The quickly erectable canopy shelters include a plurality of legs connected together by an extendible perimeter assembly of link members. The roof structure is formed by a pole members pivotally mounted to the upper ends of the legs so as to extend across the shelter, and movable between a lowered position and a raised, upwardly arching position. The pole members are pivotally coupled to a central hub, and each of the pole members is formed of pole sections hinged to permit downward folding and upward unfolding until they are fully extended. Corner support strut members are pivotally mounted to the extendible perimeter assembly of link members adjacent to the legs, to support the pole members. The outer ends of the pole members are pivotally connected to the upper ends of the legs by pivoting link members that pivot between a lowered position and a raised position extending above the legs when the shelter is extended. In the raised position the pivoting link members rotate outwardly to absorb downward forces exerted on the roof structure and transmitted outwardly by the pole members.

1. Field of the Invention
This invention relates generally to folding, collapsible structures, and more particularly relates to a collapsible shelter structure having an elevated canopy.
2. Description of Related Art
Temporary shelters that can be easily transported and rapidly set up at emergency sites can be particularly useful in providing temporary care and housing. Such shelters can also be useful for non-emergency outdoor gatherings, such as for temporary military posts, field trips, and the like. One known quickly erectable, collapsible shelter includes a framework of X-shaped linkages, telescoping legs, and a canopy covering the framework. The legs of that shelter are capable of telescoping to about twice their stowed length, and the framework of X-shaped truss pairs is capable of horizontal extension between the legs to support a canopy. The framework can be constructed of lightweight material, and the telescoping legs can be extended to raise the framework of the shelter.
In order to increase the portability and versatility of such temporary shelters, it is important that they be not only lightweight and small enough in a folded, compact configuration so that can be readily transported and carried, but also large enough and with sufficient headroom when unfolded for a group of people to stand underneath them. As such structures have become larger and more lightweight, reinforcing features that contribute to strength, roominess, and ease of use in setting up and taking down such structures have also become increasingly important.
One modern type of tent structure provides a lightweight roof structure with four roof rods joined together at the center by a head connector member, with each of the roof rods formed of two rod members interconnected by intermediate pivot connecting members. The roof rods are supported on top of a base structure formed by four legs and scissors-type linkages connected to a top fixed connector and a lower sliding connector of each leg. Each intermediate pivot connecting member between the individual rod members of the roof rods confines upward rotation of the rod members to an upmost, upwardly arching position, but allows the roof rods to be folded downwardly when the tent is collapsed. Reinforcing linking rods provided at the corners of the roof structure are coupled at one end to the lower sliding connectors on the legs, and are slidingly coupled at the other end to the roof rods, to assist in stabilizing the roof rods in the upwardly arched position when the shelter is fully unfolded and extended. However, the slidable coupling of the corner linking rods must slide over a considerable length of the roof rods, which can lead to abrasion and wear of the roof rods and eventually interfere with the sliding of the linking rods during setting up and taking down of the structure, without providing any significant reinforcing strength or vertical support of the roof structure when the shelter is fully unfolded and extended.
Lightweight shelters with raised roof structures are particularly useful for holding gatherings in inclement weather, to provide needed headroom and shed precipitation and debris, but raised roof structures can be particularly vulnerable to downward forces placed on a roof structure by strong winds. One approach to providing a lightweight shelter with a raised roof structure has been to make the roof structure flexible so that it can move between a raised, upwardly arching configuration when weather permits, and a lowered, downwardly arching configuration, if the downward component of the wind is sufficiently strong, to automatically present a reduced profile to strong winds when necessary. However, in some shelter structures, a downward force on the canopy, such as can occur due to wind pressure, for example, can result in the transmission of excessive outward forces to the upper legs and upper brackets to which the roof structure is mounted, requiring extra strengthening or bracing of these sections of the shelter to resist such outwardly directed forces. There thus remains a need for an improved, reinforced raised roof structure for such lightweight canopy shelters that will permit the raised roof structure to withstand greater wind pressures, to be able to provide a desired headroom and shed precipitation and debris under a wider variety of weather situations. The present invention meets these and other needs.
Briefly, and in general terms, the present invention provides for an improved, lightweight erectable canopy shelter with a reinforced raised roof structure that is strengthened and stabilized to permit the roof structure to remain in a raised configuration in order to provide adequate headroom and adequately shed debris and precipitation, and to resist downward wind pressures on the roof structure.
The present invention accordingly provides, in one preferred embodiment, for an improved, lightweight and quickly erectable canopy shelter with a reinforced roof structure. The roof structure of the shelter is supported by a plurality of legs having upper and lower ends connected together by an extendible perimeter assembly of link members. In one currently preferred approach, the perimeter assembly of link members comprises pairs of link members being pivotally connected together in a scissors linkage configuration so as to be extendable from a first collapsed position extending horizontally between adjacent pairs of legs to a second extended position extending horizontally between the adjacent pairs of legs. A slider member is slidably mounted to each of the legs, and in a presently preferred aspect, the legs of the shelter comprise telescoping upper and lower sections, with the slider members mounted to upper sections of the legs. The pairs of link members of the extendible perimeter assembly preferably comprise first and second link members, with the first link member having an outer end pivotally connected to the upper end of a leg, and the second link member having an outer end pivotally connected to a slider member of a leg, and with the pairs of link members connected together at their inner ends.
In a preferred embodiment of the invention, the roof structure of the shelter is preferably provided by a canopy assembly comprised of a plurality of pole members having their outer ends pivotally mounted to the upper ends of the legs so as to extend across the shelter, and to be movable between a lowered position when the shelter is in its folded and unextended configuration, and a raised, upwardly arching position when the shelter is unfolded and extended, in which position a canopy cover may be placed over the roof structure of the canopy shelter. In a presently preferred aspect, the outer ends of the pole members are pivotally connected to the upper ends of the legs by pivoting link members that pivot between a lowered position when the shelter is unextended, and a raised position extending above the legs when the shelter is extended. In the extended configuration, the pivoting link members can advantageously rotate outwardly to accommodate downward forces exerted on the roof structure and transmitted outwardly by the pole members.
In a presently preferred aspect of the invention, the pole members are pivotally coupled at their inner ends to a central hub connector, and each of the pole members comprises a plurality of pole sections hingedly coupled together permitting inward, downward folding of the pole members to a folded configuration, and limiting upward unfolding of the pole members to a fully extended configuration.
In a preferred embodiment of the invention, corner support strut members are also advantageously provided for reinforcing and stabilizing the pole members of the canopy assembly when the shelter is unfolded and extended. The outer ends of the support strut members are pivotally mounted to the extendible perimeter assembly of link members adjacent to the legs. In one presently preferred embodiment, the support strut members may be pivotally mounted to a crank rotatably mounted to a telescoping shaft connected between two adjacent link members connected to a leg. In another presently preferred embodiment, the support strut members may be pivotally connected to a link member adjacent to a leg. In one presently preferred embodiment, the support strut members are permanently pivotally connected to the pole members, and the support strut members may be formed of telescoping sections. Thus, when the canopy assembly is unfolded and extended, the corner support struts rotate upwardly to support the pole members, and in a preferred aspect, the inner ends of the strut members each have a support bracket permanently pivotally connected to a corresponding pole member to support the pole member in the raised, upwardly extending position.
From the above, it may be seen that the present invention represents important benefits over the prior art. By using a pivotal link at the outer ends of the roof rods where they meet the top of the legs, direct outward force on the top of the legs is subsantially reduced from vertical force applied to the roof compared to prior art designs. This substantially improves the ability of the structure to absorb such forces without deflection of the primary support structure. Furthermore, in preferred embodiments, the termination of the support struts at a location offset from the slider provides important benefits to the stability of the structure during erection and when the canopy is fully erected.
These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention.

Erectable canopy with reinforced roof structure


An access tube is used for accessing an anatomic space, such as a pericardial space between the parietal and visceral pericardia. The access tube is advanced against the parietal pericardium and an anchor structure thereon embedded into the parietal pericardium. The access tube can then be used to separate the parietal and visceral pericardia and enlarge the pericardial space. After such enlargement, a needle or other access device can be introduced through the access tube into the pericardial space to provide access for a wide variety of purposes, including aspiration, infusion, and guidewire placement.

