This invention relates to an apparatus and a method for collecting debris in a wellbore. The apparatus includes a housing for receiving debris defined by an endless wall portion, first and second end portions, at least the second end portion is provided with at least one closable aperture allowing one-way flow of debris into the housing, a releasable sealing device for holding a volume of a first fluid within the housing, the volume of the first fluid having a lower pressure than ambient wellbore pressure; a retaining device for initially holding the releasable sealing device in a first portion; a releasable sealing device to move from the first position to a second position, whereby debris is entered through the closable aperture into the housing, where volume of first fluid is reduced, at least one conduit defined by an inlet and an outlet, the outlet being in the second end portion being submerged in the debris when the apparatus collects debris, the inlet in fluid communication with a pressurized second fluid contained in a chamber upon release of a valve.

This invention relates to an equalized debris bailer system for wells related to production of hydrocarbons.
In conjunction with constructing, completing, operating and maintaining wells, there is a potential for experiencing situations where debris accumulates and causes problems.
One example is debris that accumulates on top of barriers that are to be retrieved, preventing the pulling tools from engaging relevant fishing necks. Such debris could be the result of particle production from the reservoir, or a result of heavy particles settling out from a heavy fluid, such as drilling mud. In other situations, such as a recompletion operation, debris could be formed by scale or rust or other components and/or by particles falling off the old production tubing during the retrieval process. Other examples include steel cuttings from milling or cutting operations, grease that has been applied on the pipe threads of the production tubing, lost objects and more.
Another example of debris accumulation is related to deviated and horizontal wells. If the well production flow velocity is too slow to produce particles out of the well, these particles tend to settle and accumulate at particular locations in the well. Typically, debris will settle in a section of the well characterized by a certain angle of deviation. Upstream of this location, the flow velocity may be sufficient to transport the particles, but downstream of the location—typically where the well angle becomes steeper—the flow velocity is insufficient for lifting the particles out of the well. In such cases, there is a risk of relatively long dunes or accumulations being formed in the well. In worst case, such debris accumulation may potentially reduce production or even plug the well. In any case, such dunes represent a problem for wireline interventions, preventing the deployment of tools to locations below the debris or, in the worst case, causing the toolstring to become stuck in the well.
The term "bailer" is a common term for devices used to collect and bring debris out of the well. There is a variety of types. Features in common are a collector pipe for housing the gathered debris; a triggering mechanism for initiating and conducting the collection of debris; and a bottom valve/closure mechanism to prevent the debris from exiting the collector pipe during retrieval of the bailer from the well after being filled.
Typical closure mechanisms for bailers comprise flapper valves, poppet valves, and ball valves.
Pump bailers are operated by means of wireline. After landing the bailer in the debris column, the wireline is pulled up. For this type of bailer, the upper part of the downhole toolstring is connected to a shaft being connected to an inner piston of the bailer. When pulling up, this inner piston is shifted upwards, which causes debris to be sucked into the lower end of the bailer. A potential drawback is that a relatively limited suction force is generated.
Other known pump-based bailer systems are operated by electric pumps. Here, the well fluid is circulated through the system. More specifically, the well fluid is routed through the collector pipe by means of the pump. The fluid exit is provided with a screen that ensures that the debris is kept within the collector pipe. Potential drawbacks with this type of bailer are a somewhat limited suction force, and also that the bailer might not be properly filled should the screen experience premature plugging.
One alternative to the pump-based bailer systems are bailers that apply transport screws to collect and bring the debris into the collector pipe. One limitation of screw bailers is that they may not be able to remove debris located on the outside of external fishing necks (i.e. once the screw meets a steel object, no more debris can be collected).
Another family of bailer concepts is hydrostatic bailers. In a hydrostatic bailer, the collector pipe contains air being at atmospheric pressure when running into the well. After landing the bailer in the debris column, a piston is released. Initially, this piston is located at the bottom end of the collector pipe and, upon being released, the piston travels towards the upper end of the collector pipe. Because of the rear end of the piston being exposed to air at atmospheric pressure, a tremendous suction force is created at the inlet of the bailer.
Hydrostatic bailers can be capable of collecting debris located in areas where other bailer systems cannot gain access, and also of collecting debris being of such a nature that other bailers cannot collect it (for instance partly hardened debris). Despite these benefits, the industry is somewhat reluctant to use hydrostatic bailers. The reason for this is that they tend to get stuck in the well. More precisely, in some situations the bailer is sucked down into the debris column where the debris forms a pressure tight mudcake around it, thereby preventing the underpressurised collector chamber from being fully pressure-equalized with the rest of the well. As a result, the bailer sticks and cannot be retrieved without applying excessive force on the wireline, causing damage to or breaking the wireline.
Publication NO 330997 discloses a cleaning tool for use in a borehole where the cleaning tool comprises a collection volume, and where an actuator in the cleaning tool is disposed to be able to reduce an in the cleaning tool being flushing liquid volume, as a discharging flushing liquid from the flushing liquid volume is led through a jet pod and directed towards an object to be cleaned.
Publication WO 2009/153560 A2 discloses an apparatus for creating a force downhole. The apparatus comprises a tubular body defining a chamber, a plug, the plug being movable between a first position at a first chamber location to a second position at a second chamber location, a latch adapted to releasably fix the plug in the first position and a latch mechanism to release the latch.
The object of the present invention is to remedy or reduce at least one of the drawbacks of prior art.
The object is achieved in accordance with the invention, by the characteristics stated in the description below and in the subsequent claims.
According to a first aspect of the present invention there is provided an apparatus for collecting debris in a wellbore, the apparatus comprising:                a housing for receiving debris, the housing being defined by an endless wall portion, a first end portion and a second end portion, at least the second end portion being provided with at least one closable aperture allowing one-way flow of debris into the housing;        a releasable sealing device for holding a volume of a first fluid within the housing, the volume of the first fluid having a lower pressure than the ambient wellbore pressure;        a retaining device for initially holding the releasable sealing device in a first position;        a release mechanism for operating the retaining device in a manner allowing the releasable sealing device to move from the first position to a second position, whereby debris is entered through the closable aperture into the housing, whereupon said volume of first fluid is reduced,wherein the apparatus is further provided with at least one conduit extending between the end portions of the apparatus, the conduit being configured to communicate wellbore fluid from the first end portion to the second end portion to equalize any pressure differential between the end portions.
As an alternative to equalizing any pressure differential between the end portions by means of the wellbore fluid, the present invention is related to an apparatus for collecting debris in a wellbore, the apparatus comprising:                a housing for receiving debris, the housing being defined by an endless wall portion, a first end portion and a second end portion, at least the second end portion being provided with at least one closable aperture allowing one-way flow of debris into the housing;        a releasable sealing device for holding a volume of a first fluid within the housing, the volume of the first fluid having a lower pressure than the ambient wellbore pressure;        a retaining device for initially holding the releasable sealing device in a first position;        a release mechanism for operating the retaining device in a manner allowing the releasable sealing device to move from the first position to a second position, whereby debris is entered through the closable aperture into the housing, whereupon said volume of first fluid is reduced, wherein the apparatus is further provided with at least one conduit defined by an inlet and an outlet, the outlet being in the second end portion being submerged in the debris when the apparatus is in a position for collecting debris, the inlet being in fluid communication with a pressurised second fluid contained in a chamber, the second fluid having a pressure exceeding an ambient pressure so that, upon release of a valve the pressurized second fluid flows out of the outlet.
The first aspect of the invention and the alternative above have the effect that any underpressure generated in the first and/or second chamber after release of the releasable sealing device, will be pressure equalized with the second fluid even if the debris has created a fluid-tight seal around a lower portion of the bailer. Thus, the bailer according to the present invention provide a pressure equalized hydrostatic bailer that substantially removes the drawbacks of prior art hydrostatic bailers, and thus facilitates retrieval of the bailer containing debris. Even in the case where no underpressure has been generated in the first and/or second chamber after release of the piston, the pressure equalising conduit may represent a significant improvement to existing solutions. The reason is that a normal bailer operation very often entails the bailer being sucked substantially into the debris column. It is commonly experienced that because of this, even in the case where no underpressure has been formed in the first and/or second chamber, it may be difficult to retrieve the bailer. The reason is related to underpressure forming at the first portion of the bailer (i.e. the end that has been sucked the furthest into the debris) as a function of retrieving it, resulting in a suction force. Often, the nature of this effect is that the harder the wireline pull, the larger this suction force becomes. The equalisation conduit according to the present invention will allow for a pressurized fluid to flow to a location close to the first portion of the bailer, hence fill the volume or "cavity" created when pulling the bailer with pressurised fluid from the wellbore, and the bespoken suction force will be significantly dampened or eliminated.
