A rear track suspension for a snowmobile having a single resilient element for biasing both the front and rear arms. The slide rail is permitted to pitch between first and second pitching constraints in response to terrain obstacles in a gradual manner as the motion constraints are approached. This reduces jarring of the rider when the pitching constraints are met. Suspension compression exhibits an initial falling rate motion ratio, followed by a constant rate motion ratio, followed by a rising rate motion ratio. This U-shaped motion ratio profile advantageously provides cushioning upon landing along with a resistance to bottoming out of the suspension upon full compression. The result is an improved ride without sacrificing suspension performance.

Modem snowmobiles typically have two skis for supporting the front of the machine and to provide steering and a rubber track for supporting the rear of the machine and to provide traction force. The rider is typically positioned anywhere from directly over the center of the track to over the front of the track, while the engine is located between the drive track and the skis, usually as low as possible.
A snowmobile is considered to be an off-road vehicle and as such it must be able to contend with many different riding environments. The terrain may change from smooth trails to large bumps and jumps. Snow conditions can vary from grippy hard-pack to bottomless powder, from smooth trails to rough and bumpy ones. Accordingly, modem snowmobiles are equipped with long travel suspensions at the front (skis) as well as at the rear (track). The rear track suspension is mounted to the underside of the snowmobile within a tunnel that partially encloses the track and suspension. A seat for the snowmobile rider is provided on top of the tunnel and running boards are provided on either side for supporting the rider's feet.
Existing snowmobile rear suspensions are quite similar. A rubber track is driven from the front by a set of cogged drivers. A set of slide rails enclosed within the track pushes the track onto the ground and provides a sliding surface for the track and mounting points for wheels and suspension arms. There are generally two sets of pivoting suspension arms connecting the rails to the tunnel, one positioned in front of the other at similar angles to form a parallelogram. In most suspensions, both arms are biased downwards with two separate springs. The springs can be arranged in a number of ways to provide various motion ratios (i.e., spring compression versus suspension movement). Each spring is typically controlled by a hydraulic shock absorber to allow the suspension to release bump energy slower than it is absorbed and to prevent un-dampened oscillation.
A snowmobile's rear suspension must be able to perform the following functions under all conditions: isolate the rider and the machine from the full bump force; maintain track contact with the ground by allowing the rails to articulate to some degree; and, allow the snowmobile to "lean back" upon acceleration to transfer weight to the track.
In most current designs, bump absorption is obtained by using springs and shocks which are mounted in various ways to provide the desired motion ratio. A motion ratio compares spring and shock compression with suspension compression. A falling rate motion ratio is one where the shock speed decreases as the suspension compresses at a constant rate. This results in a soft and comfortable ride, but has poor resistance to bottoming over large bumps and upon landing after being airborne. A rising rate motion ratio is one in which the shock speed increases as the suspension compresses at a constant rate. This setup is typically found in sport snowmobiles and provides excellent control at high speeds and excellent bottoming protection.
Because the off-road environment is often unsmooth, the slide rails must be able to pitch forward and backward to some degree in order to maintain full track contact with the ground. If the arms and rails formed a solid parallelogram, this would not be possible. Instead, this function is typically accomplished by using a solid mounting point for only one of the arms (usually the front arm). The other (back) arm mounts indirectly to the rails using either a third smaller arm or some sort of telescoping device. The amount of rail pitch must be limited to eliminate excessive pitching of the entire machine. This is done in several different ways, usually by limiting the rotation of the third arm or limiting the amount of axial movement of the telescoping device. Once the limit is reached, the suspension is coupled, and the suspension geometry approximates a parallelogram. This forces both arms to compress at the same time. The moment at which a limit is reached is sometimes referred to as the "coupling moment". Most suspensions are coupled in both directions (front to back and back to front), but a few are coupled only in one direction, allowing unrestricted movement of the front arm or of the rear arm.
A snowmobile suspension must also provide weight transfer. Because snow provides limited traction, it is important to put as much of the vehicle weight over the track as possible during acceleration. This is typically accomplished by using the track tension during acceleration to actively pitch the rails, lifting the front of the machine to some degree. Upon acceleration, the top part of the track is in tension. A force analysis performed at the rear axle of the suspension typically shows a major component pushing the rails forward and a minor component pulling the back of the rails upward. The major forward push on the rails is transferred to the front arm where, because of its angle, it pushes the centre of the machine upwards, increasing the downward force on the front of the rails. The minor component pulling up on the back of the rails pulls the rear of the machine downwards, decreasing the downward force on the back of the rails. The result is a snowmobile with less weight on its skis and more on its track.
As mentioned above, in a typical snowmobile riding environment, bumps of all sizes may be encountered. A certain amount of rail pitch is beneficial to allow the track to maintain better contact over the smaller bumps. In some situations, however, the amount of rail pitch must be limited. This is accomplished by several means, usually involving a stopper or a bumper of some sort. The movement of a shorter third arm or a telescoping device is limited by a rubber bumper or a similar device.
When the track suspension encounters a large bump at high speed, first the front arm compresses relative to the underside of the snowmobile. Without any coupling device, the front spring may be overcome by the large bump force and the front arm may bottom harshly. If the two arms become coupled at a certain point, both front and rear arms are forced to move together. This allows the bump to be absorbed by both front and rear springs, effectively increasing the amount of bump energy that can be absorbed using a given set of springs. It is also possible to simply use stronger springs on the front arm, but this results in a harsher ride.
Another scenario in which coupling is desirable is in tail first landings. It is not uncommon for snowmobilers to launch the entire machine into the air, often landing "tail first". In this case, the rear arm in the suspension is prone to rapid bottoming. In this case, coupling also allows the impact to be absorbed by both suspension arms and their respective springs and shocks.
In most suspensions, coupling is provided by a set of bumpers or a by a set of rods that are able to telescope to a certain extent. At the instant when these suspensions couple, the overall spring force is instantly doubled as both suspension arms are forced to move and both springs are engaged. This is characterized by a harsh ride over "chatter bumps" (i.e., small to medium size evenly spaced bumps that force the coupling device to reach both its limits in rapid succession repeatedly). This is far less desirable than gradual coupling and a smooth increase of overall spring force as the suspension compresses.
There are several currently available rear suspension designs for snowmobiles.
U.S. patent application Ser. No. 10/698,980, filed Oct. 31, 2003 by Imamura et al. and published Aug. 19, 2004, includes a quadrilateral linkage system formed between a vehicle body frame, a front torque arm assembly, a rear torque arm assembly, and an extendable member. This suspension uses one coil-over spring to bias both suspension arms. The shock mounts to each arm a certain distance from its pivot so that as the suspension compresses, the shock also compresses. It is a falling rate design with a multi-rate spring that becomes progressively stiffer as it is compressed. The rear arm is mounted to the rails using a short, vertical arm. The device which limits the amount of rail pitch is the lower extendable member linking both arms together. The extendable member comprises a telescoping rod with adjustable limits.
U.S. Pat. No. 6,390,219 filed May 14, 2001 by Vaisanen discloses a snowmobile suspension that provides a substantially constant motion-ratio (i.e. reduced falling rate) over the entire suspension stroke of the suspension system. The suspension system includes a suspension assembly that includes a lower arm assembly, a suspension arm, and a shock absorber. The lower arm assembly pivotally interconnects the lower portion of the suspension arm and the lower end of the shock absorber to the slide frame at a location relative to the chassis and within the endless track. The upper portion of the suspension arm and the upper end of the shock absorber pivot independently from each other, and the upper portion of the suspension arm is positioned lower and forward of the upper end of the shock absorber. The upper end of the shock absorber is positioned relative to the chassis and within the endless track. The mounting positions defined by (i) the upper end of the suspension arm, (ii) the upper end of the shock absorber, (iii) the lower end of the suspension arm, and (iv) the lower end of the shock absorber cooperate to provide a substantially constant motion-ratio as the slide frame collapses toward the frame element. The rear arm is attached to the rails by an "upside down" third vertical arm.
U.S. Pat. No. 6,234,264 filed Nov. 24, 1998 by Boivin, et al. discloses another snowmobile track suspension. The suspension disclosed by Boivin et al. is a long travel design. The front arm is mounted directly to the tunnel and the front shock is mounted in typical fashion. The front arm is mounted to the rails by means of a sliding pivot in a slot. The rear arm is mounted directly to the tunnel and directly to the rails by means of an adjustable pivot that allows for the necessary rail pitch. The rear shock is mounted in similar fashion to the front one.
While there are numerous rear suspension designs, these designs all have several problems and disadvantages.
One problem relates to slide rail pitching. During acceleration, various suspension forces result in less pressure on the skis. In the foregoing prior art designs, the arrangement of the suspension arms has an unstable geometry. Once the rails begin to pitch (either forward or backward), there is a decreasing amount of resistance to further pitch. The result is that once the rails begin to pitch upon acceleration, they tend to continue to do so until they reach a limit at full transfer at which point the skis are not in contact with the ground. Once the skis begin to lift, they tend to "snap up", only coming down once the amount of acceleration (throttle opening) decreases by a large amount. While a controllable amount of ski lift is desirable, too much of it results in poor steering and cornering characteristics. Ideally, a rider should be able to control weight transfer more with his body movement than throttle opening.
Another problem exists in designs using a third vertical arm, such as that disclosed by Imamura. As the rail begins to pitch the angle of the third arm changes. A force analysis typically reveals that further pitch becomes progressively easier until a hard limit is reached. This characteristic encourages rapid back and forth pitching within the predetermined limits.
Yet another problem relates to the spring and shock motion ratio. This ratio describes the compression of the shock and/or spring in relation to the upward movement of the suspension rails. As mentioned above, there are three general variations: falling rate, linear, and rising rate. A falling rate suspension has a shock/spring ratio that falls as the suspension is compressed. This causes the suspension to feel softer over large bumps, but can easily bottom out the suspension with large input forces. When a suspension bottoms out, a large "jolt" is fed into the chassis. The result is rider discomfort, potential loss of control, and very high stress levels on suspension components. A rising rate suspension gets more firm as the suspension compresses. This provides excellent bottoming resistance but also results in a firm (bumpy) ride over certain bumps. A constant ratio suspension falls in the middle of the other two, combing some traits of each.
Ideally, a suspension should combine the comfort of a falling rate design with the ability to handle large bumps of a rising rate design. Much effort has been made to this effect. Falling rate suspensions are fitted with multiple springs with different rates in an effort to prevent bottoming. Many shocks are designed so that there is no effective dampening in mid-stroke to allow more comfort over small, rapid stutter bumps. While somewhat effective, these approaches involve compromise between comfort and control.
A need therefore exists for an improved snowmobile rear suspension. Consequently, it is an object of the present invention to obviate or mitigate at least some of the above mentioned disadvantages.