1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to methods and devices for accessing the pericardial space in a minimally invasive manner.
The human heart is enveloped within a tissue structure referred to as the pericardium. The pericardium includes two major portions. The portion of the pericardium which lies immediately over the surface of the heart is referred to as the visceral pericardium. The second portion is formed as a sac around the visceral pericardium and is referred to as the parietal pericardium. Normally, the visceral and parietal pericardia lie in close contact with each other and are separated only by a thin layer pericardial fluid. The space (really more of a potential space) between the visceral and parietal pericardia is referred to as the pericardial space.
Access to the pericardial space can be necessary or beneficial under a variety of circumstances. Open surgical access can be obtained via open sternotomy where the patient""s sternum is divided and the parietal pericardium exposed. Alternatively, the pericardial space can be approached from a skin incision made below the xiphoid through which the parietal pericardium is identified. Such approaches, however, are highly traumatic, requiring general anesthesia and useful only under compelling circumstances. Access to the pericardial space can also be achieved using a thoracoscopic approach. Under general anesthesia, the left lung is deflated after which multiple holes are made for the thoracoscope and various instruments. The pericardium is then entered using standard videoscopic techniques. The thoracoscopic approach typically requires the placement of a chest tube and admission to the hospital for the initial 1-2 post-operative days.
In patients who require drainage of a large pericardial effusion, a simple percutaneous approach can be used. Through a small (2-4 mm) cutaneous incision between the xiphoid and costal cartilage, a spinal needle (18-20 gauge) is advanced in a superior/posterior fashion. At appropriate intervals, the stylet is removed and fluid aspiration is attempted. If no fluid is obtained, the stylet is replaced and the needle advanced again. This cycle is repeated until fluid is aspirated. If the needle is advanced too far, the heart can be punctured and is why a large pericardial effusion must be present on ensure adequate separation of the visceral and parietal pericardia.
A minimally invasive method for accessing the pericardial space is described in U.S. Pat. No. 5,827,216 to Igo et al. A pericardiocentesis apparatus is introduced via a subxiphoid approach to the heart. A vacuum is applied at a distal end of the device to form a xe2x80x9cbleb,xe2x80x9d i.e., a locally expanded region in the pericardium. A needle can then be penetrated through the bleb, and the needle used for drawing fluids, delivering drugs, or the like. Although theoretically plausible, the ability to reliably maintain a seal against the pericardium can be problematic.
For these reasons, it would be desirable to provide additional and improved methods and apparatus for the minimally invasive access to a patient""s pericardial space. The methods and devices should be suitable for a wide variety of minimally invasive approaches to the pericardium, including at least intercostal/transthoracic and subxiphoid approaches, and the like. The methods and devices should further provide for secure and stable capture of the parietal pericardium and permit the opening of a large space or volume between the parietal and visceral pericardia. Such access methods and apparatus should be useful for a wide variety of procedures to be performed in the pericardial space, including fluid withdrawal, drug delivery, diagnostic and therapeutic electrophysiology procedures, pacemaker lead implantation, defibrillator lead placement, transmysocardial revascularization, transmysocardial revascularization with drug delivery, placement of the left ventricular assist devices, placement of the arterial bypass graphs, in situ bypass, i.e., coronary artery-venous fistulae, placement of drug delivery depots, closure of the left arterial appendage, and the like. At least some of these objectives will be met by the invention described herein.
2. Description of the Background Art
U.S. Pat. No. 5,827,216, describes a pericardial access tube which draws a vacuum on the parietal pericardium as part of an access procedure, as discussed above. U.S. Pat. No. 5,071,428, describes a method for accessing the pericardial space for defibrillation lead implantation by grasping the parietal pericardium with forceps and cutting the pericardium with a scalpel. U.S. Pat. No. 4,281,659, describes a probe system having paired helical wires for securing the probe to a patient""s skin. U.S. Pat. No. 4,164,943, describes a catheter anchor having multiple helical wires for securing the anchor to a patient""s skin. U.S. Pat. No. 5,226,890, describes a trocar cannula anchor having a tapered thread for placement in a percutaneous tissue penetration. U.S. Pat. No. 5,332,398, describes and intramedullary catheter having a threaded end for implantation into a bone.
The present invention provides methods, apparatus, and kits for accessing an anatomic space having a wall with an outer surface. The wall may consist of a membrane, a capsule or the adventia, muscularis and endothelial layers of a hollow organ or vessel. The methods, apparatus, and kits are particularly useful for minimally invasive access procedures, but could also be used for accessing internal anatomic spaces where initial access to the wall of the outer surfaces achieved via open surgical or other techniques. The present invention will be particularly useful for accessing a patient""s pericardial space for performing a wide variety of procedures, generally as set forth above.
The phrase xe2x80x9canatomic spacexe2x80x9d is meant to include any natural, potential, or created space or cavity within a patient""s body where it may be desirable to gain access for surgical, diagnostic, therapeutic, or any other purpose. Usually, the anatomic space will be within an organ or structure located beneath the patient""s skin, such as the pericardial space which lies between the visceral and parietal pericardia, both of which lie beneath the chest wall and rib cage. Other internal organs which may be accessed include the intestines, fallopian tubes, gall bladder, kidneys, and the like.
Methods according to the present invention for accessing an anatomic space having a wall with an outer surface comprise embedding a distal end of an access tube into the outer surface. An access device, such as a stylet, needle, or other piercing instrument, may then be introduced through the access tube, penetrating the wall, and into the anatomic space while the access tube stabilizes the wall. Embedding the distal end of the access tube can be achieved in a wide variety of ways. Typically, an anchor structure at the distal end is engaged against the outer surface of the anatomic space wall and subsequently penetrated into the surface. For example, the anchor structure may comprise one or more penetrating points which are embedded into the wall by rotation of the access tube, distal advancement of the access tube, or the like. While the penetrating points will typically be fixed on the access tube, it will also be possible to provide springloaded or other selectively deployable penetrating points which can be embedded into the anatomic space wall while the access tube is held stationary. After the distal end of the access tube has been embedded into the anatomic space wall, the wall will usually be drawn or otherwise manipulated increasing the available access volume therein. In particular, by increasing the available volume, the risk of accidental injury from advancement of the access device into deep structures is significantly reduced. Increasing the access volume, however, can have other benefits. For example, it can improve the ability to image the anatomic space using a fiberoptic imaging scope, permit the introduction of various devices, drug delivery structures, or the like.
In preferred aspects of the present invention, the access device will be a hollow needle or stylet, and a guidewire will be positioned through the needle and into the anatomic space. The needle can then be withdrawn, and the guidewire used for access of a variety of diagnostic, therapeutic, or other catheters and devices.
In a further aspect of the method of the present invention, a pericardial space between the visceral and parietal pericardiums is accessed by percutaneously positioning a distal end of an access tube over the parietal pericardium. Positioning can be achieved either by a transthoracic or a subxiphoid approach beneath the sternum or from the abdominal cavity through the diaphragm, or the like. Once in position, a distal end of the access tube is embedded into the parietal pericardium in a manner which does not engage the visceral pericardium. The access tube is then drawn or otherwise manipulated to separate the parietal pericardium from the visceral pericardium to enlarge the available volume of the pericardial space therebetween. An access device, again usually a needle or hollow stylet, is then advanced through the access tube penetrating the parietal pericardium entering the pericardial space. Guidewires may then be positioned and a variety of particular protocols performed, generally as listed above.
The present invention still further provides systems comprising an access tube and a needle, stylet, or other equivalent device. The access tube has a distal end which can be selectively embedded into tissue, and the needle, stylet, or other access device has a lumen which is useful for subsequent placement of a guidewire, as generally described above. Optionally, the system may further comprise the guidewire capable of being positioned in the anatomic space through the needle.
The present invention still further provides kits for accessing the pericardial space of a patient. The kits comprise an access tube having a distal end which can be selectively embedded into tissue. Exemplary access tubes are described above. Kits will further comprise instructions for use according to any of the methods set forth above. Kits may optionally further comprise a package for holding at least the access tube and usually the instructions for use. Exemplary packages include boxes, trays, pouches, tubes, and the like. Usually, at least the access tube will be maintained sterilely within the package. Optionally, the needle, stylet, or other access device, may be included. Further optionally, the guidewires used for the methods of the present invention may also be included within the kit.

Methods and apparatus for pericardial access


This invention describes the use of metal complexes that have a plasma protein bond of at least 10% as imaging diagnostic agents for locating an infarction or a necrosis using lasting positive visualization.