In one embodiment the second end portion comprises the releasable sealing device, and the aperture is defined by the sealing device.
In a preferred embodiment the releasable sealing device is a piston arranged within the housing, the piston defining at least a first chamber within the housing, and a second chamber being in fluid communication with the closable aperture.
The pressure in the second chamber may be higher than the pressure in the first chamber whereby upon operating of the release mechanism, the piston is allowed to move towards the second end portion and allow debris to be moved through the aperture into the first chamber.
In one embodiment the at least one conduit is provided in the wall portion.
As mentioned above, the inlet portion of the conduit may be in fluid communication with a chamber containing the pressurized second fluid which is arranged to be released upon release of a valve. Alternatively, the conduit extends through the end portions of the apparatus, where the pressurized second fluid is a wellbore fluid.
The conduit may be provided with means arranged in a lower portion of the conduit, whereby debris is prevented from entering into the conduit upon running the apparatus into the debris. The means may be a one-way valve.
According to a second aspect of the present invention, there is provided a method for facilitating retrieval of a hydrostatic bailer arranged for collecting debris in a wellbore, wherein the method comprises allowing pressurized fluid to flow out of a lower portion of the apparatus and into the debris, which at least reduces any underpressure generated during at least one of a debris collection process and an apparatus retrieval process from the well.
As indicated earlier, there are two distinct beneficial aspects associated with the method. The first beneficial aspect is that underpressure, which is created during activation and operation of the hydrostatic bailer, will be eliminated or reduced. The second beneficial aspect is that underpressure, which is created as part of the process dynamics when pulling the bailer out of the debris columns, is eliminated or reduced.
In the figures, similar or corresponding parts may be indicated by the same reference numerals.
Positional indications such as e.g. upper, lower, above, below, and also directions such as upwards and downwards, refer to the position shown in the figures.
FIG. 1 illustrates a generic well 1 which is used in the subsequent illustrating examples. As can be seen in the figure, the well comprises a production tubing 100 that is run inside a production casing 101. The production casing is fixed to the surrounding rock formation by an outer cement section 102. The cement also provides a barrier seal in an annular cavity between the production casing 101 and the surrounding rock formation. A production packer 103 forms a seal in the annulus between the tubing 100 and the casing 101.
The production tubing 100 is inserted or stung into a production liner 104 via a so-called stinger assembly 105. The annulus between the liner 104 and the casing 101 is sealed by a liner seal 106. In the embodiment shown, the liner 104 is cemented to the surrounding formation by means of a lower cement section 107. In order to provide a flow path between the wellbore and relevant sections of the surrounding formation, the well is perforated. A set of perforations 108 are illustrated.
A wellhead 109 is provided on top of the well 1. A person skilled in the art will appreciate that the wellhead 109 is connected to a flow line, but this is not illustrated herein for the sake of simplicity.
In a lower section of the well, a retrievable barrier 110 is installed. This barrier 110 could have been installed in conjunction with general maintenance work or recompletion work in the well. In this particular situation, the retrievable barrier 110 has been covered by a debris column 111. The debris may, for example, have arisen from drop-out of scale when recompleting the well, or may be generated by other actions or events in the well. As a main result, the retrievable barrier 110 cannot be accessed and engaged by relevant running tools. In order to do so, the debris must be removed.
FIG. 2 illustrates a so-called kick-off section or heel in the well, where the well's deviation angle changes from "mainly vertical" to "mainly horizontal". Here, a debris accumulation or dune 112 has formed in an area of the production tubing 100 where the production flow rate is too low to transport the debris in the more vertically deviated section of the well, and thus further out of the well.
FIG. 3 illustrates a hydrostatic bailer 200 according to the present invention. The hydrostatic bailer 200 comprises a collector pipe 201, a bottom flange 202 and a top flange 203. The bottom flange 202 comprises a closure valve 204, the purpose of which is to prevent gathered debris from exiting the bailer when being retrieved from the well after operation. The bottom flange 202 also comprises a manually-operated lower pressure bleed-off system 205. This is a safety feature used to manually bleed off any trapped overpressure in the system, which may be present after having operated it in the well.
A similar manually-operated upper pressure bleed-off system 206 is located in the top flange 203. The top flange 203 includes an automatic pressure relief valve 207, the purpose of which is to ensure that the majority of any trapped pressure is evacuated from the bailer 200 prior to being handled by any personnel. The wireline cable 208 is included for illustrating purposes.
A piston 209 is mounted in the bottom end of the bailer 200. This provides for maintaining atmospheric pressure inside a collector chamber 210 when deploying the bailer into the well. A seal section or piston seal 211 provides for the necessary pressure integrity of the piston 209. Lock profiles 212 physically lock the piston 209 to a recess 225 provided in the collector pipe 201 when the bailer 200 is in its initial position, as shown in FIG. 3.
The bailer is activated by means of a piston release system 213 causing the lock profiles 212 to disengage from the recess 225 in the collector pipe 201. For this illustrated embodiment, the release system 213 is connected to an activation mechanism 214 operated by an activation nose 215. It should be appreciated that the illustrated embodiment is only one of a variety of activation mechanisms, and that other activation mechanisms could be applied.
The activation nose 215 may be formed in many different ways. In one embodiment, the activation nose 215 is adapted to suit the consistence of the debris in question. As an example, if the debris is relatively compact, a relatively slim body activation nose 215 could be applied. If the debris is soft and muddy, the activation nose 215 could be formed in a manner allowing it to maximize the contact area with the debris, for instance by increasing the transverse area on the tip of the activation nose 215. In very soft mud, the tip could, for example, be formed into a somewhat large, convex parabolic shape in order to maximize drag/resistance when lowering the bailer 200 into the debris column 111.
The upper part of the piston 209 comprises a piston flange 216 and a piston equalizing port 217.
The top section of the bailer 200 comprises a direct equalizing system 218 which comprises an equalizing sleeve 219, lower seals 220, upper seals 221 and an equalizing port 222.
An equalizing conduit, which is shown as a line 223, provides for fluid communication between the top and the bottom of the bailer 200. The equalizing line 223 will equalize differential pressure that may arise during operation and thus prevents the bailer from getting stuck due to the presence of differential pressure.
A cavity or chamber 224 between the bottom flange 202 and the piston 209 is pressurised to a pressure being substantially equal to the surrounding wellbore pressure. However, after operating the bailer and/or during subsequent retrieval from the well, a pressure-tight mudcake may form around the main closure valve 204, which implies that pressure is trapped in the cavity 224. This is the main reason for including the lower, manually operated pressure bleed-off system 205 in the bottom flange 202. In another embodiment, the bottom flange 202 may comprise other bleed valves, such as automatic/mechanic pressure relief valves.
In the embodiment shown, the main closure valve 204 is arranged off-center with respect to the central axis of the bailer 200. Moreover, the main closure valve 204 is illustrated to be of a relatively small inner diameter (i.e. having a relatively small flow area). These embodiments have been chosen for illustrative purposes only. In other embodiments, modifications can be done in order to optimize the main closure valve 204 by means of location, geometry, design and dimensions. Such modifications will be appreciated by a person skilled in the art.
FIG. 4 illustrates the initial step of the debris collecting operation where the activation nose 215 is lowered into the debris column 111. The physical resistance exerted by the debris column 111 causes a push on the activation nose 215 so that it moves in an inward direction with respect to the bailer 200. This movement causes the activation nose 215 to interact with the activation mechanism 214, which in turn interacts with the release system 213 so as to cause the lock profiles 212 to disengage from a recess 225, as will be discussed further below. When the profiles 212 are disengaged from the recess 225, the piston is loose, whereby the well pressure will push the piston 209 inwards and further up into the bailer 200. When this further movement of the piston 209 occurs, parts of the debris column 111 will be sucked or driven into the collector chamber 210 of the bailer 200. This process normally takes place by virtue of the bailer 200 being sucked into the debris column 111.
FIG. 5 illustrates the situation after the piston 209 has travelled its full length in the collector chamber 201. The collector chamber 201 has now been substantially filled with debris 111. The direct equalizing system 218 has been shifted by the piston 209, and the equalizing port 222 is aligned with the piston equalizing port 217. This again has caused the collector chamber 210 to be pressure-equalized with the surrounding well pressure. This feature of pressure equalization is mainly intended to prevent pressure from becoming trapped inside the bailer upon retrieval, and which may represent a safety threat to personnel handling the bailer 200. However, the effect of operating the direct equalising system 218 may also contribute to reduce and/or avoid underpressure forming in the lower sections of the bailer 200 after activation.