The invention is a rotary draw bending machine and process for bending materials such as tubes or pipes into precise bends. A spindle holds a bending die, and a radial arm holds a counter-die. The spindle and arm are simultaneously rotated in opposite directions by a dual hydraulic drive controlled by an electro-hydraulic control system with foot pedal controls. The bend angle is preset by a protractor-like dial and limit switch mechanism. The radial arm has a slide track to align the counter-die with the bending die. The ratchet mechanism has teeth to allow incremental advancement of the counter-die when aligning it with its bending die to accurately set the gap between the dies. The machine is used with a wide variety of dies to bend a wide variety of workpiece diameters. The ratchet mechanism preferably includes a fine tuning device to provide an infinite range of alignment positions.

Many buildings, construction sites, manufacturing plants and machine shops require or use a significant quantity of bent tubes, pipes and rods to produce items such as hand rails, scaffolding, or fabricated metal products. A variety of conventional machines have been developed to facilitate the otherwise difficult task of bending of rigid metal tube or pipe into a desired shape. One type of tube bending machine is the rotary draw bender. This bending machine 5 uses a bending die with a concave groove. The groove is uniform in shape and diameter around the circumference of the die. The bending die has a corresponding counter-die, which combine to form a die set. The forward wall of the counter die has a linear channel that forms a concave groove along its length. This straight groove flushly receives the straight tubular workpiece. The diameter of the groove of the bending die is the same as its corresponding counter die, and both die can have a circular or slightly elliptical shape. The diameter of the grooves of a die set match the outside diameter of the tubular workpiece that they will bend.
A rotary draw tube bending machine 5 with a hydraulic drive is shown in FIG. 1. One drive cylinder rotates a spindle carrying the bending die. The other drive cylinder simultaneously rotates an arm carrying the counter-die. The cylinders extend during a bending cycle, and retract in a return cycle to bring the machine back to its home position shown in FIG. 1. The machine 5 simultaneously distributes pressurized hydraulic fluid to one end of each cylinder during the bending cycle, and to the other end of each cylinder during the return cycle. The pressure delivered to each cylinder is kept equal by mechanical fluid pressure splitting devices 6, and a number of supply, return and pressure balancing hoses 7. Equal pressure in the drive cylinders is important to ensure that both cylinders are extended at the same rate, and are contracted at the same rate.
The bending machine 5 uses a mounting assembly 8 to hold the counter-die. The assembly 8 has two downwardly extending bolts that are received by spaced holes 9 drilled into the top of the rotating arm. The posts are inserted into selected holes 9 to fix the assembly 8 in place, and position the counter-die with the bending die. For example, a hole 9 drilled at a location for a bending die made to form a two inch bend radius into a one inch diameter ASTM schedule 40 pipe, would be about one inch away from another hole 9 drilled for a bending die made to form a three inch bend radius into a one inch diameter schedule 40 pipe. The mounting assembly includes a pivot post and swing assembly to swing the counter-die into and out of engagement with the bending die. Swinging the counter-die out of engagement allows a straight workpiece 10 to be loaded, or a bent workpiece 15 to be unloaded. The machine 5 also includes a bend angle setting device with a protractor-like dial and a stop switch. The switch automatically deactivates the hydraulic drive when the machine reaches the desired pre-set bend angle.
An unbent workpiece 10 is loaded into the bending machine 5 by placing it in an outer concave groove of the bending die. The outer wall 12 of the workpiece 10 flushly engages the concave groove of the die. The straight workpiece 10 is tangent to the circular bending die. The bending die has a hook that engages the opposite side of the tubular workpiece to secure it to the bending die. The counter die and mounting assembly 8 are picked up and set onto the rotating arm with its posts mating selected holes 9 to set the die gap for the particular die set. The counter-die is then swung into pressing engagement with the workpiece 10 to fix the workpiece to the bending die via its hook. When the bending die is rotated, the tube 10 is drawn by the hook, pulled through the channel of the counter die, and wrapped around the groove of the bending die.
The combined rotation of the bending die and rotating arm determines the bend angle of the tube 15. The shape of the bend 16 is determined by the radius of the bending die, the shapes of the arcuate grooves of both dies, and the gap between the dies during the bending process. The groove of a typical bending die has a semi circle shape. The groove of the counter-die has an engineered shape that is slightly elliptical and slightly less than a semi-circle. The edges of the counter-die do not directly contact the edges of the bending die when they are brought together to hold and substantially surround the workpiece 10. The edges of the dies are spaced apart to form a die gap of about ⅛ inch.
The die gap must be properly set to attain a desired bend shape that is free from irregularities in the bend region 16. The bend region 16 of the tube or pipe 15 should have a continuous bend, a desired uniform radius, and a rounded outer portion 17. The die gap determines the amount of pressure the counter-die exerts on the tube 10 during the bending operation. If the gripping pressure is too high, the tube 10 will bind with the counter-die, and slide through the hook during the bending process. A properly set die gap prevents slipping. Slipping results in the tube sliding through the hook and bending die groove, disengages from the bending die, and forms a kink in the tube. This kinking creates a non-continuous bend with a non-uniform radius, which is visually and dimensionally unacceptable, so that the tube has to be scrapped.
The die gap ensures that the groove surface of the counter-die remains flushly engaged with the outer surface 12 of the tube or pipe 10 when forming the bend. During the bending process, the rounded outer portion 17 of the workpiece 10 should conform to the shape of the counter-die, even when the groove surface is slightly elliptical as shown in FIG. 3. This flush engagement is particularly important toward the working end of the counter-die where the metal flow occurs to form the bend. The flow area 19 is a narrow strip located just inside the trailing end of the counter die. When the die gap is properly set, the counter-die provides enough pressure to maintain the tube 10 in flush engagement with the counter-die in the flow area 19 so that the outer half 17 of bend 16 has a desired rounded shape as shown in FIG. 3. If the die gap is too large and the counter-die pressure is too small, the outer wall 12 of the tube or pipe 10 will pull away from the counter-die groove, which causes the outer half 17 of the bend 16 to flatten out 18 as shown in FIG. 4. Third, the die gap also avoids rubbing between the dies, which can lead to wear and tear on the dies and cause binding problems during the bending process.
Conventional tube bending machines should accommodate various dies and die sets, such as those shown in FIG. 2. A tube or pipe workpiece 10 with a particular diameter requires a particular die set. As noted above, the selected bending die and counter-die should flushly engage the outside wall or surface 12 of a tubular workpiece 10 during the bending process. A smaller diameter workpiece 10 requires a bending die and a counter die with smaller concave groove surfaces. A larger diameter workpiece 10 requires dies with larger concave groove surfaces. A particular desired bend radius requires a particular bending die. A small radius bending die produces a tube 15 with a small radius bend. A large radius bending die produces a tube 15 with a large radius bend. Die sets are changed at a job site when the diameter of the tube or workpiece 10 changes. Bending dies are changed at a job site to change the bend radius being formed into a workpiece 10.
A problem with conventional tube bending machines is that they only form a limited number of bends. The machines are specifically designed and manufactured for use with a limited number of bending dies and die sets, and thus only accommodate certain diameter tubes or pipes 10, and only form specific bend radii in those tubes and pipes. For example, the spaced linear holes 9 in the rotating arm of the rotary draw tube bending machine 5 shown in FIG. 1 only allow proper positioning of a limited number of bending dies and die sets, to form a limited number of bend radii in specific diameter workpieces. The location of each hole 9 for securing the mounting assembly 8 and its counter-die is determined prior to manufacture. Once the counter-die assembly is secured in place via a selected set of holes 9, the counter-die location is fixed. Yet, industries are constantly requiring more and more variations in bend geometry and pipe diameters. Conventional tube benders do not meet the industry need for continuously increasing flexibility in permissible workpiece sizes and bend geometries.
Another problem with conventional tube bending machines is that they do not allow field operators to adjust the die gap, such as to allow for variations in workpiece diameter. Although field operators may try to bend workpieces with a slightly different diameter than the bending machine was made, these slight changes in diameter can have a significantly negative affect on the shape and quality of the bends being formed. The workpiece can slip if the gripping pressure is reduced, or bind, break or increase wear if the workpiece is gripped too tight.
A further problem with conventional tube bending machine is its cost and difficulty to repair. Although some tube bending machines provide a hand wheel and screw assembly for setting the die gap, these machines are much more expensive. The cost of the wheel and screw assembly is significant. The wheel and screw assembly also requires a device such as a numerical counter so that the operator can repeatedly return the counter-die to the same desired position each time for repeating a particular bend on many workpieces. The operator must remember to write down the desired positioning number so that the wheel can be returned to this position each time. If the operator forgets to write down the positioning number, then they will not be able to accurately repeat the bend on a new workpiece. In addition, any damage to or wear and tear on this assembly requires immediate repair. Yet, this assembly is time consuming to remove and replace, and because of its significant cost, replacement parts are difficult to obtain, all of which leads to costly down time.
A still further problem with conventional rotary draw bending machines is operating efficiency and safety. During operation, a worker is constantly handling straight and bent pieces of tubing or piping. Straight tube must be properly placed in the machine by hand, and the bent tube must be removed from the machine by hand. Control switches are also operated by hand. Machine efficiency is reduced because a person can only reliably do one of these tasks at a time. The control switches also require the operator to be close to the machine to start and stop a bend. The worker must get close to the machine to turn it off even if something is noticeably wrong, such as a workpiece is binding, which could suddenly release in a snapping motion and injure the worker.
A still further problem with conventional rotary draw bending machines is their many hydraulic hoses. A variety of hoses are needed to balance the pressure and flow rate of the hydraulic fluid to the drive cylinders so that the drive rods extend symmetrically at the same rate. These hoses are not protected and can be easily crushed, punctured, cut or otherwise damaged in a busy construction site or manufacturing setting. The flex hoses also require many connections that can loosen or leak. Yet, hydraulic fluid leaks are both messy and lead to dangerous and slippery work conditions.
A still further problem with conventional tube bending machines is die change over time. Dies are frequently changed during operation. Yet, the dies on many machines are difficult and time consuming to change. Many conventional tube bending machines typically require special tools or the removal of several parts to change either the bending die or the counter die. Accordingly, a significant down time occurs each time a different radius bend is formed or a different diameter workpiece is loaded. Moreover, should a part that needs to be removed to change a die become jammed, stripped or damaged, the entire machine may become inoperable until it is repaired.
A still further problem with conventional tube bending machines is that they are bulky and difficult to move. A worker performing a project in a specific area of a construction site or manufacturing plant may have to haul large quantities of bulky, heavy tubing or pipe from one end of the site or plant to the other and back in order to perform his or her job. This is not only an unproductive use of work time, but can result in injury to the workers.
The present invention is intended to solve these and other problems.


