understood that the dimensions given are for a particular size of connector and that these dimensions will vary depending on the size of the connector. One end (the end to be welded to the stem) is placed in a swaging die and compressed to form a narrower neck, as shown at the far left of fig. 5. The interior of the ferrule is machined to create a series of nodes 10 and ridges 11 (5 in total shown). The nodes all have the same radial height measured from the axial centerline of the ferruleFour ridges of the frontOr the high point (as measured from the hose end of the ferrule) has a radial heightAnd the last ridge has a heightThe ridges are not equally spaced axially along the ferrule. This is because it is known that because the ferrule is swaged (starting at the hose end or inboard end), the ferrule will move axially toward the hose end of the fitting until the reinforcement is locked between the ferrule and the stem. Actual locking does not begin until the forging die is about midway along the ferrule. Before this, the inner tube and hose were free to move axially in either direction within the fitting. When locking occurs, all movement of the inner tube and hose will be towards the terminal (outside) end of the fitting.

Simple mechanical calculations based on material properties and degree of swaging to be applied allow the designer to calculate the ridge spacing such that after the fitting is swaged onto the hose, the groove 15 of the stem will fall approximately midway inside the node 10 of the ferrule and vice versa, the ridge 11 of the ferrule falls approximately midway inside the groove 14 of the stem. (see fig. 10.) the way that the final position of the groove/ridge is approximately halfway within the node/groove is the key to this device and how it achieves a sine wave lock between the stiffener and the ferrule. This concept was found in the original Baldwin patent and was used in conjunction with a clamp to achieve a fluid tight, temperature independent, high pressure swaged end connection.

The dimensions of the node and ridge heights should not be construed as limiting, but rather as an example. Similarly, the illustrated ridge spacing should not be construed as limiting, but rather as an example. In some cases (larger diameter hoses), it may be necessary to adjust the dimensions (and number) so that they vary with distance from the weld end of the connection forming an overall slope. In addition, the materials of construction should not be taken as limiting, but rather as an example.

At the end of the connector closest to the hose, the internal diameter of the ferrule is increased so that a minimum pressure will be exerted on the outer rubber and outer cover (skin layer) when the ferrule is swaged. This particular improvement inhibits creep of the hose end (inboard) which is shown as rounded.

Turning now to the left end of the ferrule (closest to the connection-away from the hose), there is a series of six ferrule holders (with teeth 12 and recesses 13). The six teeth in the prototype are actually in height fromChange toWith ferrule recess fromChange to(one embodiment considers the sine wave locking concept used in the middle section of the present device.) the teeth will now be able to exert varying forces on the reinforcement, thereby eliminating the potential 'pinch' of the reinforcement which would result in failure of the hose under pressure. The teeth are all of substantially the same width, and the recesses between the first five teeth (counted from the left) are of substantially the same width; however, the recess between the fifth and sixth teeth is slightly wider. (in embodiments employing sinusoidal locking, the recess width will vary.)

The rod of the corresponding prototype of the preferred invention is shown in cross-section in fig. 6 and consists of4130L80 bar was machined. Five grooves 15 (high points) are setAnd with ferrulesThe ridges as above do not have to be machined equidistantly in the rod. This serves to allow the groove to expand (or move relative to) during internal expansion of the stem (similar to the movement of the ridges and nodes on the collar during swaging). The groove is set atNote that the groove and recess 14 is "set down" (lower-forming an elongate step 19) in this section of the stem, which allows radial movement as the stem undergoes internal expansion. (i.e., the plug will draw the Inner Diameter (ID) from the rod as it is drawn through the rodExpand to approximatelyThis is the size of the plug, forcing the groove up into the hose and radially towards the ferrule. ) The net result of the internal expansion is to deform the elongate step 19 so that the internal diameters of the rods are all uniform.

It should be noted that no barbs are used in the present invention (unlike the original Baldwin device shown in fig. 4). This is because the barbs are ineffective when the inner tube begins to creep under the action of high temperatures. The barbs are replaced with a smooth o.d. that does not damage the inner tube, thus providing a better seal and reducing the effects of creep.

As explained above, the relative positions of the grooves on the stem and the nodes on the associated ferrule are critical to creating a sinusoidal lock between the ferrule and the reinforcement that reduces the potential for creep when the inner tube is subjected to high temperatures.

