HK1169158B - Improved end connector for high pressure 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 particularly suited to the petrochemical and drilling industries. Two embodiments of the improved connector for use with wire reinforced thin internal tube hose are disclosed: one with a diameter of 3- inches and for burst pressures up to 20, 000 psi and the other for a diameter of 5-inches and for burst pressures up to 18,000 psi. All of the improved connectors will withstand the rated burst pressure of the hose without pumping off or leaking thus any hose that utilizes the improved device will fail before the connector pops off the hose. The improved connectors are designed to meet or exceed the new API temperature ranges and new API flexible specification levels which became effective in October 2006.

Description

Improved end connector for high pressure reinforced rubber hose

Field of the invention

The present invention relates generally to the reinforced rubber hose industry and, more particularly, to swaged hose couplings (swaged hose couplings) for terminating large diameter, high pressure, flexible reinforced rubber hoses used in energy, marine, petrochemical and similar industries that are capable of meeting newer API standards.

Background

High-pressure rubber hoses are used in many industrial applications, but in particular in the mining, construction, energy, marine and petrochemical industries. Flexible rubber hoses are used to convey fluids at various pressures and temperatures between two points, one or both of which may be moved relative to each other or to another fixed point in space. The tubing at both points is usually metallic (or some other form of fixed tubing) and flexible hoses must be attached to the tubing at both ends. This requires a coupling on each end of the hose.

In the drilling industry, flexible rubber hoses run between a pump tubing system on a rig and a kelly connected to a rotating drill string. The pump system forces drilling fluid down the center of the drill pipe and back through the wellbore to flush cuttings away from the wellbore (and to provide additional stability to the wellbore, etc.). In this case, the flexible hose is subjected to high pressure. High pressure is required to convey the drilling fluid into the wellbore and overcome the static return pressure head — the deeper the wellbore, the greater the pressure.

The rotary drilling hose is subjected to further stress as it is suspended in a derrick boom supported at either end by metal couplings on the hose and drives the drill pipe up and down many thousands of times during the drilling operation. This means that the hose is also stressed at the metal coupling (in addition to being stressed throughout its length). Thus, a highly reliable bond between the hose and the coupling is required for protection of personnel and equipment. If the hose breaks loose from the coupling, it may easily fall off and cause severe damage on the floor of the rig. In a similar manner, if the hose breaks, circulation may be lost, resulting in a blowout situation.

In order to obtain high pressure flexible rubber hoses (the term rubber is used generally and not specifically to refer to naturally occurring rubber), hose manufacturers mix in reinforcing materials. Thus, the hose will consist of the inner sealing membrane-the fluid sealing element, the inner rubber element, the reinforcing element, the outer rubber element and finally a certain degree of wear protection. The reinforcing elements 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. Stiffeners are commonly used in multiple layers called "stacks" and are typically made of steel.

Hose manufacturers employ four reinforcement types, which are provided in an even number of layers, i.e., 2 layers, 4 layers, 6 layers, etc., and use a rating system to specify the burst pressure of the hose. For example, in the rotary drilling industry, a C-rated hose has a minimum burst pressure of 10,000psi, a D-rated hose has a minimum burst pressure of 12,500psi, and an E-rated hose has a minimum (guaranteed) burst pressure of 18,750 psi. The C-grade and D-grade hoses are 2-layer hoses, however some are 4-layer D-hoses. Most E-grade hoses are 4 layers. Swaged end connectors for two-layer hoses are currently available, and thus the prior art covers a range of burst pressures for C-hose and D-hose.

Hose manufacturers typically manufacture flexible hoses according to a specific order by a buyer who specifies the length, diameter, pressure, usage class, and end connections required. These flexible hoses are commonly referred to as "hose assemblies with end connectors" or "assembled hose assemblies". This term is used throughout the industry.

In an assembled hose assembly with end connections, during the manufacturing process, the manufacturer terminates the rubber hose within a buyer-specified metal fitting (end connector). Thus, the manufacturer would make the inner rubber membrane (first carcass) and the inner seal layer (canister or inner canister) associated therewith and terminate the assembly within the end connector. The manufacturer would then add wire reinforcements as needed to terminate each reinforced wire (or cable) within the terminal connector. Hose manufacturers typically use two techniques to terminate the wire reinforcement in or on the end connector itself, but both techniques are beyond the scope of this discussion. Finally, an outer rubber layer (second carcass) and an outer covering (covering) will be formed around the reinforcing wires or cables, and all the product is hardened to obtain a bonded product.