Due to the main closure valve 204 combined with any mudcake that may form in the bottom section of the bailer, the direct equalizing system 218 is not seen to be capable of eliminating underpressure forming at the very bottom of the bailer, i.e. below the main closure valve 204. In order to equalize any underpressure forming in this region, the equalizing line 223 is required.
A person skilled in the art would appreciate that the equalizing line 223 may be provided with one or more additional lines, to increase pressure-equalizing capacity. Moreover, the equalizing line 223 may be provided with one or more one-way valves or plugs to prevent accidental/premature plugging when running the tool in the well, and/or into the debris column 111. Typically, such one-way valve/plug systems would prevent debris from entering the equalizing line 223 from the lower/bottom end, and thus cause the line to plug, whereby the equalizing functionality is impaired or non-existent.
FIG. 6 illustrates retrieval of the bailer 200 after collection of the debris 111. The closure valve 204 is in the closed position and thus prevents the debris from falling out of the bailer 200 during retrieval.
FIGS. 7a and 7b illustrate, in larger scale, one embodiment of the automatic pressure relief valve 207 arranged in the top flange 203 of the bailer 200, which is shown in FIGS. 3-6. After operating the bailer 200 and during retrieval out of the well 1, the exterior 701 of the bailer 200 will be exposed to a gradually decreasing pressure. Initially, the inside 702 of the bailer 200 will hold a pressure equal to the well pressure at the relevant sample depth. As the bailer 200 is retrieved from the well, the pressure differential between the exterior 701 and the interior 702 of the bailer 200 is gradually increased.
The automatic pressure relief valve 207 comprises a piston 703, which is kept in an initial position by a shear pin 704, as shown in FIG. 7a. A pre-compressed spring 705 seeks to push the piston in an upwards direction, as shown. Once the pressure relief valve 207 is activated, a channel 706 provides for fluid communication between the exterior 701 and the interior 702 of the bailer 200. A seal 707 is also included.
Once the pressure differential between the exterior 701 and the interior 702 of the bailer 200 exceeds a certain level, the shear pin 704 shears off, and the piston 703 is shifted, as shown in FIG. 7b. There is now fluid communication from the interior 702, through the channel 706 to the exterior of the bailer 200.
As shown in FIG. 7b, the piston 703 is forced out of its channel when activated. This provides for a good visual verification that the pressure relief valve 207 has been activated.
It should be noted that if the direct equalizing system 218 of FIGS. 3-6 have been shifted, the pressure on the inside 702 of the bailer 200 will be automatically adjusted to the pressure on the exterior 701 of the bailer 200. The main intention with the automatic pressure relief valve 207 is to function as a replacement for the direct equalizing system 218, or as a contingency device should this fail to operate.
FIG. 8 illustrates another embodiment of a bailer piston 209 and associated activation and release systems suitable for use in the bailer 200. A main piston element 801 represents a body that holds the differential pressure when deploying the bailer 200 into the well. A piston core 802 is providing radial support to a finger coupling 212, keeping this in place in a recess 225 of a collector pipe 201 during deployment into the well 1. In the embodiment shown in FIG. 8, the main piston element 801 is directly prevented from moving into the bailer 200 by the finger coupling 212. A lower portion of a shaft 803 is connected to the activation nose 215, which is shown in FIGS. 3-6. An upper portion of the shaft 803 is connected to an activation shaft 804. The activation shaft 804 extends into a cylindrical extension 805 of the main piston 801. Seals 806, 807 are included to provide for pressure integrity of the bailer piston 209. Piston core rods 808, which are attached to rod extensions 809, are included to ensure that the main piston 801 and the piston core 802 do not part during operation of the bailer 200. Seals 810, 810′ are included around the piston core rods 808 to provide for pressure integrity of the bailer piston 209. An equalization channel 811 provides for fluid/pressure communication between the well surroundings and the internal chamber 812 of the cylindrical extension 805. This is required to avoid trapped pressure and/or accidental operation due to temperature effects or similar.
The activation shaft 804 comprises a radial extension 813, as shown in FIG. 8. However, it should be appreciated that more than one radial extension 813 may be provided. The radial extension 813 protrudes, through a longitudinal slot 814 of the cylindrical extension 805, to the main piston 801. When the activation shaft 804 is operated, the radial extensions 813 will push onto a shoulder 815 of the piston core 802.
FIG. 8 also illustrates guide bolts 816 that are attached to the finger couplings 212. The guide bolts 816 have a certain degree of freedom with respect to longitudinal movement inside recesses 817 of the piston core 802. More precisely, the guide bolts 816 are arranged to move freely between an upper surface 818 and a lower surface 819 of the recess 817.
The embodiment of the bailer piston 209, which is illustrated in FIG. 8, may also include springs or shear pins in order to bias or fix the activation shaft 804 towards a lower position in the bailer for the initial positioning and during deployment, hence preventing accidental activation prior to and during lowering of the bailer into the debris column. Preferably, a correct choice of shear pin strength and/or spring force in this relation is adapted to the relevant fluids and debris (compactness of debris) in the well. This would be appreciated by a person skilled in the art and is therefore not discussed in any further detail herein.
FIG. 9 illustrates the first operational step for the embodiment discussed in FIG. 8. As a result of lowering the activation nose 215, as shown e.g. in FIG. 4, into a debris column (not shown), this ultimately shifts the activation shaft 804 upwards. This again causes the radial extension 813 to push the piston core 802 upwards accordingly. When the piston core has travelled a certain distance, the finger coupling 212 will lose its radial support, and subsequently disengage from the recess 225. This is illustrated in FIG. 10. When the finger coupling 212 disengages from the recess 225, the bailer piston 209 will be pushed upwards in the collector chamber 210 of the bailer 200. This is illustrated in FIG. 11 and further in FIG. 12. As a consequence of the pressure surge created, debris 1101 is sucked into the bailer 200, more precisely into a cavity 224 between the piston 209 and a lower flange (not shown) similar to lower flange 201, shown e.g. in FIGS. 3-6.
FIG. 13 illustrates a further alternative embodiment of the bailer piston 209 and related design and philosophy of operation. A shaft 1301 is in direct connection with the activation nose (not shown), which is similar to the activation nose 215 shown in e.g. FIG. 4. The shaft 1301 extends into a cylindrical extension 805 of the main piston 801. Initially, seals 1302, 1303 on a radial extension of shaft the 1301 seals off a port 1304 in the cylindrical extension 805 of the main piston 801. The port 1304 is in fluid communication with a chamber 1305, which again is in fluid communication with a chamber 817. In this embodiment, the piston core 802 has been provided with a top seal 1306.
FIG. 14 illustrates a first step of operating the system according to the embodiment shown in FIG. 13. When the activation nose is lowered into the debris (as shown in FIG. 4), the shaft 1301 is pushed upwards and into the bailer 200. More precisely, the shaft 1301 is displaced into the cavity 812, which is best seen in FIG. 13. This displacement results in the port 1304 becoming exposed to well pressure. Because of the somewhat slimmer design of the shaft 1301 below the radial extension housing seals 1302, 1303, the fluid communication is good, and the internals of the bailer piston 209, such as the chamber 1305 and the chamber 817, are quickly filled with high-pressure fluids.
As illustrated in FIG. 15, the entry of high pressurized fluids into the bailer piston 209 causes the piston core 802 to be pushed up and inwards into the evacuated/atmospheric chamber of the bailer 200. This causes the finger coupling 212 to lose its radial support and collapse inwards. Now the bailer piston 209 is released and is free to move inside the collector pipe 201. Due to the atmospheric pressure conditions in the cavity 210, the piston is forced into this cavity by the well pressure. Subsequent to this, debris is sucked into the bailer 200 from the low side. This is further illustrated in FIGS. 16 and 17.
FIG. 18 shows yet another embodiment of the present invention. Here, the bailer 200 is run into the well on a wireline tool 1801, such as a wireline tractor. The wireline tool 1801 is connected to the bailer 200 via a crossover device 1802. For this embodiment, the bailer 200 is activated by means of a control signal and/or action, such as an electric signal and/or action. FIG. 18 illustrates an electric activation system. Here, the top section of the bailer 200 comprises an electric connector plug 1803. In one embodiment, this electric connector plug 1803 also functions as a pressure barrier in order to protect delicate components inside the wireline tool 1801 and the crossover 1802 from being exposed to high pressure after activating the bailer 200. An electric cable/lead 1804 runs from the electric connector plug 1803, through the majority of the collector pipe 201 of the bailer 200 and terminates in an electrically-operated version of the activation mechanism 214.