Moving to the left in fig. 6 (and in combination with fig. 7 item numbers, zones and identifiers are visible), the rod has a series of four grippers, including a protuberance 16 and a recess 17. The rightmost bar holder protuberance is located radially below the second ferrule holder teeth and has a rearward slope as it descends towards the region 4 on the bar. This rear slope forms an inner tube dam 18 to keep the inner tube rubber from penetrating through the reinforcement holder of zone 3 (a critical point in the present invention) when the hose is subjected to high temperatures. The four bar holder ridges may be rounded to minimize the possibility of damage to the exposed reinforcement. The pockets and protuberances have equal heights and depths, and the widths of the ridges and pockets are substantially the same.

It should be noted that in the region where grooves and recesses are employed, the section of the rod forming the interior of the connector (where fluid flow is expected) is displaced. This is region 5 between region E and region G. This is the region of the rod that will undergo internal expansion to begin the sine wave locking within region 5. It should be noted that no internal expansion occurs in the gripper region 3. An alternative embodiment using internal expansion in the region of the holder may be employed and is outside the scope of the present disclosure.

Again, the dimensions given should not be construed as limiting, but as an example. This is because the dimensions will vary with the size of the fitting and the type of reinforced hose. Any engineer with knowledge of materials and swaging can readily make adjustments to the present disclosure for different sized fittings, hoses, hose types, and materials that can be used by the fitting manufacturer. In fact, the size and location of the bumps, cavities, grooves and grooves should be chosen by trial and error to have exactly the minimum height so that the grooves and grooves cause a sinusoidal locking of the reinforcement stack within the ferrule. The location of the grooves must be matched to the nodes of the ferrule so that after a two-step expansion and swaging operation, a sinusoidal wave lock is achieved. A similar approach must be used when if an alternative sine wave lock is used in the gripper section.

The ferrule of fig. 5 is welded to the stem at the flange (point a) of the stem of fig. 6. The welds were carefully inspected to ensure quality. If the finished fitting is to be used in H₂In S plants, the fittings must then be heat treated to reduce the likelihood of hydrogen sulfide stress cracking.

The fitting is permanently attached to a reinforced high pressure rubber hose using industry standard techniques-another addition to the device. The outer covering is shaved to reveal the reinforcement. The axial scraping length is set by the axial length of the ferrule: it must be ensured that approximately 1/2 inches of the outer cover falls under the hose end of the ferrule prior to swaging. The inner tube is also shaved to reveal the reinforcement, but only to allow the gripper on the rod to contact the reinforcement (this distance is set by the length of the gripper section on the rod). The hose is then carefully placed in the cavity formed between the ferrule and the stem to abut against the stop point (B in fig. 7). From point B towards the end of the connection there is additional space (region 1 shown in figure 7) which allows for any expansion of the hose during the swaging operation.

As explained before, the preferred connection between the hose and the end connection is a two-step process starting with the internal expansion of the wand (fig. 7A). A plug is drawn through the rod which expands the channel toward the ferrule. This expansion initiates the action of sine wave locking. Note that in the prototype described, only the section of the rod that accommodates the groove and recess actually expands (unless alternative internal expansion and/or sine wave locking embodiments are employed in the gripper section).

The second operation, the swaging operation, starts at the hose (inside) end of the fitting and moves axially along the fitting to the terminating (outside) end. As the ferrule is swaged, it moves radially inward toward the stem and axially outward toward the hose. As the ferrule moves axially inward, the bar grooves act to displace all of the laminations of the reinforcement into the nodes of the ferrule, thereby completing the sine wave lock. Along the approximate middle of the ferrule (during swaging), the reinforcement at the hose end will lock in a modified sine wave (following the shape of the ferrule). As the swaging operation continues, the ferrule will move axially along the hose away from the hose end of the fitting. The sine wave lock is gradually moved with the forge until the forge is stopped just past point B (see fig. 7). A similar process would occur in the alternative sine wave stiffener clamp locking embodiment. Note that fig. 7B shows the present device without internal expansion and thus the first step (expansion) is omitted.

It must be understood that there is no mechanical lock between the inner tube of the hose and the stem. Mechanical locking occurs in the stiffener gripper section of the connection. It was found that there was a secondary lock for the reinforcement between the nodes and grooves of the ferrule, which was in a modified sine wave form. Creativity is the following recognition: a series of inclined clamps interacting with the initial Baldwin et al sinusoidal locking and associated with the improvement of the termination area will serve to retain a high pressure high temperature reinforced rubber hose inside a swaged end fitting. The mechanical lock, in combination with the modified sine wave lock in the highly inventive inner tube dam and connector body, will inhibit elastomer creep in the reinforced hose (both inner tube and outer shell) at high temperatures (hot) during swaging operations (cold). Thus, this series of cooperating inventive steps thus ensures a fitting that does not leak at high temperatures and pressures. An alternative gripper embodiment utilizing a sine wave lock is another inventive step. The present device is therefore an improvement over the double locking Baldwin device which complements the prior art and addresses a key industry problem-namely, creep of the rubber during forging and especially at high operating temperatures.

