A dedicated compression braking system is provided having at least one engine piston reciprocally mounted within a cylinder for cyclical successive compression and expansion strokes and at least one exhaust valve operable to open in a variable timed relationship with an engine piston compression stroke when the engine is operated in a compression braking mode. The braking system includes an independent exhaust valve actuator assembly, including a braking mode rocker lever and a cam lobe for imparting reciprocable movement to the exhaust valve when the engine is operated in the braking mode. The second exhaust valve actuator assembly includes a braking fluid circuit formed in the braking mode rocker lever and a braking fluid valve and three-way solenoid valve mounted on the braking mode rocker lever for controlling the flow of braking fluid in the braking mode rocker lever during compression braking. The dedicated braking system minimizes the size and weight of the engine and also permits maximum freedom in designing and controlling the operation of the braking system independent of other engine components to maximize the efficiency of compression braking.

For many internal combustion engine applications, such as for powering heavy trucks, it is desirable to operate the engine in a braking mode. This approach involves convening the engine into a compressor by cutting off the fuel flow and opening the exhaust valve for each cylinder near the end of the compression stroke.
An early technique for accomplishing the braking effect is disclosed in U.S. Pat. No. 3,220,392 to Cummins, wherein a slave hydraulic piston located over an exhaust valve opens the exhaust valve near the end of the compression stroke of an engine piston with which the exhaust valve is associated. To place the engine into braking mode, three-way solenoids are energized which cause pressurized lubricating oil to flow through a control valve, creating a hydraulic link between a master piston and a slave piston. The master piston is displaced inward by an engine element (such as a fuel injector actuating mechanism) periodically in timed relationship with the compression stroke of the engine which in turn actuates a slave piston through hydraulic force to open the exhaust valves. The compression brake system as originally disclosed in the '392 patent has evolved in many aspects, including improvements on the control valves (see U.S. Pat. Nos. 5,386,809 to Reedy et al. and 4,996,957 to Meistrick) and the piston actuation assembly (see U.S. Pat. No. 4,475,500 to Bostelman). A typical modern compression braking system found in the prior art is shown in FIG. 8, where the exhaust valves are normally operated during the engine's power mode by an exhaust rocker lever. To operate the engine in a braking mode, a control valve separates the braking system into a high pressure circuit and a low pressure circuit using a check valve which prevents flow of high pressure fluid back into the low pressure supply circuit, thereby allowing the formation of a hydraulic link in the high pressure circuit. A three-way solenoid valve, positioned upstream of the control valve, controls the flow of low pressure fluid to the control valve, and thus, controls the beginning and end of the braking mode.
Various problems have been discovered with conventional compression braking systems. First, an unnecessarily long inherent time delay exists between the actuation of the three-way solenoid valve and the onset of the braking mode. This time delay is in part due to the positioning of the solenoid valve a spaced distance from the control valve creating longer than desired fluid passages and thus response time. Also, unnecessarily long fluid passages between the master and slave pistons, that is, the high pressure circuit, disadvantageously increases the compressed fluid volume and thus the response time. In addition, in conventional compression braking systems, the braking system is a bolt-on accessory that fits above the overhead. In such systems, in order to provide space for mounting the braking system, a spacer is positioned between the cylinder head and the valve cover which is bolted to the spacer. This arrangement adds unnecessary height, weight, and costs to the engine. Many of the above-noted problems result from viewing the braking systems as an accessory to the engine rather than as part of the engine itself.
One possible solution is to integrate components of the braking system with the rest of the engine components. One attempt at integrating parts of the compression braking system is found in U.S. Pat. No. 3,367,312 to Jonsson, which discloses an engine braking system including a rocker arm having a plunger, or slave piston, positioned in a cylinder integrally formed in one end of the rocker arm wherein the plunger can be locked in an outer position by hydraulic pressure to permit braking system operation. Jonsson also discloses a spring for biasing the plunger outward from the cylinder into continuous contact with the exhaust valve to permit the cam-actuated rocker lever to operate the exhaust valve in both the power and braking modes. In addition, a control valve is used to control the flow of pressurized fluid to the rocker arm cylinder so as to permit selective switching between braking operation and normal power operation. However, the control valve unit is positioned separately from the rocker arm assembly, resulting in unnecessarily long fluid delivery passages and a longer response time. This also leads to an unnecessarily large amount of oil that must be compressed before activation of the braking system can occur, resulting in less control over the timing of the compression braking. Furthermore, the control valve is used to control the flow of fluid to a predetermined set of cylinders in the engine thereby undesirably preventing individual engine cylinders or different groups of engine cylinders from being selectively operated in the braking mode. Moreover, the control valve is a manually operated rotary type valve requiring actuation by the driver often resulting in unreliable and inefficient braking operation. Also, rotary valves are subject to undesirable fluid leakage between the rotary valve member and its associated cylindrical bore. The Jonsson braking system also relies on a single cam lobe and rocker arm assembly to move the rocker arms during both normal power and braking operations. However, this arrangement disadvantageously restricts the system's ability to provide exhaust valve operation which is independent from normal valve operation as determined by the associated normal cam profile.
U.S. Pat. No. 3,332,405 to Haviland discloses a compression braking system wherein a control valve unit, for enabling the formation of a hydraulic link, is mounted in a cavity formed in a rocker arm that operates the exhaust valves during the braking mode. Separate cam lobes are used for normal power operation and braking operation. However, a single rocker arm is used to actuate the exhaust valves during both normal and braking modes possibly causing the braking cam lobe profile design, and therefore the braking system operation, to be at least partially dependent on, or influenced by, the design of the cam lobe used for operating the exhaust valve during normal engine operation. In addition, Haviland appears to use a single solenoid for controlling compression braking for all of the cylinders, which permits either none or all of the cylinders to be used for compression braking at any one point, and therefore permits only one level of compression braking power. This restriction results in very little freedom in the operation of the compression braking system. Furthermore, the reference discloses a solenoid valve unit, for controlling the flow of fluid to the control valve, which is housed separately from the control valve unit and the rocker lever, resulting in the need for extra dedicated space in the engine; thus adding to the size and weight of the engine. In addition, the control valve as disclosed in Haviland, and conventional control valves generally, use one or more springs to bias the control valve element. However, these springs are subject to repeated reciprocal motion and excessive stress causing spring failure and thus significant reliability problems, resulting in malfunctioning of the control valve and the compression braking system.
U.S. Pat. No. 4,251,051 to Quenneville discloses a solenoid valve assembly having an inlet communicating with a supply of fluid, and one or more outlet passages communicating with respective loads requiring intermittent fluid supply and a drain passage. A respective ball valve is positioned between the inlet and each outlet and spring biased to block flow between the supply and outlet passage while opening the drain passage. An armature and pin are actuated to move the ball valve so to connect the supply to the outlet, and close the drain passage. However, when the valve assembly in the actuated position permits supply flow to the outlet passage, it does not prevent the return flow of fluid from the outlet passage into the supply passage and therefore could not permit the formation of a hydraulic link between different pressurized circuits as required by a control valve during compression braking system operation.
U.S. Pat. No. 3,921,666 to Leiber discloses a solenoid-operated valve assembly having first and second closure members and a spring positioned therebetween for biasing the members toward respective closed positions blocking fluid flow through respective fluid passages. A solenoid device operates the valve such that when the solenoid is not energized, fluid flows between a first and second connection, while a third connection is closed off by the second closure member. When the solenoid is slightly energized, the first closure member cuts off the communication between the first and second connection, while the second closure member keeps the third connection closed. A higher energization of the solenoid forces the second closure member to open, creating a path for fluid between the second and third connections. However, during higher energization of the valve permitting flow between a supply and load, the second closure member is not operable to block return flow from the load. As a result, this valve does not provide for a integral check valve for allowing fluid to enter a hydraulic circuit without allowing fluid to flow in the opposite direction; that is, from the hydraulic circuit to the supply. Therefore, this valve assembly could not be used in a braking system to create a high pressure hydraulic link between an exhaust valve and a cam lobe while permitting intermittent filling of the high pressure circuit forming the link. In addition, the intermediate stage of slightly energizing the solenoid to achieve the desired flow patterns as discussed above is incompatible with the flow characteristics desired in a compression braking system.
In addition, U.S. Pat. Nos. 2,944,565 to Dahl, 4,460,015 to Burt et al. and 4,844,119 to Martinic disclose other three-way structures for controlling fluid flow. However, these valves suffer from the same shortcomings and problems discussed hereinabove with respect to Haviland, Quenneville, and Leiber.
The timing of the opening and closing of the exhaust valves plays a major role in determining the efficiency and effectiveness of the compression braking system. Many conventional braking systems rely on existing engine components to determine the timing of the exhaust valve opening and closing during compression braking. For example, the braking system shown in U.S. Pat. No. 4,592,319 to Meistrick, utilizes a fuel injector actuation mechanism, such as a cam lobe and push rod, that is normally actuated near the end of the compression stroke. However, reliance on existing cam lobes and other actuators used to actuate other engine components severely limits the spectrum of possibilities for timing the operation of the exhaust valve, thereby precluding optimization of the braking system. U.S. Pat. Nos. 4,572,114 to Sickler and 4,898,206 to Meistrick et al. disclose similar compression braking systems suffering from the same disadvantages as the system disclosed in the '319 reference.
U.S. Pat. No. 5,146,890 to Gobert et al. discloses a method and device for compression braking wherein a dedicated cam lobe operates an exhaust valve during the braking mode. However, the cam lobe operates a dedicated exhaust valve used only during the braking mode. As a result, this design is unnecessarily expensive due to costs relating to the additional exhaust valve assembly and the redesign of the cylinder head to include the additional exhaust port and exhaust valve access passage. Also, this design undesirably creates additional packaging considerations in positioning the exhaust valve in the cylinder head.
Consequently, there is a need for a simple, compact, yet effective braking system which is capable of minimizing the size and weight of the associated engine while ensuring optimum operation of the compression braking system.