A main benefit with electric activation is that the bailer 200 can be controlled by an operator. Considering the scenario from FIG. 2, where debris may have formed a long dune or accumulation, it may be beneficial to use a wireline tractor to "shovel" or compress the dune 112 into a larger and more compact debris column prior to activating the bailer 200. A system that operates on impact may trigger too early or too late, which may result in a somewhat non-optimal debris collection process, whereas an operator-controlled system allows for a far better collection pattern for such scenarios.
FIG. 19 illustrates one example of electric activation, wherein the main piston 801 and the piston core 802 are locked together by means of lock fingers 1901 attached to the main piston by means of bolts 1902. When the bailer 200 is in its initial position, the lock fingers 1901 are radially supported by a radial extension 1903 that forms an integrated part of a shaft 1904. In this embodiment, the main piston 801 and the piston core 802 include a pre-compressed spring 1914 that seeks to push the piston core 802 upwards/inwards into the bailer 200, hence away from the main piston 801. The shaft 1904 also includes a flange 1905. An initially pre-compressed spring 1906 seeks to push the flange 1905, and thereby the shaft 1904, downwards with respect to a flange housing 1910. A set of lock profiles 1907 locks the shaft 1904 in its initial position, as the lower part of the lock profiles 1907 engage in a lock groove 1908 provided in the shaft 1904. In this embodiment, the lock profiles 1907 comprise at least two elements that form, when assembled, a cylindrical shape. Also, the lock profiles 1907 are kept in their initial assembled cylindrical shape by means of a fuse wire 1909 wrapped around the lock profiles 1907 forming a cylindrical assembly. The fuse wire 1909 is connected to the electric lead 1804. The lower end of the lock profiles 1907 rests against a top shoulder of the flange housing 1910, which is attached to the main piston 801 via connector shafts 1911. The connector shafts 1911 are fixed to the main piston 801 by a fixing means, such as a threaded connection or by other suitable fixing means that will be appreciated by a person skilled in the art. In the embodiment shown, lock nuts 1912 are used as fastening means to fasten the flange housing 1910 to the connector shafts 1911.
For the embodiment illustrated in FIG. 19, the main piston 801 has been designed with a swab cup stack 1913 as a supplement to the seal 211. Normally, the swab cup stack 1913 will have better sealing capabilities during the dynamic part of the bailer 200 operation, i.e. when the main piston 801 is moving, thereby providing the best possible optimization of the debris collecting process.
FIG. 20 illustrates a first step of the operation where an electric current has been applied on the electric lead 1804. This has caused the fuse wire 1909 (shown in FIG. 19) to burn up or at least degrade to a level where the compressed spring 1906 can overcome the holding force exerted by lock profiles 1907 on the lock groove 1908 of the shaft 1904. As a result, the shaft 1904 is free to move down, pushed by the spring 1906 exerting force on the flange 1905. In FIG. 20 the fuse wire 1809 has been burned up, hence is not shown.
FIG. 21 illustrates the next step where the shaft 1904 is shifted down whereby the radial extension 1903 no longer supports the lock fingers 1901 radially. Hence, the lock fingers 1901 disengage from the recesses and do no longer lock the main piston 801 and the piston core 802 together.
Now, as illustrated in FIG. 22, the spring 1914 pushes the piston core 802 up/inwards into the bailer 200. As a consequence, piston core 802 no longer supports the finger coupling 212 radially. The plug 209 then releases, as described in relation to explanations given for previously described embodiments herein. This is further illustrated in FIG. 23.
FIG. 24 illustrates an alternative way of effectuating operator-controlled electric activation of the bailer 200. Initially, the cylindrical lock profile 1907 assembly is held in place by a lock cylinder 2401. The lock cylinder 2401 is attached to a motor shaft 2402 that runs through an electro-motor 2403. The motor 2403 is connected to a motor flange 2404 bolted to a motor support housing 2406 via bolts 2405. The motor support housing 2406 is bolted to the flange housing 1910 via bolts 2407. By so doing, the motor assembly is fixed directly to the main piston 801.
FIG. 25 illustrates the initial step of operation for this embodiment. Here, an operator command/action is applied to operate the motor 2403. This again ensures that the lock cylinder 2401 is pulled up so that the lock profiles 1907 become unsupported. As described for the previous embodiment shown in FIGS. 19-24, this triggers a cascade of events that results in the bailer 200 becoming activated.
FIG. 26 illustrates an embodiment where the bailer 200 is provided with a chamber 2601 for containing a fluid under high pressure. For example, the fluid may be a gas, but it may also, or alternatively, be a liquid. For this embodiment, in conjunction with the operation of the bailer 200 itself, a valve 2602 is also operated, whereby high pressure fluid flows down the equalizing line 223. For the given embodiment, the valve 2602 is operated electrically via a cable 2603, but other means known per se of achieving valve 2602 operation may also be applied. A benefit of using a high pressurized fluid, as described herein, is that this will contribute to prevent the bailer 200 from sinking significantly into the column of debris 111 during the operation. Provided a correctly tuned flow capacity of the equalizing line 223 exists, the highly pressurized fluid allow the bailer 200 to be pushed gradually out of the debris 111 column after the operation. In the embodiment shown, the chamber 2601 may be filled with the fluid via the equalizing line 223.
FIG. 27 illustrates, in larger scale, a second scenario of applying a highly pressurized gas. The figure illustrates sections of a wireline tool 2701 used to retrieve the bailer 200 in case it should become stuck in the debris 111. This may occur if the equalizing line 223 becomes accidentally plugged prior to operating the bailer 200. To remedy such a situation, the wireline tool 2701 is lowered onto the top flange 203 of the bailer 200, as illustrated in previous figures such as FIG. 26, whereby a skirt with elastomeric seals 2702 enters and forms a sealing connection against the top flange 203. Systems for anchoring the wireline tool 2701 mechanically to the flange 203 might be included, but are not shown in the figure. Upon verifying a proper connection, a valve 270 inside the wireline tool 2701 is opened so as to allow highly pressurized fluid, for example a gas from a chamber 2703 in the wireline tool 2701, to be released and flow down the equalization line 223. This will cause a high pressure to form at the base of the bailer 200, which facilitates retrieval of the bailer 200 as the high pressure pushes the bailer 200 up from the lowered position in the debris column 111.
FIGS. 28a and 28b illustrate, in larger scale, a lower portion of the bailer 200 being provided with means 2801, 2802 for preventing the equalizing line 223 from becoming accidentally plugged during intervention and/or operation in the well. Such features will be part of a preferred embodiment, given that any accidental plugging of the line 223 is highly undesirable. FIG. 28a illustrates the use of a check valve 2801 to prevent the line 223 from getting plugged. FIG. 28b illustrates the use of a plug 2802, such as a plug made of an elastomeric material, for plugging off the line 223. Upon activation of the bailer 200, the check valve 2801 will be forced open, and/or the plugs 2802 will be blown out from the line 223, due to the relative high pressure emerging from the top end of the bailer and down via line 223, which ensures that the line 223 remains free from impurities until the bailer 200 is activated, whereupon the line is opened to allow for fluid flow from the top section of the bailer 200 to the bottom section of the bailer 200.
While the invention has been described with a certain degree of particularity, many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is limited only by the scope of the attached claims, including the full range of equivalency to which each element thereof is entitled.


The reactive element is introduced to the surface of the metal substrate in the form of an oxide powder and the aluminide-type coating is then formed.

The invention relates to the formation on a metal substrate of a protective coating of the aluminide type incorporating at least one reactive element.
The field of application of the invention is that of the production or repair of metal components which, because of their use at high temperatures and in an oxidizing medium, must be provided with a protective coating.
The invention is especially, but not exclusively, applicable to gas turbine components, in particular to components of the hot parts of turbojets.
To optimize their operation, it is endeavoured to make gas turbines, especially turbojets, operate at the highest possible temperatures.
The components exposed to these temperatures are usually made of a refractory metal alloy, or superalloy, based on nickel or cobalt.
In order to improve their high-temperature behaviour, in particular their corrosion and oxidation resistance, it is well known to form a protective coating on the superalloy metal substrate.
Among the constituent materials of such a protective coating, aluminide-type coatings, which especially allow the development of a protective alumina film on their surface, are commonly used.
Aluminization by cementation is the technique used most often to form aluminide-type coatings. This technique generally consists in placing the metal substrate in a closed chamber containing a cementation agent and in raising the assembly to a temperature usually between 900xc2x0C. and 1150xc2x0 C.
The aluminide-type coatings can be used by themselves, or in combination with an external coating forming a thermal barrier, such as a ceramic coating. In the latter case, the aluminide-type coating constitutes a bond coat between the substrate and the external coating, attachment of the latter being favoured by the presence of the alumina film forming an adhesion layer.