The dimensions, materials of construction, number of nodes/ridges/grooves, and number of ridges may vary with the size and duty of the hose assembly; accordingly, the disclosure set forth above should not be construed as limiting, but rather as an example.

Claims (15)

1. An end connector for permanent attachment to a reinforced hose having reinforcement, the end connector comprising: a rod having a coupling end, a hose end, an interior and an exterior; a ferrule having an inner portion secured to said outer portion of said shank near said coupling end of the shank, the ferrule extending concentrically around said shank toward said hose end of the shank, having:

a) a modified (sine x)/x wave formed within the interior of the ferrule for implementing a sinusoidal clamping and sealing device, and

b) further having a reinforcement holder device formed within the interior of the ferrule, and

c) wherein the rod comprises complementary modified (sine x)/x waves formed on the exterior of the rod for effecting the sinusoidal clamping and sealing device, and

d) further comprising complementary reinforcement holder means formed on said exterior of said rod, and

e) wherein the modified (sine x)/x wave comprises a series of nodes and ridges machined axially within the ferrule and the complementary modified (sine x)/x wave comprises a series of nodes and ridges machined axially on the exterior of the stem, and wherein the modified (sine x)/x wave and the complementary modified (sine x)/x wave are positioned such that when the end connector is swaged onto the reinforced hose, the modified (sine x)/x wave and the complementary modified (sine x)/x wave align to form the sinusoidal clamping and sealing device, and

f) further such that when said end connector is swaged onto the reinforced hose, said reinforcement holder means in said ferrule interacts with said complementary reinforcement holder means on said stem to securely hold the reinforcement of the reinforced hose, an

g) Wherein said stem has an elongated step formed within said interior of said stem for interacting with an expansion plug to expand said stem into the reinforced hose.

2. The end connector of claim 1, further comprising an inner tube dam formed within said exterior of said stem between said complementary modified (sine x)/x wave and said complementary reinforcement holder means for inhibiting creep of the inner elastomer of the reinforced hose toward said coupling end.

3. An end connector for permanent attachment to a reinforced hose having an inner tube and an outer skin layer and reinforcement between the outer skin layer and the inner tube, the end connector comprising:

a rod having a coupling end, a hose end and an outer portion;

a ferrule having an inner portion fixed to said stem near said coupling end, the ferrule extending concentrically around said stem towards said hose end of the stem, forming an annular cavity between said outer portion of said stem and said inner portion of said ferrule, and adapted to receive an end of the reinforcing hose, wherein said cavity is divided into six zones: a first zone adapted as expansion region, a second zone adapted as stop and first clamping region, a third zone adapted as second clamping region, a fourth zone adapted as third clamping region, a fifth zone adapted as fourth clamping region, and a sixth zone adapted as stress relief and termination region, wherein said first zone is located at said coupling end and said sixth zone is located at said hose end, said second zone, said third zone, said fourth zone and said fifth zone are arranged axially and numerically in sequence between said first zone and said sixth zone, and wherein said first clamping region is adapted to crimp the reinforcement between said ferrule and said stem, wherein said second clamping region is adapted to clamp the reinforcement between said ferrule and said stem, wherein said third clamping region is adapted to crimp the reinforcement and the inner tube between said ferrule and said stem, wherein said fourth clamping region is adapted to lock the reinforcement and the inner tube between said ferrule and said stem in the form of a modified sine wave between said ferrule and said stem, and wherein said stress relief and termination region is adapted to smoothly terminate the reinforced hose within the end fitting between the outer skin layer and the inner tube, and wherein said second clamping region comprises complementary mechanical locking means between said ferrule, the reinforcement and said stem, wherein said stem has an elongated step formed within said interior of said stem substantially below said fourth clamping region and extending partially below said stress relief and termination region, for interacting with an expansion plug to expand the rod into the reinforced hose, thereby helping to form a modified sine wave lock between the end connector and the reinforced hose.

4. The end connector of claim 3 wherein said first clamping area includes crimping means between said ferrule, the reinforcement and said stem.

5. The end connector of claim 3 wherein said third clamping area comprises crimping means between said ferrule, the reinforcement, the inner tube and said stem.

6. The end connector of claim 3, wherein said fourth clamping area includes a modified sinusoidal locking device between said ferrule, the reinforcement, the inner tube and said stem.

7. The end connector of claim 3 wherein the transition between said fifth zone and said sixth zone presents an acute angle, thereby serving to limit creep of the inner tube caused by high temperature fluid traveling within the reinforced hose.