The present invention relates to a new process for providing a coating layer on a moulded article comprising fibers. In the present invention, a coating dispersion is prepared that comprises microfibrillated cellulose (MFC), a slip aid and at least one hydrocolloid.

Perfluorinated carboxylic acids or PFCAs are the breakdown products of chemicals used to make non-stick and water- and stain-repellent products ranging from kitchen pans to clothing to food packaging. PFCAs, the best known of which is perfluorooctanoic acid (PFOA), are found in humans all around the world. A major source of human PFCA exposure may be the consumption and metabolism of polyfluoroalkyl phosphate esters or PAPs. PAPs are applied as greaseproofing agents to paper food contact packaging such as fast food wrappers and microwave popcorn bags. PFOA is the best-known perfluoro carboxylic acid (PFCA). Perfluorocarboxylic acids are the final degradation products (under normal conditions) of a wide range of other perfluorinated compounds.
Fluorotelomer alcohols (FTOH) are used as surfactants and intermediates in the manufacture of a variety of products. All fluorinated substances used for creating water/grease repellence paper/cardboard are FTOH derived polymers. Fluorotelomer alcohols (FTOHs) have been shown to degrade to low levels of perfluorocarboxylic acids (PFCAs), including perfluoro octanoic acid (PFOA), in atmospheric, biodegradation, and metabolism studies.
Impregnation or surface treatment of paper/cardboard with FTOH derived polymers or additives can provide both grease, oil and water repellence. Products treated this way are used for both food contact (plates, food containers, bags, and wraps) and non food contact applications.
The link between FTOH and PFCA occurs on two levels. Firstly, production of 2-perfluorodecylethanol (8:2 FTOH) causes unintended production of PFOA. Secondly, due to the stability of perfluorocarboxylic acids, these are the likely final environmental degradation products of telomer alcohols.
Thereby, migration of fluorocompounds at significant levels has been documented for e.g., food wrappers and microwave popcorn bags as well as moulded packaging.
In addition, when recycled fibers are used in manufacturing of the grease and water repellent product for food contact there is a risk for mineral oil hydrocarbons (MOH) migration. Several reports show that migration of mineral oil hydrocarbons (MOH) from recycled board into food can occur. Sources of mineral oils saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) are inks, adhesives and solvents.
Therefore, it would be desirable to avoid the use of fluorocompounds, particularly in packages that may come into contact with food. A further problem associated with manufacturing of moulded articles is stickiness or adhesion to female or male used in moulding. The moulded article has a tendency to stick to various surfaces. The male or female moulds used can be non-permeable, non-permeable textured or smooth, or semi-permeable or permeable such as wire fabrics. It is also possible that male or female have different properties in terms of material properties or physical properties such as permeability or smoothness.
WO2016/082025 discusses coating compositions comprising a multivalent metal salt complexed with nanocellulose and lignin. The coating composition is used to coat surfaces of e.g. packaging material to produce a hydrophobic surface.
WO2016/097964 is directed to a process for production of a coated substrate comprising cellulosic fibers, wherein the substrate has a dry content of less than 50% and wherein the coating composition, which comprises microfibrillated cellulose and optionally a water retention agent, is applied in an amount of more than 5 g/m2 and wherein the substrate is dewatered after the coating composition has been applied.
RU2589671 discloses a method for producing hydrophobic and lipophobic paper, wherein a paper mass of microcrystalline cellulose is prepared in the form of a hydrogel, to which a dimer of alkyl ketene and polyamide polyamine epichlorohydrin resin is added and the hydrogel is used for producing paper.
There is a need for a surface treatment or coating method and a coating layer whereby the coated object or the coating is not only renewable but also has surface properties such that it can be used in packages for food and has adequate grease/oil resistance. In particular, there is a need for such a coating method and coating dispersion which is useful for coating moulded articles comprising fibers. In addition, the coating should preferably have properties that not only improves the properties but also facilitates the manufacturing of the moulded articles as well as repulpability and recycling.

Process for providing coating layer comprising micro fibrillated cellulose


A reliable bearing wheel assembly comprising a shaft, an inner race, an outer race, and rollers or other bearing elements between the inner and outer races, wherein the inner race is reliably prevented from both rotating and moving axially relative to the shaft, even when there is bearing failure. A first pair of axially extending grooves are provided in the outer surface of an end portion of the shaft and in the inner surface of the inner race respectively which in combination define a first keyway. A second pair of axially extending grooves are provided in the outer surface of the shaft end portion and in the inner surface of the inner race respectively which in combination define a second keyway. A first key is received in the first keyway. A fastener having a threaded shank portion threadedly engages a threaded bore which extends axially in the shaft end portion. A head portion of the fastener engages the inner race and at least partially covers the first keyway to block escape of the first key therefrom. A second key is received in the second keyway, and a portion thereof extends axially outwardly of the second keyway and abuts the head portion to prevent turning of the fastener to prevent loosening thereof as well as to prevent uncovering of the first keyway and escape of the first key therefrom.

The present invention relates generally to bearing wheels for use in conveyor systems and the like.
Bearing wheels in conveyor systems typically comprise an axle to which the inner race of a ball or sleeve bearing is fixedly attached. The outer race rotates to act as a wheel. The inner race has been conventionally riveted to the axle, which disadvantageously requires that the axle be destroyed to get the wheel off. Moreover, when the wheel begins to wear out, it becomes stiff and the outer race stops rotating. As a result, the inner race starts rotating on the axle and wearing the rivet away until the wheel falls off, requiring a shut-down of the conveyor system and associated equipment. It is important to the operator not to have to shut down the system since such down-time is very expensive. The operator would therefore prefer to have a warning of wheel failure so that repairs can be made at a convenient time to avoid such a costly shut-down.
U.S. Pat. No. 3,602,150 discloses a suspended trolley construction for a power-and-free conveyor system, wherein a central casting is supported by a shaft to which wheels are attached to the shaft ends, the wheels rotatable along rails. Each wheel has an inner race and an outer race separated by bearings. The inner race is removably fixed to the shaft by an end plug which threadedly engages the end of the shaft and which has an expanded head which bears against an annular bevel of the inner race. A slot is milled longitudinally along a side of the shaft and is engaged by a radially inwardly projecting lug of the inner race to key the inner race to the shaft and thus prevent relative rotation between the shaft and inner race.
Undesirably, the screws holding the inner races on the axle of this U.S. Pat. No. 3,602,150 may loosen to cause the wheels to come apart. In addition, the radially extending lug, with its small cross-sectional area subject to shear, would undoubtedly not have as much strength as desired for preventing the inner race from rotating relative to the axle under the wheel failure conditions described above.
U.S. Pat. Nos. 4,367,905; 4,502,738; and 5,178,472 disclose a multi-sided (non-circular) shaft upon which an inner race of a bearing or bearing wheel is mounted to prevent relative rotation therebetween. U.S. Pat. No. 4,798,149 may also be of interest.
U.S. Pat. No. 3,951,076 discloses a trolley comprising a trolley body, a shaft, and a wheel on each end of the shaft. The wheel comprises an inner race having an opening through which the shaft extends, an outer race, and rollers between the inner and outer races. A cap screw is threadedly engaged in an axially extending opening in an end of the shaft, and its cap bears against a conical washer which in turn bears against a frusto conical surface of the inner race to retain the inner race on the shaft. The screw has threads which are shaped to lock against the threads in the shaft opening in order to lock the screw against rotation thereof.
In the trolley construction of this U.S. Pat. 3,951,076, no means are disclosed for preventing rotation of the inner race relative to the shaft.
It is accordingly an object of the present invention to reliably provide an early warning (before the wheel falls off) that a bearing wheel has failed.
It is another object of the present invention to provide such a bearing wheel which may be disassembled (without destroying the wheel and/or axle) and repaired.
It is a further object of the present invention to provide such a bearing wheel which is reliable, i.e., it reliably prevents rotation of the inner race relative to the shaft on which it is mounted even under conditions of bearing failure as described above, and it reliably prevents axial movement of the inner race relative to the shaft.
It is yet another object of the present invention to provide such a bearing wheel which is rugged and inexpensive.
In order to provide such a bearing wheel, in accordance with the present invention, the inner race is held on the axle by a key or other suitable means for preventing rotation of the inner race on the axle and by a screw or other suitable means for preventing axial movement of the inner race relative to the axle. The screw is prevented from rotation by a key or other suitable means.
The above and other objects, features, and advantages of the present invention will be apparent in the following detailed description of the preferred embodiment of the invention when read in conjunction with the accompanying drawings wherein the same reference numerals denote the same or similar parts throughout the several views.