To increase the lifetime of the alumina-film-generating aluminide and to limit its deterioration by spalling it is known to incorporate into the aluminide-type coating at least one reactive element usually chosen from the group consisting of zirconium, yttrium, hafnium and the lanthanides.
Such a reactive element reinforces the diffusion barrier function with respect to elements of the metal substrate which are liable to affect the alumina film, and it therefore favours the integrity and the persistence of the latter. The presence of the reactive element also results in a reduction in the rate of oxidation of the metal substrate and prevents the segregation, which is highly undesirable, of sulphur at the interface with a ceramic external coating.
Various processes have been proposed for forming an aluminide-type coating incorporating a reactive element.
A first type of known process consists in alloying or combining separately the reactive element with one or more constituents of the coating and in forming the latter by a process involving physical deposition on the metal substrate.
For example, reference may be made to the document U.S. Pat. No. 4,055,705 which describes the formation of a bond coat by the plasma spraying or sintering of NiCrAlY or depositing it using another physical technique. Reference may also be made to the document FR 96/15257 which describes the deposition, by electrophoresis, or in the form of a paint with a thermally degradable or volatile binder, of an MCrAlY (M being Ni and/or Co and/or Fe) alloy powder on a metal substrate. Electroplating an alloy containing a metal of the platinum group is then carried out before heat treatment and possible aluminization. Reference may also be made to the document U.S. Pat. No. 5,824,423 which, although envisaging the initial deposition of a reactive element on a metal substrate by physical vapour deposition followed by aluminization, preferably indicates the formation of a bond coat by the plasma spraying of an MAlY (M being Ni and/or Co and/or Fe) pre-alloyed powder.
These types of known processes require a further step of adding the reactive element to an alloy. This may require major investment.
Reference may also be made to the documents SU 1 527 320 and SU 541 896 which describe the application to the surface of a metal substrate of a suspension containing aluminium and zirconium powders and a binder, such as a varnish in solution, in order to obtain a protective coating after drying and heat treatment.
However, the handling of elements such as zirconium in divided form is particularly difficult because of the high risk of spontaneous reaction with the air.
A second type of known process consists in forming an aluminium coating incorporating a reactive element by chemical vapour deposition (CVD). Reference may be made to the document U.S. Pat. No. 5,503,874 which describes the alternating deposition of an aluminium layer and a metal oxide layer, such as yttrium oxide, zirconium oxide, chromium oxide or hafnium oxide, from organometallic precursors. A heat treatment allows the oxide to be reduced by the aluminium. Reference may also be made to the document U.S. Pat. No. 5,989,733 which describes the formation of a coating by the chemical vapour deposition of the elements Al, Si, Hf and possibly Zr, or another reactive element, preceded or followed by the electroplating of Pt, in order to obtain a modified nickel aluminide.
These types of known processes require the use of a chemical vapour deposition plant, which is expensive both in terms of investment and maintenance.
A third type of known process makes use of the aluminization technique, but by modifying it with the incorporation of the reactive element into the cementation agent. Reference may be made to the document FR 2 511 396 which proposes the use of a cementation agent containing aluminium, an aluminium alloy, an activator salt and a reactive element.
It is an object of the invention to provide a process allowing an aluminide-type coating incorporating at least one reactive element to be formed on a metal substrate in a simple and inexpensive manner.
This object is achieved by the fact that, according to the invention, the process comprises the steps which consist in:
introducing the said reactive element to the surface of the metal substrate in the form of a powder of the oxide of the reactive element; and
then forming the aluminide-type coating.
Introducing the reactive element in the form of a powder of the oxide of this element makes it possible to avoid difficulties in handling a powder of the reactive element.
The reactive element may be introduced to the surface of the metal substrate by coating with a composition containing the powder mixed with a liquid, or by spraying such a composition, or by spraying the powder on the substrate so that it becomes encrusted in its surface, or else by electrophoresis.
The process according to the invention is noteworthy in that, despite introducing the reactive element in pulverulent form, an aluminide-type coating is obtained whose microstructure and effectiveness are completely comparable to those of the similar coatings of the prior art, whereas the method of implementation of the process proves to be particularly advantageous.
This is because the process does not require expensive equipment to be installed or maintained.
The reactive element is furthermore introduced as close as possible to the metal substrate, thereby optimizing the efficiency between mass of reactive element involved and doping of the coating thus formed.
In addition, it is possible for the mass of reactive element introduced to be controlled precisely and over a very wide range.
Furthermore, the process allows the reactive element to be introduced into localized regions of the surface of the substrate, for example for the purpose of repairing a protective coating. This is not possible with the processes of the prior art, in which the reactive element is deposited in the gas phase or incorporated in a cementation agent.
The aluminide-type coating may be formed by aluminization after introducing the reactive element to the surface of the substrate. No modification to the known aluminization processes, apart from possibly the duration, is necessary. This constitutes yet another advantage of the process.
As a variant, the aluminide-type coating may be formed by depositing the constituents of the coating after the reactive element has been introduced to the surface of the substrate, and heat treatment in order to make the constituents react together.
Again as a variant, at least the aluminium is furthermore introduced to the surface of the metal substrate in the form of powder and then the aluminide-type coating is formed by heat treatment. The reactive element and the aluminium may be introduced to the surface of the substrate by coating or spraying with a liquid composition comprising a powder of the reactive element in oxide form, an aluminium powder and a binder, the coating or spraying being advantageously carried out in superposed layers in order to achieve a thickness according to that of the desired aluminide-type coating.
According to yet another variant of the process, at least one metal chosen from the group consisting of platinum, palladium, rhodium and ruthenium is furthermore deposited on the surface of the substrate.
The aluminide-type coating formed by the process according to the invention may be used by itself, or as a thermal barrier sublayer, an external coating made of ceramic then being formed which anchors to an alumina film generated at the interface between the aluminide-type coating and the ceramic external coating.
The invention also relates to metal substrates, especially gas turbine components made of a superalloy, which are provided with aluminide-type coatings as obtained by the above process.
The invention will be more clearly understood from reading the detailed description given below by way of indication, but implying no limitation.
The process according to the invention is intended more particularly, but not solely, for the production of aluminide-type protective coatings on metal substrates made of a superalloy, especially a superalloy based on nickel or cobalt, such as metal substrates of gas turbine components, particularly turbojet components.
According to one characteristic of the invention, at least one reactive element that has to be present in the aluminide-type coating is introduced to the surface of the substrate, prior to the formation of the coating, in the form of a powder of an oxide of the reactive element.
The reactive element is preferably chosen from zirconium, yttrium, hafnium and the lanthanides.
Depositing these reactive elements in the form of an oxide powder makes it possible to avoid difficulties in handling these elements which react on contact with the air.
Several simple techniques may be used to deposit the oxide powder on the surface of the substrate.
A first technique consists in preparing a composition containing the powder and a liquid, and in coating the surface of the metal substrate, or a selected part of this surface, with this composition. The liquid used is, for example, a resin to which a solvent may optionally be added. This makes it possible, after the resin has optionally been cured, to fix the powder to the surface. The coating process may be carried out very conventionally using a brush.
As a variant, such a composition containing the powder and a liquid may be sprayed onto the surface or onto a selected part thereof.
Another technique that can be used consists in spraying only the powder onto the surface of the substrate, or onto a selected part thereof. The spraying is carried out by giving the powder particles sufficient energy for them to be able to become encrusted in the surface of the substrate.
Yet another technique consists in depositing the powder on the surface of the substrate by electrophoresis. This is a technique well known per se, a brief description of which may be found in the above-mentioned document FR 96 15257.
It should be noted that, before introducing the oxide powder to the surface of the substrate, an optional initial step of the process may consist in forming, on the surface of the substrate, a coating made of a precious metal chosen from platinum, palladium, rhodium and ruthenium. Such a metal coating may be formed, in a manner known per se, by sputtering or by electroplating, a diffusion heat treatment then being often carried out. As a variant, such a coating with a metal from the platinum group could be formed after introducing the powder of the oxide of an active element to the surface of the substrate.
The next step of the process consists in forming the aluminide-type coating.
Advantageously, a conventional cementation aluminization process is employed.
Pack cementation, with contact between a cementation powder and the substrate, consists in varying the latter in a powder containing (i) an aluminium alloy, generally a chromium-aluminium alloy, (ii) an inert constituent, such as alumina, in order to prevent sintering, and (iii) a halogen-containing activator (for example, NH4Cl, NH4F, AlF3, NaF, NaCl, etc.) which makes it possible to transfer the metal to be deposited between the cementation agent and the substrate. The assembly is raised to a temperature of, for example, between 900xc2x0 C. and 1150xc2x0 C. in a furnace.