It is time consuming to manufacture hose assemblies with end connections using this method, but often such hoses are almost immediately needed in the industry. To meet this demand, a separate industry, called local market distributor, has evolved. Local market distributors hold bulk (bulk) reinforced hoses in inventory-hoses without connectors. The buyer can specify the hose requirements-diameter, length, pressure rating and end connector-to the local market distributor. The local market distributor then removes the bulk reinforced rubber hose from inventory, cuts the hose to the required length, and places a coupler on each end of the hose. Bulk hoses are available in various lengths from hose manufacturers, and the actual bulk length (between 90 and 110 feet) 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 (crimped) hose, wherein the term "placing" is used to include swaging and/or crimping operations. Care should be taken that swaging and crimping achieve a similar end result.

The state of the art in swaging (or crimping) connectors has evolved to use an external ferrule with a ridge (internal ridge) that is compressed around the end of the reinforced hose around the stem that is inserted into the end of the hose. The stem may or may not have barbs for improving the "grip" between the hose and the end connector. Typically, the outer layer of the reinforced hose is "skived", meaning that the outer skin layers (rubber outer layer and wear protection cover) are removed, revealing the reinforcement (however some local distributors do not shave).

The reinforced hose is actually held within the end connector by the ridge of the ferrule that grips the reinforcement by compression of the hose against the stem. The compression operation (swaging or crimping) of the ferrule against the reinforcement and against the inner stem creates dangerous stresses and strains within the rubber of the hose and particularly the reinforcement.

It is known that multi-layer reinforced hoses can contain manufacturing defects (virtually all reinforced hoses can contain defects). During manufacturing, the layers may come out of position. I.e. there may be voids (of course filled with rubber) between the layers, rather than laying next to each other; the layers may be off center; alternatively, one or more of the cables may extend out (i.e., slightly above the other cables). Defects can lead to failure if they are within or near the range of the swaged or crimped connection.

The cause of failure is quite simple and in turn is related to the stress applied to the stack by the terminal connector. If the cable or layer is out of position, the element will be compressed more than the other elements. This additional compression places more stress on the reinforcement at the point of disengagement, which can lead to failure.

The development of high pressure swaged end connectors for rubber hoses has been in progress for many years and the technology has advanced protective gloves from low temperature and/or low pressure applications to high temperature and/or high pressure applications. The hose diameters range from a few tenths of a centimeter [ a fraction of an inch ] to a few tenths of a meter [ a few tens of inches ], and the manufacturer/supplier of the connector recognizes 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. Pat. No. 7,388,090 to Baldwin et al, which is incorporated by reference in its entirety into the present disclosure, most 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 (ridges) into the outer layer of the hose and reinforcement within the ferrule and may cause the teeth (or barbs) of the stem to bite further into the liner.

Baldwin et al teach that standard techniques cause 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 propose an invention consisting of a "corrugated" ferrule and stem which connects the end connector to a flexible reinforced rubber hose, thereby forming a "double sine wave lock" between the ferrule and stem, but which is formed primarily within the ferrule (see US 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 manner as typical "raised" ferrule and "barbed" stem fittings. The ridges of the ferrule and the high points of the stem form a sinusoidal shape-a wave-rather than having straight sides. The wave pattern has the appearance of a wave on the pond caused by throwing stones into the water.

The 'double sine wave locking' invention allows all of the plies of the hose reinforcement to be locked within the end connector, between the stem and the ferrule, compressed in a sine wave against the ferrule and stem to provide the fitting with an overall strength exceeding that of a stand-alone hose (without an end connector) whether or not the hose is under pressure. Class E hoses have a minimum burst pressure of 18,750 psi; thus when using E-grade hose, the present device will have an overall strength greater than 18,750 psi. (at these pressures, depending on the cross-sectional area, the extraction forces involved may reach or exceed 240,000 lbf.) the present invention contemplates the materials forming the ferrule and stem, the relative movement of these materials when attaching the end connector to the hose, and the unpredictable nature of the rubber and flexible hose structure, with due care to minimize induced stresses within the hose reinforcement. 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 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 the ferrule and stem, with the reinforcement layer and hose locked into the end connector by compressing the hose 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 (rip) away from the rubber hose are minimized. The relative axial displacement is minimized to induce sinusoidal-like waves by the use of high tensile strength steel, minimal non-attachment gaps between the hose and the end connector, 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 for use with any cable or wire high pressure reinforced hose and has in fact replaced 'assembled' hoses with end connectors because hoses utilizing Baldwin double sine wave end connectors do not fail between the hose and the end connector. Any failure of the hose under pressure will be within the hose itself. The end connector will not come loose from the hose: this statement cannot be made for assembling hoses. Thus, the 'double sine wave locked' Baldwin terminal connector improves safety in the workplace. In all areas where equipment is damaged and personnel are injured, the hose cannot come loose and fall off again.