Bearing wheel for conveyors and the like


The present invention relates to a method of reducing or elimination pressure pulsations and noise created by blowers in a gas separation plant. The method employs two identical and 180° out of phase blowers synchronized together to provide both a large flow of air and active noise cancellation to eliminate pressure pulsations. The two blowers are synchronized in such a way that pressure pulses created by one blower will actively be cancelled by the pulses generated by the other blower. At the same time, both blowers will work together to force a large quantity of gas flow in or out of the plant. The twin set of blowers can be used for feed or vacuum applications in the plant. This way large tonnage plant capital costs can be reduced by eliminating the need for an expensive silencer and a single large custom-made blower.

Non-cryogenic gas separation processes, especially adsorptive processes, are used to separate various components from a gaseous mixture, e.g., oxygen from air. Pressure swing adsorption (PSA) processes, including superatmospheric adsorption/desorption processes, subatmospheric vacuum swing adsorption (VSA) and transatmospheric vacuum pressure swing adsorption (VPSA) processes have been used for decades for air separation and are well known in the art.
Conventional PSA, VSA and VPSA processes employ positive displacement blowers for either fluid feed into or exhaustion from the adsorbent vessel. Large tonnage gas separation plants, including VPSA plants, require high flow of gas in and out of adsorption beds. Commercially available off-the-shelf blowers cannot supply the required flow of air into the plant, and custom-made blowers in this size range become prohibitively expensive. In addition, larger blowers generate higher pressure pulses in the plant that might damage the equipment and lead to louder noise levels.
In VPSA plants, blowers displace a large quantity of gas from inlet on the intake side to outlet on the discharge side at relatively constant volume via pockets between the lobes of each blower and the housing. The flow of gas in and out of a blower is not steady, rather it is a discrete action. Due to pressure differences between the gas pockets and piping, every time the rotor tips clear the housing, it causes pressure fluctuations. Such fluctuations create pressure pulsations. These pulsations are a function of blower size and speed. Within the piping and plant equipment, these pulsations manifest themselves as vibrations, which shake the piping and plant equipment and can result in severe damage. In ambient air, these pulsations manifest as noise, which can be extremely loud. As the demand for higher throughput out of these plants increases, the size of the plant and the size of the blowers in the plant increase. However, larger blower sizes and higher rotation speeds create higher pulsations, which could be detrimental to plant equipment such as the after-cooler, beds and pipes, and may also generate higher noise levels. Generally, the most damaging pulsations are generated at low frequency. The primary frequency of the pulsations generated by the blowers is the lowest frequency in the frequency spectrum, which makes it extremely challenging to cancel these pulsations.
To minimize the impact of the pulsations, gas separation plants may utilize blower inlet and/or discharge silencers. However, such silencers become prohibitively expensive for larger plants, and they decrease plant efficiency by inducing pressure drop in the flow. Even though these silencers can reduce the pulsations and noise, nonetheless, the pulsation problem is still present and needs to be eliminated by some other means.
Prior attempts to solve the pulsation and noise problem include the installation of a Helmholtz-type pulsation dampener, also known as a Helmholtz resonator (U.S. Pat. No. 5,957,664), cylindrical metal shell discharge silencers (U.S. Pat. Nos. 5,957,664 and 5,658,371), and underground type concrete silencers (U.S. Pat. No. 6,451,097). In particular, cylindrical metal shell type silencers are widely used in the industry, but they are not very effective for use with high amplitude and low frequency pulsations. In order to improve their effectiveness, it has been suggested that cylindrical metal shell type silencers be used in conjunction with a Helmholtz resonator (U.S. Pat. No. 5,957,664). However, these resonators are only effective in cancelling pulsations at certain frequencies. These silencing methods are based on reactive and absorptive sound cancellation principles. The biggest hurdle in designing a large gas separation plant is that it requires a much higher flow rate which can only be achieved either by using a single larger than commercially available blower or two smaller off-the-shelf blowers simultaneously. U.S. Pat. No. 5,656,068 disclosed a four-bed VPSA process, operated as two pairs of 2-bed systems, referred to as 2×2 cycle/system, to produce oxygen from air. Each pair of beds is operated 180° out of phase and the two pairs of beds are operated out of phase by one-half of a half-cycle. Two compressors (one Roots or positive displacement and one centrifugal) and two vacuum pumps (one Roots or positive displacement and one centrifugal) are used and one of the two compressors is periodically in the idle or vent mode. Although the use of two relatively small blowers instead of one large blower has been disclosed in U.S. Pat. No. 5,656,068, the active noise cancellation concept is not taught or used.
U.S. patent application Ser. No. 11/395,140 disclosed another approach that employs a silencer for reducing noise level to about 90 dB level at the discharge of the vacuum blower in large tonnage oxygen VPSA plants. The silencer comprises reactive chambers to attenuate low frequency pulsations and absorptive chambers to attenuate medium to high frequency noise. Outer and interior walls of the silencer are made of concrete. Unlike steel-shelled silencers, the concrete silencer will not vibrate or act as a noise source. The low frequency noise is cancelled by expanding and contracting flow in series of reactive chambers that have multiple openings in the dividing walls. The absorptive chambers enforce a serpentine flow, and their entire interior walls are covered with sound absorbing material to effectively cancel noise at high frequencies. However, this approach still requires the use of a large custom-made blower or multiple blowers to provide a sufficient feed gas supply.
Thus, there is a continuing need for low cost and reliable solutions to prevent pulsation damage and reduce noise levels while providing high flow of gas in and out of the plant in a cost effective manner.


A curtain wall system for a building structure, comprising: a frame structure with a plurality of wall panels secured thereto to define an outer building structure wall; a plurality of supporting chair members extending laterally away from a corresponding frame member of the frame structure for receiving a corresponding wall panel, each chair member being sufficiently rigid for supporting the corresponding wall panel in a cantilevered configuration relative to the corresponding frame member, each supporting chair member having an appendage connector located at a distal side end thereof; and an exterior appendage member having a distal chair connector for engaging the appendage connector of at least one supporting chair member to attach the appendage member to the at least one supporting chair member such that the exterior appendage member extends away from the at least one supporting chair member and towards the exterior of the building structure.

Curtain wall systems are used to form non-structural outer walls for building structure. A curtain wall system typically includes a frame structure and a plurality of relatively lightweight panels such as glass panels secured vertically to the frame structure.
Different systems have been proposed to secure the panels to the frame structure. According to one system, each horizontal frame members includes a "nose" portion which generally consists of a support panel which projects away from the horizontal members and towards the exterior of the building. The nose portion is adapted to receive and support the glass panel in a cantilevered configuration.
In some systems, the glass panel may further be sandwiched between the horizontal frame member and a vertically-extending pressure plate which is adapted to be attached to the nose panel using mounting screws. Typically, a cap member is further clipped over the pressure plate to hide the pressure plate and mounting screws. In this system, the nose portion is integrally formed with the horizontal frame member to define a rigid support for the glass panel.
In an alternative system, the nose portion is instead provided as a separate element from the horizontal frame member. In this system, the nose portion is connected to the horizontal frame member by a thermal break member made of a material with relatively low thermal conductivity to prevent thermal transfer by conduction through the nose portion from the exterior of the building to the horizontal frame member. In this case, the glass panel can instead be supported by a chair member which extends generally horizontally above the nose portion and which is distinct from the nose portion.
In yet another system, the glass panel is supported by a chair member connected to the horizontal frame member and the cap member is connected to a dedicated cap clip member which is distinct from the frame structure and from the chair member. Specifically, the cap clip member is connected to the horizontal frame member and extends from the horizontal frame member below the chair member and beyond the chair member to connect with the cap member.
Unfortunately, the systems above require multiple parts to structurally hold the glass panel and to hold the cap member and may therefore be relatively expensive and complex to manufacture and assemble.
In yet another system, the glass panel may be supported by a chair member extending from the horizontal frame member and be secured in place using silicone glazing sealant, which simultaneously serves as a sealant and an adhesive. Specifically, the silicone glazing sealant may be provided between the glass panel and the horizontal frame member to thereby secure the glass panel to the horizontal frame member. Additional silicone glazing sealant may be used to seal the gap around the chair member and between the glass panel and other glass panels located directly above and below the glass panel. Unfortunately, this system does not provide means for exterior appendages such as decorative cap members, sunshades or other features and ornaments to be secured to the building structure.
There is therefore a need for a curtain wall system which may alleviate or overcome at least one of the above-identified drawbacks.