The cementation may also be carried out without contact with the substrate, the cementation agent being provided elsewhere in the furnace. In the latter case, the halogen-containing activator may be incorporated into the cementation agent or may be introduced separately into the furnace.
During the aluminization, the oxide of the reactive element, introduced beforehand to the surface of the substrate, may be at least partially reduced. When the oxide is dispersed in a resin, the latter is rapidly degraded by the halides formed by the activator element and by the heat.
Thermochemical reactions take place between the halides, the cementation agent, the oxide of the reactive element and the metal alloy of the substrate which make it possible to form the aluminide coating and to disperse the reactive element within the aluminide coating formed. With a substrate made of a nickel-based superalloy, a nickel aluminide containing the reactive element is obtained.
Processes other than aluminization may be used to form the aluminide-type coating. For example, constituents of the desired coating may be deposited on the substrate by physical vapour deposition processes, such as sputtering or plasma spraying, or chemical vapour deposition processes using gaseous precursors. These processes are known per se. Reference may be made, for example, to the documents GB 2 005 729, U.S. Pat. No. 5,741,604 and U.S. Pat. No. 5,494,704. The constituents may be deposited as superposed alternating layers. A heat treatment is used to obtain the desired aluminide with possible reduction of the oxide introduced beforehand to the surface of the substrate and dispersion of the liberated reactive element within the coating.
According to yet another variant, a hybrid coat, consisting of a powder of the oxide of the reactive element and aluminium powder is deposited on the surface of the metal substrate. The coat may be deposited by a coating or spraying process using a composition containing the oxide powder, the aluminium powder and an inorganic or organic binder, such as a resin optionally diluted in a solvent. Several superposed layers are formed according to the thickness of the coating to be produced. A heat treatment is then carried out at a temperature of preferably between 800xc2x0 C. and 1100xc2x0 C. in order to form an aluminide by diffusion from the metal substrate and the dispersion of the reactive element within the coating.
The metal substrate may be used just with the aluminide coating providing protection against corrosion and oxidation at high temperatures.
It is also possible to add an external coating made of ceramic, for example zirconia, yttrium oxide or yttriated zirconia. This external coating, obtained by a physical deposition process such as, for example, sputtering, thermal spraying or electron beam evaporation, constitutes a thermal barrier. The function of the aluminide-type intermediate coating is then especially to act as a bond coat allowing attachment of the ceramic external coating via an alumina film formed on the surface of the bond coat.
Examples of methods of implementing the process will now be described by way of indication, but implying no limitation.

Formation of an aluminide coating, incorporating a reactive element, on a metal substrate


A packaging machine is disclosed for packing cartons with beverage cans in two overlying layers. The packaging machine has a selector flight, a can flight, and a carton flight, all synchronously movable. A single infeed assembly directs first groups of cans into selector bays on the selector flight, sweeps them into adjacent can bays, and directs second groups of cans into the same selector bays, all on the same level. The selector flight and the second groups of cans then ramps up to an elevated level, from where the second groups of cans are swept into the adjacent can bays atop the first groups of cans. The thus staged cans are pushed into open cartons on the carton flight.

When packaging articles such as soft drink and beer cans into cartons, it sometimes is desirable to group the articles in two layers within the carton, with an upper layer of upright articles overlying a lower layer of upright articles. It is common to separate the layers with a paperboard divider pad on which the upper layer rests. Such a packaging configuration is sometimes referred to as "twin layer packaging." Packaging machines for obtaining twin layer packaging of articles are known, one such machine being exemplified in U.S. Pat. No. 5,758,474 of Ziegler, which is commonly owned by the assignee of the present application. Such packaging machines generally comprise an infeed assembly that progressively directs articles in groups into the bays of a synchronously moving conveyor flight. The infeed assembly includes an upstream infeed belt and associated infeed lanes for directing the bottom layer of articles into the bays. A separate downstream infeed belt and associated infeed lanes, which are disposed at an elevated level relative to the upstream infeed belt and lanes, progressively directs the top layer of articles into the bays atop the already loaded bottom layer of articles. The articles thus are staged in two overlying layers in the bays and subsequently are pushed with a pusher assembly into an open carton on an adjacent and synchronized carton flight. The cartons are then closed to complete the packaging process. The use of separate infeed assemblies, one for the bottom layer of articles and one for the top, increases the complexity of these packaging machines and takes up valuable additional space within them.
A need exists for an improved packaging machine for obtaining twin layer packaging of articles such as beverage cans and it is to the provision of such a packaging machine that the present invention is primarily directed.


A composition containing caffeine solubilized with para-amino benzoic acid is described. Preferably the caffeine is delivered in the form of an aqueous microdispersion including a non-metallic microparticulate carrier. Still more preferably, there is present in the aqueous microdispersion niacin. When administered orally, in small volumes, containing small doses of these agents, this composition has been demonstrated to have stimulant and antisoporific actions that result in elevated mood, decreased fatigue and increased capacity for work that is apparent almost immediately.

The compositions of the invention contain as active pharmacologic agents caffeine or caffeine solubilized with para-aminobenzoic acid, preferably in the form of aqueous microdispersions including a non-metallic microparticulate carrier for the caffeine. This composition, when administered orally, by spray pump, in a dosage of 2-6 drops (about 0.1-0.3 mls) contains about 12-17% caffeine. The composition of the invention preferably contains about 0.25-1.5% nicotinic acid. The resultant compositions have marked stimulant and antisoporific actions that result in elevated mood, decreased fatigue, increased capacity for work and more rapid and clearer flow of thoughts. The solubilization of the caffeine with the PABA permits the delivery of increased amounts of caffeine per unit dose. The microparticles act to extend the time the caffeine or caffeine and niacin remain active in the system and the niacin is effective in counteracting the effect of the caffeine on the blood vessels.
The amount of caffeine delivered of the herein described compositions in a 0.1 ml dose (about 2 drops) is about 14 mgs. One cup of coffee contains about 80-85 mgs of caffeine. The amount of caffeine provided in the compositions of the invention is therefore about 1/6 th the amount of caffeine in a cup of coffee. The amount of niacin in 0.1 ml of a composition is about 0.5 mg. The conventional starting dose for niacin therapy is 100-200 mg TID and the maintenance dose is 0.65-2.0 rams TID. It should be apparent that the dosage of active agents as used in the instant compositions are very low.
The stimulating effects, antisoporific activity, mood elevation, decreased fatigue etc. are evident when the composition is formulated as an aqueous microdispersion of PABA solubilized caffeine, but even further advantages are realized when niacin is included.
The action of these two agents, solubilized caffeine and niacin, appears to be synergistic, i.e., their joint action or combined effect is greater than the algebraic sum of their individual effects. This synergistic action of caffeine has been noted previously, for example, caffeine is one of the best known "adjuvants" when used with pain relieving drugs such as aspirin or acetaminophen.
The compositions of the invention preferably contain in addition to the caffeine and niacin, when the latter is present an agent to increase the solubility of the caffeine. The solubility increasing component is para-aminobenzoic acid. It has been found that this solubilizer is most effective and not only has enhanced solubilizing activity but there are no disadvantages associated with its use. A non-metallic microparticulate carrier for the PABA solubilized caffeine per se or in admixture with niacin is preferably included. The non-metallic microparticles (about 3-10 .mu.m) can be silica, alumina, charcoal or other organic particles in appropriate form. The particles can also e present as liposomes. In addition saccharin in the form of its sodium salt, peppermint oil, licorice or vanilla extract can also be admixed into the compositions of the invention to make them more palatable. A surfactant, for example Tween 20 is also preferably included. The final volume is adjusted with water.
Caffeine is an alkaloid obtained from the leaves and seeds of the Coffea arabica or coffee plant and from the leaves of Thea sinensis or tea. Caffeine is a methylated xanthine having the formula C.sub.8 H.sub.10 N.sub.4 O.sub.2, is anhydrous and has a molecular weight of 194.19. The solubility of methyl xanthine is low. In accordance with the invention a mixture of caffeine and PABA the latter for increasing the solubility of the caffeine (methyl xanthine) is preferred. Such mixture contains anhydrous caffeine and about equal amounts of solubilizer, (PABA) and is freely soluble in water and alcohol.
Although caffeine occurs naturally, it is prepared synthetically for commercial drug use. Both forms are equally suitable for use herein.
The known pharmacologic actions of caffeine include: (1) the relaxation of smooth muscle, notably bronchial muscle and the stimulation of voluntary skeletal muscle, increasing the force of contraction and decreasing associated muscular fatigue, (2) caffeine stimulates all levels of the central nervous system. In oral doses of 100-200 mg, the drug stimulates the cerebral cortex producing a more rapid and clearer though flow, wakefulness, or arousal in fatigued patients and improved psychomotor coordination as well as increased capability for sustained intellectual effort and decreased reaction time, and (3) action on the kidney to produce diuresis.