Dedicated rocker lever and cam assembly for a compression braking system


A torque converter is designed to control the torque capacity C and prevent a constant torque capacity C when the speed ratio E is in the middle to high operational range. The torque converter includes a bladed pump impeller driven by an internal engine, a bladed turbine runner in fluid flow relation with the pump impeller, and a bladed stator for redirecting fluid to produce a toroidal flow path of hydraulic fluid. The blades of the stator have an inlet portion facing the turbine runner and to which flows hydraulic fluid from the turbine runner, an outlet portion facing the pump impeller and discharging hydraulic fluid from the stator, a pressure surface disposed on one side of the blade between the inlet portion and the outlet portion, a suction surface disposed on another side of the blade, and a plate portion disposed near the inlet portion.

One type of a torque converter is described in U.S. Pat. No. 4,180,978. This torque converter includes a pump impeller having a plurality of blades, a turbine runner, and a stator. The pump impeller is driven by the internal engine and is adapted to absorb torque from the engine. The turbine runner is in fluid flow relation with the pump impeller. The stator redirects fluid from the turbine runner to the pump to produce a toroidal flow path of hydraulic fluid. The blades of the pump impeller have a negative tip angle displaced in the range of 20 degrees to 30 degrees from the toroidal flow path at the fluid outlet of the pump impeller. Further, the blades of the stator have a sharp nose displaced circumferentially and angularly from the entrance flow to the stator from the turbine runner to induce turbulence in the toroidal flow path at the stator inlet at stall speeds.
In the apparatus, when the speed ratio E is small, that is to say that the turbine runner does not rotate in spite of rotating the pump impeller, the torque capacity C becomes small. The speed ratio E is the rotational speed of the turbine runner divided by the rotational speed of the pump impeller. The torque capacity C is equal to Tp/Ne.sup.2, where Tp equals the pump impeller torque and Ne equals the rotational number. The torque capacity C is one of the factors deciding the peak torque of the engine. Therefore, when the engine is idling, the fuel expense of the engine becomes economical.
However, in the apparatus described above, the torque capacity C is not controlled when the speed ratio is in both the middle range and the high range. Therefore, the peak torque of the engine become small such that the fuel expense is not economical.
A need thus exists for a torque converter in which during a middle and high range of operation, the torque capacity is controlled to be generally constant and less than in other known torque converters.


The present invention discloses a preparation method of a Cu-based resistive random access memory, and a memory. The preparation method includes: performing composition and a chemical combination treatment on a lower copper electrode (10) to generate a compound buffer layer (40), wherein the compound buffer layer (40) is capable of preventing the oxidation of the lower copper electrode (10); depositing a solid electrolyte material (50) on the compound buffer layer (40); and depositing an upper electrode (60) on the solid electrolyte material (50) to form the memory. In the above technical solution, the compound buffer layer (40) capable of preventing the oxidation of the lower copper electrode (10) is inserted between the lower copper electrode (10) and the solid electrolyte material (50) to efficiently prevent the oxidation of the lower copper electrode (10) in a growth process of the solid electrolyte material (50), such that an electrode interface does not become rough due to the oxidation, thereby solving the technical problem of relatively low reliability and yield of the device resulting from the rough electrode interface of the Cu-based resistive random access memory in the prior art, and thus the reliability and the yield of the device are improved.

As a novel non-volatile memory technology, the resistive random access memory has attracted a great deal of attention due to its high density, low cost and capability of breaking through the limitations of the technology. The materials used are phase change materials, metal oxide materials, organic materials and the like. A metal bridge type resistive random access memory dominated by Cu ions or Ag ions is one of the main types of resistive devices, and its structure is usually composed of active metal electrodes such as Cu or Ag, solid electrolyte materials (such as chalcogenide materials, metals oxides and the like), and inert electrodes (such as Pt, Pd, Ru, TaN and the like). The mechanism of the metal bridge type resistive random access memory may be described by the redox reaction of Cu or Ag ions. Taking a Cu-based resistive device as an example, during programming, Cu atoms are ionized by an electric field and then are injected into a solid electrolyte material to be reduced to Cu atoms through combination with electrons, and when the metal electrodes on both ends are connected by a Cu metal filament, the resistance state of the device changes from a high resistance state into a low resistance state; and an erasing process is just opposite to the programming process, a metal conducting channel breaks under the action of an external electric field, and the resistance of the device changes from the low resistance state into the high resistance state.
Cu is widely used as an interconnecting wire material in an advanced semiconductor preparation process, and thus the Cu-based resistive random access memory may be integrated in a back end preparation process of a standard CMOS process easily. The solid electrolyte material is usually a metal oxide and is grown on the Cu electrode by sputtering or thermal oxidation and other methods. However, in the growth process, due to the presence of oxygen, the surface of the Cu electrode is easily oxidized to roughen the electrode interface, resulting in problems of low reliability and low device yield.

This patent is subject to a terminal disclaimer.

Preparation method of Cu-based resistive random access memory, and memory

THE INSTITUTE OF MICROELECTRONICS OF CHINESE ACADEMY OF SCIENCES


A method of forming a lubricating film on a surface, comprising applying to a surface a multiphasic composition comprising at least one (per)fluoropolyether (PFPE) lubricant, water and from 0.1 to 3% by weight of water of at least one thickening agent, said multiphasic composition having a viscosity, when measured at 21° C. at a shear rate of 1 sec−1 of at least 10 Pa×sec so as to form a layer, and drying said layer to form a lubricating film. The Applicant has found that by the use of the multiphasic composition as above detailed it is advantageously possible to convey to surface to be lubricated the PFPE lubricant by using application techniques (doctor blade, metering rod, . . . ) as those suitable for solid-like greases, while the actual conveyed lubricant behaves in lubrication as an oil, avoiding the use of fluorinated solvents.

(Per)fluoropolyether (PFPE) lubricants are well-known engineered lubricants combining high-temperature performance, nonflammability, thermal and oxidative stability, and chemical inertness under a wide range of conditions.
For applying PFPE lubricants on sliding/moving parts, said lubricants can be applied as neat compounds. Nevertheless, kinematic viscosity of these fluids is such that their application on surface of difficult accessibility can be improper and/or their metering might be uneasy to control, so that uneven or inappropriate distribution of the lubricant is obtained.
Thus, in certain cases, to solve above mentioned issues, it has been suggested to dilute/suspend the same in suitable fluids so as to obtain a PFPE lubricant-containing composition having a substantially modified kinematic viscosity, so that different techniques, including dipping, spin coating, spraycoating, and the like, becomes suitable methods for conveying said PFPE lubricant to the surface to be lubricated.
Thus, JP 59107428 (SUWA SEIKOSHA KK) of Jun. 21, 1984 discloses a method of forming a lubricating film on a surface, wherein a perfluoropolyether lubricant is dissolved in a halogenoalkane solvent such as perfluoroalkane or chlorofluoroalkane, so obtained solution is then applied to the target surface by means of dipping, spin coating, spray coating or the like, final drying yielding the lubricating film. Nevertheless, in this method, use is made of fluorinated solvents like CFC 113, whose use has raised serious environmental concerns.
Certain low boiling point halogenated solvents have also been proposed for conveying PFPE lubricants; nevertheless, an appropriate recovery of the fluid during drying/evaporation is generally required, due to above mentioned environmental concerns.
Alternative solutions avoiding the use of such low boiling point halocompounds have been suggested; in particular, U.S. Pat. No. 5,149,564 (HITACHI LTD) of Sep. 22, 1992 teaches the use of water-borne emulsion comprising the PFPE lubricant and a suitable surfactant, preferably a polyoxyethylene alkylether surfactant for forming lubricating film on surfaces. Nevertheless, only very diluted emulsions possess suitable stability against phase separation for being actually used at industrial level, so that extensive drying is required, with consequent limitation of real applicability of this solution.
Aqueous based PFPE microemulsions such as those taught in U.S. Pat. No. 4,990,283 (AUSIMONT SPA (IT)) of Feb. 5, 1991 or in U.S. Pat. No. 5,211,861 (AUSIMONT S.R.L.) of May 18, 1993 might also provide an effective way of conveying the exceptional properties of PFPE lubricants to surfaces; nevertheless, these technologies requires use of fluorinated surfactants which might raise environmental concerns.
Nevertheless, none of the above detailed solution offers a reliable method for forming adequate lubricating films, in particular on vertical surfaces.


Methods and compositions which are useful in the treatment of amyloidosis. In particular, methods and compositions are provided for inhibiting, preventing and treating amyloid deposition, e.g., in pancreatic islets, wherein the amyloidotic deposits are islet amyloid polypeptide (IAPP)-associated amyloid deposition or deposits. The methods of the invention involve administering to a subject a therapeutic compound which inhibits IAPP-associated amyloid deposits. Accordingly, the compositions and methods of the invention are useful for inhibiting IAPP-associated amyloidosis in disorders in which such amyloid deposition occurs, such as diabetes.