Curtain wall system and panel support assembly therefor

OLDCASTLE BUILDING PRODUCTS CANADA, INC.


A fixing device for an anti-slip cable locker is disclosed. The fixing device provides a connection such that after the cable is engaged, and a single screw action, the cable can be locked after engagement, and therefore, article hooked to the locker will be securedly locked. The fixing device allows a quick installation, rapid engagement with the cable locker and provides anti-slip from the cable locker.

(a) Technical Field of the Invention
The present invention relates to a fixing device for an anti-slip cable locker, and in particular, a fixing device which can rapidly install, position a cable locker in a secured position.
(b) Description of the Prior Art
FIG. 1 is a conventional cable fixing device A1 employing a tension spring A13, auxiliary steel beads A15 to urge a cable A2 to be locked. At normal situation, the steel beads A15 urge by the elastic spring A13 to form a constantly engaged state. The structure of the conventional fixing device A1 comprises a front nut cap A11, a fixing device body A12, a tension spring A13, a displacement axle core A14 and steel balls A15 provided to the displacement axle core A14. The front nut cap A11 is connected to the fixing device body A12, and the inner edge of the front nut cap A11 is a tapered converging wall A111 corresponding to the converging face A141 of the displacement axle core A14 and the steel beads A15, which can be fully controlled within the fixing device body A12.
Thus, the front nut cap A11, the steel beads A15 and the displacement axle core A14, together with the tension spring A13, and the displacement of the axle core A14, the steel beads A15 achieves the effect of fastening or releasing the cable A2.
However, the conventional fixing device A1 has the drawback that the device can be used for engagement but it does not provide a locking or fixing effect. If the tension of the spring A13 is insufficient or the displacement axle core A14 is retreated, the suspended article will fall down.


A shoe donning device is provided comprising a generally U shaped body 20, having an external portion 22 and an internal portion 24 extending downwardly from a top portion 26. The external portion having a top region, and spaced from said internal region for preventing said body from migrating forwardly from the rear of the shoe. The internal portion has an internal top region, and an internal bottom region which has at least one upwardly extending slot 50 cut in its rear region. Two side extensions extend forwardly from the rear portion and have grip enhancers to provide positive engagement between the shoe and the device. Each of the side extensions has a finger grips coupled to its upper side. The rear portion of the internal region is forwardly biased. The device is made of resilient, smooth, semi rigid material, such as molded plastic.

For people with motion limitations the simple everyday task of donning one's shoe is often a daunting task. People with back problems, people that suffered a stroke and even some overweight people find the task difficult. Sometimes, a second person is required to achieve the task, which detracts from personal independence and contributes to feeling of inadequacy.
Several attempts have been made to resolve the problem. The age old solution of a shoehorn is well know but is often impractical: a short shoehorn requires the extended reach, while a long shoehorn is bulky and requires the use of at least one hand. Additionally, oftentimes the person required to use the shoehorn suffers from other dexterity problems that makes the task difficult. Specialized devices exist that are based on various implementations of an 'extended hand': an actuator placed at the end of an elongate rod, and operable by the person. This type of solutions are not as safe because they require the use of at least on hand and require twisting of the upper body (which can jeopardize balance). In addition these other solutions are relatively bulky and tend to be costly to produce.
In U.S. patent application publication Ser. No. 2002/0008124, published Jan. 24, 2002, Runge teaches a shoe chute comprising semi rigid material which fits over the back of the shoe and forms an internal "chute" which guides the foot into the shoe. The device has a body formed generally into a U shape which is slipped into the opening of the shoe, where the portion that extends into the shoe is angled slightly forward towards the front of the shoe. The outside portion is formed substantially parallel to the rear portion and parts of the sides of the shoe upper. However the Runge's device still presents some unresolved problems. Primary amongst them is a difficulty to insert the device into the shoe, an apparent narrowing of the shoe by the device, a tendency of the front of the device to 'climb' out of the shoe during foot insertion, and removing the device when the leg is inside the shoe are hard.
There is therefore a clear and unresolved need for a show donning device that will allow easy insertion of a foot into a shoe, operable by persons with motion limitations, and allowing easy removal of the device once the foot is inserted in the shoe.


A plug arrangement for a plurality of individual plugs with individual hongs and each having at least one contact pin, with the individual plugs being connectable in a holder into a uniformly manipulatable plug, wherein the individual housing of each individual plug is surrounded by a cylindrical sleeve, rectangular in cross section, which is open at one end for insertion and has in an end wall on the opposite side, an opening to allow at least one contact of individual plug to pass through. The plug arrangement is especially usable for medical equipment in conjunction with body electrodes. Adaptation to different plug bushings from different equipment manufacturers is made possible by using sleeves with different wall thicknesses. In addition, a required colored marking of the individual plugs can be provided by using sleeves of different colors, so that individual plugs can all be made the same color.

1. Field of the Invention
The present invention generally relates to a plug arrangement for a plurality of individual plugs with individual housings, each having at least one contact pin, with the individual plugs being connectable in a holder to form a uniformly manipulatable plug. More particularly, plug arrangements are provided for the connection of body electrodes to medical diagnostic and treatment equipment.
2. Background Description
Plug arrangements for a plurality of individual plugs with individual housings are known, for example, from DE 30 12 174 C2 and DE 38 07 645 A1. The individual plugs, which have essentially rectangular individual housings, are inserted or pushed into holders that are open on both sides in the lengthwise direction. By virtue of a positive connection between the holder and the correspondingly designed individual housings of the individual plugs, the individual plugs are locked in the holder in the lengthwise direction. In the embodiment disclosed in DE 38 07 645 A1, the individual plugs have grooves that are flush with one another, into which a foldable rib of the otherwise one piece holder engages to insure axial locking.
In the embodiment according to DE 30 12 174 C2, the holder is provided with specially shaped chambers, to whose shape the outside contour of the individual housings of the individual plugs is adapted. The holder has a foldable lid. When the lid is open, the individual plugs can be inserted from above into the chambers of the holder.
With the known plug arrangements, it is possible to connect the individual plugs to form a uniformly manipulatable plug arrangement, which can be inserted into a uniform matching piece. According to DE 38 07 645 A1, the holder has a tab pointing in the insertion direction, said tab cooperating with a matching recess in the matching piece to produce protection against twisting. The locking of the plug arrangement in the matching piece is accomplished by locking grooves which are formed on the contact pins of the plug arrangement and cooperate with matching locking elements in the matching piece.
While the type and dimensions of the contact pins of individual plugs have been standardized for many applications, there is no such uniformity for the dimensions of the individual housings of the individual plugs, 50 that the matching parts (generally device plugs) into which the plug arrangement is intended to be inserted, have different distances between the contact sets of the individual plugs, since the matching pieces are provided for differently dimensioned individual housings.
This means that different cable sets must be used with the individual plugs for the various matching pieces, for example, for different device plugs from different medical equipment manufacturers. If the cable sets are on body electrodes, this results in a considerable stocking cost for using body electrodes with medical equipment from different manufacturers. In practice, this problem arises for AAMI plugs which have been standardized as far as the contact arrangements of the individual plugs are concerned, for which plugs the various equipment manufacturers have provided contact spacings of different sizes in the bushings that form the matching pieces.
For using the plug arrangements mentioned hereinabove in conjunction with body electrodes, provision is also made such that the individual plugs, corresponding to the placement of the corresponding body electrodes on the body, have certain, different colors. Consequently, the individual plug housings must be made from materials with different colors, which naturally increases the manufacturing cost.

Plug arrangement for a plurality of individual plugs

Kendall-Medizinsche Erzeugnisse--Gessellschaft mit beschraenkter Hauftung


A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers are included in the cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth are obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber.