The invention relates to the subject that is characterized in the claims, i.e., the use of metal complexes that have a plasma protein bond of at least 10% as imaging diagnostic agents for locating an infarction or a necrosis based on the persistent accumulation of substances in the infarction or necrosis area.
Detection, location, and monitoring of necroses or infarctions is an important area in medicine. Myocardial infarction does not immediately result in irretrievable, non-functioning tissue; rather, it initiates a dynamic process that extends over a prolonged period (weeks to months). The disease proceeds in about three phases, which overlap rather than being distinctly separated from one another. The first phase, the development of myocardial infarction, comprises the 24 hours after the infarction, in which the destruction progresses like a shock wave (wave front phenomenon) from the subendocardium to the myocardium. The second phase, the already existing infarction, comprises the stabilization of the area in which the formation of fibers (fibrosis) takes place as a healing process. The third phase, the healed infarction, begins after all destroyed tissue is replaced by fibrous scar tissue. During this period, extensive restructuring takes place.
Up until now, no precise and reliable process has been known that would make it possible to diagnose the current phase of a myocardial infarction in a living patient. For evaluating a myocardial infarction, it is of decisive importance to know the extent of the portion of tissue that is definitively lost in the infarction and at what point the loss took place since the type of treatment depends on this information.
Infarctions occur not only in the myocardium but also in other tissues, especially in the brain.
While infarction can be healed to a certain extent, in the case of necrosis, locally limited tissue death, only the harmful sequelae for the rest of the organism can be prevented or at least mitigated. Necroses can develop in many ways: due to injuries, chemicals, oxygen deficits, or radiation. As with infarction, knowing the extent and nature of a necrosis is important for further medical treatment.
It is known that infarction and necrosis can be represented by antibodies that are directed against biomolecules that occur intracellularly and by porphyrins, metalloporphyrins and their derivatives. Antibodies and porphyrins can be produced only at great expense, however, and are problematical in terms of handling and compatibility in several respects.
It has now been shown that, surprisingly enough, metal complexes that have a plasm protein bond of at least 10% are suitable as imaging diagnostic agents for locating necroses that are produced by infarction or caused in some other way. In this case, the basic advantage consists of a persistent positive (bright) dyeing of necrotic areas with little to no signal enhancement of the environs. Non-protein-bonded, otherwise comparable complexes lead for only a short time to signal enhancement of well-perfused tissue, whereby underperfusedxe2x80x94even vitalxe2x80x94tissues remain unaffected. The blood supply to the tissues can also be detected using T2 or T2-star (susceptibility) effects, but differentiates non-vital from necrotic tissue. The plasma protein bond is, as is familiar to one skilled in the art, determined by equilibrium dialysis.
Preferably suitable are metal complexes that have a plasma protein bond of at least 50%, especially preferably of at least 80%. The metal complexes according to the invention have a molecular weight of at least 350 Da, and preferably at least 400 Da.
They have a T1-relaxivity of at least 2.0 [sxe2x88x921mMxe2x88x921], measured at 37xc2x0 C. and 20 MHz in plasma (see, e.g., Chem. Rev. 1987, 87, 901). Their stability constant is at least 1015 (logK=15).
The metal complexes according to the invention are metal derivatives of, e.g., polyaminopolycarboxylic acids, polyaminopolyphosphonic acids, porphyrins, texaphyrins, sapphyrins, peptides and their derivatives, as they are described in, e.g.,
If the metal complexes according to the invention are used for NMR diagnosis, the metal must be paramagnetic. This can be an element from the series of transition metals or lanthanides. Suitable ions include those of the elements iron, manganese, gadolinium, and dysprosium.
If the metal complexes according to the invention are used for radiodiagnosis, the metal must be radioactive. This can be an isotope from the series of elements Tc, In, Rh, Ga, Sc, Bi, Y, Fe, Sm, Ho, Co, Cu, Gd, and Eu.
As suitable chelating agents, the following can be mentioned by way of example:
2-(4-Ethoxybenzyl)-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecane-1,11-dicarboxylic acid (ligand of Eovist(copyright), EP 405704
2-(4-benzyloxybenzyl)-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecane-1,11-dicarboxylic acid, EP 405704
2-(4-butylbenzyl)-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecane-1,11-dicarboxylic acid, WO 95/28179
2,5,8,11-tetrakis(carboxymethyl)-2,5,8,11-tetraazabicyclo[10,4,0]-hexadecane, U.S. Pat. No. 5,358,704
2,5,12,15-tetrakis(carboxymethyl)-2,5,12,15-tetraazatricyclo[10,4,0,06,11]-icosane, U.S. Pat. No. 5,358,704
10-[1-methyl-2-oxo-3-aza-5-oxo-5-{4-perfluorooctylsulfonyl-piperazin-1-yl}-pentyl]-1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane, WO 97/26017
10-[2-hydroxy-4-aza-5-oxo-7-oxa-10,10,11,11,12,12,13,13,14,14,15,15,16,16,17,17,17,-heptadecafluoroheptadecyl]-1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane, WO 97/26017
2-[1,4,7,10-tetraaza-4,7,10-tris(carboxymethyl)cyclododecan-1-yl]-3-benzyloxypropionic acid, WO 89/05802
2-benzyloxymethyl-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecane-1,11-dicarboxylic acid, EP 230893
DTPA-Lys-Asp-Asp-4-pentylbicyclo[2,2,2]-octane-1-carboxylic acid, Mallinckrodt MP-2269, Vancouver SMRM, April 1997
4-[hydroxymethyl-(4,4-diphenyl)cyclohexyloxy-phosphoric acid diester]-3,6,9-carboxymethyl-3,6,9-triazaundecane-1,11-dicarboxylic acid (MS-325), WO 96/23526
4-[hydroxymethyl-(10-phenyl)-decyloxy-phosphoric acid diester]-3,6,9-carboxymethyl-3,6,9-triazaundecane-1,11-dicarboxylic acid (MS-323, WO 96/23526)
N-(4-Decylphenylcarbamoylmethyl)-diethylenetriamine-N,Nxe2x80x2,Nxe2x80x3,Nxe2x80x3-tetracetic acid, EP 603403
4,5-Diethyl-10,23-dimethyl-9,24-bis(3-hydroxypropyl)-16,17-bis[2-[2-(2-methoxyethoxy]ethoxy]-13,20,25,26,27-pentaazapentacyclo [20.2.1.]3,6.18,11.014,19]heptacosa-3,5,8,10,12,14,16,18,20,22,24-undecane. U.S. Pat. No. 5,583,220.
The production of the pharmaceutical agents is carried out in a way known in the art by the corresponding complex compoundsxe2x80x94optionally with the addition of the additives that are commonly used in galenicalsxe2x80x94being suspended or dissolved in an aqueous medium and then the suspension or solution optionally being sterilized. Suitable additives are, for example, physiologically harmless buffers (such as, for example, tromethamine), additives of complexing agents or weak complexes (such as, for example,
diethylenetriaminepentaacetic acid or the Ca complexes that correspond to the metal complexes according to the invention) orxe2x80x94if necessaryxe2x80x94electrolytes such as, for example, sodium chloride orxe2x80x94if necessaryxe2x80x94antioxidants such as, for example, ascorbic acid.
If suspensions or solutions of the agents according to the invention in water or in a physiological salt solution are desired for enteral or parenteral administration or for other purposes, they are mixed with one or more adjuvant(s) that are commonly used in galenicals [for example, methyl cellulose, lactose, mannitol] and/or surfactant(s) [for example, lecithins, Tween(copyright), Myrj(copyright)] and/or flavoring substances for taste correction [for example, ethereal oils].
In principle, it is also possible to produce the pharmaceutical agents without isolating the complexes. Special care must always be taken to perform chelation in such a way that the complexes according to the invention are virtually free of uncomplexed metal ions that have a toxic action.
This can be ensured with the aid of, for example, color indicators such as xylenol orange by control titration during the production process. The invention therefore also relates to the process for the production of complex compounds and their salts. As a final precaution, there remains purification of the isolated complex.
The pharmaceutical agents preferably contain 0.1 xcexcmol-1 mol/l of the complex and are generally dosed in amounts of 0.0001-5 mmol/kg. They are intended for enteral and parenteral administration. The complex compounds are used
1. for NMR diagnosis in the form of complexes of them with the ions of elements with atomic numbers 21-29, 42, 44 and 58-70;
2. for radiodiagnosis in the form of complexes of them with the radioisotopes of elements with atomic numbers 27, 29, 31, 32, 37-39, 43, 49, 62, 64, 70, 75 and 77.
The agents meet the varied requirements for suitability as contrast media for nuclear spin tomography. They are thus extremely well suited for improving the image, obtained with the aid of the nuclear spin tomograph, as regards its informational value after oral or parenteral administration by increasing the signal intensity. They also show the great effectiveness that is necessary to burden the body with the smallest possible amounts of foreign substances, and the good compatibility that is necessary to preserve the noninvasive nature of the studies.
The good water solubility and low osmolality of the agents make it possible to produce highly concentrated solutions, i.e., to keep the volume load on the circulation within reasonable bounds and to offset the dilution by bodily fluids. In addition, the agents have not only high stability in vitro, but also surprisingly high stability in vivo, so that release or exchange of the bonded ionsxe2x80x94which are inherently toxicxe2x80x94in the complexes occurs only extremely slowly within the time during which the contrast media are completely eliminated.
In general, the agents for use as NMR diagnostic agents are dosed in amounts of 0.0001-5 mmol/kg, preferably 0.005-0.5 mmol/kg. Owing to their advantageous radioactive properties and the good stability of the complex compounds contained therein, the agents are also suitable as radiodiagnostic agents. Details on such use and dosage are described in, e.g., xe2x80x9cRadiotracers for Medical Applications,xe2x80x9d CRC Press, Boca Raton, Fla.
In in-vivo administration of the agents, the latter can be administered together with a suitable vehicle such as, for example, serum or a physiological common salt solution or together with a protein such as, for example, human serum albumin. In this case, the dosage depends on the type of cellular disruption, the metal ion used, and the type of imaging method.
The agents are usually administered parenterally, preferably i.v. They can also be administeredxe2x80x94as already discussedxe2x80x94intravascularly or interstitially/intracutaneously.

Lipophilic metal complexes for necrosis and infarction imaging


Headset cellular phones which may be worn continually and use voice recognition/speech activation for dialing telephone numbers and controlling other aspects of operation. Cell phones according to the present invention can include a microphone and preferably include both internal and external speakers to allow the user to communicate unobtrusively, check voice mail and conduct other activities while at the same time being able to hear ambient noise in the environment. Voice recognition/speech command functionally may also be used to generate and send touch tone or DTMF tones such as in response to call trees or voice recognition/speech activation functionality used by airlines, credit card companies, voice mail systems, and other applications.