Amyloidosis refers to a pathological condition characterized by the presence of amyloid. Amyloid is a generic term referring to a group of diverse but specific intra- and extracellular protein deposits which are associated with a number of different diseases. Though diverse in their occurrence, all amyloid deposits have common morphologic properties, including that they stain with specific dyes (e.g., Congo red), and have a characteristic birefringent appearance (sometimes characterized as xe2x80x9cred-greenxe2x80x9d) in polarized light after staining. They also share common ultrastructural features and common x-ray diffraction and infrared spectra.
Amyloidosis can be classified clinically as primary, secondary, familial and/or isolated. Isolated forms of amyloidosis are those that tend to involve a single organ system. Different amyloids are also characterized by the type of protein present in the deposit. For example, neurodegenerative diseases such as scrapie, bovine spongiform encephalitis, Creutzfeldt-Jakob disease and the like are characterized by the appearance and accumulation of a protease-resistant form of a prion protein (referred to as AScr or PrP-27) in the central nervous system. Similarly, Alzheimer""s disease, another neurodegenerative disorder, is characterized by congophilic angiopathy, neuritic plaques and neurofibrillary tangles, all of which have the characteristics of amyloids. In this case, the plaque and blood vessel amyloid is formed by the beta protein. Other diseases, such as juvenile and adult-onset diabetes, complications of long-term hemodialysis and sequelae of long-standing inflammation or plasma cell dyscrasias are characterized by the accumulation of amyloids systemically. In each of these cases, a different amyloidogenic protein is involved in amyloid deposition.
Islet amyloid polypeptide (IAPP) is known to be capable of forming fibrils which are deposited in the pancreas of patients with Type II diabetes, forming deposits. Once these amyloid deposits have formed, there is no known therapy or treatment which significantly reduces or clears the deposits in situ.
This invention provides methods and compositions which are useful in the treatment of amyloidosis. In particular, methods and compositions are disclosed for inhibiting, preventing and treating amyloid deposition, e.g., in pancreatic islets wherein the amyloidotic deposits to be treated are, e.g., islet amyloid polypeptide (IAPP)-associated amyloid deposits having at least some xcex2-sheet structure. The methods of the invention involve administering to a subject a therapeutic compound which inhibits, reduces or disrupts amyloid deposits, e.g., IAPP-associated amyloid deposits. Accordingly, the compositions and methods of the invention are useful for inhibiting amyloidosis in disorders in which such amyloid deposition occurs, such as diabetes.
In one embodiment, a method for inhibiting amyloid deposition, particularly IAPP-associated amyloid deposition, in a subject is provided, wherein an effective amount of an IAPP-inhibiting compound, or a pharmaceutically acceptable salt thereof, is administered to the subject such that said IAPP-associated amyloid deposition is inhibited. Such compounds include those of the following general formula
wherein C is carbon, N is nitrogen, l, m, o, p and q are independently 0 or 1; n is an integer from 0 to 3; W is hydrogen or an anionic group at physiological pH; Y is an anionic group at physiological pH; R1 and R2 are independently hydrogen, alkyl, an anionic group at physiological pH, or R1 and R2, taken together with the nitrogen to which they are attached, may form an unsubstituted or substituted heterocycle having from 3 to 7 atoms in the heterocyclic ring; R3 is hydrogen, halogen, thiol or hydroxyl; R4, R5, and R6 are independently hydrogen or halogen; and A is hydrogen or C1 to C6 alkyl; or a pharmaceutically acceptable ester, acid or salt thereof.
Preferred therapeutic compounds include 3-(3-hydroxy-1-propyl)amino-1-propanesulfonic acid; 2-amino-5-phosphovaleric acid; 4-phenyl-1-(3xe2x80x2-sulfopropyl)-1,2,3,6-tetrahydropyridine; cyclohexylsulfamic acid; O-phospho-L-serine; hexafluoroglutaric acid; 3-amino-2-hydroxy-1-propanesulfonic acid; 8-methoxy-5-quinolinesulfonic acid; and 3-dimethylamino-1-propanesulfonic acid, the compounds depicted in FIGS. 10-14, and pharmaceutically acceptable esters, acids or salts thereof.
In another embodiment a method for inhibiting amyloid deposition, particularly IAPP-associated amyloid deposition, in a subject is provided, wherein an effective amount of an IAPP-inhibiting compound, or a pharmaceutically acceptable ester, acid or salt thereof, is administered to the subject such that said IAPP-associated amyloid deposition is inhibited. Such compounds include those of the following general formula
wherein A1, A2, A3, A4, A5 and A6 are independently alkyl, O, S, or xe2x80x94NH; m and n (for each individual A group) are independently 0 or 1; l, p and q are independently 0, 1, or 2; R7, R8, R9, R10, R11, R12, R13, and R14 are independently hydrogen, alkyl, alicyclyl, heterocyclyl or aryl, and adjacent R groups (e.g., R7 and R8) may form an unsubstituted or substituted cyclic or heterocyclic ring. In an embodiment, R13 may be anionic.
Preferred therapeutic compounds include 1,2,3,4-tetrahydroisoquinoline, and the compounds depicted in FIGS. 1-9.
In another embodiment the invention relates to a method for reducing IAPP-associated amyloid deposits in a subject having IAPP-associated amyloid deposits, the method comprising administering to a subject an effective amount of an IAPP inhibiting compound, or a pharmaceutically acceptable ester, acid or salt thereof, such that IAPP-associated amyloid deposits are reduced.
The therapeutic compounds of the invention are administered to a subject by a route which is effective for inhibiting IAPP-associated amyloid deposition. Suitable routes of administration include oral, transdermal, subcutaneous, sublingual, buccal, intravenous and intraperitoneal injection. The therapeutic compounds can be administered with a pharmaceutically acceptable vehicle.
The invention further provides pharmaceutical compositions for treating amyloidosis. The pharmaceutical compositions include a therapeutic compound of the invention in an amount effective to inhibit IAPP-associated amyloid deposition, and a pharmaceutically acceptable vehicle.

Methods and compounds for inhibiting amyloid deposits


An inkjet printer includes: an ink container having an outlet port and a return port; a printhead having a first ink port and a second ink port; a first ink line interconnecting the outlet port and the first ink port; a second ink line interconnecting the return port and the second ink port; a bypass line interconnecting the first and second ink lines; a valve system for controlling fluid flow through the first ink line and the bypass line; and a controller for controlling the valve system. During printing, the controller is configured to open the first ink line and the bypass line.

Most inkjet printers have a scanning printhead that reciprocates across the printing width as the media incrementally advances along the media feed path. This allows a compact and low cost printer arrangement. However, scanning printhead based printing systems are mechanically complex and slow in light of accurate control of the scanning motion and time delays from the incremental stopping and starting of the media with each scan. Media width printheads resolve this issue by providing a stationary printhead spanning the media.
Larger printheads help to increase print speeds regardless of whether the printhead is a conventional scanning type or a media width printhead. However, larger printheads require a higher ink supply flow rate and the pressure drop in the ink from the ink inlet on the printhead to nozzles remote from the inlet can change the drop ejection characteristics. Large supply flow rates necessitate large ink tanks which exhibit a large pressure drop when the ink level in low compared to the hydrostatic pressure generated when the ink tank is full. Individual pressure regulators integrated into each printhead is unwieldy and expensive for multi-color printheads, particularly those carrying four or more inks. For example, a system with five inks would require 25 regulators.
Inkjet printers that can prime, deprime and purge air bubbles from the printhead offer the user distinct advantages. Removing a depleted printhead can cause inadvertent spillage of residual ink if it has not been de-primed before decoupling from the printer.
Air bubbles trapped in printheads are a perennial problem and a common cause of print artifacts. Actively and rapidly removing air bubbles from the printhead allows the user to rectify print problems without replacing the printhead. Active priming, de-priming and air purging typically use a lot of ink, particularly if the ink is drawn through the nozzles by vacuum or the like. This is exacerbated by large arrays of nozzles as more ink is lost as the number of nozzles increases.
Thus, there is a need to have a fluid distribution solution that is simpler, more reliable and more effective for media wide printing systems.


[Object] To have excellent maintenance properties and restrain parallel light (collimated light) from being directly emitted to the outside of an optical connector during non-optical coupling.

Recently, there is a demand for a larger transmission capacity along with the increase in the amount of communication over the Internet and the like. In conventional transmission systems via copper cables, it is becoming difficult to achieve such a large transmission capacity. Therefore, optical communication that can achieve a larger transmission capacity has been proposed.
A so-called physical contact (PC) system of abutting optical fibers to each other in a connector is adopted for optical communication cables generally used at present. In the PC system, however, highly-accurate adjustment is required for aligning the both optical fibers. In addition, in the abutment of the optical fibers, the both optical fibers need cleaning every time connection is made in order to prevent waste or the like from adhering to the tips of the optical fibers to damage the optical fibers. Further, in the PC system, in order to suppress a coupling failure in a gap between the leading ends of the optical fibers, injection of a refractive index adjuster into the gap is indispensable. From these results, it is difficult for general users to insert and remove optical fibers by the PC system.
As a method for solving these problems, a collimating optical coupling system has been proposed. In the collimating optical coupling system, each lens is mounted with the optical axis aligned at the tip of each optical fiber, and an optical signal is turned into parallel light to transfer the optical signal between opposed lenses. By using such a collimating optical coupling system, the accuracy in aligning connectors of optical fibers to each other is relaxed. Further, in the collimating optical coupling system, since optical fibers are optically coupled to each other in a contactless state, an adverse effect on transmission quality caused by waste or the like intruded between the optical fibers is also suppressed, and the need for frequent and careful cleaning is also eliminated.
In the meanwhile, parallel light used in the collimating optical coupling system is theoretically less likely to attenuate even at a distance from an output section, and, depending on the intensity, it is difficult to satisfy standards concerning laser light, such as IEC 60825-1 and IEC 60825-2. Therefore, at present, a shutter for shielding parallel light during disconnection is provided for an optical communication connector.
In addition, Patent Literature 1 proposes an optical connector having an object to prevent laser hazard due to collimated light (parallel light). Specifically, an optical connector for performing collimating optical coupling is disclosed in which opposed two projection-recess structures are provided for an optical fiber fixing section and a collimating lens. In this optical connector, during disconnection of the optical connector, the collimating lens separates from the optical fiber fixing section, and the projection-recess structures scatter light from optical fibers. On the other hand, in this optical connector, during connection of the optical connector, the collimating lens is pressed, so that the collimating lens comes into contact with the optical fiber fixing section with the two projection-recess structures interposed therebetween to eject parallel light.