A "double-locking" terminal connector requires a two-step connection process. The connector is placed over the hose and expanded inside the wand. The resulting assembly is then placed in a pipe joint crimping machine (crimping press) and the ferrule is swaged onto the hose/stem. In improving their invention, the inventors contemplate whether this two-step process is required and whether (relatively) large ridges and grooves on the stem are required. It is known that the actual locking takes place between the ferrule and the reinforcement, while there is some slight locking (transmission of the extraction force) between the rod and the reinforcement. An improved device would result if the rod could be designed with a small bump and if the attachment step could be eliminated. More importantly, the removal of the expansion step will reduce the amount of material movement within the hose during the swaging/expansion process. The improved sealing and locking will result in a reduction of induced stresses due to a reduction of material movement within the hose itself.

Over the past years, hose manufacturers (particularly in europe) have made lightweight high pressure reinforced rubber hoses. This hose uses wire or cable reinforcement, but uses a thinner inner barrel. The inner barrel is a non-leaking flexible conduit through which high pressure fluid passes. The expansion force is transmitted to a reinforcement that resists bursting of the inner barrel. To reduce the total hose weight, manufacturers use thin barrels and thin outer covers. As these materials become thinner, the need for movement between the hose components (i.e., inner barrel, reinforcement and outer covering) becomes more important. There is thus still a need for a sine wave locking device that generates little stress during the connection process between the connector and the reinforced hose used in the rotary hose and other high pressure rubber hoses.

In 2006, 10, API (american petroleum institute, which is a defined standard established by the industry) established a more stringent standard for rotary hoses. These more stringent standards yield three temperature ranges and three "flexible gauge classes" (standards) for high pressure rotary hoses. The temperature criteria are as follows.

Temperature range I: -20 ℃ to +82 [ -4 ° F to +180 ° F ]

Temperature range II: -20 ℃ to +100 [ -4 ° F to +212 ° F ]

Temperature range III: -20 ℃ to +121 [ -4 ° F to +250 ° F ]

The flexibility specification grades are as follows:

FSL 0: bonding hoses only (hose) without pulsation

FSL 1: rotary, vibrating and jumper (jumper) hoses-only working normally-have no high frequency pulsations.

FSL 2: rotary, vibrating, and jumper hoses-can experience high frequency vibrations in excess of 6.9MPa [1000psi ] during operation.

Unfortunately, these new API standards cause a series of failures for most, if not all, of the forged terminal connectors during testing, especially in temperature range III and FSL 2. In the case of temperature range III, the inner barrel (the actual liquid containing element within the high pressure reinforced hose) melts, resulting in the disconnection of the connector from the hose, leakage within the end connector, or both. Unfortunately, the same failures can occur for the assembled hose and for the same reasons. These conditions are not tolerable and thus there is still a need for high voltage terminal connectors that can meet the new API standards.

Summary of The Invention

Both embodiments of the invention consist of an improvement to the sine wave locking disclosed in US 7,338,090 to Baldwin et al, where the improvement is a ferrule in which all grooves follow a modified (sine x)/x function in that the grooves run from a maximum height at the terminating end of the connector to a minimum height at the hose end of the connector. The ridges between the grooves are inclined or curved following a modified (sine x)/x function. The associated stem has a series of mating lugs that align within the center of the ridge of the ferrule when the swaging operation is completed. Although the bumps have a height that varies from a maximum at the terminating end of the connector to a minimum at the hose end of the connector, there may be no true correction (sine x)/x (unlike the original Baldwin et al invention) for defining the bumps. The stem and ferrule are joined together by a suitable process such as welding.

The end connector is connected to the reinforced hose in a standard manner which may include a shaved outer sheath for the first embodiment and shaved outer sheath and inner skin layers for the second embodiment. In the first embodiment, the hose is carefully placed within the cavity of the end connector formed between the ferrule and the stem, to the point where the end of the inner barrel rests just beyond the last groove, and within the last ridge at the terminating end of the connector. In the second embodiment, the inner barrel still rests so that it just passes over the last groove and within the last ridge, but the reinforcement continues into the connector again, with a series of additional grooves and ridges that will contact the exposed reinforcement. The fitting is then preferably swaged onto the hose using standard techniques.

As the swaging process progresses, the small bump on the stem creates a biasing force that causes the reinforcement to expand into the ridge of the ferrule, creating a sinusoidal lock between the reinforcement and the ridge and groove of the ferrule.

During manufacture or at any time, the stem may be coated with a friction reducing material that allows the inner barrel of the reinforced hose to slide more freely along the stem during the process of swaging (or crimping) the connector to the hose. An expansion region for excess rubber and other 'by-products' of the swaging operation (such as extruded reinforcement material) is provided at the terminating end of the connector (i.e., between the ferrule and the stem at the terminating end of the connector).

Brief Description of Drawings

Fig. 1 shows a cross-section of a typical cable-reinforced flexible rubber hose.

Figure 2 shows a state of the art cross-sectional view of a standard terminal connector with NTP terminals. (this is an old-fashioned connection that has been used for decades.)

Figure 3 shows a cross-sectional view of a ferrule used in the state of the art improved 'double locking sine wave' end connector. ('double locking sine wave' terminal connectors have been used in the past five years.)