Cellular telephones and other radio frequency (RF) messaging, personal digital assistance, and other organizational and communication devices which use the airwaves, whether via satellite or terrestrial propagation (hereinafter for purposes of disclosure, but not in a limiting fashion "cell phones") are ubiquitous. However, most of these devices are hand-held and thus constrain the user from performing other tasks as effectively as possible when in use. For example, persons who are operating an automobile while at the same time planting a cell phone against the ear with one hand can compromise their effectiveness and performance behind the wheel. Those who wish to take notes or be free to use both hands for other things are similarly compromised. Various devices according to the present invention address such issues.
Cell phone users are often perceived as loud and conspicuous perhaps not as much because of their nature or character, but because of the way cell phone instrument must be used. Ring tones in public places, need to talk and hear over ambient noise, difficulty in knowing whether the ringing cell phone is yours or another's, breakage from dropping, difficulty in removing from the belt and hitting the keys unlock combination are some of the issues. Additionally, cell phones with cables for the earpiece can snag on objects that break the wire, extract the plug from the phone or otherwise exasperate the user. Additionally, buttons and keys can be pressed inadvertently and in any event are often difficult to press correctly without missed cues. Lack of clarity in communication caused by the microphone being distant from the mouth is another issue which calls for improvement.
Cell phones according to the present invention fit on the head using various structures, and they contain other features such as voice recognition/voice activated dialing and operation which free the user from distraction, the need to use hands, and other physical constraints. Thus, operating heavy equipment using a headset cell phone according to the present invention could be safer than doing while using one hand to cradle a conventional cellphone against the ear. Moreover, operating a vehicle while talking to another on a cell phone according to the present invention could actually be safer than driving a vehicle while carrying on a conversation with another passenger, since the headset cell phone does not require head movement or physical gestures. Similarly, such headsets are in some ways safer than speaker phones in cars, because the driver is no longer inclined to incline the head toward the speaker in order to avoid ambient noise or conversation. Furthermore, a conventional handset cell phone in the car is easily misplaced and in any event distracts the driver from the road to locate and dial it. From a safety point of view, a hands-free headset is easier to use in an emergency context, particularly if the driver is injured or is otherwise in extremis.
One feature which enables complete headset operation without tactile intervention or manipulation is the use of voice recognition and speech activation. Such functionality typically includes computing capacity connected to a transducer such as a microphone/speaker, and digitizes and compares incoming sounds against a table or database of digitized sound files in order to identify or draw inferences about what is being said and to act on it. For instance, cell phones according to the present invention can "hear" a spoken telephone number and dial the number, can hear the command "on" and activate, can hear the command "2" in response to a call tree and send the dtmf tone combination corresponding to the numeral "2" on a conventional keypad. Accordingly, cell phones according to the present invention do not need keypads or other buttons, or displays, although they may certainly be included if desired.
Thus, tending in the direction of simplicity in men-machine interface design, headset cell phones according to present invention need contain minimal or no tactile interfaces, such as buttons or switches. Instead, voice activation and speech recognition can control all phases of operation. Control of off-hook/on-hook state, dialing of numbers, programming of speed-dial numbers, and other functions can occur using larger or smaller sets of voice commands which can be learned by software in cell phones according to the present invention. Such commands can be processed and implemented using conventional speech recognition and voice activation techniques, including those used in certain vehicular-based cell phone applications currently.
From another point of view, quietness is an advantage of headset cell phones according to the present invention. For example, a call may be answered or a ring tone may be heard permitting the user to answer with a virtually silent tone in the ear that cannot be heard by others in the vicinity such as in a meeting. The user may then leave the room or very quietly answer or communicate. Tones, rings, caller i.d., voicemail and other cues or information can be heard through an internal speaker while not disturbing others nearby.
In another aspect, the headset cell phones can be beneficial to those who have circulatory problems which prevent or hinder their ability to hold the handset on the ear for extended periods of time. In addition, those with medical conditions which inhibit mobility can also potentially communicate more quickly and more effectively without the need for manual intervention to do so.
According to various embodiments of the present invention, headset cell phones can have a special design earpiece with a private internal speaker for telephone conversations. The devices can also contain an external speaker for ring tone and open conversation so that if a telephone call can, for example, be answered or a command given while the cell phone is sitting on a base charger. The base can serve not only as a battery recharger, but also can serve as the base unit for a wireless home phone functionality in headset cell phones according to this invention. The cell phone can also contain, in the earpiece, for example, a porthole which allows sounds external to the telephone to be heard by the wearer. The porthole can be adapted to be opened and closed by voice command.
A microphone can extend via a boom from the headset, and the boom can contain a switch which can control various operations. For example, retracting the boom can correspond to off state, fully extended to on for conversation, and mid-retraction for programming and other functions. Alternatively, commands can be given by voice to effect or invoke any of these functions.
A base unit can allow the cell phone to operate also as a wireless home telephone such as by incorporating two addresses or numbers in the headset cell phone. One number can be a cell phone number and the other an extension on a home wireless network or system so that the headset cell phone is capable of both cellular and "landline" operation. For example, at home the user allows the headset cell phone to communicate with the base which communicates with the public network wire line or in conventional fashion. When the user moves out of range of the home base unit, or when a command is given, the headset cell phone can transition to communicating within the cellular telephone network rather than with the base unit. Similarly, in a business context, the base unit could allow business people to be directly accessible even though not at their desks but other places in the office.
Various embodiments of headset cell phones according to the present invention can be structured in several ways to achieve the purposes of the invention. A body position adjacent an internal earpiece and, if desired, an external earpiece and a port, can contain cell phone electronics and processing and memory capacity for carrying out voice recognition and speech activation functionality. From the body can extend a microphone boom if desired which can, if desired, function as a switch to allow the user to control off-hook, on-hook, and programming states as well as an on/off state if desired. (As mentioned above, any of these can be implemented using voice recognition/speech activation as desired). A strap or positioner can extend across the top of head, around the back of the head, down the neck and around the shoulders, or omitted if desired. The strap can contain an antenna which increases, as desired, gain in signal strength as sensed by receiver circuitry in the cell phone electronics. The body can fit with a base which can act as a charger and also, as mentioned above, as a base unit for home wireless operation. The cell phone can also operate with a first-based unit at home, a second-based unit at the office, and as otherwise desired. It can contain other communications circuitry such as "blue tooth" or IEEE 803.11 to allow data and/or voice communications with other networks and devices.
Such hands-free headset cell phones according to the present invention can be useful for government agencies because of the hands-free benefits and also quietness and privacy. For example, a police officer stopping a suspicious vehicle need approach the vehicle only once without the need to leave and then risk the danger of a second approach in order to investigate the driver on a computer in the patrol car. Quietness and other auditory functionality can also help in an emergency context by keeping the noise level low and promoting a calmer environment. Similarly, headset cell phones according to present invention promotes safety in cab, truck and delivery company fleets by helping maintain the drivers' attention on the road while allowing them to communicate with the dispatchers more effortlessly. In a similar vein, doctors, nurses and other professionals can obtain information without the need to interrupt their work or distract themselves from using both hands on the patient.
Another aspect of headset cell phones according to the present invention is use with a geographical locator including GPS functionality. This functionality can be used in a reporting fashion to allow wearers to be tracked such as in a truck fleet, hiking, accident or avalanche context.
These and other advantages, features, and objects of the present invention will become apparent with respect to the remainder of this document.


A supercharged combustion engine including a cylinder block (1), a cylinder head (2) and a crankcase (3) containing oil, an induction air conduit (19, 21, 24) communicating with intake conduits (9) in the cylinder head. The induction air conduit is connected to a supercharging unit (23) and is provided with a throttle valve (26) downstream of the supercharging unit. A first evacuation conduit (40, 42) connects the crankcase, via a pressure regulator (45), to the induction air conduit (19) at a point downstream of the throttle valve for evacuation of blow-by gases from the crankcase. A second evacuation conduit (40, 43) connects the crankcase with the induction air conduit (24) at a point on the intake side of the supercharging unit. A device (29) for separating oil from the evacuated blow-by gas, at least one further evacuation conduit (46) connecting a collection container (47) or some other source of harmful emissions with the evacuation conduits and non-return valves (41, 44) in the first and second evacuation conduits (42, 43) prevent gases from flowing back into the crankcase.