Optical communication connector to restrain direct emission of collimated light

Abstract: [Solution] An optical communication connector according to the present disclosure includes: a collimating lens configured to collimate light from an optical transmission path; and a diffusion section arranged on a leading end side with respect to the collimating lens, and configured to diffuse the light from the optical transmission path output from the collimating lens. According to this configuration, in the optical communication in which insertion and removal are frequently performed, it is possible to achieve their safety during non-fitting at the same time while having an advantage because of a collimating signal since light from an optical transmission path is diffused.


An image forming apparatus equipped with a registering device to make copy paper temporarily halt before the copy paper is conveyed to an image forming section whereby the image formation of the copy sheet is in synchronization with the working of the image forming section and while the copy paper is halted, an electric resistance of the recording member is measured and an image forming condition is determined in accordance with the measurement result.

The present invention relates to an image forming apparatus in which a toner image formed on the surface of a rotating image forming body is transferred onto a transfer sheet sent by a register roller at a transfer position opposed to a transfer charger.
In the above-described image forming apparatus, transfer conditions such as discharging voltage of the transfer charger at which the maximum transfer efficiency can be obtained, etc., change when the resistance of the transfer sheet changes. Accordingly, when transfer conditions are constant, there is a problem in which the transfer efficiency is lowered due to the change of resistance of the transfer sheet. In order to solve the problem, the following image forming apparatus has been disclosed in Japanese Patent Publication Open to Public Inspection No. 34834/1979. A transfer sheet conveyance means, such as a register roller, by which the transfer sheet is sent to a transfer position, is used for an electrode from which current flows in the direction of the thickness of the transfer sheet or in the direction of conveyance of the transfer sheet so that the resistance of the transfer sheet can be measured. According to the measured information, charging conditions of the transfer charger or a separation charger are determined so that high transfer efficiency or reliability of sheet separation can be stably obtained, independent of change of moisture content. Further, the following image forming apparatus has been disclosed in Japanese Patent Publication Open to Public Inspection 14271/1981. A pick-up roller for sending the transfer sheet stacked in a sheet feed cassette is used for an electrode from which current flows in the direction of conveyance of the transfer sheet and the direction of the length, perpendicular to the direction of the conveyance of the transfer sheet so that the resistance of the transfer sheet can be measured. According to the measured information, charging conditions of the transfer charger or the separation charger are determined.
In the resistance measuring method disclosed in Japanese Patent Publication Open to Public Inspection No. 34834/1979, since the transfer sheet is not pinched when electrode rollers stop, the resistance of the transfer sheet is measured during the conveyance of the transfer sheet. Accordingly, a varied, unstable measured value is obtained as shown by amplifier outputs V2 and V4 in FIG. 5 (which will be described later). Further, in this method, when it is required to correct the measured value using a reference value which is obtained under the same conditions as the resistance measurement of the transfer sheet so that the influence due to deterioration with time of the electrode rollers or the amplifier, etc., is excluded, it can not be corrected because the reference value is obtained after the the measured value has been obtained. Accordingly, satisfactory measurement accuracy can not be obtained.
Further, in the resistance measuring method disclosed in Japanese Patent Publication Open to Public Inspection 14271/1981, considerably local resistance between two points on the surface of the stacked transfer sheet is measured. Accordingly, when the contact position of the electrode rollers with the transfer sheet changes due to the conveyance of the transfer sheet, etc., then, an easily variable, unstable measured value is obtained. Therefore, in this method, the measured value can not be corrected by the reference value, and adequate measuring accuracy can not be obtained. Further, in this method, when voltage of about 500V is not impressed upon the pick-up roller, the output of the measurement becomes too small, so that this method is dangerous. Further, in this method, there is a problem in which a measuring apparatus for resistance of the transfer sheet is necessary for each sheet feeding means.
That is, in the image forming apparatus disclosed in both patent publications, even when charging conditions of the transfer charger or the separation charger are determined according to the resistance of the transfer sheet, sufficient transfer efficiency or separation efficiency can not be obtained.

Image forming apparatus equipped with a device to measure a resistance of a transfer sheet


A master alloy for magnet production, which contains as main ingredients R representing at least one element selected from rare-earth elements including Y, T representing Fe or Fe and Co, and B, and includes columnar crystal grains substantially made up of R.sub.2 T.sub.14 B, and crystal grain boundaries composed primarily of R-enriched phases having an R content higher than that of R.sub.2 T.sub.14 B, said columnar crystal grains having a mean diameter lying in the range of 3 to 50 .mu.m. The master alloy is formed into a sintered magnet through pulverization, compacting and sintering steps. The dispersion of the R-enriched phases in the master alloy is so well-enough that the R-enriched phases can also be well dispersed in the resulting sintered magnet. In addition, the master alloy is so easily pulverized that the incorporation of oxygen at the time of pulverization can be reduced. To add to this, pulverized powders having a sharp grain size distribution can be obtained, so that the sintered magnet can have crystal grains with even diameters. Thus, the sintered magnet achieved can have high magnetic characteristics.

The present invention relates to rare earth magnet production, a master alloy used for magnet production and master alloy production.
Rare-earth magnets of high performance, typically, powder-metallurgical Sm--Co base magnets having an energy product of 32 MGOe, have been produced on a large scale. However, a serious problem with these magnets is that the raw materials, Sm and Co, cost much. Of rare-earth elements, some elements of small atomic weight, e.g., Ce, Pr, and Nd occur more abundantly and cost less than does Sm. Fe is more inexpensive than Co. For these reasons, R--T--B base magnets (wherein T stands for Fe or Fe plus Co) such as Nd--Fe--B and Nd--Fe--Co--B magnets have recently been developed, and sintered magnets are set forth in JP-A-59-46008. Sintered magnets may be produced by the application of a conventional powder metallurgical process for Sm--Co systems (melting.fwdarw.master alloy ingot casting.fwdarw.ingot crushing.fwdarw.fine pulverization.fwdarw.compacting.fwdarw.sintering.fwdarw.magnet), and may easily achieve high magnetic properties as well.
Generally, a master alloy ingot produced by casting is made up of an R.sub.2 Fe.sub.14 B phase of ferromagnetism (hereinafter referred to as the main phase) and a non-magnetic, R-enriched phase (again called the R-enriched phase), and is of a structure in which the main phase forming crystal grains is covered with the R-enriched phase forming grain boundaries. The master alloy ingot is then pulverized or otherwise reduced to a grain diameter smaller than the crystal grain diameter until magnet powders are obtained. Each or the magnet powder is chiefly composed of a magnet grain including the main and R-enriched phases and a magnet grain consisting substantially of the main phase alone or, in other words, being free from the R-enriched phase.
The R-enriched phase is converted into a liquid phase to have an action on accelerated sintering, and plays a vital role in the generation of a magnet's coercive force. It is thus preferable that the structure and size of the master alloy ingot and the conditions for pulverizing it are optimized, thereby preventing the R-enriched phase from being locally present in the compact.
Because of some difficulty involved in obtaining fine crystal grains by casting, however, a single crystal grain is usually pulverized to a number of magnet grains. This results in the incorporation in the resultant magnet powders of a large amount of magnet grains containing no R-enriched phase in addition to R-enriched phase-containing magnet grains. Further, the R-enriched phases, because of being segregated, are caused to exist locally in the master alloy ingot. There is thus some considerable difference in the volumes of the R-enriched phases between magnet grains.
This results in the marked local presence of the R-enriched phases in the compact, and so there is a lowering of its ability to be sintered, failing to yield a sintered magnet having high residual flux density. In addition, a sintered magnet, if somehow obtained, has only a reduced coercive force, due to the local presence of the R-enriched phases therein. Due to difficulty involved in breaking up the main phases, on the other hand, the larger the crystal grains, the longer the time taken to pulverize them to fine magnet grains and so the larger the amount of oxygen incorporated in them, not only making it impossible to obtain any high residual flux density, but making the proportion of much-coarser grains too large to obtain any high coercive force.
In order to obtain a magnet having high residual flux density, it is required to reduce the proportion of the R-enriched phases in the magnet. However, using a composition having a low R content as the starting material results in the precipitation of .alpha.-Fe phases in the master alloy ingot. Partly because of a lowering of magnet properties due to the presence of .alpha.-Fe phases and partly because of difficulty involved in pulverization, usually, some form of solution treatment is applied to the master alloy ingot to reduce the proportion of .alpha.-Fe phases. However, the solution treatment, because of being carried out at an elevated temperature of about 900.degree. C. or higher for about 1 hour or longer, gives rise to main phase and R-enriched phase growths, making the dispersion of the R-enriched phases in the master alloy ingot more unfavorable.
When the R content is reduced and so the dispersion of the R-enriched phases gets worse, the ability of the compact to be sintered gets worse or there is a need of carrying out its sintering for a longer time, during which the crystal grains grow, failing to achieve any high coercive force.
In view of such situations as mentioned above, a primary object of the invention is to improve the coercive force and residual flux density of R--T--B base sintered magnets.