Figure 4 shows a cross-sectional view of a rod used in the state of the art of the improved 'double locking sine wave' end connector.

Fig. 5 shows a cross-sectional view of a ferrule used in a first embodiment of the invention, which is a general improvement over 'double-locking sine wave' connectors. (Note the similarities between FIGS. 3 and 5.)

Fig. 6 shows a cross-sectional view of a lever used in a first embodiment of the invention, which is a general modification to a 'double locking sine wave' connector and forms a single locking sine wave throughout the device. (Note the difference between FIG. 4 and FIG. 6.)

FIG. 7 is a schematic representation of a first embodiment of the improved end connector, taken approximately at the longitudinal centerline and showing the ferrule connected to the stem.

Figure 8 is at about the longitudinal centerline of the ferrule of the second and preferred embodiment of the improved end connector.

Figure 9 is a side engineering view taken approximately at the longitudinal centerline of the stem of the second and preferred embodiment of the improved end connector.

FIG. 10 is a schematic representation of a second and preferred embodiment of the improved end connector, taken approximately at the longitudinal centerline and showing the ferrule connected to the stem. This figure also defines some terms used in this disclosure and the clamping section used in the claims.

Figure 11 shows a second and preferred end connector just prior to the insertion of the "double skived" high pressure reinforced hose into the end connector. Note that the inner barrel and outer cover have been removed to reveal the reinforcement.

Figure 12 shows the second and preferred end connector immediately after the "double skived" high pressure reinforced hose is inserted into the end connector and before swaging.

Figure 13 shows a second and preferred end connector with a "double skived" high pressure reinforced hose inserted into the end connector and after swaging is complete.

Fig. 14 presents a table of connector dimensions in english units for the second embodiment.

Fig. 15 gives the shaving table for the second embodiment in english units.

Description of the embodiments

Figure 1 shows a standard weight D-cable reinforced hose. E-hoses typically have 4 interlocking reinforcement stacks. Although the cross-section of the european lightweight wire reinforced hose is not shown, it is similar to figure 1 except that there are 6 interlocking cable stacks and the inner barrel comprises a thin layer of rubber.

The ferrule of the first embodiment of the invention is shown in cross-section in figure 5 and is machined from an 80 hose of the 4 "x 0.337w type. [ it is difficult to provide metric equivalents. The ferrule of the second embodiment is shown in cross-section in fig. 8 and is machined (DOM) from a 9.00x0.750 wall mechanical tube (wall mechanical tube). [ it is difficult to provide metric equivalents. One end (the end to be welded to the rod) is placed in a roll forging die and compressed to form a narrower neck portion as shown on the far left in fig. 5 and 8. The inside of the ferrule is machined to create a series of ridges and grooves (six in total as shown in fig. 5 and ten in total as shown in fig. 8).

In the first embodiment of fig. 5, the ridges all have the same height as measured from the axial centerline of the ferruleThe first and second grooves (as measured from the hose end of the ferrule) haveA third groove havingHeight of (1) and last threeEach groove is provided withOf (c) is measured. Fig. 8, which is a second embodiment, is somewhat different and will be described in detail in a later paragraph. In both embodiments, the grooves are not equally spaced axially along the ferrule. This is because it is known that because the ferrule is swaged (starting from the hose end), the ferrule will move axially toward the hose end of the fitting until the reinforcement is locked between the ferrule and the stem. The actual locking does not begin until the swaging is at about the midpoint along the ferrule. Before this, the inner barrel and hose are free to move axially away from the terminating end of the fitting. When locking occurs, all movement of the inner barrel and hose will be towards the terminating end of the fitting.

Simple mechanical calculations based on material properties and swage count to be performed allow the designer to calculate the groove spacing so that after the fitting is swaged to the hose, the lug of the stem will fall at about the midpoint inside the ridge of the ferrule. The way in which the final position of the bump is located at about the midpoint within the ridge is the key to the device and how it achieves a sine wave lock between the stiffener and the ferrule.

The dimensions of the ridge and groove heights should not be construed as limiting but as an example. Similarly, the illustrated groove spacing should not be construed as limiting but as an example. In some cases (larger diameter hoses), it may be necessary to adjust these dimensions so that they vary with distance from the end of the hose forming the entire incline.

At the end of the connector closest to the hose, the inner diameter of the ferrule is increased so that when the ferrule is swaged, minimal pressure is applied to the rubber outer cover. As shown, the hose end is rounded.