Modelocked fiber lasers are increasingly displacing traditional solid-state lasers in ultrafast optic applications. Modelocked fiber lasers can be packaged in very small spaces and also exhibit superior mechanical and thermal stability. In particular, passively modelocked fiber lasers allow compact designs because of the absence of bulky optical modulators. Fiber laser systems are pumped using diode lasers with an emission wavelength shorter than the fiber laser emission wavelength. For upconversion-type fiber lasers, the pump wavelength can be longer than the emission wavelength. Generally, similar to the majority of all laser systems, the pump wavelength differs from the emission wavelength; a fact which is well known in the art.
Passively modelocked fiber lasers often comprise saturable absorbers to initiate and stabilize the pulse formation process. Examples of laser systems using saturable absorbers in this manner are described in U.S. Pat. No. 5,689,519 ('519) to Fermann et al., which patent is hereby incorporated herein by reference, and U.S. Pat. No. 5,448,579 ('579) to Chang et al.
Semiconductor saturable absorbers have been implemented in modelocked lasers for a long time. Of particular interest are multiple-layer heterostructures as suggested in U.S. Pat. No. 4,860,296 ('296) to D. S. Chemla et al. However, these early saturable absorber designs were restricted in that they contained nonlinear layers with a spacing of exactly an integer multiple of a predetermined optical period. Moreover, the incorporation of multiple layer heterostructures as suggested by '296 relied on semiconductor layers with a thickness of less than 500 Å in order to exploit quantum-confinement effects. Such thin semiconductor layers generally restrict the bandwidth over which pulse shaping is possible with saturable absorbers.
A more workable saturable absorber solution was suggested in U.S. Pat. No. 6,252,892 ('892) to Jiang et al., where a resonant saturable absorber for passive modelocking of lasers was described. Moreover, '892 suggests distributed resonant saturable absorbers comprising layers of saturable absorber material separated by semiconductor layers not restricted to a thickness of less than 500 Å. Semiconductor layers with a thickness greater than 500 Å are indeed useful for maximizing the pulse shaping action of saturable absorbers.
As is well known in the art of passive modelocking of color center lasers (Islam et al., IEEE J. Quantum Electron. Vol. 25, pp. 4254 (1989)), the optically excited carriers in semiconductor saturable absorbers generally relax with different time constants. A first time constant of approximately 300 fs depends on the charge carrier density and excess energy of the hot photo-excited carriers due to intraband dynamics, e.g. thermalization and cooling of hot carriers to the band edge. A second longer time constant of 1 ps–30 ns is due to interband dynamics, e.g. the recombination of the carriers.
These different time constants can be easily realized if the hot charge carriers are excited well above (about an optical phonon energy above) the band edge. However, when the carriers are photo-excited at the band edge, the intraband contribution becomes weak due to the low carrier temperature. The excitation near-band edge is usually preferred in saturable absorber design because of the resulting resonant enhancement of the optical nonlinearity. In this case, the nonlinear optical response is governed by the interband dynamics including trap center assisted recombination and carrier relaxation with two different time constants cannot necessarily be observed and moreover, the ratio of carrier centers relaxing at the two different time constants cannot be controlled.
The interband dynamics are generally manipulated by introducing trap centers for photo-excited charge carriers either by arsenic anti-sites in GaAs-related material systems grown at low temperature or by implantation with ions. It has been readily reported (A. R. Hopfel, Ch. Teissl, and K. F. Lambrecht, Appl. Phys. Lett. 53, p. 12581 (1996)) that the trapping rate dominate the intraband dynamics in InP implanted with 200 keV protons (H+) at a dose of 1×1016 cm−2, when excited with 1.7 eV photons. The carrier trap time can be sub 100 fs and the cw luminescence shows a non-Fermi distribution, indicating the hot carriers undergo a recombination process before they cool down to the band edge.
For ultrafast fiber lasers modelocked by saturable absorbers as described in U.S. Pat. No. 6,252,892 it was shown that cw modelocking is initiated by Q-switched mode-locking in the very early stages of pulse formation. Hence, Q-switch pulses in the cavity are used for the start of modelocking and the support of Q-switch pulses by a slow optical modulation process in the absorber is useful.
Hence, the first longer time constant can be used to initiate pulse formation, whereas the second shorter time constant can be used to stabilize the oscillation of short femtosecond pulses. However, to date no control of the ratio of carriers relaxing at these time constants was possible.
In fiber lasers, soliton shaping and or nonlinear polarization evolution can further be used to stabilize pulse formation as described in '519. However, to compete on an equal level with modelocked solid state lasers in ultrafast optics applications, modelocked fiber lasers should include the following: 1) the output polarization state should preferably be well defined, 2) the construction of the fiber laser should preferably be adaptable to mass production, 3) the required optical elements should preferably be as inexpensive as possible, and 4) the design concept should preferably comprise saturable absorbers with well controllable parameters. It is with respect to these four factors that current, conventional, modelocked fiber laser technology still needs improvement.
Early modelocked fiber laser designs, as exemplified in '519, relied on non-fiber components for stable operation. Although these early modelocked fiber lasers could further accommodate devices that enabled wavelength tuning, a fiber pig-tailed output signal with a well-defined polarization state was not easily attainable. Similarly, '579 also included bulk optical components.
Improvements in the basic design of modelocked fiber lasers were made possible by the use of fiber Bragg gratings to control the dispersion inside the cavity or as replacements for cavity-end mirrors in Fabry-Perot-type cavity designs (U.S. Pat. No. 5,450,427 ('427) to Fermann et al., which patent is hereby incorporated herein by reference). Moreover, the incorporation of polarization maintaining fiber was further suggested in '427 to limit the sensitivity of the cavity to mechanical perturbations of the fiber. These designs allowed compact wavelength-tunable set-ups as well as synchronization to external electronic clocks. Wavelength tunable passively modelocked fiber lasers were later also described in U.S. Pat. No. 6,097,741 ('741) and U.S. Pat. No. 6,373,867 ('867) to Lin et al.
Further improvements became possible by constructing cladding-pumped modelocked fiber lasers (U.S. Pat. No. 5,627,848 ('848) to Fermann et al., which patent is hereby incorporated herein by reference).
The need for bulk polarizers was eliminated by the implementation of all-fiber polarizers as disclosed in U.S. Pat. No. 6,072,811 ('811) to Fermann et al., which patent is hereby incorporated herein by reference. Such integrated modelocked fiber lasers could also incorporate fiber Bragg gratings for output coupling. The use of fiber Bragg gratings and all-fiber polarizers in the absence of any non-fiber polarization manipulating elements constituted a great simplification compared to single-polarization fiber lasers as discussed by DeSouza et al. (Electron. Lett., vol. 19, p. 679, 1993).
Limitations in integrated cavity designs arose from the need for fiber Bragg gratings written in polarization maintaining fiber to produce a linear polarization state of the output pulses. A high degree of laser integration has also been accomplished in the subsequent '741 and '867 patents. These designs lack high polarization extinction, all-fiber elements for polarization selection, and they rely on several concatenated intra-cavity polarization-maintaining fiber elements of extended length, which can induce the generation of satellite pulses at the fiber output. Indeed, as described in U.S. patent application Ser. No. 09/809,248, in the presence of concatenated fiber sections, pulse stability requires the single-pass group delay between the polarization axes of each fiber section to be larger than the generated pulse width. This is required to prevent any coherent interaction of intra-cavity pulses propagating along the two polarization axes at any coupling point, e.g., fiber splices. Such coherent interactions can generally produce temperature and fiber stress dependent instabilities, which are preferably avoided. Similarly, no all-fiber elements for controlling the spot size on an intra-cavity saturable absorber were described in '741 and '867.
Another method for producing an integrated cavity was introduced by Sharp et al. (U.S. Pat. No. 5,666,373 ('373)) where the use of a saturable absorber as an output coupler is described. A limitation with such designs is the required precision-polishing and AR-coating at the back-end of the saturable absorber to avoid the formation of satellite pulses inside the cavity.
The construction of high-power modelocked fiber lasers, as enabled by the use of multi-mode fibers inside a fiber laser cavity, is taught in U.S. Pat. No. 6,275,512 ('512) to Fermann et al., which patent is hereby incorporated herein by reference.
A passively modelocked fiber laser particularly suitable for producing pulses with a bandwidth approaching the bandwidth of the gain medium was suggested in U.S. Pat. No. 5,617,434 ('434) to Tamura et al. where fiber segments with opposing dispersion values were implemented. This design has limited functionality due to the presence of at least two long lengths of fiber with different dispersion coefficients for dispersion compensation, as well as the presence of non-polarization maintaining fiber, greatly complicating polarization control inside the cavity.
The design principles used in the patents mentioned above were reiterated in a series of recent patents and applications to Lin et al. (U.S. Pat. No. 6,097,741; U.S. Pat. No. 6,373,867, and application Ser. No. US2002/0071454). The designs described in Pat. Nos. '741 and '867 lack appropriate all-fiber, high polarization extinction, polarizing elements that are generally required to minimize the formation of satellite pulses at the fiber output. Moreover, these patents do not describe all-fiber means to control the spot size on the intra-cavity saturable absorber; control of the spot size is required to optimize the life-time of the saturable absorber. Equally none of the prior art describes ion-implanted saturable absorber designs with controlled ion depth penetration.

Polarization maintaining dispersion controlled fiber laser source of ultrashort pulses


VPN tunnels may be established from a wireless user through a wireless network without requiring the wireless user to have a relationship with the wireless network. Instead, the wireless user interfaces with an authentication, authorization, and accounting service on a VPN host network. This allows the wireless user to sign on once to gain admittance to both the wireless network and the VPN host network. The VPN host network is able to establish accounts on various wireless network providers to alleviate the need for wireless users to have individual accounts with the wireless providers. Additionally, a wireless access point on the wireless network serves as a VPN gateway to interface between an encrypted session on the wireless network and a VPN tunnel formed between the wireless access point and the VPN host network. This allows the wireless access device to participate in a VPN tunnel without instantiating a VPN client.