Master alloy for magnet production and a permanent alloy


A substrate comprises a pair of immediately-adjacent integrated-circuit dies having scribe-line area there-between. At least one of the dies comprises insulting material above integrated circuitry. The insulating material has an opening therein that extends elevationally inward to an upper conductive node of integrated circuitry within the one die. The one die comprises a conductive line of an RDL above the insulating material. The RDL-conductive line extends elevationally inward into the opening and is directly electrically coupled to the upper conductive node. The insulating material has a minimum elevational thickness from an uppermost surface of the upper conductive node to an uppermost surface of the insulating material that is immediately-adjacent the insulating-material opening. Insulator material is above a conductive test pad in the scribe-line area. The insulator material has an opening therein that extends elevationally inward to an uppermost surface of the conductive test pad. The insulator material has a minimum elevational thickness from the conductive-test-pad uppermost surface to an uppermost surface of the insulator material that is immediately-adjacent the insulator-material opening and that is less than said minimum elevational thickness of the insulating material. Methods are disclosed.

Multiple integrated circuit structures are typically fabricated within individual die area of a larger substrate and have scribe-line area between immediately-adjacent die areas. The structures are singulated (cut) into individual dies or chips typically by mechanically sawing through the scribe-line area. Sacrificial test circuitry is often in the scribe-line area to enable testing and/or burn-in of the integrated circuitry in the die areas prior to singulation. Such test circuitry typically includes exposed test pads that are contacted by probe pins of test machinery during test and/or burn-in. Sawing through these test pads can propagate cracks into the die area that can render the die inoperable.
The integrated circuit structures typically comprise a redistribution layer that is an upper layer of integrated circuitry that comprises metal material and that makes input/output nodes for the integrated circuitry available in or at other locations within the die.

Substrates, structures within a scribe-line area of a substrate, and methods of forming a conductive line of a redistribution layer of a substrate and of forming a structure within a scribe-line area of the substrate


A double barrel adjustable clamping system adaptable for use with laminar hooks and pedicular bolts for use by a surgeon for reduction and fixation of a spinal column is disclosed which provides a rigid construct and is independent from the rod system thereby simplifying the surgical installation thereof. Also disclosed are multi-piece round and quadrilateral rod systems which are separated by novel adjustable cross bar assemblies.

The present invention relates to the field of spinal correction devices. More specifically, the present invention is directed to a double barrel spinal fixation system and method that allow an operating surgeon to construct a rigid laminal claw across one or more vertebrae and provide subsequent independent reduction and fixation of a spinal deformity.
The use of spinal fixation systems is known. Such systems are used to correct spinal deformities such as: kyphosis, lordosis, hemivertebra, spondylolisthesis, scoliosis and others. Kyphosis is a sharp, angular rearward curvature. Lordosis is a forward accentuation of the cervical or lumbar regions beyond physiological levels. Hemivertebra is a developmental error in the spine caused by lack of formation of a vertebral body growth center which results in the production of wedge-shaped vertebrae or one-half of a vertebra. Spondylolisthesis is a spinal deformity in which a vertebral body with the vertebral column above it subluxes or glides forward on the vertebral body below. Scoliosis is characterized by a lateral curvature of a segment of the spine from the normally straight midline position. Other causes of spinal deformities include, but are not limited to, fractured vertrebral bodies or dislocated spinal segments. Spinal fixation systems are also used to correct spinal instability. Primary instability may be acute, for example, as caused by trauma; or may be chronic, for example, as caused by degeneration or by a tumor. Secondary instability may be caused by resection, for example, by a facetectomy. Secondary instability may also be caused by overload, for example, by a misalignment or from stress concentrations.
Many existing spinal fixation systems include rod and hook components used for reduction and fixation of the spinal column. However, the existing systems require the assembly of many different intricate components that ultimately cause the surgical procedure to be complicated and unnecessarily delayed.
For example, U.S. Pat. No. 5,102,412 to Rogozinski shows a spinal rod system and method for instrumenting the spine in the treatment of spinal abnormalities. The system comprises many intricate parts. Such parts include U-shaped screw couplers for use with pedicular screws. The screw couplers are assembled with cross bars and set screws. The laminar clawing configuration requires the additional assembly of a hook bar and a set screw. Another example of spinal instrumentation is known as the Multiple Axial Stabilization System (MASS). This system uses open hooks and cable hooks. Clawing of lamina is accomplished by interconnecting either cable hooks with open hooks, or by interconnecting a pair of cable hooks. A longitudinal rod can subsequently be inserted into the groove in the open slot outside of the open hook. Provided absolute alignment with the groove is established, a sleeve can be positioned outside the rod and integral with the open hook to secure the hook to the rod. It has been found in practice that it is often cumbersome to align the rod with the groove in the clamp. The improper alignment between the rod and the groove can cause the insertion of the sleeve into the hook to be difficult. In addition, the cabling system is not sufficiently rigid to provide rotational stability.
The Isola spinal implant system is a further example of spinal instrumentation and is described in Spinal Instrumentation, pp. 324-351 (1992). The Isola system uses anchor components consisting of screws, posts, hooks and wires. Closed body and open body hooks are used. The anchors, and in particular, the hooks, are used to interconnect longitudinal rods to achieve the desired correction of spinal deformity about the sagittal plane. The hooks are placed in operative association with selected lamina while simultaneously interconnecting the longitudinal rod members.
Similarly, the Correl-Dubousset Instrumentation includes closed and open hook bodies. The hooks are used as anchor points to interconnect a flexible rod. A closed body hook and an open body hook may be used to span one or more lamina but such an installation is still integral to the total longitudinal rod component and does not allow an independent clawing of the selected lamina.
It is desirable to have a device that will allow an operating surgeon to construct a rigid laminal clamp that is independent of the rod system. The device should allow the surgeon to be able to concentrate upon the task of clawing one or multiple lamina without having to simultaneously coordinate the installation of the rod system. The device should also be easy to assemble and should provide torsional stability to correct rotational deformity of the spine. The device should be adaptable for use with pedicular bolts and with laminar hooks. The device should also be easy to install by allowing the surgeon to readily insert the longitudinal rod into the slot of the clamp and thereafter to secure the longitudinal rod when it is in the correct position.

Double barrel spinal fixation system and method


The techniques, methods, systems, and other mechanisms described herein include processes for determining if customized content should be generated, what information to include in the customized content, and when to provide the customized content. In general, a computing system determines that a user intends to travel to a physical venue. The computing system can determine if an entity associated with the physical venue has a web page. The computing system can determine various aspects of a predicted route of travel from the user's present location to the physical venue. The computing system can use location information indicating the user's current location and determine one or more routes of travel to the physical venue. The computing system can compare one or more determined aspects of the predicted route to threshold values to determine if customized content should be generated and presented to the user.

The Internet facilitates the exchange of information between users across the globe. This exchange of information enables content item providers to provide content to a variety of users. A content item provider can control the distribution of their content items (e.g., text, image files, audio files, video files, or other content items) based on various factors relating to users. Content item providers can identify users who may be interested in particular content based on past detected or expressed interests of the user.

Systems and methods for detection of navigation to physical venue and suggestion of alternative actions


A pressure control valve has a valve-closing member displaceable relative to the valve lifter in order to control the flow of pressurized medium between a first and second pressurized medium connection. A third pressurized medium connection is severed from the second pressurized medium connection by another valve-closing member that can be actuated by the valve lifter.

German patent DE 29 09 504 C2 discloses a pressure control valve, in which the valve lifter is designed as a slide valve for pressure control in order to establish a pressurized medium communication between a first pressurized medium connection and a second pressurized medium connection in a first switching position, and to sever the connection in a second switching position of the slide valve. In a third switching position of the slide valve, the valve lifter opens a ball check valve, as a result of which an additional pressurized medium connection from the second pressurized medium connection is opened.
However, the pressure control valve has the disadvantage that the slide valve requires a high accuracy of fit to control manufacturing or temperature dependent leakage flows. In addition, no measure is provided to ensure the pressure reduction in the connected line system in the case of jamming of the slide valve in the closed position.

Pressure control valve for hydraulic slip-controlled brake system


A semiconductor memory device for sequentially disabling activated word lines is provided. The semiconductor memory device having a plurality of word lines connected to a plurality of memory cells includes a predecoding unit for predecoding a row address received from the outside, a row decoding and word line driving block, which is connected to the predecoding unit and the plurality of word lines, for decoding an output of the predecoding unit, selecting some of the plurality of word lines, and activating the selected word lines and a controller connected to the predecoding unit and the row decoding and word line driving block, for receiving the row address, the output of the predecoding unit, and at least one control signal, generating at least one output signal, and sequentially disabling the activated word lines by enabling the at least one output signal in response to the row address and the output of the predecoding unit.