The rod of the first embodiment of the invention is shown in cross-section in figure 6 and is machined from a SMLS tube of type 3 "x.437w. Six "bumps" are all 0.06 inches and are machined equally on the rod. As mentioned above, the respective locations of the bumps on the stem and the ridges on the bonded ferrule are critical to the sinusoidal wave lock formed between the ferrule and the stiffener. Again, the dimensions given should not be construed as limiting but as an example. Since the size will vary with the size of the fitting and the type of reinforced hose. Any engineer with knowledge of materials and swaging can easily make adjustments to the present disclosure to vary fitting size, hose type, and materials that can be used by the fitting manufacturer. In fact, the size of the bump should be chosen by trial and error to have exactly the minimum height so that the bump causes a sinusoidal locking of the reinforcement stack within the ferrule. The best way to get the correct dimensions and spacing of the grooves, ridges and bumps is through trial and error. The calculation will be helpful.

The ferrule of fig. 5 is welded to the stem of fig. 6 at its flange, and the complete assembly (of the first embodiment) is shown in fig. 7. The welds were carefully inspected to ensure quality. If the finished fitting is to be used in H₂In S facilities, the fittings must be heat treated to reduce the possibility of hydrogen sulfide stress cracking.

The fitting of the first embodiment is permanently attached to a reinforced high pressure rubber hose, another attachment to the apparatus, using industry standard techniques. The outer cover is typically shaved to reveal the reinforcement. The axial length of the scraping is set according to the axial length of the ferrule: it must be ensured that about 1/2 inches of the outer covering falls under the hose end of the ferrule prior to swaging. The hose was then carefully placed within the cavity formed between the ferrule and the stem approximately 1/2 inches from the distal end of the cavity. This space allows for expansion of the hose during the swaging operation.

As explained previously, the swaging operation begins at the hose end of the fitting and moves axially along the connector fitting to a terminal end. As the ferrule is swaged, it moves radially inwardly toward the stem and axially outwardly toward the hose. The tabs of the stem serve to move all of the laminations of the reinforcement into the ridges of the ferrule as the ferrule moves axially inward. At about the midpoint along the ferrule (during swaging), the reinforcement at the hose end will lock in the form of a 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 will move progressively with the swage until the swage is stopped just by the last groove away from the hose end. The ferrule will expand substantially radially around the stem to create a volume that accommodates excess rubber from the hose.

It must be understood that in the first embodiment there is no mechanical lock between the inner barrel of the hose and the wand. A mechanical lock is established between the ridges and grooves in the form of a modified sine wave and the reinforcement of the ferrule. During testing for meeting newer API standards, the first embodiment was found to be non-compliant with the new API standards due to temperature and flexibility, and the device was further modified to yield a second embodiment. However, the first embodiment of the device is still an improvement over the double-locked Baldwin device and contributes to the technology.

We now examine a second and preferred embodiment, which is a modification of the first embodiment required for a new API standard for rotary hoses involving both temperature and flexibility. As mentioned in the background section of this patent, higher temperatures cause the inner barrel of the reinforced hose to become more or less pasty, which leads to two problems. First, the lock between the reinforcement and the connector fails because the rubber becomes gelatinous, and second, the swaged connector slips off the hose. In both cases of swaged connectors and assembled hose assemblies, the mushy inner hose leaks (due to temperature) and fluid flows out between the hose and the connector. The tendency for the swaged connector to come loose and the tendency for both the swaged connector and the assembled hose connector to leak are exacerbated by compliance standards. Therefore, the concept of the first embodiment was developed to solve this problem.

Fig. 8 shows a ferrule for the second and preferred embodiment. There are essentially three sets of grooves (lugs) and ridges (grooves) and a terminal gripping section. From the end of the connector furthest away from the hose (left in the drawing)Side) is a 'zero' or expansion region followed by a first set of four grooves each having the same radial height as the axial centerline of the ferruleAnd the ridges between the grooves of the first group are all provided withRadial depth. The second set of grooves (two) has the same radial height as the third set of grooves (four)And the ridge between the two sets of grooves hasThe radial depth of (a). The ridges between the third set of grooves haveThe radial depth of (a). Finally, a termination groove is formed fromIs inclined and tapered towards the end of the connector in contact with the outer sheath of the hose. As previously mentioned, in both embodiments, the grooves are not equally axially spaced along the ferrule.

The rod of the second embodiment of the invention is shown in cross-section in fig. 9 and is made up of 6⁵/₈An o.d. mechanical cylinder of inches gr.4130. It is also difficult to provide metric equivalents.]Starting from the end furthest from the hose (left side in the figure), there are twoAndlongitudinal flatness of relative heightAnd (4) a region. It will be seen that the first of these two regions is used to connect with the ferrule after and during swaging to form the expanded section (section 1). When the hose is placed within the completed connector, the second region acts as a stop (stop) for the stiffener and allows some movement of the stiffener during swaging until the swaging operation reaches a section where the ferrule and stem will crimp around the stiffener to form a first gripping section (section 2) when the connector is swaged.