1. Field of the Invention
The present invention relates to communication networks and, more particularly, to a method and apparatus for establishing Virtual Private Network (VPN) tunnels in a wireless network.
2. Description of the Related Art
Data communication networks may include various computers, servers, nodes, routers, switches, hubs, proxies, and other devices coupled to and configured to pass data to one another. These devices will be referred to herein as "network devices." Data is communicated through the data communication network by passing data packets (or data cells or segments) between the network devices by utilizing one or more communication links. A particular packet may be handled by multiple network devices and cross multiple communication links as it travels between its source and its destination over the network.
The various network devices on the communication network communicate with each other using predefined sets of rules, referred to herein as protocols. Different protocols are used to govern different aspects of the communication, such as how signals should be formed for transmission between network devices, various aspects of what the data packets should look like, and how packets should be handled or routed through the network by the network devices.
A Virtual Private Network may be formed by connecting two or more networks or network devices over a public network using encryption or other means, such as by attaching a unique label to traffic in a Multiprotocol Label Switching (MPLS) network, to secure the transmissions between the two or more networks or network devices. Using VPN tunnels over a public network such as the Internet enables a network having geographically separated components to be set up as a single autonomous network without requiring the network participants to lease dedicated lines through the network. As used herein, "VPN site" will be used to refer to a network or portion of a network that is to be connected to a VPN tunnel.
When a person seeks to establish or join a VPN tunnel on a wireless network, such as a network operating under one of the 802.11x protocols, the user must first log onto the wireless network and then be connected to the VPN tunnel. This requires the user to have or establish an account on the wireless network as well as an account with the network associated with the VPN site.
FIG. 1 illustrates a conventional system in which a wireless user 10 is able to obtain VPN services over a wireless network 12 through a wireless access point 14. As shown in FIG. 1, a wireless user 10 in a conventional wireless network 12 uses a two step log-on process to first establish its identity with the wireless network, and then establish its identity with the VPN host network. Specifically, upon gaining access to the wireless network, the wireless user will seek to gain admittance to the wireless network by engaging an Authentication, Authorization, and Accounting (AAA) server 16 associated with the wireless network. The process of engaging the AAA server enables the wireless network to verify the user's identity and authorization to access the network, and establish accounting entries to enable the wireless network to invoice the wireless user for admittance to the wireless network. If the wireless user is successful, a Dynamic Host Configuration Protocol (DHCP) server associated with the wireless network assigns the wireless user an IP address on the wireless network and otherwise enables communication to take place on the wireless network.
Once the wireless user has been granted admittance to the wireless network, if the wireless user desires to participate on a VPN tunnel with a VPN host network 18, the wireless user initiates a protocol exchange with the VPN host network. The VPN host network may be a corporate network to which the wireless user would like to obtain access or another network or network device. The wireless user provides the VPN host network with authentication and authorization information, such as a corporate ID and password, which is used to authenticate the user and ascertain whether the user has authorization to access the network and/or participate in VPN communications with the VPN host network. Typically, the VPN host network will utilize an AAA server 20 to perform authorization and authentication services on behalf of the VPN host network. If the authorization and authentication procedures are successful, the VPN host network grants admittance to the wireless user and assigns a VPN host network private IP address to the wireless network user using its DHCP server. The VPN host network private IP address is then used by the wireless network device as the end point for a VPN tunnel 22 between the wireless user 10 and the VPN host network 18. The VPN tunnel 22 may extend through the Internet 24 or other network.
Requiring the wireless user to log onto the wireless network as well onto the VPN host network thus results in a duplication of services. Specifically, both the wireless network point and the VPN host network must authenticate and authorize the user before the user can establish a VPN tunnel to the VPN host network. This duplication results in added setup time as well as added expense.
Additionally, communications on the wireless network may involve double encryption, over the wireless portion of the VPN tunnel. Specifically, in the conventional scenario discussed above in connection with FIG. 1, the VPN tunnel extends from the wireless user to the VPN host network. Thus, communications between the VPN host network and the wireless user are typically encrypted using an encryption protocol such as IP Sec. Additionally, to prevent other wireless users from intercepting communications on the wireless network, communications on the wireless link are typically encrypted using Wired Equivalency Protocol (WEP), Temporal Key Integrity Protocol (TKIP), or another protocol that may be used to secure 802.11 wireless LANs. The double encryption between the user and the wireless access point (WEP/TKIP and IP Sec) increases the latency associated with transmissions between the corporation and the wireless user. This double encryption also uses additional resources on the wireless device, which may reduce the amount of time a battery powered wireless device is able to participate in wireless communications.
The fact that the wireless access point is not participating in establishing the VPN tunnel between the VPN host network and the wireless user requires the wireless user to have VPN software, such as a VPN client, loaded on the wireless access device. Where the wireless access device is a small computing device, such as a personal data assistant (PDA) or telephone handset, it may be unreasonable to expect the wireless access device to be able to support a VPN client or to engage in an IPSec protocol exchange.

Method and apparatus for establishing virtual private network tunnels in a wireless network


An alkanediol and a dialkyl carbonate are prepared in a process comprising:    (a) reacting an alkylene carbonate and an alkanol feedstock in a first reaction zone under transesterification conditions to obtain a product mixture of dialkyl carbonate, unconverted alkanol, the alkanediol, unconverted alkylene carbonate and dimers of the alkanediol;    (b) separating dialkyl carbonate and alkanol from the product mixture to obtain a bottom product stream containing alkanediol, unconverted alkylene carbonate and dimers of the alkanediol;    (c) recovering the dialkyl carbonate; and    (d) separating alkanediol from the bottom product stream to leave a recycle stream comprising unconverted alkylene carbonate and dimers of the alkanediol, which process further comprises    (e) passing at least part of the recycle stream to a second reaction zone in which the dimers of the alkanediol are converted to higher-boiling oligomers of alkanediol, yielding an oligomers-containing effluent;    (f) separating the higher-boiling oligomers from the oligomers-containing effluent yielding an alkylene carbonate-containing remaining stream; and    (g) recycling the alkylene carbonate-containing remaining stream to the first reaction zone.

A process for preparing a dialkyl carbonate is described in U.S. Pat. No. 5,359,118. The patent discloses a process in which di(C1-C4 alkyl) carbonates are prepared by transesterification of an alkylene carbonate with a C1-C4 alkanol. The alkylene carbonate and an alkanol feedstock are reacted countercurrently in a column with the aid of a catalyst. The catalyst is usually homogeneous, although the use of heterogeneous catalysts is also suggested. The alkylene carbonate is introduced into the upper part of the column and trickles down from above. The alkanol feedstock comprising a pure alkanol and a stream, comprising the alkanol and also the dialkyl carbonate, is fed into the column at a lower part. The alkanol flows upward and reacts countercurrently with the alkylene carbonate to obtain dialkyl carbonate with unreacted alkanol as the top effluent and the alkanediol with any entrained alkanol as the bottom effluent. The top effluent is subjected to distillation treatments to yield an alkanol-rich stream comprising the alkanol and minor amounts of the dialkyl carbonate. This stream is fed to the column as part of the alkanol feedstock. The bottom stream is worked-up resulting in an alkylene glycol stream and a catalyst-containing concentrate that is partly recycled.
The patent discloses the formation of high-boiling by-products, such as polyglycols. In the process these high-boiling by-products are contained in the catalyst-containing concentrate. Part of the concentrate is recycled to the transesterification, whereas another part is discarded.
Although the process discloses the formation of polyglycols, it does not address the problem of the removal of such polyglycols, in particular the dimers of the alkanediol, also known as dialkylene glycols. Moreover, the process presumes that no alkylene carbonate leaves the reactor unconverted. In practice, the transesterification to dialkyl carbonate will not be 100%. Therefore, the bottom product of the process will contain not only polyglycols, as suggested in U.S. Pat. No. 5,359,118, but also some unconverted alkylene carbonate. In view of their boiling points it is very difficult to separate dialkylene glycols from the corresponding alkylene carbonates. This has not been acknowledged in the process according to U.S. Pat. No. 5,359,118. Therefore the bottom product contains contaminants that bear the risk of building up during continuous recycle.
It is an object of the present invention to overcome this drawback.

Process for the preparation of an alkanediol and a dialkyl carbonate


Breakaway foam packing is disclosed. In one aspect, the present disclosure teaches a breakaway packing system for packaging an information handling system including a packing support designed to receive at least a portion of an information handling system. The packing support secures the information handling system within a shipping container. The breakaway packing system also includes at least one detachable joint formed in the packing support. The detachable joint operably detachable to cause the packing support to separate into sections.

As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems including desktop and server systems are generally packaged for storage or shipment. One the goals of the packaging design is to create an optimal balance between factory throughput, cost, and customer satisfaction. Usually, the optimal balance desires a low cost material that allows for quick and automated application, which are easy to use by the consumer.
However, on some of the larger or bulky information handling systems, consumers have experienced dissatisfaction with the packaging. Because of the snug fit formed between the packaged system and the shipping box and the weight/size of the system, consumers found it difficult to remove the system from the shipping box. In some instances, the packing foam would "stick" to the shipping box preventing the removal of the system. In certain situations, the "stuck" packing foam would cause the consumer to attempt removal of the system by using an elbow, leg, head or other body part to remove the shipping box while holding onto the packaged system. In another example, the consumer had to rock the system back and forth to remove the packaged system from the box.
FIG. 1 illustrates a prior art packing foam unit that is one attempt to correct this problem. As shown, computer system 9 is set between bottom packing foam panel 4 and top packing foam panel 6. Top packing foam panel 6 and bottom packing foam panel 4 encloses system 9 when placed inside of shipping box 2, which includes box tops 2a. Once received, the consumer opens the shipping box 2 at top panels 2a and removes top packing foam panel 6 in order to remove computer system 9. However, this arrangement requires a significant amount of shipping material and a cost increase for each packed system.
Another attempt to correct this problem creates the shipping foam in four separate pieces instead of two. The four separate pieces would be placed two along the bottom edges and two along the top edges. Thus, the consumer would merely remove the top edge pieces in order to remove the system. However, this attempt causes factory throughput problems since there are four pieces to install instead of two. This attempt becomes even more difficult when applied in an automated facility.