1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particularly, to a semiconductor memory device having sequentially disabling activated word lines.
2. Description of the Related Art
When a semiconductor memory device is manufactured, the semiconductor memory device undergoes a burn-in stress test and a function test. The burn-in stress test ensures that the semiconductor memory device works under prescribed stress conditions, such as a boosted voltage applied to the semiconductor memory device. The function test is for testing whether the semiconductor memory device operates normally according to a predetermined product specification.
Generally, a method of simultaneously activating a plurality of word lines or sequentially activating a plurality of word lines is used to reduce the time required for the burn-in stress test or the function test. Then, the plurality of activated word lines are simultaneously disabled after the activation of the plurality of word lines. When the plurality of activated word lines are simultaneously disabled, precharge noise is generated during a process where the plurality of word lines are transited from a high level to a low level. The precharge noise can have a critical influence on operations of the semiconductor memory device.
Therefore, a need exists for a semiconductor memory device having function of sequentially disabling the activated word lines to prevent the precharge noise from occurring at the time of disabling the activated word lines.

Semiconductor memory device having sequentially disabling activated word lines


Ophthalmic composition with prolonged residence time on the eye, in particular in the form of a gel which can be administered as drops, of an ointment or the like, containing a free-flowing vehicle with increased viscosity and a preservative, and, where appropriate, one or more active ingredients and conventional additives such as tonicity agents, substances to adjust the pH etc. The preservative is essentially formed according to the invention by a benzyllauryldimethylammonium salt. The invention furthermore relates to the use of a benzyllauryldimethylammonium salt as preservative for producing ophthalmic compositions intended for repeated use over lengthy periods and/or formulated for a lengthy residence time on the eye after each use, whereby irritation and/or damage to the tissue of the eye are avoided.

The invention relates to an ophthalmic composition with prolonged residence time on the eye, in particular in the form of a gel which can be administered as drops, of an ointment or the like, containing a free-flowing vehicle with increased viscosity and a preservative, and, where appropriate, one or more active ingredients and conventional additives such as tonicity agents, substances to adjust the pH etc. The invention additionally relates to the use of a benzyllauryldimethylammonium salt for producing ophthalmic compositions.
Ophthalmic compositions may, like other pharmaceutical products too, be contaminated by microorganisms of a wide variety of species. The possibility of such microorganisms entering the eye and getting onto the mucosa of the eye on use of the ophthalmic composition must be avoided. Ophthalmic products must therefore comply with strict sterility requirements. This is why products of this type are always produced under sterile conditions.
In order to increase the sterility and, in particular, the shelf life of ophthalmic products which are not intended for immediate use, preservatives are added to them. On the one hand, the latter must have a sufficiently microbicidal effect to ensure the permanent sterility of the product, and on the other hand they must not themselves lead to irritation or tissue damage in the eye, which is, after all, often already damaged.
These requirements are particularly crucial in the case of ophthalmic compositions which must be used repeatedly over lengthy periods (one or more days or longer) so that a permanent level of preservatives is set up in the eye. In this case the risk of irritation or even tissue damage by the preservative is particularly great.
This is similarly true of those ophthalmic compositions, which show prolonged (by comparison with products which can easily be washed out by tear fluid, such, as for example, conventional aqueous dropper solutions) residence time on or in the eye after a single use. Products of this type are, with regard to their consistency, adjusted to have an increased viscosity. One example are aqueous products which are gelatinously thickened by adding water-soluble polymers, is particular gels which can be administered as drops. Another example are the well-known ointments, usually in the form of spreadable emulsions.
Preservatives used for such purposes are, for example, thiomersal, cetrimide and similar substances.
Another preservative which is frequently suggested for ophthalmic products is benzalkonium chloride.
Benzalkonium chloride is the international nonproprietory name for N-alkyl-N-benzyl-N,N-dimethyl-ammonium chloride with alkyl radicals between C8H17 and C18H37. Benzalkonium chloride is normally obtained from natural fats or oils and is a mixture of varying composition, depending on the raw materials used, of the quaternary compounds described above.
Unless other indicated, the term xe2x80x9cbenzalkoniumxe2x80x9d in this application always means such a mixture with different alkyl radicals, with the number of carbon atoms in the alkyl radical varying from C8 to C18.
U.S. Pat. No. 4,053,628 discloses a clear solution of sodium cromoglicate to which a large number of preservatives can be added. Suggested and exemplified besides thiomersal, cetrimide, benzethonium chloride and others is also benzalkonium chloride. The possibility of adjusting the viscosity of such solutions is mentioned in general; however, the examples relate exclusively to solutions without viscosity-modifying additives. The risk of eye irritation due to the preservative is not mentioned in this publication.
U.S. Pat. No. 4,271,143 has disclosed the use of benzalkonium chloride as preservative in an ophthalmic gel for delayed release of active ingredient. There is no report of eye irritation with the envisaged long residence time in the eye. The tests on the eye described in U.S. Pat. No. 4,171,143 each lasted only a few hours. This is possibly the reason why the problems which occur with such gels on prolonged use apparently were not observed.
Benzalkonium chloride has excellent antiseptic properties even in ophthalmic preparations, especially in aqueous ophthalmic preparations. However, benzalkonium chloride is, as has emerged since publication of the abovementioned patents, poorly tolerated and may lead to irritation and even damage of the eye. B. Lopez et al. (Current Eye Research, 1991, 10 (7) 645 to 656) report on the injurious effect of preservatives in simulated tear fluids on the cornea of rabbits. The effect of tear fluids preserved with 0.01% benzalkonium chloride, 0.001% polyquat or 0.004% thiomersal was related to that in a comparison group in which the simulated tear fluid was used without preservative.
The measure chosen for the damage to the cornea was the increase in the ability to take up carboxyfluorescein. Simulated tears which contained polyquat or thiomersal brought about an increase in uptake of one to four-fold. Simulated tears which contained benzalkonium chloride brought about an increase in uptake of about 10 to 100-fold.
Checks by examination under the electron microscope demonstrated that the increase in the ability to take up carboxyfluorescein was associated with increased cell damage in the cornea. As a result, urgent advice against the use of benzalkonium salts in ophthalmic products was given.
Individual benzalkonium components have attracted interest recently. Thus, JP-A 1246227 describes a method for avoiding incompatibilities in liquid aqueous ophthalmic compositions, especially eye drops, which contain benzalkonium chloride. A large number of medicinal active ingredients shows incompatibility with benzalkonium chloride in the dosage form as aqueous solution, leading to the formation and flocculation of soluble compounds. It is therefore impossible to use benzalkonium chloride as preservative in such aqueous compositions. When virtually pure benzyllauryldimethylammonium chloride, that is to say the C12 homologue from the benzalkonium chloride mixture, is used, the described incompatibilities do not occur. It is thus possible to preserve eye drops whose active ingredient is incompatible with benzalkonium chloride by using benzyllauryldimethylammonium chloride.
This prior art has no relation to the problem of the lack of tolerability of benzalkonium chloride in the eye.
It is an object of the present invention to provide an ophthalmic composition of the type mentioned at the outset which is well tolerated by the eye, even on persistent exposure, and which overcomes the disadvantages of the prior art without, at the same time, losing the advantageous effects of the benzalkonium salts as preservatives.
Achievement of this object is made possible according to the invention by the features of the independent claims.
The independent claims define advantageous embodiments of the invention.
It has been found, surprisingly, that on use of benzyllauryldimethylammonium salts as preservatives in ophthalmic products there is distinctly less or even no irritation and damage in the eye, which are observed, however, on use of other preservatives, including benzalkonium chloride.
The invention therefore makes it possible in particular to preserve those ophthalmic compositions intended to have a prolonged residence time on the eye by comparison with eye drops or the like. It is possible, in particular in this way to produce gels which can be administered as drops, ointments and the like to which the eye is exposed for a very long time after a single use, because they are only slowly washed out by the tear fluid, the preservative having all the advantages of the known benzalkonium chloride but without eye-irritant or even eye-damaging effect.
The ophthalmic compositions according to the invention are preferably those which have as vehicle an aqueous basis for a gel which can be administered as drops. In this case, a viscosity-increasing synthetic or natural polymer in aqueous solution or aqueous dispersion will be employed in a known manner.
Particularly suitable for this purpose are the carboxyvinyl polymers already known as gel formers, especially carboxypolymethylenes which are commercially available under the trade name xe2x80x9cCarbopolxe2x80x9d. It is alternatively possible to employ the ethylene/maleic anhydride copolymers which are commercially available under the trade name xe2x80x9cEMAxe2x80x9d.
Particularly suitable natural polymers are the various cellulose derivatives which are in turn already known for ophthalmic gels, especially alkylcelluloses, hydroxycelluloses, hydroxyalkylcelluloses etc. It is possible with advantage to use in addition or as alternative natural gums such as, for example, guar gum, xanthan gum etc. Other example of natural polymers which can be used advantageously according to the invention are dextran and its derivatives.
It may be advantageous to formulate the ophthalmic composition according to the invention as in principle a single-phase aqueous liquid in which the other ingredients occur in solution or as dispersed particles.
It is an alternative and often even more advantageous possibility to build up the composition as a two-phase liquid with an aqueous and a hydrophobic phase. Especially if the product contains particular active ingredients such as, for example, vitamin A, it will be preferred to provide a continuous, aqueous phase with droplets of the hydrophobic phase emulsified therein. Suitable as hydrophobic phase are oils, medium chain-length triglyerides etc. Medium chain-length triglycerides will advantageously be used as hydrophobic phase particularly in products which contain vitamin A as active ingredient.
The concentration of the benzyllauryldimethylammonium salt corresponds to the usual concentrations employed for benzalkonium chloride. The benzyllauryldimethylammonium salt is preferably simply the chloride.
Besides the ophthalmic compositions which have just been described and have been formulated for prolonged residence time on the eye after each use, the advantage of the invention can also be utilized for those ophthalmic compositions which, although they contain no viscosity-increasing ingredients, (which thus delay washing out), must be used repeatedly over lengthy periods and thus likewise result in a continuously elevated level of preservative in the eye. Products of this type may also lead to irritation or even tissue damage if harmful preservatives are present, and therefore the advantage of the invention may also be used for such products by employing the benzyllauryldimethylammonium salt as preservative in place of these preservatives.
Examples thereof are not only eye drops but also simulated tear fluid as in the test reported by Lopez et al.