This application claims priority to Swedish Application No. 0000220-4, filed Jan. 26, 2000, which is expressly incorporated herein by reference.
The invention relates to a supercharged internal combustion engine having a cylinder block, a cylinder head, a crankcase containing oil and an air intake conduit. The air intake conduit communicates with air intake channels in the cylinder head, and which is connected to a supercharging unit and a throttle valve located downstream of the supercharging unit. A first evacuation conduit is provided that connects the crankcase and the air intake conduit via a pressure regulator at a point downstream of the throttle valve for evacuating gases, so called xe2x80x9cblow-byxe2x80x9d, from the crankcase. A second evacuation conduit connects the crankcase to the air intake conduit at a point upstream of the supercharging unit. A device for separating oil from the evacuated blow-by gases is also provided. At least one further evacuation conduit is provided which can connect a collecting vessel, or another source of harmful emissions, with the evacuation conduits. Non-return valves are provided in the first and second evacuation conduits in order to prevent gases from flowing back into the crankcase.
It is a known that it is not possible to achieve a piston ring seal, between a piston and a cylinder wall, which gives a complete sealing effect between a combustion chamber and a crankcase during normal operation of an internal combustion engine. A certain amount of combustion gases, hereinafter termed xe2x80x9cblow-byxe2x80x9d, will, with few exceptions, flow past the piston rings into the crankcase of the engine. In order to avoid a high positive pressure in the crankcase, it must be ventilated, whereby the gases are removed leaving a low positive pressure, or a slight negative pressure in the crankcase.
Preferably, the crankcase is ventilated to atmospheric pressure, but for environmental reasons, it is not suitable to ventilate the gases directly to the surrounding atmosphere. In order to use the existing purification equipment of the engine, the blow-by must be returned to the combustion chamber, which is achieved by leading the gases into intake conduit(s) of the engine where the blow-by is mixed with the induction air. The simplest way of achieving this is to connect an evacuation conduit from the crankcase to the intake conduit at a point before the supercharging unit. At this point, between the intake air filter and the supercharging unit, the air pressure will be atmospheric, or near atmospheric. Although an oil separator of some form has traditionally been used, it has been inevitable that a certain amount of oil vapor has been included in the blow-by from the crankcase, through the evacuation conduit and into the supercharging unit. This oil vapor may condense and collect in the supercharging unit, and, depending on the amount of oil and the temperature, may disturb the function of the supercharging unit. In those cases where an intercooler is connected between the supercharging unit and the intake conduit, there is a risk of clogging the cooling channels causing a deterioration of the function of the intercooler.
The problem of oil collecting in the supercharging system can be avoided by connecting the evacuation after the throttle valve. There is often a significant negative pressure in this part of the conduit, however, especially at low engine load, which may cause an undesirable, very low negative pressure in the crankcase. In addition, it is not possible to evacuate the blow-by to this point of the conduit when the engine is being supercharged. One method for solving this problem, at least in part, is to use two evacuation conduits. One conduit is connected before the supercharging unit and one before the throttle valve. The latter is connected to the intake conduit via a throttling device, which limits the flow to the intake conduit, and a non-return valve which prevents flow in a direction away from said conduit. It is, however, difficult to achieve a balance in a system of this type, both for a normally aspirated engine, which has a negative pressure in the intake conduit at all times, and for a supercharged engine, which has a negative pressure in the intake conduit at low load and a positive pressure at high load. In one crankcase ventilation system for a supercharged engine, the evacuation conduit is connected to the intake conduit upstream of the supercharging unit and is provided with a pressure regulator arranged to maintain an almost constant pressure approximately equal to atmospheric pressure in the crankcase. At high load, gases will flow through the latter evacuation conduit to the suction side of the supercharging unit. Under this condition, there will be a positive pressure in the intake conduit, downstream of the throttle, causing the non-return valve in the other evacuation conduit to close and prevent air from flowing back into the crankcase. At low load and subsequent negative pressure downstream of the throttle valve, blow-by gases from the crankcase will flow via the non-return valve and the throttling device to the intake conduit. Under certain operating conditions, however, air may simultaneously be sucked from the intake conduit upstream of the supercharging unit, via the pressure regulator, to the intake conduit downstream of the throttle valve. Such an alternating flow of hot gases and cold air in opposite directions may result in condensation and a risk of freezing during cold weather conditions. One solution to this problem is to use a heating coil containing hot coolant around the evacuation conduit upstream of the throttle valve, although this adds to the cost of the system.
A similar problem occurs during evacuation of the vehicle canister. The canister is used for absorbing fuel vapor from the fuel tank in order to avoid ventilation of vapors to the atmosphere. Especially during filling of the tank, or during periods of high ambient temperatures, it is necessary for the canister to be able to absorb relatively large amounts of fuel vapor. The function of the canister itself is well known and will not be described here, in detail. In order to avoid saturation of the canister, it must be provided with an evacuation conduit, which, using negative pressure, sucks vapor from the canister, via a ventilating valve, to the induction system of the engine. A known solution is to split the evacuation conduit into two branches after the ventilating valve. A first conduit is connected downstream of the throttle valve and a second conduit is connected upstream of the supercharging unit, whereby each conduit is provided with a non-return valve.
Due to the degree of packing; i.e., the space used for assembly and installation of the engine and engine compartment components in relation to the available space, the introduction of new components and changes in the positioning of existing components is a problem. A new component can, for instance, be a system for purification of exhaust gases from the vehicle in front, whereby induction air, air for the passenger compartment and air passing through the engine compartment can be purified with respect to particles, nitrous oxides, etc. Such a system would require further conduits, and in certain cases, needs to be ventilated into the induction system of the engine.
The present invention, in its several disclosed embodiments, alleviates the drawbacks described above with respect to combined crankcase and canister ventilation systems and incorporates several additional beneficial features.
An object of the invention is to provide a supercharged combustion engine with pressure regulated crankcase ventilation, which eliminates the problems cited above. According to the invention, this is achieved by way of a combustion engine as described above, wherein the first and second evacuation conduits are connected in communication with a pressure regulator arranged to maintain a substantial constant pressure in the crankcase. Both evacuation conduits are provided with valves arranged to limit or prevent the flow of gases from the intake conduit to the crankcase. In addition, the system is provided with at least one further evacuation conduit, which can be used for ventilation of a collecting vessel of emissions, and the like, and is connected to the first and second conduits at a point between the pressure regulator and the valves.
According to the invention, pressure regulated crankcase ventilation is achieved both when the engine is normally aspirated (low load) and when it is supercharged (high load). During normally aspirated operation, virtually all blow-by will pass through the first evacuation conduit to the intake conduit downstream of the throttle, as the valve(s) in the second evacuation conduit prevents or limits the flow of intake air in the opposite direction; i.e., to the crankcase. During supercharged operation, with a positive pressure in the intake conduit, virtually all blow-by instead passes through the second evacuation conduit to the intake conduit upstream of the supercharging unit, as the valve means in the first evacuation conduit prevents or limits the flow from the intake conduit towards the crankcase.
By interconnecting existing evacuation conduits with further evacuation conduits for other types of emissions; for example, from a canister for fuel tank vapors or a catalytic purification device for cleaning ambient air, the number of new conduits and the accompanying couplings for the connection of these may be reduced significantly. This will simplify the installation of conduits, reduce the number of possible sources of leakages, and have a positive effect on the degree of packing of the engine. This is particularly true regarding the intake manifold, where it is often difficult to find room for more than one connection. Further advantages are that the system gives a stable negative pressure in the crankcase, and that the system diagnostics will be reliable, since a leakage exceeding the normal flow in any of the conduits will cause the engine to stop during idling, due to the large influx to the intake conduit. The emissions may be supplied continuously to the evacuation conduits, or be collected in a container in some form, such as a canister or a regenerative catalytic converter, for subsequent intermittent ventilation. In the latter case, a regulated valve is often required in order to control to the flow to the evacuation conduit.

Combined crankcase and canister ventilation system


A rotor and a method of constructing a rotor are disclosed. The rotor includes a hub that is capable of being supported by a shaft that extends along an axis, a plurality of laminations, and a plurality of wire windings supported by the plurality of laminations. The hub includes an inner structure configured to support the hub relative to the shaft, an outer structure that supports the laminations, and an intermediate structure that is coupled to the inner and outer structures and supports the inner and outer structures relative to one another.

The present invention relates to high speed generators and, more particularly, to the structure of the rotors of such generators.
Generator systems that are installed in aircraft may include three separate brushless generators, namely, a permanent magnet generator (PMG), an exciter, and a main generator. The PMG includes permanent magnets on its rotor. When the PMG rotates, AC currents are induced in stator windings of the PMG. These AC currents are typically fed to a regulator or a control device, which in turn outputs a DC current. This DC current next is provided to stator windings of the exciter. As the rotor of the exciter rotates, three phases of AC current are typically induced in the rotor windings. Rectifier circuits that rotate with the rotor of the exciter rectify this three-phase AC current, and the resulting DC currents are provided to the rotor windings of the main generator. Finally, as the rotor of the main generator rotates, three phases of AC current are typically induced in its stator windings, and this three-phase AC output can then be provided to a load such as, for example, electrical aircraft systems.
Among the important components in such generator systems are the rotors of the exciters. Conventional exciter rotors are formed from multiple laminations that are thin plates that are stacked axially along the generator shaft. The rotors often have many (e.g., more than eight) poles, and also support the rectifier circuits that convert the AC power generated in the rotor windings into the DC power that is to be provided to the main generator rotor.
Such conventional exciter rotors have several limitations. Because the generators installed in aircraft will often be variable frequency generators that rotate in the speed range of 12,000 rpm to 24,000 rpm, large centrifugal forces are imposed upon the rotors of the generators. Because the structure of the rotor includes multiple laminations, and because the laminations often are made from materials that are limited in their strength, imbalances in the rotor can occur when changes or shifts in the laminations affect the relative alignment of the laminations with one another or with respect to the generator shaft. Additional imbalances can occur when shifting or other changes in the positioning of the laminations affect the positioning of the many wire windings or rectifier circuits being supported by the laminations. Such imbalances can create inefficiencies in the operation of the generators or risk potential failures.
Additionally, the use of laminations in the exciter rotors makes it difficult to accurately and consistently manufacture such rotors. Slight variations in the thicknesses of the laminations of the exciter rotor can make it difficult to predictably manufacture exciter rotors having a given overall axial thickness. Further, the complicated shape of the laminations, with their many radially protruding pole extensions and deep radial cut-outs, often renders it difficult to manufacture and assemble the laminations.
Hence, there is a need for a new exciter rotor assembly that is reliable, robust and can be easily manufactured within tolerances both in terms of the shape of the outer perimeter of the rotor and the axial thickness of the rotor. Additionally, there is a need for a new exciter rotor assembly that is capable of maintaining proper balance when operating at high speeds even though it includes multiple laminations and supports many wire windings and rectifier circuits.
The present inventors have recognized that a new exciter rotor assembly can be developed that includes a hub that is supported by the generator shaft and in turn supports narrow ring-type laminations around its outer perimeter. The laminations are shrunk fit onto the hub, which is made from a strong material, is carefully manufactured to have a particular axial thickness, and in turn is shrunk fit onto the generator shaft. By incorporating such a hub in between the narrow ring-type laminations and the generator shaft, the radial width of the laminations is significantly reduced and the above-described problems associated with the manufacture and use of the laminations are alleviated.
In particular, the present invention relates to a rotor that includes a hub configured to be supported by a shaft that extends along an axis, a plurality of laminations, and a plurality of wire windings supported by the plurality of laminations. The hub includes an inner structure configured to support the hub relative to the shaft, an outer structure, and an intermediate structure that is coupled to the inner and outer structures and supports the inner and outer structures relative to one another. The plurality of laminations are supported by the outer structure.
The present invention further relates to a generator that includes a stator, a shaft, and a rotor supported by the shaft. The rotor includes a plurality of laminations, a plurality of wire windings wrapped around the plurality of laminations, and a means for supporting the laminations relative to the shaft. The means for supporting has a first radial width extending from the shaft to the laminations that is larger than a second radial width of the laminations that extends from the means for supporting to an outer circumference of the rotor.
The present invention also relates to a hub for implementation in a high-speed generator rotor, where the hub includes an inner structure configured to support the hub relative to a shaft, an outer structure configured to support a plurality of laminations, and an intermediate structure that is coupled to the inner and outer structures and supports the inner and outer structures relative to one another. The intermediate structure defines a plurality of cavities within the hub.
The present invention additionally relates to a method of constructing a rotor. The method includes providing a hub having an outer structure with a cylindrical support surface and a retaining ring, an inner structure forming a cylindrical cavity, and an intermediate structure coupled to the inner and outer structures and configured to support the inner and outer structures relative to one another. The method further includes positioning a plurality of ring-type laminations and a pair of insulating rings onto the cylindrical support surface. A first of the pair of insulating rings is positioned on a first side of the plurality of laminations and a second of the pair of insulating rings is positioned on a second side of the plurality of laminations. The laminations and insulating rings are positioned so that the first of the pair of insulating rings abuts the retaining ring. The method additionally includes shrink-fitting the ring-type laminations and insulating rings onto the cylindrical support surface, positioning a balancing ring onto the cylindrical supports surface so that the balancing ring abuts the second of the pair of insulating rings, shrink-fitting the balancing ring onto the cylindrical support surface, and wrapping a plurality of wire windings onto the laminations.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.