Then also hasFour grooves of relative height. It will be seen that this set of grooves and ridges will align with the first set of grooves and ridges of the ferrule after swaging to form the second gripping section (section 3). The ridge between the grooves hasRelative depth of (d). The last groove is somewhat different and is followed by a groove havingAnother (third) longitudinal flat region of relative height. It will be seen that this region will align with the second set of grooves and ridges in the ferrule to form a third gripping section (section 4) which will act somewhat like a double crimp when the connector is swaged. (Note the backward tilt in the transition between the groove and the flat spot-this is not necessary but will be explained.) it follows to haveA series of four bumps of height, with ridges between the bumps havingRelative height of (a). It will be seen that these lugs will align with the third set of grooves and ridges in the ferrule to form a positive stopA fourth clamping section (section 5) in the shape of a chord.

Then smoothly transits back to haveA relatively high flat area. It will be seen that this transition acts in conjunction with the ferrule to form the pressure reduction and termination section (section 6). As explained above, the relative positions of the bumps and grooves on the stem and the ridges on the coupled ferrule are critical to creating a sinusoidal wave lock between the ferrule, the stiffener, and the stem.

Again, the dimensions given should not be construed as limiting but as an example. As this dimension may vary with the size of the fitting and the type of reinforced hose. Any engineer with knowledge of materials and swaging can easily make adjustments to the present disclosure to vary fitting size, hose type, and materials that can be used by the fitting manufacturer. In fact, the size of the bump should be chosen by trial and error to have exactly the minimum height so that the bump causes a sinusoidal locking of the reinforcement stack within the ferrule. The same technique, i.e. trial and error, used in the first embodiment to obtain the correct height, depth and spacing must be employed.

The collar of fig. 8 is welded to the stem of fig. 9 at the flange of the stem, and the complete assembly (of the second embodiment) is shown in fig. 10. The welds were carefully inspected to ensure quality. If the finished fitting is to be used in H₂In S facilities, the fittings must be heat treated to reduce the possibility of hydrogen sulfide stress cracking.

The fitting of the second embodiment is permanently attached to the reinforced high pressure rubber hose using highly modified industry standard techniques. First, the outer cover is shaved to reveal the reinforcement. The axial length of the external scraping is set according to the axial length of the ferrule: it must be ensured that about 1/2 inches of the outer covering falls under the hose end of the ferrule prior to swaging. Second, the inner skin, which is essentially an inner cylinder, is shaved to reveal the reinforcement (not a common procedure in rotary hoses). The axial length of the internal scraping is set according to the axial length of the fitting between points "B" and "D" (see fig. 10).

The hose is then carefully placed in the cavity formed between the ferrule and the stem, and at the approximate location where the reinforcement will reside against the "B" point which acts as a reinforcement stop and the inner barrel will reside against the "D" point, thus ensuring proper placement of the hose within the connector. The space between points "a" and "B" allows for expansion of the hose and or reinforcement during the swaging operation.

As explained above, the swaging operation starts at the hose end of the fitting and moves axially along the fitting to the coupling end. As the ferrule is swaged, the ferrule moves radially inward toward the stem and axially outward toward the hose. The tabs of the stem serve to move all of the laminations of the reinforcement into the ridges of the ferrule as the ferrule moves axially inward. At about the "D" point within the connector (during swaging), the reinforcement of the hose end will lock in the form of a sine wave (following the shape of the ferrule). As the swaging operation continues beyond point "D" to point "a", the ferrule will move axially along the hose end away from the fitting. The sinusoidal locking between the stem, the reinforcement and the ferrule will move progressively with the swage until the swage is stopped just past the last groove near the "B" point. Sometimes the forging will continue to a point between points "B" and "a". The ferrule will expand virtually radially around the stem creating a volume that will accommodate the excess rubber from the hose (section 1).

It must be understood that there is a mechanical lock between the rod and the ferrule between the "B" point and the "C" point like a 'crimp' (first clamping segment — segment 2), and then there is an important mechanical lock between the "C" point and the "D" point to correct the sine wave form (segment 3). It is this sinusoidal locking (second clamping section) that holds the connector to the hose. Another mechanical lock is then established between points "D" and "E", which is a third clamping section (section 4) formed between a second set of grooves and ridges on the ferrule and a third flat region of the stem.

The set of lugs located between points "E" and "F" on the stem interact with the third set of grooves and ridges on the ferrule to form a fourth gripping section (section 5) which causes a modified sine wave form between the inner skin and the reinforcement. It is this locking that prevents leakage of fluid around the stem of the connector and to the outside of the hose when the inner barrel becomes pasty due to high temperatures. Essentially, this sinusoidal locking is the same as the first embodiment.

Finally, the transition zone between point "F" and the end of the connector interacts with the termination groove of the ferrule to form a fifth clamping and termination section (section 6). This process is illustrated in fig. 11 to 13. As in the first embodiment, the second scraping (i.e. the section of hose falling into section 5) may be omitted; however, the possibility of fluid leakage will now occur.