8. The end connector of claim 3, further comprising an inner tube dam located between said third zone and said fourth zone for inhibiting creep of the inner tube of the reinforced hose towards said coupling end.

9. The end connector of claim 6 wherein said sinusoidal locking means comprises a plurality of grooves and ridges formed in said ferrule which are complementary to a plurality of ridges and grooves formed in said stem such that when said end connector is permanently attached to the reinforced hose, the reinforcement assumes the shape of a modified sinusoidal wave thereby mechanically locking between said ferrule and said stem.

10. The end connector of claim 3 wherein said elongated step continues from said fourth gripping region to below said third gripping region and said second gripping region to assist in forming said grip of said second gripping region on the reinforcement between said ferrule and said stem.

11. A high pressure reinforced hose assembly comprising:

a high pressure reinforced hose section having first and second ends, reinforcement, an inner tube, an outer layer, and a covering forming an outer skin layer; and the end connector of any one of claims 1-10, said end connector comprising a first end connector and a second end connector, each comprising a ferrule and a rod; and wherein the high pressure reinforced hose section is first shaved at both ends by removing a portion of the outer skin layer and the inner tube prior to permanent attachment to said first and second end connectors, thereby sufficiently revealing the reinforcement, thereby allowing direct contact of the reinforcement with said ferrule and said stem; and wherein a further portion of the outer skin layer is removed, allowing only direct contact of the reinforcement with the ferrule, and wherein said first end connector and said second end connector each have a plurality of clamping means formed between said ferrule and said rod, with a first reinforcement clamping means and a second sinusoidal clamping means of said plurality separated by an inner tube dam; and wherein said first end connector is permanently attached to said first end of said high pressure reinforced hose section, thereby forming a mechanical lock for the reinforcement between said first end of said high pressure reinforced hose section and said first end connector directly at said first reinforcement gripping means of the first end connector; and wherein said first end connector is further permanently attached at said second sinusoidal gripping means between said ferrule, said reinforcement, said inner tube and said rod, thereby forming a sinusoidal lock; and wherein said second end connector is permanently attached to said second end of said high pressure reinforced hose section, thereby forming a mechanical lock for the reinforcement between said second end of said high pressure reinforced hose section and said second end connector directly at said first reinforcement gripping means of the second end connector; and wherein said second end connector is further permanently attached at said second sinusoidal gripping means between said ferrule, said reinforcement, said inner tube and said rod, thereby forming a sinusoidal lock.

12. The high pressure reinforced hose assembly of claim 11, said high pressure reinforced hose section further having high temperature and high pressure ratings, wherein creep of said inner tube within said high pressure reinforced hose section is inhibited by the combined action of said inner tube dam and said sinusoidal locking within each said end connector, thereby allowing said high pressure reinforced hose assembly to operate at the rated temperature and pressure of said high pressure reinforced hose section.

13. The high pressure reinforced hose assembly of claim 12, further comprising a stress relief and termination area providing additional means for inhibiting creep of said inner tube and said outer skin layer.

14. A high pressure reinforced hose assembly for use as a swivel hose, comprising:

a high pressure reinforced rubber hose section having first and second ends, reinforcement, an inner elastomeric layer, and an outer skin layer;

the end connector of any one of claims 1-10, said end connector comprising a first end connector and a second end connector, each comprising a ferrule and a stem, and having a sinusoidal clamping means and a reinforcement holder means formed between said ferrule and said stem, and wherein said first end connector is permanently attached to said first end of said high pressure reinforced rubber hose section comprising a sinusoidal lock between said first end connector in the region of the high pressure reinforced rubber hose section containing the reinforcement and the inner elastomer layer at said first end of said high pressure reinforced rubber hose section and further comprising a reinforcement holder lock at said first end of said high pressure reinforced rubber hose section to the reinforcement of said high pressure reinforced rubber hose section, and wherein said second end connector is permanently attached to said second end of said high pressure reinforced rubber hose section, thereby forming a kind of sine-like locking and a kind of reinforcement holder locking between said second end connector and said second end of said high pressure reinforced rubber hose section.

15. The high pressure reinforced hose assembly of claim 14, wherein the high pressure reinforced rubber hose section is first shaved by removing a portion of the outer skin layer and a portion of the inner elastomer layer prior to permanent attachment to said first and second end connectors, thereby revealing the reinforcement, and wherein the reinforcement is in contact with said ferrule in the portion containing said first and second end connectors of the sinusoidal gripping device, and wherein the inner elastomer layer is in contact with said stem in the portion containing said first and second end connectors of the sinusoidal gripping device, and wherein the reinforcement is in contact with the reinforcement gripping device in both said ferrule and said stem.