Caffeine is esentially non-toxic. The FDA has indicated that no fatal caffeine poisoning has ever been reported as the result of an overdose of this compound. The short term lethal dose of caffeine in adults is 5-10 grams. At moderate doses, caffeine poses little or no risk of developmental toxicity for the human fetus. These is no evidence that consumption of caffeine is causally related to the development of cancer or increased incidence of coronary heart disease.
Caffeine is readily absorbed after oral, rectal or parenteral administration. Maximal plasma concentrations are achieved within 1 hour. Caffeine has a half-life in plasma of 3-7 hours.
Caffeine is the only over-the-counter stimultant that meets the FDA standards for stimulants. The FDA has concurred that caffeine is both safe and effective. The recommended dose is 100-200 mg not to be administered more often than every 3 or 4 hours. The FDA has noted that, in contrast to the irritating qualities of many coffee extracts, caffeine itself, does not cause irritation of the gastro-intestinal tract in the usual doses. This is an advantage when the drug is used for its stimultant properties. The FDA, in its publications has stated that the evidence establishes that caffeine restores alertness when a person is drowsy or fatigued.
It has been estimated that the per capita intake of caffeine in the United States averages 170-200 mg/day. About 50% of this amount results from drinking coffee. One cup of coffee contains about 95 mg of caffeine, one cup of tea contains about 50 mg of caffeine, and cocoa contains about 5 mg per cup. A 12 oz (360 ml) bottle of cola contains 40-50 mg of caffeine, half of which has been added by the manufacturer.
Niacin the preferred additional active agent in the compositions of the invention occurs in two chemical forms, nicotinic acid and niacinamide and is a water soluble B vitamin having the formula C.sub.6 H.sub.5 O.sub.2 N and a molecular weight of 123.1. Niacin and tryptophan (an amino acid that is converted to niacin in vivo) are found in yeast, liver, meat, fish, legumes, whole grains and enriched cereal products. Nicotinic acid functions in the body after conversion to either nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP serve a vital role in metabolism as coenzymes for a wide variety of proteins that catalyze oxidation-reduction reactions essential for tissue respiration. It functions to maintain growth, maintain energy supply, maintain the respiratory cycle, maintain anabolism of hormones proteins and lipids. Nicotinic acid is readily absorbed from all portions of the intestine and the vitamin is distributed to all tissues. The niacin is used herein to counteract the effect of the caffeine on the circulatory system and namely its action as a vaso-constrictor.
The therapeutic or replacement dose of niacin is 100-1000 mg/day. There is no toxicity unless dosage exceeds 1-4 gms/kg. One third of a consumed total dose is excreted in 24 hours (half life). In daily doses of 1 gram or greater niacin decreases low density lipoproteins (LDL) and increases serum high density lipoproteins (HDL) in normal individuals or in those with hyperlipoproteinemia. Serum cholesterol and triglycerides are also decreased. The mechanism for this is unknown but is independent of the drug's role as a vitamin. Niacin in large doses produces peripheral vasodilation, the property taken advantage of herein. At usual doses, niacin-induced vasodilation is limited to cutaneous vessels.
Niacin is readily absorbed following oral administration, The amount needed for physiological function, as a vitamin, is (12-18 mg/day) Niacin is metabolized to nicotinamide which is widely distributed into body tissues. Nicotinamide is further metabolized in the liver and excreted in the urine.
PABA (para-aminobenzoic acid) is used in sun screens and has been shown to be very effective and also very safe. It is the standard against which all other sun screens are judged. It is widely used as a preservative. It has now been found by the inventor, herein to constitute a very effective solubilizer for caffeine.
The particulate matter suitable for use herein can be selected from a variety of differing materials including silica, alumina, charcoal and other organic particles. The particles are required to be of a size classified as microparticles and namely to have a particle diameter not exceeding 10 .mu.m but preferably not exceeding 5 .mu.m. Silica is a particularly preferred material. Silica particles are available in three main types: macroparticulate, microparticulate and pellicular. Macroparticular particles have a mean particle diameter larger than 40 .mu.m and are not suitable for use herein; microparticulate particles have a mean particle diameter of between 3 and 10 .mu.m, and have either a spherical or irregular shape. They have the highest efficiency and the greatest loading capacity because of the increase in surface area provided. Pellicular silica is characterized by having a thin pellicle or porous layer coated on solid micro-glass beads. The microparticulare silica particles are the preferred particles for uses herein. The microparticles, for example silica microparticles can be used directly. They are ionically charged, i.e., they carry a negative charge. The particles can be used directly or modified by first coating or chemically bonding an active phase onto the silica particle.
Liposomes are spherical particles in an aqueous medium formed by a lipid bilayer enclosing an aqueous compartment. Liposomes are formed by sonicating a lipid in an aqueous medium. They consist of spheres of lipid bilayers that enclose part of the aqueous medium. The liposome, "membrane", lipid bilayers allow for movement of active agents in and out of the sphere.
The pharmacologically active ingredients in the compositions of the invention, comprising caffeine solubilized by PABA or the latter solubilized caffeine and niacin, will be attached during the admixing of the components of the composition and microparticles to the charged ionic groups of the microparticles, directly or on to the modified or coated particles in such a manner that the active agents can readily and controllably be released for absorption through the mucous membrane of the oral cavity. Absorption through mucous membranes, unlike the skin, is rapid and has many advantages, and is therefore preferred in many instances as the route for administration of many medicaments, e.g., nitroglycerin, aspirin, antihistamines etc. The medicament enters the blood stream rapidly and by-passes the metabolism that occurs during oral ingestion. While not claimed herein, the use of the non-metallic microparticles as a carrier for such and other medicaments is proposed by the inventor herein.
The method for producing the basic composition takes place as follows:
The constituent ingredients for the composition of the invention, are continually stirred in a mixing vessel with a homogenizer (a high shear mixer (Greerco)). The constituent reagents are added to the water, under constant stirring in the mixing vessel. The first agent introduced into the water present in the mixing vessel is a preservative which can be any member of the group consisting of Sutacide A, in an amount between 0.3 and 0.5%, preferably 0.3% by volume; methylparaben in an amount between 0.5 and 2.0% but preferably 1.0% by volume; propylparaben in an amount between 0.1% and 0.2% but preferably 0.15% by volume; (the latter two can be used together); butylparaben; benzyl alcohol 0.9% by volume; sodium benzoate 0.1%, benzyl alkonium chloride etc. The ionically charged microparticles or liposomes (suspended in water) are added next in an amount between 4.0 and 4.1% but preferably 4.0% by volume. The preferred microparticles for use in the compositions of the invention are ionically charged silica particles, having a particle size of about 3 .mu.m. The caffeine is then introduced into the vessel so that it will be present in an amount between 12 and 17% but preferably 14% by volume. The para-aminobenzoic acid for solubilizing agent is added in an amount between 12 and 17%, but preferably 14% by volume as the solublizer combines with the caffeine, molecule for molecule to form a salt. The solubilizers are added to the mixture while stirring is continued, as just noted to provide an amount wherein one molecule of solublizer will form a salt with one molecular of caffeine. If nicotinic acid is to be included, the nicotinic acid is then introduced and admixed using an amount of between 0.25 and 1.0% but preferably 0.5%. At this point, the pH of the admixture is adjusted to pH 7.03 with sodium hydroxide. A surfactant, such as Tween 20 is preferably included in an amount between 3.0 to 9.0% but preferably 4.0%. An agent for increasing the palability of the compositions such as sodium saccharinate, peppermint oil, vanilla extract, chocolate flavoring, licorice or the like can also be present, Any one member or more than one of these agents can be added next and is added as follows: sodium saccharinate in an amount between 0.25 to 1.0% but preferably 0.5%, peppermint oil in an amount between 0.35 to 0.75% but preferably 0.5%, vanilla extract in an amount between 0.1 to 0.5% but preferably 0.3%, or chocolate or licorice flavoring in an amount between 0.1 and 0.5% but preferably 0.3% by volume. Water is added to bring the total percentage to 100%.
The admixture may be dispensed for oral delivery in a number of ways: (1) atomizer (2) metered pump (3) squeeze bottle, or (4) bottle with a dropper having the prescribed amount of medication calibrated on the dropper. The container for application of the medication could be plastic, glass, stainless steel or treated metal. The atomizer or metered pump are preferable delivery systems. The atomizer yields a fine droplet spray or mist over a considerable oral area but the volume delivered is more difficult to control. The metered pump is used by first priming the pump, two depressions of the handle and then depressing the handle to deliver a given volume of fine spray or mist to the oral cavity (a given volume is dispensed with each depression of the handle).