Carbon nanotubes are dissolved in organic solutions by attaching an aliphatic carbon chain (which may contain aromatic residues) so as to render the carbon nanotubes soluble.

The present invention relates to the dissolution of full length or, unshortened carbon nanotubes in solutions and more particularly, to a method of dissolving carbon metals and semiconductors in organic solutions.
All previous work on carbon nanotubes (both single-walled and multi-walled) has been carried out on the usual intractable, insoluble form of this material [Yakobson, B. I.; Smalley, R. E., Fullerene Nanotubes: C1,000.000 and Beyond. American Scientist 1997, 85, 324-337.] This form of the material is not amenable to many of the processing steps that are necessary if the carbon nanotubes (CNTs) are to reach their full potentialxe2x80x94particularly in applications that require these materials in the form of polymers, copolymers, composites, ceramics and moldable forms.
While present forms of the CNTs can be heterogeneously dispersed in various media, the interactions between the CNTs and host and between the CNTs themselves are simply physical, and without the formation of chemical bonds. Thus, the advantageous properties of the CNTs are unlikely to be realized on a macroscopic level. What is needed is a method to prepare well-dispersed forms of CNTs perhaps by inducing them to exfoliate from the bundles and dissolve in organic solvents. Although long believed to be impossible, [Ebbesen, T. W., Cones and Tubes: Geometry in the Chemistry of Carbon. Acc. Chem. Res. 1998, 31, 558-566] we now teach such a procedure for the dissolution of all types of CNTs [Chen, J.; Hamon, M. A.; Hu, H.; Chen, Y.; Rao, A. M.; Eklund, P. C.; Haddon, R. C., Solution Properties of Single-Walled Carbon Nanotubes. Science 1998, 282, 95-98; Hamon, M. A.; Chen, J.; Hu, H.; Chen, Y.; Rao, A. M.; Eklund, P. C.; Haddon, R. C., Dissolution of Single-Walled Carbon Nanotubes. Adv. Mater. 1999, 11, 834-840].
In accordance with the present invention, a simple method of solubilizing carbon nanotubes is provided. The resulting solutions are anticipated to be useful in the functionalization chemistry of the ends, the exterior walls or convex face and the interior cavity or concave face of carbon nanotubes and processing useful nanotube based polymer, copolymer and composite products and devices for a multitude of applications in various industries including aerospace, battery, fuel cell, healthcare and electromagnetic radiation shielding.
Advantageously, as a result of the present invention, functionalization chemistry of the CNTs can be achieved through the study of both the ionic and covalent solution phase chemistry with concomitant modulation of the single wall nanotube band structure.
Additional advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, a novel and improved method of dissolving CNT metals and semiconductors in common organic solutions is provided. The method comprises the attaching of an aliphatic carbon chain (which may contain organic residues) to the CNTs so as to render the CNTs soluble in the selected organic solvent.
The attaching step includes directly reacting the carbon nanotubes with an amine having a formula RNH2 or R1R2NH wherein R, R1 and R2=(CH2)nCH3 where n=9-50. Alternatively, the attaching step includes directly reacting the carbon nanotubes with an alkylaryl amine having a formula RNH2 Or R1R2NH wherein R, R1 and R2=(C6H4)(CH2)nCH3 where n=5-50.
In accordance with yet another aspect of the invention, the attaching step includes the steps of (a) mixing the carbon nanotubes with an amine or alkylaryl amine having a formula RNH2 or R1R2NH wherein R, R1 and R2=(CH2)nCH3 and n=9-50 or R, R1 and R2=(C6H4)(CH2)nCH3 and =5-50; and (b) heating the resulting mixture to a temperature between 50-200xc2x0 C. More preferably, the heating step is to 60-100xc2x0 C. for at least 70 hours.
The method may also be described as including the further step of dissolving the resulting carbon nanotubes with attached aliphatic carbon chain in the selected organic solvent. That organic solvent may be an aromatic or chlorinated solvent. Solvents in which the CNTs of the present invention may be solubilized include but are not limited to chlorobenzene, dichlorobenzene, trichlorobenzene, tetrahydrofuran, chloroform, methylene chloride, diethylene glycol dimethyl ether, carbon disulfide, benzene, toluene, tetrachlorocarbon, pyridine, dichloroethane, diethyl ether, xylene, naphthalene, nitrobenzene, ether and mixtures thereof. The solubilities of the carbon nanotubes in these solvents range from about 0.01-5.0 mg/ml.
Advantageously, such a solution not only allows the study of the functionalization chemistry of the open ends, the exterior walls or convex face and the interior cavity or concave face of the nanotubes, but also processing of the nanotubes into useful products for various applications including as intermediates in the preparation of polymer, copolymer and composite materials.
In the following description, there are shown and described various embodiments of this invention, simply by way of illustration of several modes and alternate embodiments best suited to carry out the invention. As it will be realized, the invention is capable of still other and different embodiments, and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the descriptions will be regarded as illustrative in nature and not as restrictive.
In the novel method of the present invention, we begin with raw, as prepared, CNT soot (AP-CNTs). The AP-CNTs come in two basic forms: AP-single-walled carbon nanotubes (AP-SWNTs) available from CarboLex, Inc. of Lexington, Ky. and AP-multi-walled carbon nanotubes (AP-MWNTs) available from MER Corporation of 7960 South Kolb Rd, Tucson, Ariz. 85706. The AP-SWNTs are prepared by use of an electric arc technique similar to that described by Journet, C.; Maser, W. K.; Bernier, P.; Loiseau, A.; Lamy de la Chappelle, M.; Lefrant, S.; Deniard, P.; Lee, R. and Fischer, J. E., in Large Scale Production of Single-Walled Carbon Nanotubes by the Electric-Arc Technique. Nature 1997, 388, 756-758. The estimated purity of this material is 40-60% SWNT by volume. Batches of 10 grams may be prepared in a single run and there is considerable scope for further increase in scale. Thus it is possible to contemplate the very large-scale production of this material in the future. The AP-MWNTs are of an estimated purity of less than 10% and the nanotubes are of poor quality with many defective and fused together CNTs. We describe herein routes to soluble CNTs, starting from AP-SWNTs and AP-MWNTs.
In accordance with the present invention, full length or unshortened carbon nanotubes are solubilized. This is accomplished utilizing a simple procedure which advantageously preserves the length of the carbon nanotubes which is one of their primary attractions in many applications.
In a prior art approach described in copending U.S. patent application Ser. No. 09/409,787 filed on Sep. 30, 1999 now U.S. Pat. No. 6,368,569, and entitled xe2x80x9cMethod of Solubilizing Unshortened Carbon Nanotubes In Organic Solutionsxe2x80x9d, there are basically two steps in all of the procedures: (1) a pretreatment, or purification step that serves to add carboxylic acid functionalities to the nanotubes and (2) a chemical functionalization step that modifies the carboxylic acid in a way that attaches a long aliphatic carbon chain to the end of the nanotube, and thereby renders the CNTs soluble in some organic solvents.
We have now found a way to simplify this process so that the introduction of carboxylic acid groups is not necessary. This has been achieved through the direct (noncovalent) interaction of the SWNTs with a long chain amine such as octadecylamine (ODA). One of the major advantages of this method is its simplicity and ease of use. The CNTs do not require any pre-treatment. The AP-CNTs are used directly in the dissolution step. Furthermore, the CNTs are not subjected to strong acid, and extra functionality is not introduced. IR spectroscopy of these CNTs, either before or after dissolution, shows no evidence for the functional groups that are usually introduced by the acids used in the purification. [Chen, J.; Hamon, M. A.; Hu, H.; Chen, Y.; Rao, A. M.; Eklund, P. C.; Haddon, R. C., Solution Properties of Single-Walled Carbon Nanotubes. Science 1998, 282, 95-98; Liu, J.; Rinzler, A. G.; Dai, H.; Hafner, J. H.; Bradley, R. K.; Boul, P. J.; Lu, A.; Iverson, T.; Shelimov, K.; Huffman, C. B.; Rodriguez-Macias, F.; Shon, Y.-S.; Lee, T. R.; Colbert, D. T.; Smalley, R. E., Fullerene Pipes. Science 1998, 280, 1253-1255; Rinzler, A. G.; Liu, J.; Dai, H.; Nilolaev, P.; Huffman, C. B.; Rodriguez-Macias, F. J.; Boul, P. J.; Lu, A. H.; Heymann, D.; Colbert, D. T.; Lee, R. S.; Fischer, J. E.; Rao, A. M.; Eklund, P. C.; Smalley, R. E., Large-Scale Purification of Single-Wall Carbon Nanotubes: Process, Product and Characterization. Appl. Phys. A 1998, 67, 29-37.]
Furthermore, the CNTs may be liberated from the amine by acidification. Thus, treatment of solutions of the CNT [amine] solvate with hydrochloric acid leads to precipitation of the unchanged CNTs due to protonation of the amine. Hence, this method is an ideal way to introduce CNTs into polymer mixtures and blends and to form films, from which the amine may be easily removed because it is not chemically bonded to the CNTs.
The nature of the noncovalent and presumably nonionic long chain aminexe2x80x94CNT interaction is not fully understood at this point but could involve micelle formation with the head of the amine group interacting with the wall of the CNTs leading to a colloidal dispersion. This interaction would allow the amine to radiate out from the CNTs and create a micelle-like particle. These particles could then form colloidal solutions in organic solvents. In this scenario the dissolution process of AP-CNTs takes the form of a noncovalent interaction with the long-chain amine, which is presumably similar to the interaction of ammonia with benzene. [Rodham, D. A.; Suzuki, S.; Suenram, R. D.; Lovas, F. J.; Dasgupta, S.; Goddard III, W. A.; Blake, G. A., Hydrogen Bonding in the Benzene-Ammonia Dimer. Nature 1993, 362, 735-737.
By means of the present invention, it is possible to directly attach an aliphatic carbon chain such as an amine or alkylarylamine to as-prepared carbon nanotubes and single walled carbon nanotubes produced by a modified electric arc discharge. This attachment is accomplished by mixing the single walled carbon nanotubes with an amine having a formula RNH2 or R1R2NH wherein R, R1 and R2=(CH2)nCH3 where n=9-50 and/or an alkylarylamine having a formula RNH2 or R1R2NH wherein R, R1 and R2=(C6 H4)(CH2)nCH3 where n=5-50. The mixture of AP-CNTs or AP-SWNTs and amine and/or alkylarylamine is then heated to a temperature of 60-100xc2x0 C. for at least 70 hours. Preferably the mixture is mildly agitated during this time to insure more complete reaction and to increase yields. As a result of this process amines and/or alkylarylamines are attached to some of the AP-CNTs or AP-SWNTs undergoing processing.