The present invention is an apparatus and method for increasing the amount of data on a transmission path on a printed circuit board. Conventional methods allow only one data signal to be transmitted on the transmission path. The present invention uses multiple transmitters to modulate multiple data signals to form multiple modulated signals. The modulated signals are transmitted, possibly simultaneously, on the transmission path to receivers configured to demodulate individual modulated signals and recover the original data signals.

As shown in FIG. 1, a common computer system (100) includes a central processing unit (CPU) (102), memory (104), and numerous other elements and functionalities typical of today's computers (not shown). The computer (100) may also include input means, such as a keyboard (106), a mouse (108), and an output device, such as a monitor (110). Those skilled in the art will understand that these input and output means may take other forms in an accessible environment. In one or more embodiments of the invention, the computer system may have multiple processors and may be configured to handle multiple tasks.
The CPU (102) is an integrated circuit (IC) and is one of many integrated circuits included in the computer (100). Integrated circuits may perform operations on data and transmit resulting data to other integrated circuits. The performance of the computer depends heavily on the speed and efficiency with which data is transmitted between integrated circuits.
FIG. 2 shows a block diagram of a prior art system (200) for transmitting data from a transmitting IC (202) to a receiving IC (250) using a transmission path (248). A data source (210) represents computing elements of the transmitting IC (202). The data source (210) may produce data for the transmitting IC (202) to transmit to the receiving IC (250). Data to be transmitted is sent by the data source (210) to the transmitting output buffer (212) to be put onto the transmission path (248). The transmission path (248) propagates the data signal to the receiving IC (250) where the data signal is received at the data destination (262), which represents the receiving IC's (250) input buffer and computing elements.
The rate of data transmission on the transmission path (248) between the transmitting IC (202) and the receiving IC (250) on a printed circuit board (PCB) is limited by a bandwidth of the transmission path (248). However, the rate at which data can be put onto the transmission path (248) is limited by the speed at which output buffer (212) on the transmitting IC (202) can operate. Using current technologies, the rate at which data can be put onto the transmission path (248) may be substantially lower than the rate at which the transmission path (248) may transmit.
If the output buffer (212) is incapable of using the entire bandwidth of the transmission path (248), then part of the bandwidth of the transmission path (248) is wasted. In order to transmit more data, more transmission paths (like 248) must be used. Additional transmission paths result in increased cost of materials and increased design complexity. Each of the added transmission paths must also use a package pin to drive the data signals on those transmission paths, increasing complexity and cost still more.
Printed circuit boards are commonly constructed from a glass fiber epoxy laminate called FR4. Transmission paths are traces of metal on the PCB. The traces of metal form wires along which electrical signals may be propagated. The traces of metal are commonly constructed from copper. One of ordinary skill in the art will understand that materials other than FR4 may be used for the PCB and that materials other than copper may be used for the metal traces. Properties of the metal traces and of the PCB material determine the bandwidth of the transmission path formed by the metal traces on the PCB. A significant property of the metal traces is resistivity, which, along with geometry, determines the resistance of the traces. A significant property of the PCB material is the dielectric constant, which, along with geometry, determines the capacitance between metal traces.
A PCB may connect to another PCB through a PCB connector. A PCB connector may include multiple conductive elements to connect multiple metal traces on a first PCB to multiple metal traces on a second PCB. A transmission path may traverse a metal trace on a first PCB, a PCB connector, and a metal trace on a second PCB.

Simultaneous multi-band transmission on a printed circuit board


A memory system of an embodiment includes a memory controller and a non-volatile memory. The memory controller executes error correction encoding on user data received from a host to generate first encoded data, adds the first encoded data to each of one or more pieces of second encoded data, obtained by performing error correction encoding on each of one or more pieces of predetermined data, to generate one or more pieces of third encoded data, obtained by executing error mitigation encoding on the first encoded data, and selects any one piece of encoded data from the first encoded data and the one or more pieces of third encoded data. The non-volatile memory stores the selected encoded data.

In recent years, the degree of integration of the storage density have increased in storage devices, whereas reliability of one storage element has decreased. In order to maintain practical reliability, many storage devices employ an error correction code (ECC). In the case of a storage element whose reliability changes depending on a pattern of stored information, conversion is sometimes further executed so as to make a pattern less likely to cause an error during writing. Such conversion is called an error mitigation code (ENC) or a constrained code. The error mitigation code can reduce the number of errors, but is generally used together with the error correction code since it is difficult to ensure practical reliability only with the error mitigation code.

Memory system and method of controlling non-volatile memory


The invention provides BASB020 polypeptides and polynucleotides encoding BASB020 polypeptides and methods for producing such polypeptides by recombinant techniques. Also provided are diagnostic, prophylactic and therapeutic uses.

Moraxella catarrhalis (also named Branhamella catarrhalis) is a Gram-negative bacteria frequently isolated from the human upper respiratory tract. It is responsible for several pathologies the main ones being otitis media in infants and children, and pneumonia in elderlies. It is also responsible of sinusitis, nosocomial infections and less frequently of invasive diseases.
Otitis media is an important childhood disease both by the number of cases and its potential sequelae. More than 3.5 millions cases are recorded every year in the United States, and it is estimated that 80% of the children have experienced at least one episode of otitis before reaching the age of 3 (Klein, J O (1994) Clin. Inf. Dis 19:823). Left untreated, or becoming chronic, this disease may lead to hearing losses that could be temporary (in the case of fluid accumulation in the middle ear) or permanent (if the auditive nerve is damaged). In infants, such hearing losses may be responsible for a delayed speech learning.
Three bacterial species are primarily isolated from the middle ear of children with otitis media: Streptococcus pneumoniae, non typeable Haemophilus influenzae (NTHi) and M. catarrhalis. They are present in 60 to 90% of the cases. A review of recent studies shows that S. pneumoniae and NTHi represent both about 30%, and M. catarrhalis about 15% of the otitis media cases (Murphy, T F (1996) Microbiol. Rev. 60:267). Other bacteria could be isolated from the middle ear (H. influenzae type B, S. pyogenes etc) but at a much lower frequency (2% of the cases or less).
Epidemiological data indicate that, for the pathogens found in the middle ear, the colonization of the upper respiratory tract is an absolute prerequisite for the development of an otitis; other are however also required to lead to the disease (Dickinson, D P et al. (1988) J. Infect. Dis. 158:205, Faden, H L et al. (1991) Ann. Otorhinol. Laryngol. 100:612). These are important to trigger the migration of the bacteria into the middle ear via the Eustachian tubes, followed by the initiation of an inflammatory process. These factors are unknown todate. It has been postulated that a transient anomaly of the immune system following a viral infection, for example, could cause an inability to control the colonization of the respiratory tract (Faden, H L et al (1994) J. Infect. Dis. 169:1312). An alternative explanation is that the exposure to environmental factors allow a more important colonization of some children, who subsequently become susceptible to the development of otitis media because of the sustained presence of middle ear pathogens (Murphy, T F (1996) Microbiol. Rev. 60:267).
The immune response to M. catarrhalis is poorly characterized. The analysis of strains isolated sequentially from the nasopharynx of babies followed from 0 to 2 years of age, indicates that they get and eliminate frequently new strains. This indicates that an efficacious immune response against this bacteria is mounted by the colonized children (Faden, H L et al (1994) J. Infect. Dis. 169:1312).
In most adults tested, bactericidal antibodies have been identified (Chapman, A J et al. (1985) J. Infect. Dis. 151:878). Strains of M. catarrhalis present variations in their capacity to resist serum bactericidal activity: in general, isolates from diseased individuals are more resistant than those who are simply colonized (Hol, C et al. (1993) Lancet 341:1281, Jordan, K L et al. (1990) Am. J. Med. 88 (suppl. 5A):28S). Serum resistance could therfore be considered as a virulence factor of the bacteria. An opsonizing activity has been observed in the sera of children recovering from otitis media.
The antigens targetted by these different immune responses in humans have not been identified, with the exception of OMP B1, a 84 kDa protein which expression is regulated by iron, and that is recognized by the sera of patients with pneumonia (Sethi, S, et al. (1995) Infect. Immun. 63:1516), and of UspA1 and UspA2 (Chen D. et al. (1999), Infect. Immun. 67:1310).
A few other membrane proteins present on the surface of M. catarrhalis have been characterized using biochemical method, or for their potential implication in the induction of a protective immunity (for review, see Murphy, T F (1996) Microbiol. Rev. 60:267). In a mouse pneumonia model, the presence of antibodies raised against some of them (UspA, CopB) favors a faster clearance of the pulmonary infection. Another polypeptide (OMP CD) is highly conserved among M. catarrhalis strains, and presents homologies with a porin of Pseudomonas aeruginosa, which has been demonstrated efficacious against this bacterium in animal models.
The frequency of Moraxella catarrhalis infections has risen dramatically in the past few decades. This has been attributed to the emergence of multiply antibiotic resistant strains and an increasing population of people with weakened immune systems. It is no longer uncommon to isolate Moraxella catarrhalis strains that are resistant to some or all of the standard antibiotics. This phenomenon has created an unmet medical need and demand for new anti-microbial agents, vaccines, drug screening methods, and diagnostic tests for this organism.