Let us now try to understand the operation of swaged connectors when the hose is subjected to high temperature fluids which tend to cause the inner barrel to become mushy (i.e. the inner barrel loses strength and turns to a jelly). The lip at point "D" inhibits the passage of the paste rubber back towards the open end of the connector. Similarly, the respective tapered sections of the ferrule and stem at the hose end of the connector (which taper toward each other upon swaging) along with the double crimp lock between the "D" and "E" points of the connector and the sine wave lock between the "E" and "F" points of the connector act to retain the mushy inner skin layer, thus preventing fluid from leaking from the connector. Finally, the connector cannot be withdrawn from the hose due to the sine wave lock between the reinforcement, stem and ferrule (between points "C" and "D"). The withdrawal force is transferred from the first connector (at one end of the hose) through the hose (the actual reinforcement) to the reinforcement and onto the second connector (at the other end of the hose). The reinforcement is provided without damage (point of sine wave locking) and then the reinforcement will not fail within the connector. However, any failure will occur within the hose, which makes the entire assembly safer.

Inventively, it is achieved that a series of nubs in the stem can replace the initial double sine wave locking of the Baldwin et al device. In addition, this device eliminates the need for expansion of the rod and eliminates the need for a step in the rod to reduce column buckling. In addition, the machining is simplified and the number of elements (double locking sinusoid) is reduced to a single locking sinusoid. A second embodiment of this device is an improvement over the double-locked Baldwin device, contributing to the technology, and meeting new API specifications.

It must be borne in mind that all dimensions given in this disclosure are for example purposes and should not be construed as limiting, as the dimensions will vary with the diameter and pressure rating of the hose. The number of corresponding grooves and ridges will be set according to the diameter and pressure rating of the hose and thus may be varied. Two examples are given, one for a three inch hose (first embodiment) and one for a five inch hose (second embodiment). Fig. 14 and 15 show two tables giving the basic dimensions and details about the shaving dimensions for the connector of the second embodiment. The techniques described in this disclosure allow one skilled in the manufacturing art to replicate both of these embodiments for various diameters and pressure ratings.

According to either of the two embodiments disclosed above, a hose manufacturer or local dealer can easily assemble a particular high pressure hose of a particular length into a high pressure rotary hose assembly. The hose assembly may be swaged according to the second and preferred embodiment as the specification requirements for temperature and flexibility increase.

Claims (14)

1. An end connector for permanent attachment to reinforced hose, comprising:

a stem having a coupling end and a hose end and an exterior;

a ferrule having an interior secured to the stem near the coupling end, the ferrule extending concentrically around the stem toward the hose end of the stem,

the ferrule also has a sinusoidal clamping device similar to a modified (sine x)/x wave formed within the interior of the ferrule,

the rods having bump means formed on the exterior of the rods for implementing the sinusoidal clamping means, the bump means having no true modified (sine x)/x wave,

an expansion region between the ferrule and the stem of the end connector, an

A first clamping section located between the expansion region and the sinusoidal clamping device, and wherein the first clamping section is adjacent to the expansion region and a longitudinal rod surface of the first clamping section is flat.

2. The end connector of claim 1 wherein said sinusoidal gripping means comprises a series of ridges and grooves machined axially into said ferrule and positioned such that said ridges align with said lug means of said stem when said end connector is swaged onto said reinforced hose.

3. The end connector of claim 1 for permanent attachment to a reinforced hose having an inner barrel and an outer skin and having reinforcement located between the outer skin and the inner barrel, the end connector comprising:

a stem having a coupling end, a hose end and an exterior;

a ferrule having an interior secured to the stem proximate the coupling end, the ferrule extending concentrically around the stem toward the hose end of the stem; thereby forming

An annular cavity between the exterior of the stem and the interior of the ferrule, and adapted to receive an end of the reinforced hose, wherein the cavity is divided into six sections, a first section adapted to act as an expansion region, a second section adapted to act as a stop and first clamping region, a third section adapted to act as a second clamping region, a fourth section adapted to act as a third clamping region, a fifth section adapted to act as a fourth clamping region and a sixth section adapted to act as a stress relief and termination region, wherein the first section is located at the coupling end and the sixth section is located at the hose end, and the second, third, fourth and fifth sections are arranged axially and in numerical order between the first and sixth sections, and wherein the first clamping region is adapted to crimp the reinforcement between the ferrule and the stem, wherein said second clamping area is adapted to lock said reinforcement between said ferrule and said stem in a modified sine wave, wherein said third clamping area is adapted to lock said reinforcement and said inner barrel between said ferrule and said stem, wherein said fourth clamping area is adapted to lock said reinforcement and said inner barrel between said ferrule and said stem in a modified sine wave between said ferrule and said stem, and wherein a stress relief and termination area is adapted to gradually terminate said hose within said end connector between said outer skin and said inner barrel.