Method of solubilizing carbon nanotubes in organic solutions

University of Kentucky Research Foundation


A client computer runs an operating system that executes additional applications by loading them using an application loader and executes device drivers for peripheral devices by loading the drivers using a device loader. The operating system restricts the functionality of the operating system, such as by making selected portions and functionality of the operating system unavailable to the user or by limiting the user's ability to add software applications or device drivers to the computer. Additionally, various techniques can be used to remove or reduce the functionality limitations of the computer.

Computer technology is continually advancing, resulting in new computers that are more powerful and cheaper than their predecessors. Such advancement has had a significant affect on people, expanding the types of tasks people perform with their computers as well as increasing the number of people who use computers.
Many computers are currently manufactured with a general purpose "open architecture" operating system installed. An open architecture operating system refers to an operating system that makes numerous functions available to the user and also allows the user to modify the computer by installing additional software programs on the computer that provide additional functionality to the user or by removing software programs from the computer. The operating system can make a wide variety of functionality available to the user, such as recreational or educational programs, reference programs, productivity programs (such as word processing or database functionality), communications programs, etc.
One problem inherent in open architecture systems is they are generally licensed with complete use rights and/or functionality that may be beyond the need or desire of the system purchaser. Consequentially, the purchase price of these systems being indifferent to usage scenarios means users with limited needs pay the same rate for these systems as those with universal needs.
An additional problem with open architecture systems is that virtually anyone can write an application that can be executed on the system. Some applications or devices may not operate properly due to a problem with the application or associated driver, yet many users associate such problems with the manufacturer of the system. Thus, it would be beneficial to provide a way for the manufacturer of the system to control the extensibility of the system.
The invention described below addresses these disadvantages by providing restricted software and hardware usage on a computer.

Restricted software and hardware usage on a computer


An emergency ejection seat with a propulsion system is disclosed. The propulsion system may be provided by a propeller-equipped brushless motor. The emergency ejection seat includes speed controllers that can accelerate and move the seat with two different speeds. Several wedge-shaped recesses along the rear of the seat help limit the effects of a vacuum.

In aircraft, an ejection seat or ejector seat is a system designed to rescue the pilot or other crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an explosive charge or rocket motor, carrying the pilot with it. The concept of an ejectable escape crew capsule has also been tried. Once clear of the aircraft, the ejection seat deploys a parachute. Ejection seats are common on certain types of military aircraft.

Emergency ejection seat with propulsion system


A system for high-pressure natural gas storage includes at least one underground bored tunnel, suitable for holding natural gas under pressure and a process for storing natural gas under pressure.

Gas storage is principally used to meet seasonal load variations. Gas is injected into storage during periods of low demand and withdrawn from storage during periods of peak demand. It is also used for a variety of secondary purposes, including:                Balancing the flow in pipeline systems. This is performed by mainline transmission pipeline companies to maintain operational integrity of the pipelines, by ensuring that the pipeline pressures are kept within design parameters.        Maintaining contractual balance. Shippers use stored gas to maintain the volume they deliver to the pipeline system and the volume they withdraw. Without access to such storage facilities, any imbalance situation would result in a hefty penalty.        Leveling production over periods of fluctuating demand. Producers use storage to store any gas that is not immediately marketable, typically over the summer when demand is low and deliver it when in the winter months when the demand is high.        Market speculation. Producers and marketers use gas storage as a speculative tool, storing gas when they believe that prices will increase in the future and then selling it when it does reach those levels.        Insuring against any unforeseen accidents and or planed or unplanned system shut down for maintenance. Gas storage can be used as an insurance that may affect either production or delivery of natural gas. These may include natural factors such as hurricanes, or malfunction of production or distribution systems.        Meeting regulatory obligations. Gas storage ensures to some extent the reliability of gas supply to the consumer at the lowest cost, as required by the regulatory body. This is why the regulatory body monitors storage inventory levels.        Reducing price volatility. Gas storage ensures commodity liquidity at the market centers. This helps contain natural gas price volatility and uncertainty.        Offsetting changes in natural gas demands. Gas storage facilities are gaining more importance due changes in natural gas demands. First, traditional supplies that once met the winter peak demand are now unable to keep pace. Second, there is a growing summer peak demand on natural gas, due to electric generation via gas fired power plants.


A domestic oven is controlled for use in proofing and cooking bread. In accordance with the invention, at least one heating element of the oven is first energized to bring the oven to a first high temperature representing an overshoot temperature which allows activation of yeast inside dough. Once the first high temperature is reached, the temperature is allowed to drop to a second level which is maintained by cycling the heating element(s) on and off to allow proofing of the bread. A fan is also provided to circulate air in the oven when a rapid proofing sequence is selected.