The desired dose to be delivered by spray metered pump or atomizer is two to six drops. Each drop will contain 0.05 ml and the total dosage will be 0.1 to 0.3 ml or 14.0-42.0 mg of caffeine and 0.5-1.5 mg of niacin.


An apparatus for the assisted portage of automobile types of infant-seats separate from an automobile includes a coiled holder with an extensible strap that is attached to one side of the infant-seat and a screw-eye that is attached to the other side. The extensible strap includes a first end with a fastening device such as a spring clip that is attached to the screw-eye when the strap is extended out of the coiled holder and over the shoulder of a user. The extensible strap is set to any desired length and is locked at that position by the coiled holder or it is automatically retracted therein depending upon the position of a locking toggle on the coiled holder. Preferably, the coiled holder is attached to one side of a handle of the infant-seat at a pivot axis for the handle and the screw-eye is attached to the opposite side. The pivot axis is disposed proximate the center of gravity and therefore optimally supports the infant-seat. When it is draped over the shoulder and locked in position, the extensible strap is used as a shoulder strap to assist in supporting some of the weight of the infant-seat.

1. Field of the Invention
The present invention, in general relates to automobile infant-seats and, more particularly, to devices that provide assistance when carrying an infant-seat.
Regulations require that infants, when placed in an automobile, be secured in an approved type of a car seat, also known as an infant-seat.
Infant-seats are well known types of devices that are secured to the automobile by the restraint system (i.e., the seat belt) of the automobile and which, in turn, secure the infant thereto, thus protecting the infant in the event of an impact or a sudden stop.
Because the design of infant-seats are regulated, they must contain certain features and therefore, share close similarities. For example, all common types of infant-seats include a pivotal carrying handle that pivots about an axis that is located approximately at the center of gravity axis of the infant-seat.
The location chosen for placement of the handle is intentional. When the handle is pivoted upward and is used to support both the infant-seat and an infant placed therein, the seat is then held in the normal (i.e., level) position. Obviously, it would be undesirable for the handle to support the infant-seat in such a manner so as to tilt the infant-seat and increases the risk that the infant might fall out of it.
Parents or caregivers then routinely carry the infant-seat by the handle along with the infant therein to stores, shops, and the like. Needless to say, the weight of carrying both the infant and the infant-seat wears upon the person over time.
Furthermore, the handle can tend to apply all of the weight of both the infant and the seat to a relatively small area of the arm, for example, of the person that is supporting them. The pressure is greater than if the infant were carried by him or herself in which case the weight would be distributed over a greater area of contact. The area of contact by the handle tends to create a pressure point.
If the person carrying the infant and the infant-seat by the handle becomes fatigued there is at best some discomfort for the person having to carry the infant-seat and at worst there is risk of dropping the seat and of harming the infant who is disposed in it.
Awareness of the underlying discomfort of carrying the infant and infant-seat in that manner can manifest itself as a tendency to leave the infant in the infant-seat resting upon a surface while the parent or caregiver runs a xe2x80x9cquickxe2x80x9d errand. The absence of proximal care by the parent or caregiver increases the risk of an abduction or other possible form of abuse occurring to the infant.
Though the known prior art shows little or no recognition of the aforementioned problems, the use of a shoulder strap, for example, to directly support an infant (not an infant-seat) is known though not to support an infant-seat itself. The variations that do exist from manufacturer to manufacturer of infant-seats produced have precluded discovery of a solution heretofore.
Also, as there are many infant-seats already in use, it would indeed be desirable to provide a solution to the problem of safely and comfortably transporting an infant-seat that can both be utilized with new products being sold or developed and also retrofitted to work with existing infant-seats that have already been sold and are now in use.
Another impediment that has prevented solution thus far relates to increasing the weight or bulk of current infant-seats. Any type of an assist, if added to the infant-seat, can potentially increase either the weight or size (bulk) of the infant-seat. Neither type of an increase is desirable.
A further obstacle tending to preclude a solution is that any type of an assist to aid in carrying the infant-seat, if added to the seat, then becomes an added encumbrance when it is not in use. Any type of assist, such as a strap, can snag on an object, for example, when the person carrying the infant-seat passes by the object if the assist is not actively being used. This is a real possibility if the person carrying the infant-seat is only going to traverse a short distance and does not feel that he or she needs an assist. A strap, for example, if not used would then dangle from the infant-seat if not used.
If this were to occur, there is risk that the forward motion of the infant-seat (and infant) would be stopped abruptly, thereby possibly dislodging the infant-seat from the person and causing it to fall.
Furthermore, additional straps and the like, if used, pose a health hazard to the infant when they are not in use. There is risk that the infant can become ensnared in any such type of an accessory and that it could, for example, become wrapped around the infant""s neck, thereby creating a choking hazard.
Another difficulty is that parents and caregivers are of different physical sizes and have different preferences as to the ideal position for carrying an infant-seat. Some would prefer to carry the infant-seat high on their person while others would prefer that it be carried low about or even below their waist. Therefore, an ideal assist would also have to be adjustable.
Compounding the requirement of an assist being adjustable, a mother might carry the infant-seat and then hand it over to a father to carry who would then have to readjust any possible type of an assist to suit his needs and preferences. Therefore, the assist device should be readily adjustable to accommodate such changing requirements.
As such, a solution to the problem of providing an assist to carry an infant-seat has proven itself to be elusive.
Accordingly, there exists today a need for a retractable infant-seat shoulder strap that provides an assist to a person carrying the infant-seat that does not provide a significant increase in weight or bulk, nor substantially increase the risk of it becoming an encumbrance or a hazard to the well being of the infant when it is not in use.
Clearly, such an apparatus would be a useful and desirable device.
2. Description of Prior Art
Infant carriers and accessories are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 2,689,672 to Thompson, Sep. 21, 1954;
U.S. Pat. No. 2,804,249 to Manalo, Aug. 27, 1957;
U.S. Pat. No. 4,234,229 to Arnold, Nov. 18, 1980;
U.S. Pat. No. 4,487,346 to Fischer, Jr., Dec. 11, 1984;
U.S. Pat. No. 5,011,057 to Perruzza et al., Apr. 30, 1991;
U.S. Pat. No. 5,020,709 to Hoaglan, Jun. 4, 1991;
U.S. Pat. No. 5,267,680 to Torok, Dec. 7, 1993;
U.S. Pat. No. 5,490,620 to Bergqvist, Feb. 13, 1996;
U.S. Pat. No. 5,522,528 to Petricola, Jun. 4, 1996;
U.S. Pat. No. 5,540,365 to LaMair, Jul. 30, 1996;
U.S. Pat. No. 5,573,156 to McConnell, Nov. 12, 1996;
U.S. Pat. No. 5,732,861 to Jakobson, Mar. 31, 1998; and
U.S. Pat. No. 5,813,580 to Fair, Sep. 29, 1998.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.
It is an object of the present invention to provide a retractable infant-seat shoulder strap that is easy to use.
It is also an important object of the invention to provide a retractable infant-seat shoulder strap that can be used with newly manufactured infant-seats.
Another object of the invention is to provide a retractable infant-seat shoulder strap that can be retrofitted to already manufactured infant-seats.
Still another object of the invention is to provide a retractable infant-seat shoulder strap that does not substantially increase the weight or bulk or the infant-seat.
Still yet another object of the invention is to provide a retractable infant-seat shoulder strap that does not provide a hazard when not in use.
Yet another important object of the invention is to provide a retractable infant-seat shoulder strap that includes a shoulder strap that can retract when not in use.
Still yet another important object of the invention is to provide a retractable infant-seat shoulder strap that includes a shoulder strap that can be secured (i.e., locked) in place at a desired length when it is in use.
Still one other object of the invention is to provide a retractable infant-seat shoulder strap that is readily adjustable.
Still one other important object of the invention is to provide a retractable infant-seat shoulder strap that can fit a wide variety of infant-seats with minimal modification.
Briefly, a retractable infant-seat shoulder strap for use with automobile types of infant-seats that is constructed in accordance with the principles of the present invention has a coiled holder with an extensible strap attached thereto to one side of the infant-seat. The extensible strap includes a first end with a fastening device such as a spring clip that is attached thereto. The first end can be extended from the coiled holder and the extensible strap can be set to any desired length and locked at that position by the coiled holder for as long as desired. The fastening device (i.e., the spring clip) is attached to a mating member such as a screw-eye that is disposed on a side of the infant-seat opposite that of the coiled holder. The extensible strap is then used as a shoulder strap to assist in supporting the infant-seat.