4. The end connector of claim 3 wherein the first clamping area comprises a crimp arrangement between the ferrule, the reinforcement and the stem.

5. The end connector of claim 3 wherein said second clamping area comprises a mechanical locking means between said ferrule, said reinforcement and said stem.

6. The end connector of claim 3 wherein the third gripping area comprises a crimp arrangement between the ferrule, the reinforcement, the inner barrel and the stem.

7. The end connector of claim 3 wherein said fourth gripping area comprises a modified sinusoidal locking means between said ferrule, said reinforcement, said inner barrel and said stem.

8. The end connector of claim 3 wherein the transition between the fifth and sixth sections is presented as an acute angle for inhibiting creep of the inner barrel caused by high temperature fluids operating within the reinforcing hose.

9. The end connector of claim 3 wherein the sinusoidal locking means of the second clamping area comprises a plurality of grooves and ridges formed in the ferrule that mate with a plurality of ridges and grooves formed in the stem such that when the end connector is permanently attached to the reinforced hose, the reinforcement assumes the shape of a modified sine wave, thereby mechanically locking between the ferrule and the stem.

10. The end connector of claim 7 wherein in the fourth gripping region the stem further has a plurality of bumps formed on the exterior of the stem, the bumps being free of true modified (sine x)/x waves, wherein the sinusoidal gripping means comprises a series of ridges and grooves machined axially within the ferrule and positioned such that when the end connector is permanently attached to the reinforced hose, the ridges align with the bumps on the stem, wherein mechanical interaction between the grooves and ridges on the ferrule and the bumps on the stem causes the reinforcement to assume the shape of a modified sine wave, thereby sealing the ferrule and the stem to the reinforced hose.

11. A high pressure reinforced hose assembly comprising:

a length of high pressure reinforced rubber hose having first and second ends, reinforcement, inner and outer rubber layers, and first and second end connectors according to claim 1.

12. The high pressure reinforced hose assembly of claim 11, wherein said hose is first shaved by removing a portion of said outer skin layer prior to permanent attachment to said end connector thereby revealing said reinforcement, and wherein said reinforcement comes into contact with said ferrule within the portion of said end connector containing said sinusoidal gripping means, and wherein said inner rubber layer comes into contact with said stem within the portion of said end connector containing said sinusoidal gripping means.

13. The high pressure reinforced hose assembly of claim 11, comprising:

a length of high pressure reinforced rubber hose having a first end, a second end, a reinforcement, an inner rubber layer and an outer skin layer;

a first terminal connector and a second terminal connector, the first terminal connector and the second terminal connector comprising a ferrule and a stem; and wherein the hose is first skived at both ends by removing a portion of the outer skin layer and the inner rubber layer prior to permanent attachment to the end connector, thereby fully revealing the reinforcement, allowing the reinforcement to be in direct contact with the ferrule and the stem; and wherein the connectors each have a plurality of gripping devices formed between the ferrule and the stem, the plurality of gripping devices having a first sinusoidal gripping device and a second sinusoidal gripping device therein; and wherein the first end connector is permanently attached to the first end of the hose, thereby forming a sinusoidal lock for the reinforcement between the first end of the hose and the first end connector at the first sinusoidal gripping means of the first end connector; and wherein the second end connector is permanently attached to the second end of the hose, thereby forming a sinusoidal lock for the reinforcement between the second end of the hose and the second end connector at the first sinusoidal gripping means of the second end connector.

14. The high pressure reinforced hose assembly of claim 11, comprising:

a length of high pressure reinforced rubber hose having a first end, a second end, a reinforcement, an inner rubber layer and an outer skin layer;

a first terminal connector and a second terminal connector, the first terminal connector and the second terminal connector comprising a ferrule and a stem; and wherein the hose is first skived at both ends by removing a portion of the outer skin layer and the inner rubber layer prior to permanent attachment to the end connector, thereby fully revealing the reinforcement, allowing the reinforcement to be in direct contact with the ferrule and the stem; and wherein a further portion of the skin layer is removed, thereby allowing only the stiffener to be in direct contact with the ferrule, and wherein the connectors each have a plurality of gripping devices formed between the ferrule and the stem, the plurality of gripping devices having first and second sinusoidal gripping devices therein; and wherein the first end connector is permanently attached to the first end of the hose, thereby forming a sinusoidal lock for the reinforcement between the first end of the hose and the first end connector directly at the first sinusoidal gripping means of the first end connector; and wherein the first connector is further permanently attached at the second sinusoidal clamping device between the ferrule, stiffener, inner barrel and stem; and wherein the second end connector is permanently attached to the second end of the hose, thereby forming a sinusoidal lock for the reinforcement between the second end of the hose and the second end connector directly at the first sinusoidal gripping means of the second end connector; and wherein the second connector is also permanently attached at the second sinusoidal clamping device between the ferrule, stiffener, inner barrel and stem.