1. Field of the Invention
The present invention relates to a domestic bread proofing oven and a method for controlling the oven. Upon activation for a rapid proofing operation, the oven of the invention will heat-up to a first temperature, before cooling and being maintained at a second lower temperature. This procedure allows for proofing of uncooked dough, selectively at an increased rate, without killing the yeast.
2. Discussion of the Prior Art
Generally, the process for making bread at home includes mixing yeast, sugars, flower, liquids, and salt in proper proportions to form a dough, which is then repeatedly kneaded and allowed to rise for a precise period of time. Traditionally, the ingredients were mixed by hand and the dough was set aside to rise. Following the rising period, the dough is then baked and cooled.
Once the yeast has been added, the dough begins to rise. This period is called proofing. During proofing, the yeast is growing and fermenting as it is consuming the added sugar. During this fermenting process, the yeast emits carbon dioxide and other gasses which bubble through the dough causing the dough to expand, or rise.
Because proofing often takes an extended period of time, and health reasons prevent leaving the dough unrefrigerated for as long as it takes for bread to proof, proofing is often conducted in a cooled environment such as a refrigerator. But yeast fermentation is slowed considerably when in a cooled environment. Therefore, placing the unproofed bread inside a refrigerator extends the proofing time extensively.
Similarly, conventional ovens cannot be used to proof dough because the lowest available temperature settings will kill the yeast before proofing has been completed. Specifically, it is desired to maintain the dough at a temperature just high enough to allow the yeast to properly grow, while neither cooking the dough nor killing the growing yeast, e.g. approximately 110xc2x0 F. (43xc2x0 C.). Unfortunately, traditional ovens are not provided with such settings.
Recently, machines have been developed which automates the entire bread making process. Users simply place the correct measurements of ingredients into the machine and the machine takes over. Automatically, the ingredients are mixed forming a dough, and the dough is permitted to rise. Once a specific amount of rising time has elapsed, the baking procedure begins. In order to make the cooking process as easy as possible, all of the ingredients are placed inside the cooking chamber. While this may make the bread making procedure significantly faster and simpler, the resulting bread is often inferior in quality.
Automatic bread making machines, while often convenient and easy to use, have additional limitations. Primarily, users are required to have a separate appliance in their kitchen, which only has limited uses. Because most kitchens have limited counter space, these automatic bread makers must be stored away when not use. This means that whenever someone wants to use one of these automatic bread makers, they need to retrieve the machine from wherever it is stored, carry it to the kitchen and, when finished, return it to storage. For homes with limited storage space, finding adequate storage is also a problem. In any event, it would be preferable to avoid the need for a dedicated domestic bread machine. Instead, it would be beneficial to specifically adapt a conventional oven for use in optimally proofing uncooked bread, preferably in a manner in which actually reduces the overall operation time.
The present invention is particularly directed to a method and apparatus for proofing bread without requiring a separate appliance by incorporating a proofing methodology into a conventional oven. The oven of this invention includes a bread proofing option which is activated via a separate control sequence. Selecting the bread proofing option activates a respective control algorithm which operates the existing heating element(s) inside the oven to allow proofing of dough therein.
In accordance with a preferred rapid proofing embodiment of the invention, the control algorithm of the invention activates the heating element(s) of the oven. First, the temperature of the oven cavity is elevated beyond that which required to proof the dough. Advantageously, this temperature overshoot allows for the quick activation of the yeast without baking the dough. Activation of the yeast starts the fermentation process, which causes the yeast to emit carbon dioxide. It is the carbon dioxide that causes the bread to rise. The remainder of the proofing process is best carried out at a temperature lower than that necessary to initially activate the yeast. Therefore, once the activation temperature is reached, the proofing oven of the invention automatically lowers the temperature of the oven cavity to a temperature high enough to proof the bread rapidly, without baking the dough.
The algorithm of the invention controls the heating element to maintain this lower temperature for a specified time. Accordingly, this lower temperature is achieved by cycling on and off the heating element at the lower temperature. This prevents the dough from reaching a temperature on either side of a target temperature. This cycling on and off of the heating element, and hence the maintenance of the oven cavity temperature, is accomplished by lowering the heat output of the heating element.
When the oven of the invention is an electric oven, the heat output can be controlled by varying the voltage to one or more of the available heating elements. During normal baking, the lower or bake heating element is energized with 240 volts. When the same heating element is used during the proofing process, 120 volts is used. This lower voltage prevents the heating element from reaching temperatures necessary to bake the unproofed dough.
Once proofing, is complete, the dough is ready for baking. At this point, the normal operations of the oven can be utilized. By providing this process in an oven which is capable of both proofing and baking the dough, the number of appliances necessary to make the bread is reduced and the overall operational efficiency and convenience is enhanced.


A method of producing injection molded in-line skate wheels is disclosed. The method includes heating an injection molding unit suitable for injecting molten polyurethane, placing a thermoplastic polyether type polyurethane into the unit and heating the polyurethane until it is molten or at about 380.degree. to about 460.degree. F. A polyurethane hub is placed in a mold whereby the mold and hub are of shapes and sizes suitable for producing in-line skate wheels. The hub-containing mold is heated to about 50.degree. to about 100.degree. F. in order to prevent the molten polyurethane from prematurely hardening. Once the mold is heated, about 46 to about 50 g of polyurethane is injected into the mold at about 75 to about 100 psi. The polyurethane is cooled to about 120.degree. to about 130.degree. F. to allow the polyurethane to harden and the resulting wheel is removed from the mold.

Since the invention of the first pair of in-line skates in the early 1980's, in-line skating is rapidly increasing in popularity and is successfully competing and co-existing with traditional roller skating. In fact, in-line skating has become so popular that nearly a worldwide market now purchases in-line skates. To this end, the in-line skate industry is continually developing new skates to meet the consumer's demands for lighter, faster skates.
Wheels of in-line skates are a critical component which manufacturers constantly strive to improve. Early wheels were manufactured of high friction material which resulted in prohibitively slow wheels. The industry quickly started producing the wheels from materials which had a lower coefficient of friction against the pavement and thereby created faster wheels.
In addition to demanding faster wheels, in-line skaters have another demand. In order to be suited for in-line skating, the wheels must contain a certain amount of rebound. One subjective test for rebound is to bounce a wheel on a hard surface such as a table top. If the wheel bounces, it may have desirable and suitable rebound properties for use in an in-line skate. Rebound is necessary to absorb the unevenness of pavement, loose pebbles and gravel which a skater may encounter when skating. The rebound of the wheels in part acts as a "shock absorber" for the person wearing the skates.
Currently, in-line skate wheels are produced only by the method of casting or pour molding from thermoset polyurethane. Thermoset polyurethanes are characterized by rebound suitable for use in in-line skates, however, thermoset polyurethanes are not injection moldable. Two other problems are associated with thermoset polyurethanes for in-line skate wheels. First, the material requires a 3 minute cure time which slows the manufacturing time of in-line skate wheels and raises manufacturing costs. Second, thermoset plastics are not recyclable once they have cured. That is, once a thermoset plastic has set it cannot be melted and recast and it is therefore not environmentally sound to use thermoset plastics.
Several other problems are associated with cast molding of in-line skate wheels. First, the process of cast molding is very labor-intensive. Second, cast molded wheels require machining after the wheels are molded to remove excess material. Third, besides temporal constraints, quality control problems also exist with cast wheels because air bubbles are often trapped in the cast-molded wheels. Air entrapped wheels obviously must be discarded or scrapped thus increasing production costs and creating nonrecyclable waste.
In addition to manufacturing problems, the currently available wheels are also inferior because adhesives are routinely used to bond the tread to the hub. With time and use, the adhesive breaks down causing the tread portion of the wheel to pull away from the hub. If this occurred while a skater was skating on the wheels, such an event could injure a skater.
A desirable method of manufacturing in-line skate wheels would be characterized by a method faster than the currently used cast-molding method. Such a method would also eliminate quality control problems such as air bubbles in the wheels, and further would create a safer wheel by eliminating the hub portion separating away from the tread portion. Such a method would additionally result in polyurethane wheels having necessary rebound.

Method of producing polyurethane injection molded in-line skate wheels


A self-guided system for trenching water bottoms for the installation of a pipeline. The preferred embodiment of the present invention teaches a system which is configured to be mounted about the pipeline to be buried, and which further contemplates a uniquely configured, forward mounted trenching/drive mechanism incorporating a cutter wheel generally about the width of the desired trench, the mechanism configured to propel the system as well as trench the desired area. An alternative embodiment of the contemplates a frontal high pressure jet array in lieu of the cutter head. The trenching/drive mechanism of the preferred embodiment of the present invention further includes a high pressure spray array mounted about the frontal cutter wheel area, and a suction/mud pump assembly to the rear of the cutter wheel. The high pressure spray array provides the dual purpose function of loosening the area to be trenched, as well as cleaning and removing the trenched matter from the cutter wheel. The present invention further includes first and second buoyancy chambers which are configured to be uniformly lowered to the lower periphery of the unit frame, to provide skids for utilization of the present system in shallow water. An alternative embodiment of the present invention teaches the incorporation of a framed system similar to that as taught in the present invention, but without the trenching/drive mechanism, and with the addition of a pipe cutter mounted to the rear of the unit frame, for utilization of pipeline recovery and dismemberment operations. Other features of the present invention which are taught, and which may be implemented, include G.P.S. (global positioning system) receiver/data transmission for precise monitoring of the system during operations, thruster propulsion, and bottom loading of pipe into the frame via hinged bottom rollers, which may be powered.

1. Invention Field
The present invention relates to underwater trenching systems, and more particularly to a self-guiding system for trenching water bottoms for the installation of a pipeline. The preferred embodiment of the present invention teaches a system which is configured to be mounted about the pipeline to be buried, and which further contemplates a uniquely configured, forward mounted trenching/drive mechanism incorporating a cutter wheel generally about the width of the desired trench, the mechanism configured to propel the system as well as trench the desired area. An alternative embodiment of the contemplates a frontal high pressure jet array in lieu of the cutter head.
The trenching/drive mechanism of the preferred embodiment of the present invention further includes a high pressure spray array mounted about the frontal cutter wheel area, and a suction/mud pump assembly to the rear of the cutter wheel. The high pressure spray array provides the dual purpose function of loosening the area to be, trenched, as well as cleaning and removing the trenched matter from the cutter wheel.
The present invention further includes first and second buoyancy chambers which are configured to be uniformly lowered to the lower periphery of the unit frame, to provide skids for utilization of the present system in shallow water.
Other features of the present invention which are taught, and which may be implimented, include G.P.S. (global positioning system) receiver/data transmission for precise monitoring of the system during operations, thruster propulsion, and bottom loading of pipe into the frame via hinged bottom rollers, which may be powered.
Another alternative embodiment of the present invention teaches the incorporation of a framed system similar to that as taught in the present invention, but without the trenching/drive mechanism, and with the addition of a pipe cutter mounted to the rear of the unit frame, for utilization of pipeline recovery and dismemberment operations.