Ophtalmic compound with extended dwell time on the eye


A spatial Fourier transforming apparatus jointly Fourier transforms a plurality of input images to obtain a Joint Fourier transform image of the plurality of input images. The apparatus comprises: input means for inputting a plurality of input images; a mask member having a plurality of aperture edges for defining a plurality of apertures each for transmitting a part of a corresponding one of the plurality of input images, the plurality of aperture edges having low correlation; and Fourier transforming means for jointly Fourier transforming the parts of the plurality of input images having passed through the plurality of apertures and for obtaining a Joint Fourier Transform image of the plurality of input images.

1. Field of the Invention
The present invention relates to an optical information processing technique using spatial Fourier transform operation, and more particularly to an optical pattern recognition technique using joint transform correlation.
2. Description of the Related Art
Optical information processings have been developed which use spatial Fourier transform operation. Typically, image correlation methods have been proposed for optical image recognition systems. Various types of optical correlators have been proposed for detecting correlation between multiple images.
For example, a Vander-Lugt optical correlator has been proposed in "Pattern Recognition with the Use of a Phase Filter in an Optical Correlation System" (Applied Physics, 58, 6 (1989).) The Vander-Lugt optical correlator, however, requires precise positioning of a hologram image, and therefore is not practically applicable.
A Joint Transform Correlator (which will be referred to as "JTC," hereinafter) has been proposed in "Fourier Transform in Optical Information Processings" (Optics, 21, 6, pp. 392-399). The Joint Transform Correlator does not necessitate the precise positioning of the hologram image, and is practically applicable. For example, Japanese Unexamined Patent Application Publication No.3-204625 has proposed one type of the JTC.

Apparatus for performing a joint fourier tranform utilizing apertures of low correlation


A process and apparatus that includes multiple counterflow rinsing of chemically treated, anodized, plated or otherwise processed workpieces, utilizing a single on-line spray-rinse tank or station with successively less concentrated or contaminated rinse solutions that are sequentially pumped from one or more off-line tanks or reservoirs that provide at least three overlapping counterflow spray rinse cycles that cover the treated workpiece or workpieces which can be supported individually or together in a bulk processing barrel in the spray-rinse tank, whereby the workpiece or pieces are decontaminated for any additional processing of a finished part using a minimum amount of water or rinse solution during the rinsing process.

1. Field of the Invention
This invention relates generally to the rinsing or cleaning of surface-treated articles or workpieces, and more particularly to an environmental waste-control apparatus and process for counterflow spray rinsing of chemically treated, anodized, plated or otherwise processed workpieces, utilizing a single on-line rinse tank or station with successively less contaminated rinsing solutions that are stored in a plurality of off-line tanks.
2. Description of the Prior Art
As is well known in the art, various problems and difficulties are encountered in providing suitable and efficient water-rinsing means for rinsing or cleaning of chemically treated articles or workpieces. Rinsing of a workpiece is generally required after it has been chemically or similarly treated by one of several processes whereby the workpiece or article is cleaned to prevent staining or to prevent the contamination of any sequential processes that might be necessary. This rinsing is generally done by placing the treated parts in a tank of running water or rinse solution, or sequentially dipping the parts in several tanks. However, sprays using water-rinsing solutions have been utilized for a rinsing method wherein several rinse stations are sequentially employed. Sprays have also been utilized in combination with flooded rinse tanks.
The combination of rinsing, using both the flooded tanks and sprays, is advocated by H. L. Pinkerton and A. Kenneth Graham, in their chapter on rinsing in "Electroplating Engineering Handbook", third edition, edited by A. Kenneth Graham, 1971 (Library of Congress Catalog Card No. 75-12904), where they stated:
"Water Economy PA1 Where space is limited, tank and spray combinations offer many advantages. Indeed they offer advantages even where space is not limited. These combinations are excellent with most rack rinsing. They are not of much value in barrel rinsing. PA1 The particular advantage of combining a spray with a tank is this: the spray can tremendously increase the rinsing efficiency as it may provide the equivalent of one or more additional rinse tanks! Consider the arrangement shown in FIG. (68). It is a single rinse tank with a double spray. The work leaving the plating is sprayed over the plating tank by the water exiting from the rinse tank. Now the work goes into the rinse tank for a soak rinse, then as it is lifted out it gets sprayed by the incoming clean water feed to the rinse tank. The sprays are activated only when work leaves the tanks."
Several means for achieving economy of water have already been mentioned: PA2 (1) Multiple countercurrent rinsing. PA2 (2) Spray rinsing. PA2 (3) Spray-and-dip rinsing. PA2 Additional water may be saved if sprays are fed by water pumped from a succeeding rinse tank."
Further, Joseph B. and Arthur S. Kushner state in their book "Water and Waste Control for the Plating Shop", dated 1972, on page 213:

Environmental waste-control process for spray rinsing chemically treated articles


An actuator unit including a step-up which varies over an adjustment path, between a control motor and a wheel connected to the throttle body in a manner fixed against relative rotation offers the advantage that in certain positions of the throttle body, the required increased torque can also be brought to bear by a relatively low-torque control motor. The actuator unit is intended in particular for internal combustion engines for motor vehicles.

1. Field of the Invention
The invention is directed to an improved actuator unit for controlling movement of a throttle body.
2. Description of the Prior Art
German Published, Nonexamined Patent Application DE-A 195 25 510 and U.S. Pat. No. 5,672,818 show an actuator unit with a control motor and a throttle body. In the known actuator unit, between the control motor and the throttle body, which takes the form of a throttle valve, there is always the same gear ratio in every position. As is now known, the torque required at the throttle body is of various magnitudes in the various positions of the throttle body. For this reason, the torque of the control motor must be designed to be high enough that this torque suffices in every position of the throttle body. The control motor must also be designed such that in all the adjustment ranges, the throttle valve can be adjusted fast enough. Both requirements necessitate a powerful and thus relatively large, expensive control motor. This makes the overall actuator unit relatively large and requires a relatively large amount of installation space.


A method and apparatus for cleaning filter media in dewatering apparatus in situ includes an applicator which sprays a mixture of water and a cleaning agent onto a filter media as the applicator and media undergo relative movement. The cleaning solution contains selected oxidizers and dispersants to break the polymer bond and remove polymeric residues from the media without the need for removing the media from the apparatus.

Polymers are commonly used in water treatment equipment to aid in the removal of solids suspended in water. Ionic polymers, or polyelectrolytes, carry an electrostatic charge which attracts particles suspended in water and build a strong cell-like structure which permits mechanical dewatering of the solids in such a structure using pressure. Such dewatering apparatus includes belt presses and plate presses which carry filter media. Such apparatus is commonly known in the art and specific examples thereof will not be given herein. The filter media is typically a filter cloth of fine mesh material which allows water to pass therethrough and prevents solids from passing therethrough.
A common problem with the use of polymers in dewatering processes is that polymeric residues can contaminate hard surfaces and filter media in and around places where polymers are used. In some applications, the resultant residues can be removed through hard scrubbing and excessive water
rinsing, however such removal is difficult and time-consuming in as much as the polymers provide a sticky solution which is difficult to remove from the machinery. Furthermore, the wet residual polymer solutions are extremely slippery and are the cause of injuries to plant personnel due to falls.
As will be appreciated, deposition of the polymeric residue on the filter media results in a clogging or blinding thereof which greatly reduces the effectiveness of the filter material in producing dry solids. Accordingly operating costs of a plant with presses of reduced effectiveness are increased when the insufficiently dried solids must be recycled through the treatment facility. The blinding problem is intensified in applications where oil and/or grease is deposited in solutions with the polymer residue.
High pressure rinses have been installed in the dewatering apparatus to attempt to flush the contaminants from the filter media. However rinsing does not totally remove the polymer/oil and grease problem. Also methods of applying polymer cleaners using brooms and hand-held sprayers have not been known to achieve a clean deposit-free filter and as noted above are unsafe and time-consuming. Using currently known methods, filter media must be replaced after a short period of time at considerable cost in labor and materials as well as down time for the equipment.


A height adjustable pedestal comprises a base, a height adjustment column disposed above the base and supported thereon, and a table top or chair seat support disposed above the height adjustment column. The height adjustment column comprises at least two spring actuated telescoping height adjustment mechanisms. The height adjustment column typically additionally includes at least one stand tube each having a first and a second end. The first end includes an opening or hole through which a telescoping height adjustment mechanism passes. The second end of each stand tube is proximate to the base. At least one support, disposed vertically above or below the base of the pedestal, for securing the stand tubes together, may also be included. Telescoping height adjustment mechanisms used in the pedestal are typically gas springs. Supports for securing the stand tubes together may comprise a platform. Such platforms include attachment means to attach the platform to the base. Each of the stand tubes in this version extend vertically from the platform and is supported therefrom. Supports for securing the stand tubes together may also comprise at least one attachment bracket. Such attachment brackets are vertically separated from the base.

Height adjustable work chairs are used in home, office, education, and industry. These height adjustable chairs typically include a seat that swivels in relation to the base of the chair. The height adjustment is typically obtained from a telescoping height adjustment mechanism which is usually a gas spring. This gas spring is a telescoping column that includes a gas cylinder which includes a pressurized gas such as nitrogen; a piston extending downwardly from the cylinder which supports the cylinder in an elevated position and includes an end which secures the gas spring to the chair base; and a valve located within the cylinder which allows the movement of gas within the cylinder.
The top of the cylinder is secured within the seat support mechanism which is the mechanism that supports the chair seat and chair back. The seat support mechanism is also known as the chair tilt mechanism, particularly on chairs with adjustable backrests or chairs having a tilting chair seat. Also included in the seat support mechanism is a lever that actuates the valve located in the gas spring. The valve typically includes a pin extending from the top of the cylinder which when depressed by the lever allows gas to move through the valve and lower the cylinder if a force exceeding gas pressure is applied on the spring or raise the cylinder if no force is applied on the spring. The gas spring may additionally include an air or oil damping mechanism which slows the rate of compression and extension for the gas spring.
The gas spring which is responsible for height adjustment in work chairs also allows the seat to swivel in relation to the base. The gas spring cylinder which is secured to the chair seat through the seat support mechanism rotates freely in relation to the piston which supports it. It is this rotation which provides the swivel in most work chairs. Additionally the end of the piston which is attached to the chair base may also include ball bearings or other means to allow the piston to rotate in relation to the base while remaining secured to the base. In this way, the gas spring which is a very inexpensive mechanism to manufacture provides both height adjustment and swivel movement of the chair seat in relation to the base.
The gas spring is supported in a vertical position between the chair base and the chair tilt mechanism by a vertical stand tube. The stand tube includes a top opening sized so that the cylinder of the gas spring can move vertically and rotationally in relation to the stand tube, yet remain supported by the stand tube regardless of the vertical or rotational position of the cylinder.
The stand tube is typically a metal cylinder which includes top and bottom ends. An opening on the top end which is sized to accommodate a gas spring cylinder which moves vertically in relation to the stand tube. In some instances a bushing may be disposed within the opening to minimize friction between the gas spring cylinder and the stand tube. The opening serves to both guide the gas spring cylinder as well as to vertically support the gas spring which extends between the chair seat support mechanism and the chair base.
The bottom end of the stand tube cylinder typically is tapered for insertion into the chair base. The tapered bottom end is typically pressed into a tapered socket at the hub or center of the chair base. The stand tube bottom may include an opening through which the piston of the gas spring can extend so as to be secured to the chair base. Alternatively, the stand tube bottom end can include an appropriate structure for securing the gas spring piston. This structure also may include an opening in the stand tube bottom end.
An alternative to the gas spring is a metal coil type spring which includes an oil damping mechanism. The application of a spring of this type is shown in U.S. Pat. No. 5,078,351. An alternative to the typical stand tube arrangement is shown in U.S. Pat. No. 5,433,409. The inventors of both of these alternative chair components believe that their components address structural deficiencies found in existing chair component assemblies.
These structural deficiencies are most often derived from the use of a gas spring as both the structural support for the chair as well as the mechanism which provides vertical adjustability to the chair. The dual purpose of the gas spring, as well as the manner that the gas spring is supported, and the manner that the gas spring is attached to the chair seat support mechanism and the chair base, may cause the gas spring or the supporting structure for the gas spring to fail.
Gas spring mechanisms are remarkably strong despite the light gauge metal used in their construction. The cylinder portion of the gas spring, which is typically constructed of light gauge metal, is a sealed assembly which includes an internally held compressed gas. The cylinder also comprises the structure which provides the attachment between the height adjustable chair pedestal and the chair seat. Typically, the cylinder of the gas spring is attached to the seat support or chair tilt mechanism within a tapered socket or a hole within the seat support or chair tilt mechanism. Accordingly, all of the weight on the chair seat must be transferred through the light gauge cylinder wall. The forces exerted on the cylinder may include high bending moments, if the weight of the chair user is not sitting on center of the chair seat, in addition to the compressive forces acting downward on the cylinder of the gas spring due to the users weight.
These compressive and bending forces may result in considerable stresses exerted on the light gauge cylinder walls which can result in a catastrophic failure of the cylinder. Additionally, the concentration of stresses in each of the chair components results in shape distortions to occur in these components. These distortions result in play or looseness developing, particularly at the high stress attachment points of the components. Play is known to develop particularly early at the attachment location of the cylinder to the seat support or tilt mechanism. This play, once created, can further accentuate stress concentrations at specific locations on the cylinder wall which also can lead to a catastrophic failure of the cylinder wall.
Similar forces exist between the gas spring cylinder and the stand tube. As has been previously described, the stand tube supports the gas spring by providing a top opening through which the cylinder of the gas spring passes. The gas spring cylinder moves vertically, as well as rotationally in relation to this opening. The stand tube may include a bushing to reduce friction between the cylinder and the stand tube.
Forces exerted on the gas spring cylinder may be transferred to the stand tube at the opening location. As the opening must be made larger than the cylinder to permit both vertical and rotational movement of the cylinder, these forces may be transferred from a small segment of the thin wall of the cylinder to the stand tube along the short support surface provided by the opening. This concentration of forces can cause failure of the cylinder either by shearing the cylinder wall or by causing a small dent in the cylinder wall which could lead to the cylinder buckling at a later time. Forces that are not transferred to the stand tube are transferred first to the piston of the gas spring cylinder and then to the chair base. The forces on the piston can also cause the small diameter rod of the piston to buckle.
Other stand tubes include a honeycomb structure within the interior of the stand tube cylinder to prevent a concentration of forces on the gas spring cylinder at an opening. In this design, forces on the gas spring that are transferred to the stand tube are transferred over a large surface of the honeycomb structure within the stand tube interior. The honeycomb structure flexes in response to such forces assuring a large contact surface for force transfer and minimizing shear forces on the gas spring. The excessive flexure within this design results in a chair having a non-rigid pedestal having a great deal of play. Accordingly, chairs having this construction do not appear sturdy and durable to consumers. Additionally, the flexing of the gas spring allowed by the flexible honeycomb structure may also cause the gas spring to eventually fail. It is also likely that this excessive flexing of gas springs may contribute to gas leakage from the gas spring.
Additionally, the forces resulting from pressurized gas within the cylinder are increased by forces on the chair seat which also are transferred through the gas spring. Gas losses through the cylinder seals are affected by the forces exerted on the gas spring. Should forces be applied to the gas spring which are either too high for the gas spring or are applied at an excessive rate, the gas spring seals can also fail, resulting in the immediate loss of gas pressure and a sudden complete compression of the gas spring. Such a failure could also result from normal use of the chair over a long period of time. Gas losses resulting from a progressive loss of the high pressure gas are evident in all gas springs and are most pronounced in those having the highest initial gas pressures.
Other areas where failures can occur are at the chair base hub socket where the stand tube is attached to the chair base. This area is particularly prone to failure in chairs having a one piece molded base that includes a center hub having a tapered socket for receiving the tapered bottom end of the stand tube, and a plurality (typically 5) of spokes which radiate from the hub. The molded plastic hub socket wall supports the rigid metal stand tube in a vertical position. Forces transmitted through the stand tube are transferred to the hub at this location. The high strength, and highly rigid steel stand tube may first become loosely held within the plastic chair base hub socket due to normal use of the chair. The socket wall also may be prone to breakage due to material fatigue stresses, or as a result of the uneven application of forces on the socket, which result from play within this joint. All metal chair bases are also prone to developing play in this joint, but are understandably less likely to fail.
All of the described modes for height adjustable chair pedestals may result in injuries to the chair user as well as property damage. Obviously, a catastrophic failure of a chair may cause the person on the chair to fall from the chair without any warning.
All of the previously mentioned problems with height adjustable pedestals used in office type chairs have prevented the widespread use of similar height adjustable pedestals in tables. Off center forces exerted on a table top close to the perimeter of the table top are a considerable distance from the center pedestal supporting the table top. Such forces obviously result in high bending moments on a small diameter gas spring cylinder which is incorporated into the pedestal for supporting a vertically adjustable table top.
Due to the current limitations of gas spring height adjustment in table constructions, height adjustable table manufacturers have typically used either hydraulics or electric motors to provide vertical adjustability. Such mechanisms, which have been in use for decades, are typically very durable and do not have failure modes consistent with gas spring height adjustment. These mechanisms, however, are not in widespread use because of their considerable expense. Tables that incorporate these devices are, or course, very expensive which limits the use of height adjustable tables in residential, office, educational, and industrial environments.
For the foregoing reasons, there is a need for a height adjustable pedestal for use with chairs and tables commonly used in homes, offices, schools, and industry which provide the benefits of height adjustment at an economical price and are not subject to dangerous catastrophic failures.
In particular, there is a need for a height adjustable pedestal that allows forces to be transferred from the chair seat or table top to the floor which will not cause excessive concentrations or stresses within the elements of the height adjustable pedestal which can lead to catastrophic failure of these elements.
There is a need for a height adjustable pedestal for chairs and tables that are able to be assembled from currently available low cost components, such as gas springs, yet overcome the deficiencies of these components. There is a further need that existing low cost assembly practices can be used in the chairs and tables using these height adjustable pedestals.
There is also a need for a height adjustable pedestal that is constructed to minimize wear in the components of the pedestal assembly. By minimizing wear, such chairs and tables would not develop excessive play within the structural joints connecting components of the pedestal assembly.
There is a need for a height adjustable pedestal that is low cost, low in weight, high in strength and durability, and high in aesthetics which will provide greater widespread use of height adjustment in both tables and chairs.

Height adjustable pedestal for chairs and tables